Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications

In-situ synthesis of magnetic nanoparticles/wood-structural holocellulose hybrid for metal ions adsorption

Effective removal of metal ions from water is crucial for reducing pollution during manufacturing processes. To address this issue, we have developed a block Fe3O4/wood-structural holocellulose hybrids (MW) for removing heavy metal ions from industrial wastewater. By employing chemical pretreatment, solvent-induced self-impregnation, and in-situ deposition, Fe3O4 nanoparticles were attached into the cell's lumen while also embedded within the cell walls, achieving a loading capacity of 35.89 %. The MW exhibited notable magnetic responsiveness. Adsorption experiments were then conducted to evaluate the performance of MW in adsorbing Pb2+, and the adsorption mechanism was elucidated based on density functional theory (DFT) calculations. The results demonstrated that MW exhibited high adsorption efficiency for Pb2+ (537.63 mg/g), This is primarily attributed to the porous structure of MW and the interactions among -COOH, -OH, and FeO groups within the structure with Pb2+. The adsorption process followed the pseudo-second-order kinetic model and the Langmuir isotherm model. After three consecutive reuse cycles, the adsorption capacity remaining at 77.62 % after three cycles. Furthermore, DFT calculations indicated that the composite of Fe3O4 and cellulose could enhance the adsorption energy between Pb2+ and MW. This indicates that MW offers high adsorption, recyclability, and magnetic control, making it a promising material for wastewater treatment.

Gold nanoparticles-wood nanohybrid as peroxidase-like for simple and selective detection of mercury ion

We present the design and synthesis of a gold nanoparticle-wood nanohybrid (AuNPs@Wood), synthesized via the in-situ growth of gold nanoparticles (AuNPs) within a hierarchical wood flour nanostructure under mild conditions. The AuNPs@Wood exhibited remarkable peroxidase-like activity, attributed to the unique hierarchical architecture of the wood flour. Furthermore, the use of AuNPs@Wood in conjunction with T-rich DNA (P1) results in the development of a label-free colorimetric approach for detecting mercury ions. The peroxidase-like activity of the AuNPs@Wood-P1 system was found to increase with rising concentrations of Hg (II), demonstrating a linear response to Hg (II) concentration with a correlation coefficient of 0.9917. The detection limit for Hg (II) was determined to be 0.016 μM based on three times the standard deviation (σ). Additionally, sensing Hg2+ ions remained unaffected by other metal ions, underscoring the exceptional selectivity of AuNPs@Wood-P1. In comparison to traditional methods, this approach offers advantages such as high selectivity, sensitivity, cost-effectiveness, and ease of operation without requiring complex instrumentation, thereby presenting significant potential for biosensing applications.

Biomass-Based Sustainable Graphene for Advanced Electronic Technology: A Review

Through its remarkable mechanical, electrical, and thermal qualities, graphene has become a revolutionary material in electronics. Sustainable graphene synthesis from biomass residues offers a possible path toward adhering to the demand for economical and ecologically friendly graphene production methods. The present study thoroughly examines the numerous biomass sources used for graphene synthesis, such as plant-derived materials, agricultural waste, and other organic leftovers. The benefits and drawbacks of several synthesis methods are examined, including pyrolysis, chemical exfoliation, and hydrothermal carbonization. The study also explores the possible uses of graphene produced from biomass in electronics, including sensors, energy storage devices, electronic devices with flexibility, and electromagnetic interference (EMI) shielding. This review highlights how biomass-based graphene can revolutionize the electronics sector by bridging the gap between electronic applications, synthesis techniques, and biomass supplies.

Lignin reinforced eco-friendly and functional nanoarchitectonics materials with tailored interfacial barrier performance

Exploring innovative and sustainable routes for the production of biodegradable biomass-based materials is critical to promote a circular carbon economy and carbon neutrality goals. Fossil-based non-biodegradable plastic waste poses a nonnegligible threat to humans and the ecological environment, and biomass-based functional materials are becoming increasingly viable alternatives. Lignin, a naturally occurring macromolecular polymer, is green and renewable resource rich in aromatic rings, with biodegradability, biocompatibility, and excellent processability for eco-friendly composites. Moreover, versatile and high tunable lignins can be valorized into functional materials, which are crucial building blocks in the fabrication of biomass-derived composites. Lignin's unique chemical structure, solvent resistance, anti-aging, and anti-ultraviolet functional properties make it highly potential for the fabrication of sustainable biobased barrier materials. This review systematically summarizes the progress in the fabrication and application of lignin-based functional composites, with a particular focus on barrier materials. First, the structural diversity of lignins from different sources and fractionation methods, and the structural modification strategies of lignins are briefly introduced. Then, the multiple barrier performances of lignin-based composites are listed, and the fabrication methods of different composites based on the polymer matrix systems are elaborated. In terms of diverse applications, this review highlights the multifaceted barrier properties of lignin-based composites in oxygen barrier, water vapor barrier, ultraviolet barrier, flame retardant and antibacterial applications. These functional barrier materials are widely used in food/pharmaceutical packaging, agricultural protection, construction, etc., providing an excellent option for sustainable materials with high barrier performance requirements. Finally, the main challenges faced by lignin-based barrier materials and the future directions are proposed.

Valorizing wood to toxic heavy metal ions biosorbent through in situ sulfation of its cellulose

In this work, H2SO4, ClHSO3, and NH2SO3H were used to prepare the sulfated wood (SW), respectively, which can be applied as biosorbent for removing heavy metal ions from wastewater. The accessibility of wood for sulfation was improved by using molten urea as a protective agent. The sulfate groups amount of SW-H2SO4, SW-ClHSO3 and SW-NH2SO3H was determined as 0.98, 1.37, and 1.71 mmol g-1, respectively, and the corresponding maximum adsorption of Ni2+ was 37.3, 51.3 and 66.2 mg g-1. The efficient modification of SW-NH2SO3H was attributed to the stronger nucleophilic property of -NH2. The kinetic and thermodynamic studies showed that the adsorption process of SW for Ni2+ followed the second order kinetic models and Freundlich model, which was a spontaneous adsorption process. The adsorption process of SW was elucidated as the coordination of Ni2+ by O, N, and S of SW, with the sulfate group playing a major role. A simple and effective method was proposed for the preparation of SW, realizing the valorization of wood into biosorbent for the wastewater remediation.

Perspective of nanocellulose production, processing, and application in sustainable agriculture and soil fertility enhancement: A potential review

Nanocellulose, a promising green material derived from various bio-sources, has potentiality on and off-site in the agricultural sector. Due to its special qualities, which include high strength, hydrophilicity, and biocompatibility, it is a material that may be used in a variety of industries, especially agriculture. This review explores in this article production processes, post-processing procedures, and uses of nanocellulose in soil fertility increment and sustainable agriculture. A variety of plant materials, agricultural waste, and even microbes can be used to isolate nanocellulose. Nanocellulose is produced using both top-down and bottom-up methods, each of which has benefits and limitations of its own. It can be applied as nano-biofertilizer in agriculture to enhance beneficial microbial activity, increase nutrient availability, and improve soil health. Moreover, nanocellulose can be used in fertilizer and pesticide formulations with controlled releases to increase efficacy and lessen environmental effects. Innovative approaches to sustainable agriculture are provided by nanocellulose technologies, which also support the UN's Sustainable Development Goals (SDGs), especially those pertaining to eradicating hunger and encouraging responsible consumption. Nanocellulose promotes climate action and ecosystem preservation by increasing resource efficiency and decreasing dependency on hazardous chemicals, ultimately leading to the development of a circular bioeconomy. Nonetheless, there are still issues with the high cost of production and the energy-intensive isolation procedures. Despite its various potentialities, challenges such as high production costs, environmental concerns, and regulatory issues must be addressed for nanocellulose to be widely adopted and effectively integrated into farming practices.

Natural polysaccharides-based smart sensors for health monitoring, diagnosis and rehabilitation: A review

With the rapid growth of multi-level health needs, precise and real-time health sensing systems have become increasingly pivotal in personal health management and disease prevention. Natural polysaccharides demonstrate immense potential in healthcare sensors by leveraging their superior biocompatibility, biodegradability, environmental sustainability, as well as diverse structural designs and surface functionalities. This review begins by introducing a variety of natural polysaccharides, including cellulose, alginates, chitosan, hyaluronic acid, and starch, and analyzing their structural and functional distinctions, which offer extensive possibilities for sensor design and construction. Further, we summarize several principal sensing mechanisms, such as piezoresistivity, piezoelectricity, capacitance, triboelectricity, and hygroelectricity, which provide a theoretical and technological foundation for developing high-performance healthcare sensing devices. Additionally, the review discusses the most recent applications of natural polysaccharide-based sensors in diverse healthcare contexts, including human body motion tracking, respiratory and heartbeat monitoring, electrophysiological signal recording, body temperature variation detection, and biomarker analysis. Finally, prospective development directions are proposed, such as the integration of artificial intelligence for real-time data analysis, the design of multifunctional devices that combine sensing with therapeutic functionalities, and advancements in remote monitoring and smart wearable technologies. This review aims to provide valuable insights into the development of next-generation healthcare sensors and propose novel research directions for personalized medicine and remote health management.

Extraction and characterization of natural cellulosic fiber from the bark of the Wikstroemia monnula plant as potential reinforcement in composites

The aim of this paper is to study the possibility of using of Wikstroemia monnula (W. monnula) fibers as reinforcement in composites. The fibers are extracted from the stem bark of W. monnula plant, which are notable for their strength and length. To use these cellulosic fibers as reinforcement in composites, it is necessary to investigate their intrinsic properties. Through multi-scale characterization, the fibers demonstrate exceptional structural and functional properties. The low density (1.32 g·cm-3) combined with the fiber porosity of 49.22 %, provides lightweight advantages while reducing energy consumption during composite processing. The high cellulose content (46.25 %) and crystallinity index (63.22 %) work synergistically to enhance mechanical strength. The fibers demonstrate superior thermal stability, with a maximum degradation temperature of 345 °C and a kinetic activation energy of 94.64 kJ·mol-1, ensuring thermal resistance during processing. The fiber bundles achieve a tensile strength of 305.31 MPa and a Young's modulus of 15.76 GPa, surpassing that of conventional plant fibers. The fibers are hydrophobic, with a contact angle of 133.4°, which minimizes the risk of moisture absorption. The smooth fracture morphology eliminates sharp edges, addressing safety concerns. These findings indicate that W. monnula fiber is a potential reinforcement for composites.

Biocomposites of 2D layered materials

Molecular composites, such as bone and nacre, are everywhere in nature and play crucial roles, ranging from self-defense to carbon sequestration. Extensive research has been conducted on constructing inorganic layered materials at an atomic level inspired by natural composites. These layered materials exfoliated to 2D crystals are an emerging family of nanomaterials with extraordinary properties. These biocomposites are great for modulating electron, photon, and phonon transport in nanoelectronics and photonic devices but are challenging to translate into bulk materials. Combining 2D crystals with biomolecules enables various 2D nanocomposites with novel characteristics. This review has provided an overview of the latest biocomposites, including their structure, composition, and characterization. Layered biocomposites have the potential to improve the performance of many devices. For example, biocomposites use macromolecules to control the organization of 2D crystals, allowing for new capabilities such as flexible electronics and energy storage. Other applications of 2D biocomposites include biomedical imaging, tissue engineering, chemical and biological sensing, gas and liquid filtration, and soft robotics. However, some fundamental questions need to be answered, such as self-assembly and kinetically limited states of organic-inorganic phases in soft matter physics.

Aldehyde-Stabilization Strategies for Building Biobased Consumer Products around Intact lignocellulosic Structures

Dwindling fossil resources and their associated environmental concerns have increased interest in biobased products. In particular, many approaches to convert lignocellulosic biomass into small-molecule building blocks are being explored via thermal, chemical, and biological processes. Depending on their structure, these molecules can be used as direct (i.e., drop-in) or indirect (different molecule from what is used today) substitutes for petrochemicals. In all such cases, biomass must be deconstructed, which involves the depolymerization of lignin and polysaccharides as well as their further transformation to produce these substitutes. Deconstruction often requires harsh conditions that cause degradation, and further upgrading implies multiple conversion steps, especially for drop-in molecules, all of which lead to low atom economy. Our group has developed an aldehyde-stabilization strategy that facilitates the depolymerization of lignocellulose to monomers in high yields by stabilizing intermediates under biomass deconstruction conditions. This strategy has now been adapted to prepare indirect substitutes for petrochemicals with very high atom economy including biobased solvents, plastic precursors, adhesives, and surfactants, which have widespread applications in modern society.In this Account, we first introduce the function of aldehydes using formaldehyde (FA) as an example. Specifically, we discuss their role in assisting lignin isolation and their ability to stabilize lignin by looking at the lignin monomer yields that can be obtained after hydrogenolysis of the associated aldehyde-functionalized lignin. Highly selective production of lignin monomers was achieved using acetaldehyde (AA) or propionaldehyde (PPA) as a stabilization reagent via either reductive or oxidative depolymerization. In a typical FA-assisted fractionation, hemicellulose was directly converted into diformylxylose (DFX), while cellulose with properties similar to those obtained by organosolv was isolated but could be converted to diformyl-glucose isomers (DFGs) by further hydrolysis. These stable molecules provide us a new method to preserve sugar molecules that often degrade during acidic fractionation, which will be discussed in Section 3. Besides, DFX can also be used as a green solvent (Section 4), while FA-lignin exhibits excellent adhesion properties for plywood preparation (Section 5). Biobased glyoxylic acid (GA) was used to convert hemicellulose into a high yield of dimethylglyoxylic-acid-xylose (DMGX), a terephthalic acid (TA) substitute for bioplastics production (Section 6), while GA-lignin demonstrates great amphiphilic properties and finds applications as surfactants in cosmetic products (Section 7). When fatty aldehydes were used as stabilization reagents, both lignin and hemicellulose were converted to surfactants by downstream defunctionalization (Section 7). We will also discuss the current limitations of this aldehyde-stabilization strategy for biomass utilization as well as potential solutions and improvements to said limitations. With this Account, we hope to spur further interest in aldehyde stabilization as a tool to deconstruct biomass and build new consumer products around functionalized and thus largely preserved natural structures.

An Investigation of the Mechanical Properties of Ti Films Reinforced with Wood Composites by Growing Ti Particles on a Wood Substrate

Table tennis racquet blades (TTRBs) are specialized wood materials known for their excellent mechanical properties. As one of the widely used physical vapor deposition technologies, magnetron sputtering has become the most effective method for preparing various thin film materials. In this study, the surface of the TTRB is coated with a Ti film with different thicknesses by magnetron sputtering to improve the performance of the TTRB. The surface roughness, crystal structure, viscoelasticity of the TTRB were analyzed by means of non-contact surface profilometry, X-ray diffraction (XRD), and dynamic mechanical analysis (DMA). In order to effectively test TTRB properties, three types of testing devices were designed, including free-fall rebound, laser vibration measurement, and the dynamic rebound test. The results reveal that the deposition of a Ti film on the surface of the TTRB improves the rigidity and rebound efficiency of the TTRB. Under optimized conditions, the initial amplitude, vertical rebound distance, and rebound rate can reach 2.1 μm, 23.7 cm, 13.7%, respectively, when the deposition thickness is 5 μm. It is anticipated that the modification and the corresponding detection methods developed in this study can foster innovative product development, standardize the TTRB industry, and contribute to the advancement of table tennis.

Cellulose Nanomaterials Functionalized with Carboxylic Group Extracted from Lignocellulosic Agricultural Waste: Isolation and Cu(II) Adsorption for Antimicrobial Application

In this study, we reported the isolation of COOH-functionalized nanocrystal cellulose from agricultural waste, particularly dragon fruit foliage (DFF), by two methods, the citric acid/HCl acid (CA) method and the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-mediated oxidation method. Chemical component quantification and physiochemical characterization techniques, such as FT-IR spectroscopy, XRD, TGA, XPS, and AFM, were employed to analyze DFF, bleached cellulose, and extracted CNs. We determined the contents of lignin and hemicellulose removed, while the signals for the cellulose contents remain the same for DFF-CA and DFF-TEMPO. The DLS, AFM, and SEM results indicated that the DFF-CA sample has a smaller average particle size (250 ± 50 nm) with a rod-like shape, compared to the DFF-TEMPO sample (600 ± 100 nm) with a fiber-like shape. Importantly, CNs extracted from DFF, including DFF-TEMPO, DFF-CA, and DFF-bleached, exhibited excellent properties for Cu (II) adsorption with a maximum adsorption of 227 mg·g-1 (for DFF-CA samples), and the adsorption is almost independent of the -COOH content. Notably, we were also able to prepare Cu-containing cellulose gels showing promising antimicrobial activity. Our work opens new possibilities for the use of unexplored cellulosic byproducts in the agricultural industry as well as potential applications of Cu-containing cellulose gels as antimicrobials.

Construction of Nanocellulose Aerogels with Environmental Drying Strategy without Organic Solvent Displacement for High-Efficiency Solar Steam Generation

Solar desalination is one of the effective means to alleviate water scarcity, in which aerogel-like evaporators have attracted extensive attention in the field of efficient desalination. However, the current preparation methods for aerogels still mainly rely on high-cost solutions, such as freeze-drying or supercritical drying. Herein, a preparation scheme for aerogels that can be realized under atmospheric pressure conditions is reported. In this paper, a foam skeleton template (FST) strategy is proposed, in which flake graphite is entangled by cellulose nanofibers (CNFs) and codispersed between the foam cell walls, and subsequently connected with the nascent Ca2+ in the inner wall to form a tough and stable three-dimensional network structure, which can effectively avoid the structural collapse caused by atmospheric drying. The cellulose/graphite aerogel (CGA) prepared using the FST strategy possesses lightweight (36 mg cm-3) and porous (porosity >97%) properties. The 3D porous structure and wetting characteristics of the CGA provided excellent energy management, rapid water transport capability, and a reduced enthalpy of evaporation, which enabled it to achieve a fast water evaporation rate of 3.8 kg m-2 h-1 with 98.4% energy efficiency. This FST strategy provides a solution for the low-cost development of aerogel and desalination.

Cellulose-Derived Battery Separators: A Minireview on Advances Towards Environmental Sustainability

Cellulose-derived battery separators have emerged as a viable sustainable alternative to conventional synthetic materials like polypropylene and polyethylene. Sourced from renewable and biodegradable materials, cellulose derivatives-such as nanofibers, nanocrystals, cellulose acetate, bacterial cellulose, and regenerated cellulose-exhibit a reduced environmental footprint while enhancing battery safety and performance. One of the key advantages of cellulose is its ability to act as a hybrid separator, using its unique properties to improve the performance and durability of battery systems. These separators can consist of cellulose particles combined with supporting polymers, or even a pure cellulose membrane enhanced by the incorporation of additives. Nevertheless, the manufacturing of cellulose separators encounters obstacles due to the constraints of existing production techniques, including electrospinning, vacuum filtration, and phase inversion. Although these methods are effective, they pose challenges for large-scale industrial application. This review examines the characteristics of cellulose and its derivatives, alongside various processing techniques for fabricating separators and assessing their efficacy in battery applications. Additionally, it will consider the environmental implications and the primary challenges and opportunities associated with the use of cellulose separators in energy storage systems. Ultimately, the review underscores the significance of cellulose-based battery separators as a promising approach that aligns with the increasing demand for sustainable technologies in the energy storage domain.

Biodegradable origami enables closed-loop sustainable robotic systems

Robots are increasingly integral across various sectors due to their efficiency and superior capabilities, which enable performance beyond human potential. However, the development of robotic systems often conflicts with the sustainable development goals set by the United Nations, as they generate considerable nondegradable waste and organic/inorganic pollutants throughout their life cycle. In this paper, we introduce a dual closed-loop robotic system that integrates biodegradable, sustainable materials such as plasticized cellulose films and NaCl-infused ionic conductive gelatin organogels. These materials undergo a closed-loop ecological cycle from processing to biodegradation, contributing to new growth, while the self-sensing, origami-based robot supports a seamless human-in-the-loop teleoperation system. This innovative approach represents a paradigm shift in the application of soft robotic systems, offering a path toward a more sustainable future by aligning advanced robotic functionalities with environmental stewardship.

Nitrogen-Doped Porous Nanofiber Aerogel-Encapsulated Staphylo-Ni3S2 Accelerating Polysulfide Conversion for Efficient Li-S Batteries

The low conductivity of sulfur substances and the fussy effect of lithium polysulfides (LPS) limit the practical application of lithium-sulfur batteries (LSBs). In this work, Ni3S2 is in situ synthesized on N-doped 3D carbon nanofibers with an optimized pore structure as a cathode material for LSBs. The conductive carbon nanofiber skeleton with a hierarchical (micropore-mesopore-macropore) structure etched by Cd2+ can reduce the interface resistance of the cathode and remiss volume expansion during charge-discharge progress. The Ni was vulcanized and nitrogen-doped successively during the annealing process. In addition, the polar Ni3S2 and N-doped carbon structure can promote the catalytic conversion of LPS and regulate the 3D nucleation of Li2S, which could reduce the reaction energy barrier. Therefore, the NCF-Cd-Ni3S2-NC cathode can maintain a high initial capacity (1080.2 mAh g-1) and excellent stability at 0.1C. This work provides an important basis for the synthesis of high efficiency and inexpensive cathode carrier materials for LSBs.

Controllable reconstruction of lignified biomass with molecular scissors to form carbon frameworks for highly stable Li metal batteries

Lithium metal batteries (LMBs) promise high-energy-density storage but face safety issues due to dendrite-induced lithium deposition, irreversible electrolyte consumption, and large volume changes, which hinder their practical applications. To address these issues, tuning lithium deposition by structuring a host for the lithium metal anode has been recognized as an efficient method. Herein, we report a supercritical water molecular scissor-controlled strategy to form a carbon framework derived from biomass wood. Proximate-supercritical water treatment is used to selectively cleave the β-O-4 bonds in lignin, with the extent of degradation controlled by adjusting the treatment environment's acidity. The enhanced thermal power of supercritical water molecules significantly accelerates the etching rate of lignin, increasing the porosity and permeability of the transformed carbon framework. Experimental results and multi-physics simulations show that the interconnected carbon-based pores and inner skeletal multilevel hierarchical structure facilitate rapid electron and ion transfer during battery operation and enhance electrolyte infiltration. Impressively, the as-obtained lithium metal anode exhibits long-term cycling stability for over 2000 hours at 0.5 mA cm-2 with low voltage overpotential. The water-treated Pinus (WTP)-Li//LiCoO2 full cells maintain a high capacity retention rate of 93.3% and a specific capacity of 142 mA h g-1 at 0.5C for 100 cycles.

Mechanically Resilient, Self-Healing, and Environmentally Adaptable Eutectogel-Based Triboelectric Nanogenerators for All-Weather Energy Harvesting and Human-Machine Interaction

Triboelectric nanogenerators (TENGs) have garnered significant attention for mechanical energy harvesting, self-powered sensing, and human-machine interaction. However, their performance is often constrained by materials that lack sufficient mechanical robustness, self-healing capability, and adaptability to environmental extremes. Eutectogels, with their inherent ionic conductivity, thermal stability, and sustainability, offer an appealing alternative as flexible TENG electrodes, yet they typically suffer from weak damage endurance and insufficient self-healing capability. To overcome these challenges, here, we introduce an internal-external dual reinforcement strategy (IEDRS) that enhances internal bonding dynamics within the eutectogel matrix, composed of glycidyl methacrylate and deep eutectic solvent, and integrates plant-derived lignin as an external reinforcer. Notably, the resultant eutectogel, named GLCL, exhibits appealing collection merits including superior mechanical robustness (1.53 MPa tensile stress and 1.85 MJ/m3 toughness), ultrastrong adhesion (4.76 MPa), high self-healing efficiency (84.7%), and significant environmental adaptability (-40 to 100 °C). These improvements ensure that the assembled triboelectric nanogenerator (GLCL-TENG) produces stable and robust electrical outputs, maintained even under dynamic and postdamage conditions. Additionally, the GLCL-TENG exhibits significant extreme environmental tolerance and durability, maintaining high and consistent electrical outputs over a wide temperature range (-40 to 100 °C) and throughout 10,000 cycles of repeated contact-separation. Leveraging these robust performances, the GLCL-TENG excels in all-weather biomechanical energy harvesting and accurate individual motion detection and functions as a self-powered interface for wireless vehicular control. This work presents a viable material design strategy for developing tough and self-healing eutectogel electrodes, emphasizing the potential application of TENGs in all-weather smart vehicles.

Paper-Based Sensors: Fantasy or Reality?

This article analyzes the prospects for the appearance of paper-based sensors on the sensor market. It is concluded that paper-based sensors are not a fantasy but a reality. It is shown that paper has properties that make it possible to develop a wide variety of paper-based sensors, such as SERS, colorimetric, fluorescent, conductometric, capacitive, fiber-optic, electrochemical, microfluidic, shape-deformation, microwave, and various physical sensors. The use of paper in the manufacturing of various sensors opens up new possibilities both in terms of new approaches to their manufacturing and in terms of new areas of their application. However, it must be recognized that for the widespread use of paper and the appearance of paper-based sensors on the sensor market, many obstacles must be overcome.

Self-healing cellulose-based hydrogels: From molecular design to multifarious applications

Self-healing cellulose-based hydrogels (SHCHs) exhibit wide-ranging potential applications in the fields of biomedicine, environmental management, energy storage, and smart materials due to their unique physicochemical properties and biocompatibility. This review delves into the molecular design principles, performance characteristics, and diverse applications of SHCHs. Firstly, the molecular structure and physicochemical properties of cellulose are analyzed, along with strategies for achieving self-healing properties through molecular design, with particular emphasis on the importance of self-healing mechanisms. Subsequently, methods for optimizing the performance of SHCHs through chemical modification, composite reinforcement, stimulus responsiveness, and functional integration technologies are discussed in detail. Furthermore, applications of SHCHs in drug delivery, tissue engineering, wound healing, smart sensing, supercapacitors, electronic circuits, anti-counterfeiting systems, oil/water separation, and food packaging are explored. Finally, future research directions for SHCHs are outlined, including the innovative development of new SHCHs, in-depth elucidation of cooperative strengthening mechanisms, a further expansion of application scope, and the establishment of intelligent systems. This review provides researchers with a comprehensive overview of SHCHs and serves as a reference and guide for future research and development.

Hijacking plant skeletons for biomedical applications: from regenerative medicine and drug delivery to biosensing

The field of biomedical engineering continually seeks innovative technologies to address complex healthcare challenges, ranging from tissue regeneration to drug delivery and biosensing. Plant skeletons offer promising opportunities for these applications due to their unique hierarchical structures, desirable porosity, inherent biocompatibility, and adjustable mechanical properties. This review comprehensively discusses chemical principles underlying the utilization of plant-based scaffolds in biomedical engineering. Highlighting their structural integrity, tunable properties, and possibility of chemical modification, the review explores diverse preparation strategies to tailor plant skeleton properties for bone, neural, cardiovascular, skeletal muscle, and tendon tissue engineering. Such applications stem from the cellulosic three-dimensional structure of different parts of plants, which can mimic the complexity of native tissues and extracellular matrices, providing an ideal environment for cell adhesion, proliferation, and differentiation. We also discuss the application of plant skeletons as carriers for drug delivery due to their structural diversity and versatility in encapsulating and releasing therapeutic agents with controlled kinetics. Furthermore, we present the emerging role played by plant-derived materials in biosensor development for diagnostic and monitoring purposes. Challenges and future directions in the field are also discussed, offering insights into the opportunities for future translation of sustainable plant-based technologies to address critical healthcare needs.

Interconnecting EDOT-Based Polymers with Native Lignin toward Enhanced Charge Storage in Conductive Wood

The 3D micro- and nanostructure of wood has extensively been employed as a template for cost-effective and renewable electronic technologies. However, other electroactive components, in particular native lignin, have been overlooked due to the absence of an approach that allows access of the lignin through the cell wall. In this study, we introduce an approach that focuses on establishing conjugated-polymer-based electrical connections at various length scales within the wood structure, aiming to leverage the charge storage capacity of native lignin in wood-based energy storage electrodes. We demonstrate that poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) PEDOT/PSS, integrated within the cell wall lumen, can be interfaced with native lignin through the wood cell wall through in situ polymerization of a water-soluble S-EDOT monomer. This approach increases the capacitance of the conductive wood to 315 mF cm-2 at a scan rate of 5 mV s-1, which is seven and, respectively, two times higher compared to the capacitance of conductive wood made with the single components PEDOT/PSS or S-PEDOT. Moreover, we show that the capacitance is contributed by both the electroactive polymers and native lignin, with native lignin accounting for over 70% of the total charge storage capacity. We show that accessing native lignin through in situ creation of electrical interconnections within the wood structure offers a pathway toward sustainable, wood-based electrodes with improved charge-storage capacity for applications in electronics and energy storage.

Ultraviolet (UV) assisted fabrication and characterization of lignin containing cellulose nanofibrils (LCNFs) from wood residues

This study aimed to explore the synergistic mechanism of lignin chromophore modifications via UV treatment and to analyze the effects of mechanical treatments on LCNF properties for future uses. The procedure involved two steps: first, lignin's chromophore modification via UV illumination, and then the ball milling process was proceeded for 1 h, followed by high-intensity ultrasonic for 15-135 min. Characterization included preserved lignin content percentage, FTIR, UV-vis NMR, and color analysis for UV-modified samples, and to access the influence of mechanical treatment on LCNF samples further yield, zeta potential analysis, XRD, thermogravimetric analysis, atomic force microscopy, and scanning electron microscopy were performed. LCNFs S-120 demonstrated a zeta potential of -21.7 mV, indicating enhanced stability compared to the S-135 sample (-10.95 mV). The S-120 sample also showed the highest yield (74.02 %) and TGA at 391 °C. In XRD analysis, the S-120 sample demonstrated the highest CrI 64.3 %, than the S-15 sample (48.2 %). Preserved lignin in the LCNFs led to a slight reduction in crystallinity across all samples but improved thermal stability for all the prepared LCNFs samples. The UV and ultrasonication improved the homogeneity and durability of the LCNF samples, enabling a process that may be used to industries.

Alphabet Handwriting Recognition: From Wood-Framed Hydrogel Arrays Design to Machine Learning Decoding

Handwriting recognition is a highly integrated system, demanding hardware to collect handwriting signals and software to deal with input data. Nonetheless, the design of such a system from scratch with sustainable materials and an easily accessible computing network presents significant challenges. In pursuit of this goal, a flexible, and electrically conductive wood-derived hydrogel array is developed as a handwriting input panel, enabling recognizing alphabet handwriting assisted by machine learning technique. For this, lignin extraction-refill, polypyrrole coating, and polyacrylic acid filling, endowing flexibility, and electrical conduction to wood are sequentially implemented. Subsequently, these woods are manufactured into a 5 × 5 array, creating a matrix of signals upon handwriting. Efficient handwritten recognition is then achieved through appropriate manual feature extraction and algorithms with low complexity within a computing network, as demonstrated in this work, the strategic choice of expertise-based feature engineering and simplified algorithms effectively boost the overall model performance on handwriting recognition. With potential adaptability, further applications in customized wearable devices and hands-on healthcare appliances are envisioned.

Natural and Nature-Inspired Biomaterial Additives for Metal Halide Perovskite Optoelectronics

This comprehensive review meticulously categorizes and discusses the applications of diverse biomaterials, specifically natural and nature-inspired synthetic materials in metal halide perovskite optoelectronics. Applications range from solar cells to light-emitting diodes, photodetectors, and X-ray detectors. Emphasis is placed on the intricate interactions between bio-additives and perovskite crystals, highlighting their influence on the grain size, crystal orientation, grain boundaries, and surface passivation. This review also explores the advantages and disadvantages of each natural or nature-inspired material and their unique properties compared with conventional additives. Special attention is given to the mechanistic and functional viewpoints, showing how these biomaterials enhance device performance. Through additive engineering with ecofriendly biomaterials, defects in metal halide perovskite thin films can be effectively passivated, thus extending the photostability or in some cases mechanical flexibility of devices. This review provides valuable insights for selecting and designing next-generation biomaterial additives, offering new prospects for achieving high-performance perovskite layers and advancing the field of peorvskite- based optoelectronics.

Recent advances in moisture-induced electricity generation based on wood lignocellulose: Preparation, properties, and applications

Moisture-induced electricity generation (MEG), which can directly harvest electricity from moisture, is considered as an effective strategy for alleviating the growing energy crisis. Recently, tremendous efforts have been devoted to developing MEG active materials from wood lignocellulose (WLC) due to its excellent properties including environmental friendliness, sustainability, and biodegradability. This review comprehensively summarizes the recent advances in MEG based on WLC (wood, cellulose, lignin, and woody biochar), covering its principles, preparation, performances, and applications. In detail, the basic working mechanisms of MEG are discussed, and the natural features of WLC and their significant advantages in the fabrication of MEG active materials are emphasized. Furthermore, the recent advances in WLC-based MEG for harvesting electrical energy from moisture are specifically discussed, together with their potential applications (sensors and power sources). Finally, the main challenges of current WLC-based MEG are presented, as well as the potential solutions or directions to develop highly efficient MEG from WLC.

MXene film electrodes with high mechanical strength, graded ion channels and high pseudocapacitive activity enabled by lignin-containing cellulose fibers

Cellulose nanofiber (CNF) has been widely used in MXene film electrodes to improve its mechanical properties and rate capability for supercapacitors. However, all the above enhancements are obtained with inevitably sacrificing the capacitance, because of the non-electrochemically-active characteristic of CNF. Herein, to address this issue, lignin-containing cellulose fibers (LCNF) is innovatively used to substitute CNF. Specifically, LCNF play a role as a bridge to significantly reinforce mechanical strength of LCNF/MXene film electrode (LM) by binding the adjacent MXene nanosheets, reaching a tensile strength of 34.2 MPa. Lignin in LCNF contributes to pseudocapacitance through the reversible conversion of its quinone/hydro-quinone (Q/QH2), thus yielding an excellent capacitance of 364.4 F g-1 at 1 A g-1. Meanwhile, LCNF has different diameters in which microfibers form a loose structure for LM, nanofibers enlarge d-spacing between adjacent MXene nanosheets, and fibers self-crosslinking creates abundant pores, thus constructing graded channels to achieve an outstanding rate capability of 87 % at 15 A g-1. The fabricated supercapacitor demonstrates a large energy density of 1.8 Wh g-1 at 71.3 W g-1. This work provides a promising approach to decouple the trade-off between electrochemical performance and mechanical properties of MXene film electrodes caused by using CNF, thus obtaining high-performance supercapacitors.

Pristine Wood-Supported Electrodes With Intrinsic Superhydrophilic/Superaerophobic Surface Intensify Hydrogen Evolution Reaction

Wood, as a renewable material, has been regarded as an emerging substrate for self-supporting electrodes in large-scale water electrolysis due to numerous merits such as rich pore structure, abundant hydroxyl groups, etc. However, poor conductivity of wood can greatly suppress the performance of wood-based electrodes. Carbonization process can improve wood's conductivity, but the loss of hydroxyl groups and the required high energy consumption are the drawbacks of such a process. Here, a facile strategy is developed to prepare pristine wood-supported electrode (Ni-NiP/W) for enhanced hydrogen evolution reaction (HER); this improves electrical conductivity of wood while retaining its excellent intrinsic properties. The preparation process involves the deposition of copper on the untreated wood followed with the loading of Ni-NiP catalyst at room temperature. Encouragingly, the Ni-NiP/W exhibits conductive and inherited pristine wood's superhydrophilic and superaerophobic properties, that effectively boost mass and charge transfer. It demonstrates high activity and excellent stability in acidic, alkali, and seawater conditions as well as high current densities of up to 2000 mA cm-2; particularly a record-low HER overpotential of 206 mV in acidic conditions at 1000 mA cm-2. This work fully unlocks the admiring potential of pristine wood as superior substrate for high-performance electrochemical electrodes.

One-step green synthesis of melamine-modified cellulose nanofiber composite aerogels for efficient removal of Pb(II) and Cu(II): Experiments and DFT calculations

A composite aerogel (CGMA) with high porosity (98.32 %) and multiple active sites was prepared for the adsorption of Pb(II) and Cu(II) by sol-gel combined with freeze-drying process using melamine and (3-Glycidyloxypropyl)trimethoxysilane as cellulose nanofiber modifying materials. Characterized by SEM-EDS, XPS, FTIR, BET, MIP and TG, CGMA has a hierarchical pore structure and abundant adsorption sites. At pH = 6, the adsorption reached equilibrium within 120 min, following the Pseudo second-order kinetic model and the Langmuir model, with maximum capacities of 268.1 mg/g for Pb(II) and 152.6 mg/g for Cu(II). The process was primarily governed by homogeneous chemisorption. The coexisting ion, organic matter, and water quality experiments confirmed the excellent anti-interference properties of CGMA. Competitive adsorption experiments showed that CGMA has excellent selective adsorption performance for Pb(II). After 5 cycles, Pb(II) and Cu(II) adsorption performance decreased to 79.21 % and 83.40 %, respectively. FTIR, XPS, DFT and RDG analysis showed that amino groups and oxygen-containing groups were the main sites of adsorption. CGMA forms coordination bonds and complexes with Pb(II) and Cu(II) via amine and oxygen groups and adsorbs via electron transfer, hydrogen bonding, and van der Waals forces, with Pb(II) being more selective. CGMA has good prospects for application in heavy metal ion treatment.

Bacterial cellulose materials in sustainable energy devices: A review

This article provides a comprehensive review of the processing and applications of bacterial cellulose (BC) for energy conversion and storage devices. These emerging technologies enable the transformation of sustainable energy sources into electricity. Once converted, energy storage devices are vital for stable energy supply. To promote green manufacturing practices in this field, bio-based materials are explored as alternative materials for energy devices, addressing the growing demand for sustainable solutions. From a research and development perspective, the materials chosen for energy devices must exhibit exceptional mechanical, electrical, and thermal properties, along with the necessary chemical reactivity to unlock new applications. Furthermore, for successful commercialization and industrialization, these materials must be suitable for large-scale production within practical timeframes. BC fulfills all of these requirements. The review begins with an overview of BC growth, detailing the composition and operating parameters of the culture medium and the design of bioreactors for large-scale production. It then defines and summarizes both in-situ and ex-situ modifications and processing strategies, offering a comprehensive perspective on these techniques. Unique and interesting properties linking BC's structure to its properties are reviewed to demonstrate its potential as a substitute for benchmark materials. The exceptional performance and synergistic effects of BC-derived hybrid materials highlight their potential for state-of-the-art applications in energy devices, and are suitable for the next-generation energy devices. The papers reviewed in this work have gained significant attention and been widely cited over the past 10 years for their relevance to various practical applications, allowing readers to have a better understanding in development of BC based materials for energy conversion and conversion devices.

Advanced Flexible Wearable Electronics from Hybrid Nanocomposites Based on Cellulose Nanofibers, PEDOT:PSS and Reduced Graphene Oxide

The need for responsible electronics is leading to great interest in the development of new bio-based devices that are environmentally friendly. This work presents a simple and efficient process for the creation of conductive nanocomposites using renewable materials such as cellulose nanofibers (CNF) from enzymatic pretreatment, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), and/or reduced graphene oxide (rGO). Different combinations of CNF, rGo, and PEDOT:PSS were considered to generate homogeneous binary and ternary nanocomposite formulations. These formulations were characterized through SEM, Raman spectroscopy, mechanical, electrical, and electrochemical analysis. The binary formulation containing 40 wt% of PEDOT:PSS resulted in nanocomposite formulations with tensile strength, Young's modulus, and a conductivity of 70.39 MPa, 3.87 GPa, and 0.35 S/cm, respectively. The binary formulation with 15 wt% of rGO reached 86.19 MPa, 4.41 GPa, and 13.88 S/cm of the same respective properties. A synergy effect was observed for the ternary formulations between both conductive elements; these nanocomposite formulations reached 42.11 S/cm of conductivity and kept their strength as nanocomposites. The 3D design strategy provided a highly conductive network maintaining the structural integrity of CNF, which generated homogenous nanocomposites with rGO and PEDOT:PSS. These formulations can be considered as greatly promising for the next generation of low-cost, eco-friendly, and energy storage devices, such as batteries or electrochemical capacitors.

Programmable and flexible wood-based origami electronics

Natural polymer substrates are gaining attention as substitutes for plastic substrates in electronics, aiming to combine high performance, intricate shape deformation, and environmental sustainability. Herein, natural wood veneer is converted into a transparent wood film (TWF) substrate. The combination of 3D printing and origami technique is established to create programmable wood-based origami electronics, which exhibit superior flexibility with high tensile strength (393 MPa) due to the highly aligned cellulose fibers and the formation of numerous intermolecular hydrogen bonds between them. Moreover, the flexible TWF electronics exhibit editable multiplexed configurations and maintain stable conductivity. This is attributed to the strong adhesion between the cellulose-based ink and TWF substrate by non-covalent bonds. Benefiting from its anisotropic structure, the programmability of TWF electronics is achieved through sequentially folding into predesigned shapes. This design not only promotes environmental sustainability but also introduces its customizable shapes with potential applications in sensors, microfluidics, and wearable electronics.

Microcrystalline cellulose and itaconic acid pH sensitive semi-interpenetrating network hydrogel for oral insulin delivery

Diabetes mellitus is one of the important causes of death worldwide. Generally, a subcutaneous route is used for insulin administration, but has showen low patient compliance. Extensive research has been conducted to identify molecules capable of delivering insulin orally, for this hydrogel based on microcrystalline cellulose and itaconic acid have been produced and explored. Free radical polymerization as a technique was employed for manufacturing the hydrogels using potassium persulphate as initiator and N, N'-methylene bisacrylamide (NNMBA) as a crosslinker. These pH-sensitive exhibited a swelling capacity of up to 20.38 g/g in distilled water and also revealed stronger swelling in glucose solutions than saline solutions. The pH sensitivity of the hydrogels was confirmed by studying the swelling in different pH solutions. Alkaline solutions showed higher swelling than acidic solutions. SEM established the porous nature, and the structure was examined by FTIR analysis. Thermal degradation was examined using TGA. In-vitro release study was done by Bradford assay at 595 nm. The result was further confirmed by in-vivo investigations on male Wistar adult rats and hence is an excellent vehicle for oral insulin administration.

Valorization of diverse waste-derived nanocellulose for multifaceted applications: A review

The study underscores the urgent need for sustainable waste management by focusing on circular economy principles, government regulations, and public awareness to combat ecological threats, pollution, and climate change effects. It explores extracting nanocellulose from waste streams such as textile, paper, agricultural matter, wood, animal, and food waste, providing a detailed process framework. The emphasis is on waste-derived nanocellulose as a promising material for eco-friendly products. The research evaluates the primary mechanical and thermal properties of nanocellulose from various waste sources. For instance, cotton-derived nanocellulose has a modulus of 2.04-2.71 GPa, making it flexible for lightweight applications. Most waste-derived nanocelluloses have densities between 1550 and 1650 kg/m3, offering strong, lightweight packaging support while enhancing biodegradability and moisture control. Crystallinity influences material usage: high crystallinity is ideal for packaging (e.g., softwood, hardwood), while low crystallinity suits textiles (e.g., cotton, bamboo). Nanocelluloses exhibit excellent thermal stability above 200 °C, useful for flame-retardant coatings, insulation, and polymer reinforcement. The research provides a comprehensive guide for selecting nanocellulose materials, highlighting their potential across industries like packaging, biomedical, textiles, apparel, and electronics, promoting sustainable innovation and a more eco-conscious future.

Recent advances in sustainable nature-based functional materials for biomedical sensor technologies

The lightweight, low-density, and low-cost natural polymers like cellulose, chitosan, and silk have good chemical and biodegradable properties due to their individually unique structural and functional elements. However, the mechanical properties of these polymers differ from each other. In this scenario, chitosan lacks good mechanical properties than cellulose and silk. The synthesis of nano natural polymer and reinforcement with suitable chemical compounds as the development of nanocomposite gives them promising multidisciplinary applications. Many kinds of research are already published with innovative bio-derived polymeric functional materials (Bd-PFM) applications. Most research interest is carried out on health concerns. Lots of attention has been paid to biomedical applications of Bd-PFM as biosensors. This review aims to provide a glimpse of the nanostructures Bd-PFM biosensors.

Cellulose nanocrystals from agriculture and forestry biomass: synthesis methods, characterization and industrial applications

Agricultural and forestry biomass wastes, often discarded or burned without adequate management, lead to significant environmental harm. However, cellulose nanocrystals (CNCs), derived from such biomass, have emerged as highly promising materials due to their unique properties, including high tensile strength, large surface area, biocompatibility, and renewability. This review provides a detailed analysis of the lignocellulosic composition, as well as the elemental and proximate analysis of different biomass sources. These assessments help determine the yield and characteristics of CNCs. Detailed discussion of CNC synthesis methods -ranging from biomass pretreatment to hydrolysis techniques such as acid, mineral, solid acid, ionic liquid, and enzymatic methods-are provided. The key physical, chemical, and thermal properties of CNCs are also highlighted, particularly in relation to their industrial applications. Recommendations for future research emphasize the need to optimize CNC synthesis processes, identify suitable biomass feedstocks, and explore new industrial applications.

Lignin Nanoparticles: Transforming Environmental Remediation

In the face of escalating environmental challenges driven by human activities, the quest for innovative solutions to counter pollution, contamination, and ecological degradation has gained paramount importance. Traditional approaches to environmental remediation often fall short in addressing the complexity and scale of modern-day environmental problems. As industries transition towards sustainable paradigms, the exploration of novel materials and technologies becomes crucial. Lignin nanoparticles have emerged as a promising avenue of exploration in this context. Once considered a mere byproduct, lignin's unique properties and versatile functional groups have propelled it to the forefront of environmental remediation research. This review paper delves into the resurgence of lignin from an environmental perspective, examining its pivotal role in carbon cycling and its potential to address various environmental challenges. The paper extensively discusses the synthesis, properties, and applications of lignin nanoparticles in diverse fields such as water purification and soil remediation. Moreover, it highlights the challenges associated with nanoparticle deployment, ranging from Eco toxicological assessments to scalability issues. Multidisciplinary collaboration and integration of research findings with real-world applications are emphasized as critical factors for unlocking the transformative potential of lignin nanoparticles. Ultimately, this review underscores lignin nanoparticles as beacons of hope in the pursuit of cleaner, healthier, and more harmonious coexistence between humanity and nature through innovative environmental remediation strategies.

Application progress of rosin in food packaging: A review

Foodborne illness caused by Gram bacteria is the most important food safety issue worldwide. Food packaging film is a very important means to extend the shelf life of food. It reduces microbial contamination and provides food safety assurance during the sales process. However, the food packaging material is derived from plastic. Most plastics are not only non-degradable but also harmful to human health. Biodegradable natural polymers are an ideal substitute, but their poor mechanical properties, hydrophilicity and weak antibacterial properties limit their applications. Rosin is an oily pine ester in the pine family, which is a natural renewable resource with a wide range of sources. It is widely used in various fields, such as surfactants, adhesives, drug loading, antibacterial, etc. However, there are only a few reports on the application of rosin in food packaging. It is worth noting that the unique hydrogenated phenanthrene ring structure of rosin can enhance the thermal stability, hydrophobicity and antibacterial properties of food packaging. More importantly, rosin has a wide range of sources, good biocompatibility, and can be degraded in nature. These advantages are conducive to the application of rosin in food packaging. However, previous reviews focused on resins, silicone rubbers and surfactants. In this review we will focus on the application of rosin in food packaging.

Electrochemical identification of reductive enantiomers in wood channels: A low-cost and scalable platform for chiral sensing

Chirality, an inherent characteristic of natural substances (such as sugars, peptides, proteins, and nucleic acid), plays a vital role in human metabolism and exerts substantial impacts. In general, chiral drugs can display diverse pharmacological and pharmacokinetic properties. One enantiomer may exhibit therapeutic effects, while the other could cause adverse reactions. Selective recognition of enantiomers is thus a significant task in the biomolecular and pharmaceutical fields. Despite the development of several chiral identification techniques, low-cost enantioselective sensing methods remain highly desirable. Here, we designed and developed an electrochemical sensing device for reductive enantiomer identification using natural wood channels as the substrate. The wood channels were endowed with oxidase-like activity through the in-situ growth of cerium oxide nanoparticles (CeO2). Chiral recognition capability was further introduced by incorporating a layer of chiral ZIF-8 (L-ZIF) as the chiral selector. To demonstrate the enantioselective sensing performance, 3,4-dihydroxyphenylalanine (DOPA) enantiomers were employed as model analytes. Due to the oxidase-like activity and the confinement effect of the proposed channels, the captured DOPA enantiomers were effectively oxidized to their quinone structure, and the Ce(IV) in CeO2 was reduced to Ce(III). These changes led to alterations in the surface charge of the channels, thereby modulating their ionic transport properties. This sensing mechanism also proved useful for the identification of other reductive enantiomers. The limits of detection for l-DOPA and d-DOPA were determined as 2.41 nM and 1.56 nM, respectively. The resulting wood channel-based sensing device not only can be used for the recognition and detection of reductive enantiomers, but also is expected to be applied to the non-electochemically active substances. Moreover, this study offers a novel type of solid-state channel material with low cost, reproducibility, and easy accessibility for electrochemical chiral sensing.

Sulfuric acid solvolysis of cellulose in a butanol-1/benzene mixture for isolating cellulose nanocrystals

The absence of a universal method for isolating cellulose nanocrystals (CNCs) has prompted researchers to explore alternative approaches to traditional sulfuric acid hydrolysis. In this study, the authors continue their previous research by investigating CNC synthesis through cellulose solvolysis in an alcoholic environment. The CNCs were successfully obtained utilizing controlled sulfuric acid solvolysis of sulfate cellulose in a butanol-1/benzene mixture. The highest CNC yield (over 60 %) was achieved at strictly controlled acid-to-benzene ratios in a butanol-1/benzene/sulfuric acid reaction mixture, with a significant reduction in the optimal acid concentration. The study also analyzes the physicochemical properties of the isolated CNCs. No surface alkylation of the synthesized CNCs was observed during the cellulose solvolysis in the butanol-1/benzene mixture. Besides, the properties of these CNCs closely resembled those obtained through traditional sulfuric acid hydrolysis. The paper also discusses the potential mechanism of cellulose solvolysis in the process of CNC production.

pH-sensitive semi-interpenetrating network of microcrystalline cellulose and methacrylic acid hydrogel for the oral delivery of insulin

Insulin is commonly administered to diabetic patients subcutaneously and has shown poor patient compliance. Due to this, research has been carried out extensively to find molecules that could deliver insulin orally. In this context, a new type of pH-responsive hydrogel, composed of microcrystalline cellulose and methacrylic acid-based hydrogels, has been developed and studied for the oral delivery of insulin. These hydrogels were prepared by free radical polymerization using potassium persulphate as initiator and N, N'-methylenebisacrylamide as a cross-linker. These pH-sensitive hydrogels showed swelling in distilled water as high as 5800 %. The hydrogels were investigated for swelling in saline and glucose solutions, and pH sensitivity was confirmed by swelling in solutions of different pH. The morphological shape was established by SEM, and the structure was analyzed by FTIR. Thermal degradation was investigated by TGA. In vitro release studies have confirmed pH sensitivity, showing lower insulin release at pH 1.2 than at pH 6.8. The encapsulation efficiency was determined to be 56.00 ± 0.04 %. It was further validated by in-vivo investigations for which insulin was loaded into hydrogels and administered orally to healthy and diabetic Wistar rats at 40 IU/kg, showing maximum hypoglycemic effect at 6 h, which was sustained for 24 h. In the stomach's acidic environment, the gels remained unaffected due to the formation of intermolecular polymer complexes. Insulin remained in the gel and was protected from proteolytic degradation. Thus, pH-responsive methacrylic acid-based hydrogels are promising for biomedical applications, especially oral drug delivery.

Interfacially Ordered NiCoMoS Nanosheets Arrays on Hierarchical Ti3C2Tx MXene for High-Energy-Density Fiber-Shaped Supercapacitors with Accelerated Pseudocapacitive Kinetics

Balancing electrochemical activity and structural reversibility of fibrous electrodes with accelerated Faradaic charge transfer kinetics and pseudocapacitive storage are highly crucial for fiber-shaped supercapacitors (FSCs). Herein, we report novel core-shell hierarchical fibers for high-performance FSCs, in which the ordered NiCoMoS nanosheets arrays are chemically anchored on Ti3C2Tx fibers. Beneficial from architecting stable polymetallic sulfide arrays and conductive networks, the NiCoMoS-Ti3C2Tx fiber maintains fast charge transfer, low diffusion and OH- adsorption barrier, and stabilized multi-electronic reaction kinetics of polymetallic sulfide. Consequently, the NiCoMoS-Ti3C2Tx fiber exhibits a large volumetric capacitance (2472.3 F cm-3) and reversible cycling performance (20,000 cycles). In addition, the solid-state symmetric FSCs deliver a high energy density of 50.6 mWh cm-3 and bending stability, which can significantly power electronic devices and offer sensitive detection for dopamine.

A COBRA family protein, PtrCOB3, contributes to gelatinous layer formation of tension wood fibers in poplar

Angiosperm trees usually develop tension wood (TW) in response to gravitational stimulation. TW comprises abundant gelatinous (G-) fibers with thick G-layers primarily composed of crystalline cellulose. Understanding the pivotal factors governing G-layer formation in TW fiber remains elusive. This study elucidates the role of a Populus trichocarpa COBRA family protein, PtrCOB3, in the G-layer formation of TW fibers. PtrCOB3 expression was upregulated, and its promoter activity was enhanced during TW formation. Comparative analysis with wild-type trees revealed that ptrcob3 mutants, mediated by Cas9/gRNA gene editing, were incapable of producing G-layers within TW fibers and showed severely impaired stem lift. Fluorescence immunolabeling data revealed a dearth of crystalline cellulose in the tertiary cell wall (TCW) of ptrcob3 TW fibers. The role of PtrCOB3 in G-layer formation is contingent upon its native promoter, as evidenced by the comparative phenotypic assessments of pCOB11::PtrCOB3, pCOB3::PtrCOB3, and pCOB3::PtrCOB11 transgenic lines in the ptrcob3 background. Overexpression of PtrCOB3 under the control of its native promoter expedited G-layer formation within TW fibers. We further identified 3 transcription factors that bind to the PtrCOB3 promoter and positively regulate its transcriptional levels. Alongside the primary TCW synthesis genes, these findings enable the construction of a 2-layer transcriptional regulatory network for the G-layer formation of TW fibers. Overall, this study uncovers mechanistic insight into TW formation, whereby a specific COB protein executes the deposition of cellulose, and consequently, G-layer formation within TW fibers.

Pushing Trap-Controlled Persistent Luminescence Materials toward Multi-Responsive Smart Platforms: Recent Advances, Mechanism, and Frontier Applications

Smart stimuli-responsive persistent luminescence materials, combining the various advantages and frontier applications prospects, have gained booming progress in recent years. The trap-controlled property and energy storage capability to respond to external multi-stimulations through diverse luminescence pathways make them attractive in emerging multi-responsive smart platforms. This review aims at the recent advances in trap-controlled luminescence materials for advanced multi-stimuli-responsive smart platforms. The design principles, luminescence mechanisms, and representative stimulations, i.e., thermo-, photo-, mechano-, and X-rays responsiveness, are comprehensively summarized. Various emerging multi-responsive hybrid systems containing trap-controlled luminescence materials are highlighted. Specifically, temperature dependent trapping and de-trapping performance is discussed, from extreme-low temperature to ultra-high temperature conditions. Emerging applications and future perspectives are briefly presented. It is hoped that this review would provide new insights and guidelines for the rational design and performance manipulation of multi-responsive materials for advanced smart platforms.

Scalable Cathodic H2O2 Electrosynthesis using Cobalt-Coordinated Nanocellulose Electrocatalyst

Converting hierarchical biomass structure into cutting-edge architecture of electrocatalysts can effectively relieve the extreme dependency of nonrenewable fossil-fuel-resources typically suffering from low cost-effectiveness, scarce supplies, and adverse environmental impacts. A cost-effective cobalt-coordinated nanocellulose (CNF) strategy is reported for realizing a high-performance 2e-ORR electrocatalysts through molecular engineering of hybrid ZIFs-CNF architecture. By a coordination and pyrolysis process, it generates substantial oxygen-capturing active sites within the typically oxygen-insulating cellulose, promoting O2 mass and electron transfer efficiency along the nanostructured Co3O4 anchored with CNF-based biochar. The Co-CNF electrocatalyst exhibits an exceptional H2O2 electrosynthesis efficiency of ≈510.58 mg L-1 cm-2 h-1 with an exceptional superiority over the existing biochar-, or fossil-fuel-derived electrocatalysts. The combination of the electrocatalysts with stainless steel mesh serving as a dual cathode can strongly decompose regular organic pollutants (up to 99.43% removal efficiency by 30 min), showing to be a desirable approach for clean environmental remediation with sustainability, ecological safety, and high-performance.

Utilizing Natural Materials in Electronic Devices: Inching Toward "Herbal Electronics"

Sustainable development is the primary key to address global energy challenges. Though the scientific community is engaged in developing efficient ways to not only maximize energy production from natural resources like sun, wind, water, etc. but also to make all the electronic gadgets power efficient, despite all this, the materials used in most of the electronic devices are largely produced using various materials processing techniques and semiconductors, polymers, dielectrics, etc. which again increases the burden on energy and in turn affects the environment. While addressing these challenges, it is very important to explore the possibility to directly, or with minimum processing, utilize the potential of natural resources in the development of electronic devices. Recent articles are focused on the development of herbal electronic devices that essentially implement natural resources, like plants, leaves, etc., either in their raw or extracted form in the device assembly. This review encompasses the recent research developments around herbal electronic devices. Furthermore, herbal electronics has been discussed for several functional applications including electrochromism, energy storage, memresistor, LED, solar cell, water purification, pressure sensor, etc. Moreover, advantages, disadvantages, and challenges encountered in the realization of "herbal electronics" have been discussed at length.

Effect of Melamine Formaldehyde Resin Encapsulated UV Acrylic Resin Primer Microcapsules on the Properties of UV Primer Coating

Ultra-Violet (UV) coatings are widely adaptable of substrates and produce low emissions of volatile organic compounds. UV coatings can extend service life by adding self-healing microcapsules that restore integrity after sustaining damage. In this study, UV coating was used as a core material; microcapsules were produced and added to the UV coating to enhance its self-healing property, providing a good protection for both the UV coating and the substrate. UV primer microcapsules were prepared with UV primer as the core material and melamine formaldehyde resin as the wall material. The UV primer containing more than 98.0% solids content was mainly composed of epoxy acrylic resin, polyester acrylic resin, trihydroxy methacrylate, trimethyl methacrylate, and photo initiator. The preparation process of the UV primer microcapsules was optimized. Further, the UV coating was prepared with better UV primer microcapsules, and the effects of the UV primer microcapsules alongside the comprehensive properties of the coating were studied. The best preparation process for the UV primer microcapsules was as follows: the wall-core mass ratio was 1:0.50, Triton X-100 and Span-20 as emulsifiers with an HLB value of 10.04, the microcapsule reaction temperature was 70 °C, and the reaction time of the was 3.0 h. When the quantity of the UV primer microcapsules increased in the coating, color difference ΔE of the coating increased, gloss decreased, transmittance decreased, elongation at break increased and then decreased, roughness increased, and self-healing rate first increased and then decreased. When the addition of the UV primer microcapsules reached 2.0%, the color difference ΔE of the coating was 1.71, the gloss was 106.63 GU, the transmittance was 78.80%, the elongation at break was 3.62%, the roughness was 0.204 μm, and the self-healing rate was 28.56%, which were the best comprehensive properties of the UV primer. To improve the comprehensive properties of the UV coatings, the UV coatings were modified by a microcapsule technology, which gave the UV coatings a better self-healing property. The application range of microcapsules for the UV coatings was broadened. Based on the previous research of microcapsules in UV coatings, the results further refined the study of the effects of adding self-healing microcapsules to UV coatings using the UV coating itself as the core material.

Strong Yet Tough Transparent Paper with Superb Foldability

Transparent paper manufactured from wood fibers is emerging as a promising, cost-effective, and carbon-neutral alternatives to plastics. However, fully exploring their mechanical properties is one of the most pressing challenges. In this work, a strong yet tough transparent paper with superior folding endurance is prepared by rationally altering the native fiber structure. Microwave-assisted choline chloride/lactic acid deep eutectic solvent (DES) pulping is first utilized to isolate wood fibers from spruce wood. During this process, the S1 layer within the fibers is partially disrupted, forming protruding microfibrils that play a crucial role in enhancing cellulose accessibility. Subsequently, carboxymethylation treatment is applied to yield uniformly swollen carboxymethylated wood fibers (CM fibers), which improves the interaction between CM fibers during papermaking. The as-prepared transparent paper not only shows a 90% light transmittance (550 nm) but also exhibits impressive mechanical properties, including a folding endurance of over 26 000, a tensile strength of 248.4 MPa, and a toughness of 15.6 MJ m-3. This work provides a promising route for manufacturing transparent paper with superior mechanical properties from wood fibers and can extend their use in areas normally dominated by high-performance nonrenewable plastics.

Electronic Skin for Health Monitoring Systems: Properties, Functions, and Applications

Electronic skin (e-skin), a skin-like wearable electronic device, holds great promise in the fields of telemedicine and personalized healthcare because of its good flexibility, biocompatibility, skin conformability, and sensing performance. E-skin can monitor various health indicators of the human body in real time and over the long term, including physical indicators (exercise, respiration, blood pressure, etc.) and chemical indicators (saliva, sweat, urine, etc.). In recent years, the development of various materials, analysis, and manufacturing technologies has promoted significant development of e-skin, laying the foundation for the application of next-generation wearable medical technologies and devices. Herein, the properties required for e-skin health monitoring devices to achieve long-term and precise monitoring and summarize several detectable indicators in the health monitoring field are discussed. Subsequently, the applications of integrated e-skin health monitoring systems are reviewed. Finally, current challenges and future development directions in this field are discussed. This review is expected to generate great interest and inspiration for the development and improvement of e-skin and health monitoring systems.