Enhancing supercapacitor electrochemical performance through acetate-ion intercalation in layered nickel-cobalt double hydroxides

Enhancing the performance of layered nickel-cobalt double hydroxides (NiCo-LDH) as electrode materials for supercapacitors represents a promising strategy for optimizing energy storage systems. However, the complexity of the preparation method for electrode materials with enhanced electrochemical performance and the inherent defects of nickel-cobalt LDH remain formidable challenges. In this study, we synthesized acetate-ion-intercalated NiCo-LDH (NCLA) through a simple one-step hydrothermal method. The physical and chemical structural properties and supercapacitor characteristics of the as-prepared NCLA were systematically characterized. The results indicated that the introduction of Ac- engendered a distinctive tetragonal crystal structure in NiCo-LDH, concomitant with a reduced interlayer spacing, thus enhancing structural stability. Electrochemical measurements revealed that NCLA-8 exhibited a specific capacitance of 1032.2 F g-1 at a current density of 1 A g-1 and a high specific capacitance of 922 F g-1 at 10 A g-1, demonstrating a rate performance of 89.3%. Furthermore, NCLA-8 was used to construct the positive electrode of an asymmetric supercapacitor, while the negative electrode was composed of activated carbon. This configuration resulted in an energy density of 67.7 Wh kg-1 at a power density of 800 W kg-1. Remarkably, the asymmetric supercapacitor retained 82.8% of its initial capacitance following 3000 charge-discharge cycles at a current density of 10 A g-1. Thus, this study demonstrates the efficacy of acetate-ion intercalation in enhancing the electrochemical performance of NiCo-LDH, establishing it as a viable electrode material for supercapacitors.

Use of Interfacial Interactions and Complexation of Carbon Dots to Construct Ultra-Robust and Efficient Photothermal Film From Micro-Carbonized Polysaccharides

Solar energy conversion technologies, particularly solar-driven photothermal conversion, are both clean and manageable. Although much progress has been made in designing solar-driven photothermal materials, significant challenges remain, not least the photobleaching of organic dyes. To tackle these issues, micro-carbonized polysaccharide chains, with carbon dots (CDs) suspended from the chains, are conceived, just like grapes or tomatoes hanging from a vine. Carbonization of sodium carboxymethyl cellulose (CMC) produces just such a structure (termed CMC-g-CDs), which is used to produce an ultra-stable, robust, and efficient solar-thermal film by interfacial interactions within the CMC-g-CDs. The introduction of the CDs into the matrix of the photothermal material effectively avoided the problem of photobleaching. Manipulating the interfacial interactions (such as electrostatic interactions, van der Waals interactions, π-π stacking, and hydrogen bonding) between the CDs and the polymer chains markedly enhances the mechanical properties of the photothermal film. The CMC-g-CDs are complexed with Fe3+ to eliminate leakage of the photothermal reagent from the matrix and to solve the problem of poor water resistance. The resulting film (CMC-g-CDs-Fe) has excellent prospects for practical application as a photothermal film.

Synthesis and characterization of a bio-aldehyde-based lignin adhesive with desirable water resistance

Wood-based panels find widespread application in the furniture and construction industries. However, over 90 % of adhesives used are synthesized with formaldehyde, leading to formaldehyde emission and associated health risks. In this study, an entirely bio-based adhesive (OSL) was innovatively proposed through the condensation of multi-aldehyde derived from the oxidization of sucrose (OS) with sodium lignosulfonate (L). This approach positioned oxidized sucrose (OS) as a viable substitute for formaldehyde, ensuring safety, simplicity, and enhance water resistance upon reaction with L. The optimization of the OSL adhesive preparation process involved determining the oxidant level for high sucrose conversion to aldehyde (13 % based on sucrose), the mass ratio of OS to L (0.8), and hot-pressing temperature (200 °C). Notably, the shear strength of 3-plywood bonded with the developed adhesive (1.04 MPa) increased to 1.42 MPa after being immersed in hot water at 63 ± 3 °C for 3 h. Additionally, the plywood specimens exhibited excellent performance after soaking in boiling water for 3 h, resulting in a shear strength of 1.03 MPa. Chemical analysis using Fourier-transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) confirmed an addition reaction between L and OS, forming a dense network structure, effectively enhanceing the water resistance of OSL adhesives. Furthermore, compared with lignin-formaldehyde resin adhesive (LF), the OSL adhesive exhibited superior wet shear strength. This study offered an innovative approach for developing lignin-based adhesives utilizing a biomass aldehyde (OS), as a promising substitute for formaldehyde in the wood industry. The findings indicated that this approach may advance lignin-based adhesives, ensuring resistance to strength deterioration under highly humid environmental conditions.

Chitosan-based fluorescent probe for the detection of Fe3+ in real water and food samples

Iron ions play a crucial role in the environment and the human body. Therefore, developing an effective detection method is crucial. In this paper, we report CNS2, a chitosan-based fluorescent probe utilizing naphthalimide as a fluorophore. CNS2 is designed to "quench" its own yellow fluorescence through the specific binding of compounds containing enol structures to Fe3+. Studying the fluorescence lifetime of CNS2 in the presence or absence of Fe3+ reveals that the quenching mechanism is static. The presence of multiple recognition sites on the chitosan chain bound to Fe3+ gave CNS2 rapid recognition (1 min) and high sensitivity, with a detection limit as low as 0.211 μM. Moreover, the recognition of Fe3+ by CNS2 had a good specificity and was not affected by interferences. More importantly, in this study, CNS2 was successfully utilised to prepare fluorescent composite membranes and to detect Fe3+ in real water samples and a variety of food samples. The results show that the complex sample environment still does not affect the recognition of Fe3+ by CNS2. All the above experiments obtained more satisfactory results, which provide strong support for the detection of Fe3+ by the probe CNS2 in practical applications.

Towards high performance wood composites through interface customization with cellulose-based adhesive

How to efficiently produce high performance plywood is of particular interest, while its sensitivity to moisture is overcome. This paper presents a simple and scalable strategy for the preparation of high-performance plywood based on the chemical bonding theory; a wood interfacial functionalized platform (WIFP) based on (3-aminopropyl) triethoxysilane (APTES) was established. Interestingly, the APTES-enhanced dialdehyde cellulose-based adhesive (DAC-APTES) was able to effectively establish chemically active adhesive interfaces; the dry/wet shear strength of WIFP/DAC-APTES adhesive was 3.15/1.31 MPa, which was much higher than 0.7 MPa (GB/T 9846-2015). The prepared plywood showed excellent wood-polymer interface adhesion, which exceeded the force that the wood itself could withstand. In addition, the DAC-APTES adhesive exhibits moisture evaporation-induced curing behavior at room temperature and can easily support the weight of an adult weighing 65.7 Kg. This research provides a novel approach for functionalized interface design of wood products, an effective means to prepare high-performance plywood.

Achromobacter species (sp.) outbreak caused by hospital equipment containing contaminated water: risk factors for infection

BACKGROUND

Nosocomial outbreaks of urinary tract infections caused by Achromobacter spp. have been rare in recent decades.

AIM

To identify the origin of an Achromobacter sp. outbreak, conduct multi-modal infection control measures, and finally to stop the outbreak. To this end, an epidemiological outbreak investigation and risk factor analysis were performed.

METHODS

Achromobacter sp. was detected in 22 patients in our urology wards and six environmental cultures of specimens obtained from the operating rooms. Strains isolated were submitted for antimicrobial susceptibility testing. An on-site epidemiological investigation, evaluation of patient medical records, and environmental sampling were performed to identify the source of the outbreak, and implementation of infection control intervention. A case-control study was performed to analyse the potential risk factors.

FINDINGS

Environmental sampling showed that the source of the infection for 22 patients was an ISA-IIIA-type medical pressurizer containing contaminated water. A case-control analysis showed that the risk factors for infection were: diagnosis of kidney/ureteral stones, surgery, placement of a double-J stent, and history of hospitalization in the past three months.

CONCLUSION

It was concluded that the outbreak occurred in patients who underwent internal lithotripsy and double-J stent placement, due to contact transmission with the contaminated sensor and connecting tubes of the ISA-IIIA-type medical pressurizer.

Developing high performance biodegradable film based on crosslinking of cellulose acetate and tannin using caprolactone

The use of metal catalysts during the production process of cellulose acetate (CA) film can have an impact on the environment, due to their toxicity. Diphenyl phosphate (DPP) was used instead of toxic metal catalyst to react with cellulose acetate, tannin (T) and caprolactone (CL) for preparation of cellulose acetate-caprolactone-tannin (CA-CL-T) film. The results show that DPP can produce a cross-linked network structure composed of tannin, caprolactone and cellulose acetate. The maximum molecular weight reached 113,260 Da. The introduction of tannin and caprolactone into cellulose acetate caused the resulting CA-CL-T film acquire excellent strengthening/toughening effect, in which a tensile strength of 23 MPa and elongation at break of 18 % were attained. More importantly, the resistance of the film to UV radiation was significantly improved with the tannin addition, which was corroborated by the CA-CL-T film still exhibiting a tensile strength of 13 MPa and elongation at break around 13 % after continuous exposure to UV radiation for 9 days. On the other hand, the insertion of caprolactone provoked enhancement of the overall moisture resistance. Five days treatment of the films with Penicillium sp. induced gradual drop in quality, indicating the CA-CL-T film show response to biodegradation. In all, the effective crosslinking between the components of the developed material is responsible for the acquired set of these distinct characteristics.

Synthesis and application of hypochlorite ratiometric fluorescence probe based on cellulose

Cellulose is the most abundant natural polymer with good biocompatibility and easy modification characteristics. In this paper, a novel cellulose fluorescence probe CNS for detecting ClO- was prepared by modifying microcrystalline cellulose (MCC). The fluorescence detection results indicate that CNS exhibits a highly specific "ratiometric" and "colorimetric" fluorescence response to ClO-. In the presence of ClO-, the fluorescence color changes from green to cyan. In addition, the color of the solution changes from yellow to colorless, which can be observed with the "naked eye". Considering the good selectivity and anti-interference ability of CNS, the probe can be used for the detection of ClO- in real water samples. Importantly, CNS composite films and test papers were prepared and showed practicability in the detection of ClO-, highlighting its broad application potentials.

Lobster-Inspired Chitosan-Derived Adhesives with a Biomimetic Design

Polysaccharide-based adhesives, especially chitosan (CS)-derived adhesives, serve as promising sustainable alternatives to traditional adhesives. However, most demonstrate a poor adhesive strength. Inspired by the inherent layered structure of marine arthropods (lobsters), a core-shell structure (SiO2-NH2@OPG) with amine-functionalized silica (SiO2-NH2) as the core and oxidized pyrogallol (OPG) as the shell is prepared in this study. The compound is blended with CS to produce a structural biomimetic wood adhesive (SiO2-NH2@OPG/CS) with excellent performance. In addition to thermocompressive curing, this adhesive exhibits a water-evaporation-induced curing behavior at room temperature. With reference to the design mechanism of the lobster cuticle, this microphase-separated structure consists of clustered nanofibers with varying amounts of SiO2-NH2@OPG particles between the fibers. This intriguing microphase structure and its mechanical effects could offer a powerful solution for improving the functional modification of wood composites.

Sustainable, efficient, and synergistic photocatalytic degradation toward organic dyes and formaldehyde gas via Cu2O NPs@wood

Cuprous oxide (Cu2O) nanoparticles (NPs) was anchored on wood by simple spraying method, then both soft and hard wood has been endowed efficient function photocatalytic degradation toward organic dyes and formaldehyde gas synergistically. The best recycle ability of wood based photocatalyst toward organic pollutants was achieved, which was characterized by photocatalytic degradation efficiency of methylene blue (MB) more than 95% after 100 cycles, and formaldehyde gas over 85% after 60 cycles. Cu2O NPs@wood performed much lower forbidden bandwidth (Eg), which accelerated to generate much more radical of e- and finally promoted the capacity of photocatalytic degradation. The proposed Cu2O NPs@wood catalysts has potential to be applied both in the field of wastewater and air pollution remediation.

A flavonol-labelled cellulose fluorescent probe combined with composite fluorescent film imaging and smartphone technology for the detection of Fe3

Fe3+ is one of the most widely distributed and abundant elements on earth. Realizing efficient and real-time monitoring of Fe3+ is of great significance for the natural environment and the health of living organisms. In this paper, a flavonol-labelled cellulose-based fluorescent probe (ACHM) was synthesized by using dialdehyde cellulose (DAC) as the backbone and combining with flavonol derivatives (AHM - 1). The mechanism of recognizing Fe3+ was verified by characterizing the structure of ACHM by NMR, HRMS (High Resolution Mass Spectrometry), FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-ray Diffraction), TG (Thermogravimetry) and SEM (Scanning Electron Microscopy). The H2O solution of the probe ACHM showed good fluorescence properties. It has quenching fluorescence properties for Fe3+, with a low limit of detection (LOD) of 0.10 μM and a fast response time of only 20 s. In addition, in order to expand the application range of the probe, ACHM was prepared as a fluorescent composite film with an average tensile strength of 32.9 MPa and an average elongation at break of 3.39 %. It shows its superiority in mechanical properties. The probe also demonstrated its practical application value for detecting Fe3+ in smartphone imaging applications.

Preparation and fire resistance modification on tannin-based non-isocyanate polyurethane (NIPU) rigid foams

Non-isocyanate polyurethane (NIPU) as a new type of polyurethane material has become a hot research topic in the polyurethane industry due to its no utilization of toxic isocyanates during the synthesis process. And the developing on recyclable biomass materials has also much attention in the industrial sector, hence the preparation and application of bio-based NIPU has also become a very meaningful study work. So, in this paper, tannin as a biomass material was used to synthesize tannin based non-isocyanate polyurethanes (TNIPU) resin, and then successfully prepared a self-blowing TNIPU foam at room temperature by using formic acid as initiator and glutaraldehyde as cross-linking agent. The compressive strength of this foam as high as 0.8 MPa, which is an excellent compressive performance. Meanwhile it will return to the state before compression when removing the pressure. This indicating that the foam has good toughness. In addition, formic acid can react with the amino groups in TNIPU to form amide substances, and generated enough heat to initiate the foaming process. Glutaraldehyde, as a crosslinking agent, reacts with the amino group in TNIPU to form a network structure system. By scanning electron microscope (SEM) observation of the cell shapes, it can be seen that the foam cells were uniform in size and shape, and the cell pores showed open and closed cells. The limiting oxygen index (LOI) tested value of this TNIPU foam is 24.45 % without any flame retardant added, but compared to the LOI value of polyurethane foam (17 %-19 %), TNIPU foam reveal a better fire resistance. It has a wider application prospect.

Handheld UV spectrophotometer device for detection of methamphetamine hydrochloride based on supramolecular sensing platform

The realization of drug detection in drug-using crime sites can provide law enforcement officials with direct evidence. This research has developed and demonstrated an easy-to-use handheld sensor that can quickly detect methamphetamine (MA) in the field. The core of the handheld UV spectrophotometer device (HUVSD) is the STM32F103 series of single-chip micro-controller, which has a 32-bit microcontroller and two embedded 12-bit high-precision analog-to-digital converter (ADC) modules. Through Bluetooth-wireless transmission protocol, the spectral information can be displayed in the cell phone's app, and it is possible to visually determine whether the test sample contains methamphetamine hydrochloride substances based on the characteristic peak at 410 nm. The readily available and inexpensive inducible compound 3A and the phosphate pillar[5]arene@silver nanoparticle (PP5@AgNPs) colloidal solution were used as the reactants. The PP5@AgNPs colloidal solution and 3A were mixed and reacted at room temperature, and the color changed to gray-black. The color change was caused by the aggregation of AgNPs induced by the molecular recognition between the induction compound 3A and PP5 on the AgNPs surface. After continuing to add the drug MA, the color of the colloidal solution turned yellow again. This is due to the occurrence of competitive molecular recognition, and the interaction between PP5 and 3A/MA was investigated by molecular docking simulations. The HUVSD has high sensitivity, simple equipment, time-saving, color change visualization and suitable for on-site deployment. It only needs a Pasteur pipette, which has great potential to realize rapid on-site detection.

Electrospun microcrystalline cellulose/chitosan porous composite nanofibrous membranes modified by non-thermal plasma for gaseous formaldehyde adsorption

To develop a green and facile adsorbent for removing indoor polluted formaldehyde (HCHO) gas, the biomass porous nanofibrous membranes (BPNMs) derived from microcrystalline cellulose/chitosan were fabricated by electrospinning. The enhanced chemical adsorption sites with diverse oxygen (O) and nitrogen (N)-containing functional groups were introduced on the surface of BPNMs by non-thermal plasma modification under carbon dioxide (CO2) and nitrogen (N2) atmospheres. The average nanofiber diameters of nanofibrous membranes and their nanomechanical elastic modulus and hardness values decreased from 341 nm to 175-317 nm and from 2.00 GPa and 0.25 GPa to 1.70 GPa and 0.21 GPa, respectively, after plasma activation. The plasma-activated nanofibers showed superior hydrophilicity (WCA = 0°) and higher crystallinity than that of the control. The optimal HCHO adsorption capacity (134.16 mg g-1) of BPNMs was achieved under a N2 atmosphere at a plasma power of 30 W and for 3 min, which was 62.42 % higher compared with the control. Pyrrolic N, pyridinic N, CO and O-C=O were the most significant O and N-containing functional groups for the improved chemical adsorption of the BPNMs. The adsorption mechanism involved a synergistic combination of physical and chemical adsorption. This study provides a novel strategy that combines clean plasma activation with electrospinning to efficiently remove gaseous HCHO.

Synthesis of biomass hyperbranched polyamide resin from cellulose and citric acid for wood adhesive

Traditional wood adhesives have the problems of excessive dependence on fossil resources and environmental pollution. Cellulose, a renewable biomass resource with a low price and huge output, provides a basis for preparing biomass wood adhesives. In this study, a new type of polyamide resin was prepared by modifying microcrystalline cellulose and reacting with natural citric acid. Specifically, toluenesulfonyl cellulose (TS) was synthesized, and functional amino cellulose (AC) was prepared by a nucleophilic substitution reaction with hyperbranched polyamide (HP). Then cellulose-based hyperbranched polyamide resin (CHP) was prepared by polycondensation with citric acid. The structure of CHP resin was investigated by FTIR, XPS, 13C NMR and GPC, and plywood was prepared to study its mechanical properties. Due to the formation of hyperbranched cross-linked network structure inside the resin, the prepared plywood has excellent properties. The dry shear strength reaches 2.24 MPa, and the strength reaches 1.25 and 1.31 MPa after soaking in water at 63 °C and 93 °C for 3 h. The resin in this study has a simple preparation process and excellent performance, which provides a solid foundation for developing high-performance cellulose-based wood adhesives.

Sucrose-tannin-nanosilica hybrid bio-adhesive based on dual dynamic Schiff base and disulfide bonds with enhanced toughness and cohesion

Herein, a high-performance sucrose-tannin bio-based adhesive is developed based on consisting of oxidized sucrose (OS), tannin acid (TA), SiO2 nanoparticles and 2,2'-disulfanediylbis (ethan-1-amine) (DBA) by a facile chemical cross-linking strategy. The OS-TA and OS-TA@SiO2 bio-based adhesives are characterized by XPS, FTIR, and 13C NMR, while the bonding performance is also investigated using shear strength test. Results show that the optimal formulation of OS-TA bio-based adhesive is a 2:1:1 mass ratio for OS: TA: DBA. When the mass fraction of SiO2 is 15 % and the solid content of main components is 50 %, the OS-TA@SiO2 bio-based adhesive has excellent bonding strength. Relative to OS-TA, the wet bonding strength of the OS-TA@SiO2 enhanced from 1.16 MPa to 1.85 MPa, while the dry bonding strength improved from 1.90 MPa to 2.50 MPa. The wood failure rate of the plywood fabricated by using the OS-TA@SiO2 bio-based adhesive reaches 80 %. Therefore, relying on the high flexibility of dynamic disulfide bonds, adding SiO2 nanoparticles into the adhesive system can facilitate greatly the mechanical interlocking effect and make the chemical cross-linking network more compact through the synergistic chemical interactions. This work provides new insights into producing green and renewable bio-based wood adhesives using sucrose and tannin.

Boiling water resistant fully bio-based adhesive made from maleated chitosan and glucose with excellent performance

Biomass resources are widely considered potential alternatives to formaldehyde-based wood adhesives because of their abundance. In this study, an environmentally friendly biomass adhesive, carboxylated chitosan-glucose (CSC-G), was prepared using chitosan, maleic anhydride, and glucose. The structure and water resistance of the adhesive were analyzed in detail. Maleic anhydride act as a bridge connecting chitosan and glucose, giving the adhesive good water solubility and resistance. The improved water resistance of the CSC-G adhesive was attributed to the formation of covalent cross-linked structures and an increased degree of system cross-linking. Additionally, the curing temperature of the CSC-G adhesive was superior to those of previously reported polyester adhesives. This study not only expands the application scope of fishery waste, but also demonstrates its great potential for the preparation of high-performance plywood.

A fully bio-based soy protein wood adhesive modified by citric acid with high water tolerance

Despite the widespread application prospect of soybean meal flour (SF) as a non-toxic and renewable wood adhesive, the practical application is limited by its poor mechanical properties and water resistance. In this work, a novel SF-based wood adhesive (CSP) was developed using citric acid (CA) as a modifier, which was further designated to produce plywood on a laboratory scale. Moreover, the effects of the mass ratio of CA/SF, hot-pressing temperature, and hot-pressing time on the bonding properties and water resistance of the resulting plywood were investigated in detail. As a result, under the optimal hot-pressing conditions (180 °C, 5 min), high-performance plywood bonded by CSP (CA/SF = 15/100) adhesive was fabricated, whose dry shear strength, cold-water wet shear strength (20 °C for 24 h), and hot-water wet shear strength (63 °C for 3 h) reached 1.65 MPa, 1.99 MPa, and 1.58 MPa, respectively. Due to the easy preparation process, sustainability, and favorable properties, the proposed fully bio-based CSP wood adhesive has great potential for the large-scale fabrication of eco-friendly wood panels in industry.

Effective and eco-friendly safe self-antimildew strategy to simultaneously improve the water resistance and bonding strength of starch-based adhesive

Starch adhesive, as a sustainable biomass-based adhesive, could be used to solve environmental problems from petroleum-derived adhesive. But its application is hindered by poor water resistance, mildew resistance, and storage stability. Here, a fully bio-based citric acid-starch adhesive (CASt) with high properties was successfully introduced by a simple method. Liquid chromatography/mass spectrometry (LC-MS), and Fourier Transform Infrared spectroscopy (FT-IR) determined that esterification of citric acid (CA) and starch (St) occurred to form a stable three-dimensional crosslinking structure, which strengthened water resistance and bonding strength of the starch adhesive. Compared with native starch (100 %), the soluble content of cured CASt was 1-16 %. CASt adhesive has well storage stability and high mildew resistance. Even after being stored for 5 months, the CASt-1 adhesive (mass ratio of CA/St = 1:1, and reaction time = 1 h) still have good liquidity. And its hot water strength (1.05 ± 0.22 MPa) also satisfied the standard requirements (≥0.7 MPa). The exhibited CASt adhesive is eco-friendly with components from plant resources, which performed as a bright alternative that can substitute petroleum-based adhesives in the artificial board industry.

A Chitosan-Based Fluorescent Probe Combined with Smartphone Technology for the Detection of Hypochlorite in Pure Water

Using chitosan as a raw material, 1,8-naphthimide as the fluorescent chromophore, and sulfur-containing compounds as the recognition groups, a novel naphthimide-functionalized chitosan probe, CS-BNS, for the detection of ClO- was successfully synthesized. The modification of chitosan was verified by SEM, XRD, FTIR, mapping, 13C-NMR, TG and the structure of the probe molecule was characterized. The identification performance of the probes was studied using UV and fluorescence spectrophotometers. The results show that CS-BNS exhibits a specific response to ClO- based on the oxidative reaction of ClO- to the recognition motifs, as well as a good resistance to interference. And the probe has high sensitivity and fast response time, and can complete the detection of ClO- in a pure water system within 60 s. The probe can also quantify ClO- (y = 30.698x + 532.37, R2 = 0.9833) with a detection limit as low as 0.27 μM. In addition, the combination of the probe with smartphone technology enables the visualization and real-time monitoring of ClO-. Moreover, an identification system for ClO- was established by combining the probe with smartphone technology, which realized the visualization and real-time monitoring of ClO-.

Preparation and characterization of the bonding performance of a starch-based water resistance adhesive by Schiff base reaction

Starch is one of the important raw materials for the preparation of biomass adhesives for its good viscosity and low-cost properties. However, the drawbacks of poor water resistance and bonding performance seriously restrict its application in the wood industry. To resolve those problems, an environment-friendly renewable, and high water resistance starch-based adhesive (OSTH) was prepared with oxidized starch and hexanediamine by Schiff base reaction. In order to optimize the adhesive preparation process, the effect of different oxidation times and oxidant addition on the mechanical performance of plywood were investigated. In addition, the curing behavior characteristics, thermomechanical properties, and thermal stability of the OSTH adhesives were analyzed by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TG). Fourier-transform infrared (FTIR) spectrometry and Liquid Chromatography-Mass Spectrometry (LC-MS) were used to explain the reaction mechanisms involved. The results show this adhesive has an excellent bonding performance at the oxidation time of 12 h with 11 % (w/w, dry starch basis) NaIO4 as an oxidant. The dry shear strength, 24-hour cold water, and 3-hour hot water (63 °C) soaking shear strength of the plywood bonded with this resin were respectively 1.87 MPa, 0.96 MPa, and 0.91 MPa, which satisfied the standard requirement of GB/T 9846-2015 (≥0.7 MPa). Thus, this study provided a potential strategy to prepare starch-based wood adhesives with good bonding performance and water resistance.

High-performance bamboo composites based on the chemical bonding of active bamboo interface and chitosan

Nowadays, green, clean, and efficient sustainable development has become the world's mainstream industrial development. However, the bamboo/wood industry is still in the status quo with high fossil resource dependence and significant greenhouse gas emissions. Herein, a low-carbon and green strategy to produce bamboo composites is developed. The bamboo interface was modified directionally to a bamboo carboxy/aldehyde interface by using a TEMPO/NaIO₄ system, and then chemically cross-linked with chitosan to produce active bonding bamboo composite (ABBM). It was confirmed that the chemical bond cross-linking (CN, N-C-N, electrostatic interactions, hydrogen bonding) in the gluing region was helpful to obtain the excellent dry bonding strength (11.74 MPa), water resistance (5.44 MPa), and anti-aging properties (decreased by 20 %). This green production of ABBM solves the problem of poor water resistance and aging resistance of all-biomass-based chitosan adhesives. It can replace bamboo composites produced using fossil-based adhesives to meet the requirements of the construction, furniture, and packaging industries, changing the previous situation of composite materials requiring high temperature pressing and highly dependent on fossil-based adhesives. This provides a greener and cleaner production method for the bamboo industry, as well as more options for the global bamboo industry to achieve green and clean production goals.

Ureido Hyperbranched Polymer Modified Urea-Formaldehyde Resin as High-Performance Particleboard Adhesive

The performance of urea-formaldehyde (UF) resin and its formaldehyde emission is a natural contradiction. High molar ratio UF resin performance is very good, but its formaldehyde release is high; low molar ratio UF resin formaldehyde release is reduced, but the resin itself performance becomes very bad. In order to solve this traditional problem, an excellent strategy of UF resin modified by hyperbranched polyurea is proposed. In this work, hyperbranched polyurea (UPA_6N) is first synthesized by a simple method without any solvent. UPA_6N is then added into industrial UF resin in different proportions as additives to manufacture particleboard and test its related properties. UF resin with a low molar ratio has a crystalline lamellar structure, and UF-UPA_6N resin has an amorphous structure and rough surface. The results show that internal bonding strength increased by 58.5%, modulus of rupture increased by 24.4%, 24 h thickness swelling rate (%) decreased by 54.4%, and formaldehyde emission decreased by 34.6% compared with the unmodified UF particleboard. This may be ascribed to the polycondensation between UF and UPA_6N, while UF-UPA_6N resin forms more dense three-dimensional network structures. Finally, the application of UF-UPA_6N resin adhesives to bond particleboard significantly improves the adhesive strength and water resistance and reduces formaldehyde emission, suggesting that the adhesive can be used as a green and eco-friendly adhesive resource for the wood industry.

Synthesis of corn bract cellulose-based Au3+ fluorescent probe and its application in composite membranes

To achieve real-time monitoring of Au³⁺, a corn bract cellulose-based fluorescent probe MAC-1 for was synthesized. MAC-1 showed good fluorescence properties in DMF-H₂O (1:9, v/v, pH = 7.4) solution, showed a fluorescence emission peak at 520 nm with quenching fluorescence properties for Au³⁺. The structure of MAC-1 was analyzed by SEM (Sample microstructure images), XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), ¹H NMR, Elemental analysis, EDS, Mapping and TG (Thermogravimetry) were analyzed. The fluorescence properties of the probe were also characterized by UV spectrophotometer and fluorescence spectrophotometer. The results showed that the recognition of Au³⁺ by the probe MAC-1 exhibited high selectivity and high sensitivity. Moreover, it is highly resistant to interference and has a short response time, which can be rapidly responded within 1 min. In addition, to improve the practical application of the probe, the probe was prepared as a fluorescent composite film and the fluorescence effect shown by the fluorescent composite film is consistent with the fluorescence change of the probe MAC-1 itself. The fluorescent composite film also has excellent selectivity and good overall physical and mechanical properties. This study provides a meaningful reference for the detection of Au³⁺ and further expands the application field of agroforestry waste.

Preparation of Nanocellulose-Based Aerogel and Its Research Progress in Wastewater Treatment

Nowadays, the fast expansion of the economy and industry results in a considerable volume of wastewater being released, severely affecting water quality and the environment. It has a significant influence on the biological environment, both terrestrial and aquatic plant and animal life, and human health. Therefore, wastewater treatment is a global issue of great concern. Nanocellulose's hydrophilicity, easy surface modification, rich functional groups, and biocompatibility make it a candidate material for the preparation of aerogels. The third generation of aerogel is a nanocellulose-based aerogel. It has unique advantages such as a high specific surface area, a three-dimensional structure, is biodegradable, has a low density, has high porosity, and is renewable. It has the opportunity to replace traditional adsorbents (activated carbon, activated zeolite, etc.). This paper reviews the fabrication of nanocellulose-based aerogels. The preparation process is divided into four main steps: the preparation of nanocellulose, gelation of nanocellulose, solvent replacement of nanocellulose wet gel, and drying of nanocellulose wet aerogel. Furthermore, the research progress of the application of nanocellulose-based aerogels in the adsorption of dyes, heavy metal ions, antibiotics, organic solvents, and oil-water separation is reviewed. Finally, the development prospects and future challenges of nanocellulose-based aerogels are discussed.

Tannin-based wood adhesive with good water resistance crosslinked by hexanediamine

As a biomass material, tannins are used in the preparation of wood adhesives, but their poor strength and water resistance has greatly limited their application. Therefore, it is necessary to prepare tannin-based wood adhesives with good water resistance. In the present study, tannin and hexanediamine were simply mixed at room temperature to prepare tannin-hexanediamine (TH) adhesive and then used to prepare plywood. Effects of mass ratio of hexanediamine to tannin and pH value of TH adhesive are studied. The results indicating the effects of mass ratio and pH value are apparent on shear strength. When the mass ratio is above 25 % and the pH value is above 9, the plywood shows good water resistance. Fourier transform-infrared (FTIR), X-ray photoelectron spectroscopy (XPS), liquid chromatography-mass spectrometry (LCMS) and X-ray diffraction (XRD) are used to determine the structures of TH adhesive, confirmed the reaction between tannin and hexanediamine to form macromolecules. Simultaneous thermal analyzer (TG-DSC) and Dynamic mechanical analysis (DMA) are used to analyze the thermal properties, indicate TH resin contains a good storage module and heat resistance. Therefore, with its good shear strength and water resistance, this newly developed tannin-based adhesive has the potential to application in wood-based panel industry, as an alternative of formaldehyde-based adhesive.

Activated wood surface and functionalized cellulose co-building strong chemical wood bonding performance

Herein, an activated wood surface rich in CHO groups was constructed by spraying a sodium periodate aqueous solution on a natural wood surface. Besides, microcrystalline cellulose was functionalized to obtain aminated cellulose, which was dissolved in an aqueous solution and used as a specific adhesive. Subsequently, an ultrastrong wood bonding interface was co-constructed with the activated wood surface and aminated cellulose, which was formed by a chemical covalent reaction between aldehyde groups at the activated wood interface and amino groups on aminated cellulose. The dry, hot-water, and boiling-water lap shear strengths of the plywood specimens were 1.47, 1.07, and 1.08 MPa, respectively. The boiling-water strength of the plywood made from the activated wood surface achieved increased to 1.08 MPa from 0 MPa of the plywood constructed on the nonactivated wood surface. The chemical crosslinking reaction and bonding mechanism between the adhesive and activated wood surface were clarified by density functional theory calculations, attenuated total reflectance-Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results showed that chemical bonding (aminal NCN and imine CN) at the bonding interface played an important part in improving the water resistance and bonding strength. This work provides new concepts for designing durable and moisture-resistant wood products.

Dimensionally Stable Delignified Bamboo Matrix Phase-Change Composite under Ambient Temperature for Indoor Thermal Regulation

Energy storage materials to modulate indoor microclimates are needed to improve energy efficiency and for human comfort. Of these, phase-change material (PCM) is considered a very useful material because of its excellent latent heat energy storage. For application, some synthetic porous materials for supporting PCM are usually not friendly enough for people and housing environments due to their non-degradation characteristics. Hence, to develop an eco-friendly porous material is needed in order to encapsulate PCM composites that are always expected in indoor applications. In this work, heat-treated bamboo bricks were delignified to provide a delignified bamboo (DB) matrix. A phase-change composite was then fabricated by impregnating DB with polyethylene glycol (PEG) polymer. Impregnation was carried out under wet conditions to ensure the regular arrangement of the DB structure so as to achieve dimensional stability. The final DB/PEG composite was investigated for dimensional stability, load rate, latent heat, and phase-change temperature. Results showed that the DB matrix could be easily impregnated with PEG polymer under wet conditions, and the DB/PEG composite was found to have high enthalpy and a large phase-change temperature interval. Moreover, the composite was found to be a good regulator of indoor temperature and a stable dimension with a snow-white appearance. In summary, this DB/PEG composite is an energy storage material with the potential to modulate ambient indoor temperature and reduce building energy consumption.

Chitosan-tannin adhesive: Fully biomass, synthesis-free and high performance for bamboo-based composite bonding

Inspired by phenol-amine chemistry of mussels, a synthesis-free and fully biomass adhesive composed of chitosan and tannin (CST) was successfully developed by a facile method. The performance of CST adhesive for bonding bamboo, wood and bamboo-wood substrates were tested. When 160 °C hot-press temperature was used, dry lap shear strength above 5.00 MPa was obtained. The CST adhesive has remarkable water resistance and low cure temperature as high wet shear strength of 2.37 MPa for plybamboo specimens was achieved after 3 h boiling in water even though low hot-press temperature of 100 °C was applied. Further, high strength of 1.78 MPa remained after 72 h boiling. With higher hot-press temperatures used, wet shear strength above 3.60 MPa was achieved. The adhesion performance for wood substrate was also superior to other phenol-amine adhesives reported in literatures. The bamboo-wood composites assembled with CST adhesive show excellent mechanical performance, specifically modulus of rupture (MOR) of 100-133 MPa and modulus of elasticity (MOE) of 10-13 GPa were achieved with different hot-press temperatures used. Given the advantages including outstanding water resistance, facile preparation, fully biomass, and low cure temperature, CST adhesive exhibited great potential to be an ideal alternative to formaldehyde-based resin for wood and bamboo bonding.

Highly Branched Tannin-Tris(2-aminoethyl)amine-Urea Wood Adhesives

Condensed tannin copolymerized with hyperbranched tris(2-aminoethyl)amine-urea formed by amine-amido deamination yields a particleboard thermosetting adhesive without any aldehydes satisfying the requirements of relevant standards for the particleboard internal bond strength. The tannin-triamine-urea cures well at 180 °C, a relatively low temperature for today's particleboard hot pressing. As aldehydes were not used, the formaldehyde emission was found to be zero, not even in traces due to the heating of wood. The effect is ascribed to the presence of many reactive sites, such as amide, amino, and phenolic groups belonging to the three reagents used. The tannin appears to function as an additional cross-linking agent, almost a nucleating agent, for the triamine-urea hyperbranched oligomers. Chemical analysis by MALDI ToF and ¹³C NMR has shown that the predominant cross-linking reaction is that of the substitution of the tannin phenolic hydroxyls by the amino groups of the triamine. The reaction of tannin with the still-free amide groups of urea is rather rare, but it may occur with the rarer tannin flavonoid units in which the heterocyclic ring is opened. Due to the temperature gradient between the surfaces and the board core in the particleboard during hot pressing, the type and the relative balance of covalent and ionic bonds in the resin structure may differ in the surfaces and the board core.

Construction of a cellulose-based high-performance adhesive with a crosslinking structure bridged by Schiff base and ureido groups

Biomass-based adhesives are considered to be the preferred alternative to formaldehyde-type wood adhesives due to their wide range of sources, low cost, and sustainability. Herein, an environmentally friendly Schiff base cross-linked compact three-dimensional network structure bio-adhesive (DAC-PEI-U) derived from polyethyleneimine (PEI), urea, and cellulose was successfully prepared, verifying by detailed FTIR, NMR, and XPS analysis. Schiff base bridging between aldehyde groups in dialdehyde cellulose (DAC) and amino groups in polyurea (PEIU) not only constructed crosslinking networks but also endowed adhesives with good adhesion property. The dry bond strength of DAC-PEI-U adhesive reached 2.71 MPa, and the wet shear strength was 1.51 MPa (hot water) and 1.34 MPa (boiling water), respectively. It not only improves the water resistance and bonding process, but also displays simple synthesis and low cost. The improved performance of DAC-PEI-U adhesive is attributed to the generation of hyperbranched cross-linking structure in the adhesive system, which results in increased cross-linking density and promotes the formation of dense cross-sections in the curing adhesive. This work paves a solid way for developing cellulose-based wood adhesives with wet bonding properties, thus holding great potential as an alternative to formaldehyde-type adhesives in wood-based panel and indoor panel bonding industries.

Investigation of Novel Thermosetting Copolymer-Based Monomethylolurea-Glyoxal for Wood Manufacturing

The purpose of this investigation was to design novel alternating copolymers (monomethylolurea-glyoxal, MMU-G) as adhesives for wood manufacturing. MMU-G were synthesized under acid (pH = 5) conditions. After the 120-day storage period, the MMU-G resins were used for plywood production, which exhibited a wet shear strength of about 2.15 MPa, similar to the freshly prepared MMU-G resin. The excellent water resistance and long storage stability showed that MMU-G has particular characteristics and properties all of their own, which, in certain respects, are very different from those of urea-formaldehyde (UF) adhesives. The X-ray diffraction results showed that only a few crystallinities occurred in MMU-G resins, indicating the presence of long side chains in the MMU-G polymer structures, leading to better adhesion strength than UF resins. The structure characteristics of the MMU-G resin were studied by Fourier transform infrared and electrospray ionization mass spectrometry, and a possible molecular structure has been inferred, which is consistent with spectroscopic results.

Logistic regression analysis of risk factors for intra-abdominal hypertension after giant ventral hernia repair: a retrospective cohort study

BACKGROUND

Intra-abdominal hypertension (IAH) is a classical complication after giant ventral hernia surgery and may lead to abdominal compartment syndrome (ACS). Assessment of risk factors and prevention of IAH/ACS are essential for hernia surgeons.

METHODS

We performed a retrospective study including 58 giant ventral hernia patients in our center between Jan 1, 2017, and Mar 1, 2022, we recorded age, gender, chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), hypertension, type 2 diabetes mellitus (T2DM), hypoproteinemia, body mass index (BMI), the ratio of hernia sac volume to abdominal cavity volume (HSV/ACV), defect width, tension reduction procedure (TRP), positive fluid balance (PFB) and IAH of these patients and analyzed the data using univariate and multivariate logistic regression to screen the risk factors for IAH after surgery.

RESULTS

The multivariate analysis showed that HSV/ACV ≥ 25%, hypoproteinemia, and PFB were independent risk factors for the occurrence of IAH after giant ventral hernia repair (P = 0.025, 0.016, 0.017, respectively). We did not find any correlation between postoperative IAH and the patient's age, gender, COPD, CHD, hypertension, T2DM, BMI, defect width, TRP, and PFB.

CONCLUSION

Identifying risk factors is of great significance for the early identification and prevention of IAH/ACS. We found that HSV/ACV ≥ 25%, hypoproteinemia, and PFB were independent risk factors for IAH after giant ventral hernia repair.

Investigation of Potential Use of Soybean Protein Isolate–Chinese Bayberry Tannin Extract Cross-Linked Films in Packaging Applications

The possibility of using commercial bayberry tannin (BT) from a Chinese source as a cross-linker and functional additive to develop soybean protein isolate (SPI)-based films was explored in this study by using the solvent casting method. In particular, the impacts of BT loading on the tensile strength, microstructure, thermal stability, water resistance and antioxidant capacity were fully investigated. The results reveal that SPI incorporated with BT yielded a phenolic–protein hybrid whose relevant films exhibited an improvement in tensile strength of around two times greater compared with native SPI as a result of the formed interactions and covalent cross-links, which could be proven using FTIR spectroscopy. The introduction of BT also led to the compact microstructure of SPI–BT films and enhanced the thermal stability, while the water vapor permeability was reduced compared with the control SPI film, especially at high loading content of tannin. Additionally, the use of BT significantly promoted the antioxidant capacity of the SPI-based films according to DPPH radical scavenging assay results. On this basis, Chinese bayberry tannin is considered a promising natural cross-linker and multifunctional additive that can be dedicated to developing protein-derived films with antioxidant activity for food packaging applications.

Palladium-Catalyzed Preparation of N-Substituted Benz[c,d]indol-2-imines and N-Substituted Amino-1-naphthylamides

Here, we report a novel and facile protocol for the synthesis of benz[c,d]indol-2-imines via palladium-catalyzed C-C and C-N coupling of 8-halo-1-naphthylamines with isocyanides in a single step. The reaction features broad substrate scopes and mild conditions, providing an efficient alternative for the construction of antiproliferative agents and BET bromodomain inhibitors. If 0.1 mL of H₂O was added to this reaction, the N-substituted amino-1-naphthylamides could be obtained easily.

Dynamic reversible adhesives based on crosslinking network via Schiff base and Michael addition

It is of practical interest to obtain polymers with complex material properties in a simplified synthetic manner for a broader range of practical applications. In this work, we constructed a dynamic reversible adhesive based on branched polyamine (PA) and p-formylphenyl acrylate (FPA) by simultaneously performing Michael addition reaction and Schiff base reaction. Branched polyamines provide a large number of amino groups as reaction sites that can react with both carbon–carbon double bonds and aldehyde groups. This enables the branched polymeric adhesive system to have a large number of Schiff base bonds within it, an important property of Schiff base bonds is that they are dynamically reversible. This allows us to prepare adhesives with hyperbranched crosslinking networks and recycling properties, and we have verified that FPA–PA adhesives do not exhibit significant fatigue after multiple recycling through the gluing-destruction-gluing process. The resulting FPA–PA adhesives produce tough bonding on multi-substrates such as steel, aluminum, glass, PVC, PTFE, birch and moso bamboo, which exhibited by lap shear strength of 2.4 MPa, 1.7 MPa, 1.4 MPa, 1.3 MPa, 0.4 MPa, 1.6 MPa, and 1.8 MPa, respectively. The feasibility of the synthesis idea of simultaneous Michael addition reaction and Schiff base reaction was demonstrated, as well as the excellent performance and great application potential of FPA–PA adhesives to be recyclable on multi-substrates.

Schematic diagram of synthetic FPA–PA polymer adhesives, schematic diagram of adhesion strength on different substrates, and adhesion strength with multiple damage cycles for reuse.

Construction of a novel electrochemical sensor based on biomass material nanocellulose and its detection of acetaminophen

In this work, acidic sulfated cellulose nanocrystals (CNCs) were used as green carriers, and a novel composite material was synthesized and used to design sensors for paracetamol (AP) detection. There are negatively charged acidic sulfate groups on the surface of CNCs, which can enhance the electrostatic repulsion between nanoparticles, thereby increasing the stability and dispersibility of AgNPs in the system, making them less prone to agglomeration. Cationic pillar[5]arene (CP5) with a strong host–guest effect was used as a stable ligand for silver nanoparticles (AgNPs). AgNPs have good electrical conductivity and large specific surface area, which can significantly increase the peak current. In addition, CP5 has excellent supramolecular recognition performance, which can specifically recognize the guest molecule AP to form an inclusion complex, so that a large number of AP molecules are attached to the electrode surface, which is beneficial to the amplification of electrochemical signals. The prepared sensor is more attractive in terms of sensitivity and recognition performance; the host–guest binding constant was (3.37 ± 0.26) × 10⁴ M⁻¹, which can be obtained with good linearity (R² = 0.996), low detection limit (90 nM, LOD = 3σ/k, S/N = 3) and a wide linear range (0.5–500 μM). The electrochemical sensor showed good performance in quantitative analysis, stability, selectivity, reproducibility, and actual sample detection, providing high feasibility for real-time monitoring of paracetamol; it also provides a new idea for a green sensor.

In this work, acidic sulfated cellulose nanocrystals (CNCs) were used as green carriers, and a novel composite material was synthesized and used to design sensors for paracetamol (AP) detection.