Monodisperse CNT Microspheres for High Permeability and Efficiency Flow-Through Filtration Applications

Microfluidic Synthesis of Multifunctional Micro-/Nanomaterials from Process Intensification: Structural Engineering to High Electrochemical Energy Storage

Multifunctional micro-/nanomaterials featuring functional superiority and high value-added physicochemical nature have received immense attention in electrochemical energy storage. Microfluidic synthesis has become an emergent technology for massively producing multifunctional micro-/nanomaterials with tunable microstructure and morphology due to its rapid mass/heat transfer and precise fluid controllability. In this review, the latest progresses and achievements in microfluidic-synthesized multifunctional micro-/nanomaterials are summarized via reaction process intensification, multifunctional micro-/nanostructural engineering and electrochemical energy storage applications. The reaction process intensification mechanisms of various micro-/nanomaterials, including quantum dots (QDs), metal materials, conducting polymers, metallic oxides, polyanionic compounds, metal-organic frameworks (MOFs) and two-dimensional (2D) materials, are discussed. Especially, the multifunctional structural engineering principles of as-fabricated micro-/nanomaterials, such as vertically aligned structure, heterostructure, core-shell structure, and tunable microsphere, are introduced. Subsequently, the electrochemical energy storage application of as-prepared multifunctional micro-/nanomaterials is clarified in supercapacitors, lithium-ion batteries, sodium-ion batteries, all-vanadium redox flow batteries, and dielectric capacitors. Finally, the current problems and future forecasts are illustrated.

Collagen Fiber-Based Advanced Separation Materials: Recent Developments and Future Perspectives

Separation plays a critical role in a broad range of industrial applications. Developing advanced separation materials is of great significance for the future development of separation technology. Collagen fibers (CFs), the typical structural proteins, exhibit unique structural hierarchy, amphiphilic wettability, and versatile chemical reactivity. These distinctive properties provide infinite possibilities for the rational design of advanced separation materials. During the past 2 decades, many progressive achievements in the development of CFs-derived advanced separation materials have been witnessed already. Herein, the CFs-based separation materials are focused on and the recent progresses in this topic are reviewed. CFs widely existing in animal skins display unique hierarchically fibrous structure, amphiphilicity-enabled surface wetting behaviors, multi-functionality guaranteed covalent/non-covalent reaction versatility. These outstanding merits of CFs bring great opportunities for realizing rational design of a variety of advanced separation materials that were capable of achieving high-performance separations to diverse specific targets, including oily pollutants, natural products, metal ions, anionic contaminants and proteins, etc. Besides, the important issues for the further development of CFs-based advanced separation materials are also discussed.

Porous carbon nanotube microspheres with tailorable surface wettability areas for oil adsorption

HYPOTHESIS

Oil adsorption is significant for water purification and environmental protection. However, the conventional bulk sorbents face the predicament of uncontrollable motion as well as hydrophobic nature the whole body, which largely restricts their uptake capacity underwater. Hence, novel adsorbent material for high-efficient oil uptake both at the surface and under the water is urgently required.

EXPERIMENTS

We presented a phase-transition lysozyme coating approach to fabricate porous carbon nanotube microspheres with tailorable surface wettability areas for versatile oil adsorption. Because of the existence of magnetic nanoparticle in one hemisphere, the multi-sites coating was easily achieved by constantly changing orientations of the magnetic field. Owing to the integration of various hydrophilic functional groups in lysozyme as well as remarkable adhesion to virtually arbitrary materials, the intrinsically hydrophobic surface of the microspheres was partially modified hydrophilic on multiple sites.

FINDINGS

It was demonstrated that the unique surface wettability feature and the porous structure enabled the microspheres to adsorb multiple contaminants both floating on the water and underwater. Besides, the magnetic-responsive ability allowed for controllable collection of oil contaminants. These features, along with the reusability, make the porous carbon nanotube microspheres excellent adsorbents for water purification.

Anisotropic Carbon Nanotube Structures with High Aspect Ratio Nanopores for Li-Ion Battery Anodes

Technological advances in membrane technology, catalysis, and electrochemical energy storage require the fabrication of controlled pore structures at ever smaller length scales. It is therefore important to develop processes allowing for the fabrication of materials with controlled submicron porous structures. We propose a combination of colloidal lithography and chemical vapor deposition of carbon nanotubes to create continuous straight pores with diameters down to 100 nm in structures with thicknesses of more than 300 μm. These structures offer unique features, including continuous and parallel pores with aspect ratios in excess of 3000, a low pore tortuosity, good electrical conductivity, and electrochemical stability. We demonstrate that these structures can be used in Li-ion batteries by coating the carbon nanotubes with Si as an active anode material.

High-strength, blood-compatible, and high-capacity bilirubin adsorbent based on cellulose-assisted high-quality dispersion of carbon nanotubes

Excess bilirubin can accumulate in body organs and has serious effects on human health. In this work, a simple engineering strategy, based on cellulose-assisted high-quality dispersion of carbon nanotubes (CNTs), is proposed to produce high-performance bilirubin adsorbents. By dispersing cellulose and CNTs in NaOH/thiourea aqueous solution, a homogeneous and stable cellulose/CNTs solution is achieved. The obtained cellulose/CNTs solution is applied for the fabrication of cellulose/CNTs microspheres (CCMs), in which cellulose serves as a base material and guarantees the blood compatibility of the composite material, and CNTs contribute to the improved mechanical strength and high adsorption capacity. To further improve blood compatibility and adsorption capacity, lysine is immobilized on the CCMs. The obtained lysine-modified CCMs (LCCMs) exhibit a large surface area (171.31 m²/g) and hierarchically porous structure. Experimental results demonstrate LCCMs have high bilirubin adsorption capacity (204.12 mg/g) that is significantly higher than most of the reported adsorbents. The combination of high strength, blood compatibility, and high adsorption capacity positions the LCCMs as a promising candidate for bilirubin removal.

Quaternized Silk Nanofibrils for Electricity Generation from Moisture and Ion Rectification

Protein nanostructures in living organisms have attracted intense interests in biology and material science owing to their intriguing abilities to harness ion transportation for matter/signal transduction and bioelectricity generation. Silk nanofibrils, serving as the fundamental building blocks for silk, not only have the advantages of natural abundance, low cost, biocompatibility, sustainability, and degradability but also play a key role in mechanical toughness and biological functions of silk fibers. Herein, cationic silk nanofibrils (SilkNFs), with an ultrathin thickness of ∼4 nm and a high aspect ratio up to 500, were successfully exfoliated from natural cocoon fibers via quaternization followed by mechanical homogenization. Being positively charged in a wide pH range of 2-12, these cationic SilkNFs could combine with different types of negatively charged biological nanofibrils to produce asymmetric ionic membranes and aerogels that have the ability to tune ion translocation. The asymmetric ionic aerogels could create an electric potential as high as 120 mV in humid ambient air, whereas asymmetric ionic membranes could be used in ionic rectification with a rectification ratio of 5.2. Therefore, this green exfoliation of cationic SilkNFs may provide a biological platform of nanomaterials for applications as diverse as ion electronics, renewable energy, and sustainable nanotechnology.

Recent Progress of Microfluidic Devices for Hemodialysis

Microfluidic hemodialysis techniques have recently attracted great attention in the treatment of kidney disease due to their advantages of portability and wearability as well as their great potential for replacing clinical hospital-centered blood purification with continuous in-home hemodialysis. This Review summarizes the recent progress in microfluidic devices for hemodialysis. First, the history of kidney-inspired hemodialysis is introduced. Then, recent achievements in the preparation of microfluidic devices and hemodialysis nanoporous membrane materials are presented and categorized. Subsequently, attention is drawn to the recent progress of nanoporous membrane-based microfluidic devices for hemodialysis. Finally, the challenges and opportunities of hemodialysis microfluidic devices in the future are also discussed. This Review is expected to provide a comprehensive guide for the design of hemodialysis microfluidic devices that are closely related to clinical applications.

Polysaccharide-Based Lotus Seedpod Surface-Like Porous Microsphere with Precise and Controllable Micromorphology for Ultrarapid Hemostasis

Rapid water absorption rate has become a bottleneck that limits ultrarapid hemostatic performance of hemostatic microspheres. Herein, we reported a "lotus seedpod surface-like" polysaccharide hemostatic microsphere (PHM) with "macropits on surface" morphology and "micropores in macropits" structure. Unique macropits on surface can promote the water absorption rate because they are advantageous to quickly guide blood into the micropores. Special micropores are internally connected with each other, which endows PHM₄ with high water absorption ratio. During the process of blood entering the micropores from micropits, the pore size decreases gradually. In this way, blood clotting factors could be rapidly concentrated. PHM₄ showed the highest water absorption rate (40.7 mL/s/cm²) and rapid hemostatic property in vivo (hemostatic time shortened from 210 to 45 s). Lotus seedpod surface-like PHMs are believed to have further clinical application as an effective hemostasis.

A Review of State-of-the-Art Microfluidic Technologies for Environmental Applications: Detection and Remediation

Microfluidic systems have advanced beyond natural and life science applications and lab-on-a-chip uses. A growing trend of employing microfluidic technologies for environmental detection has emerged thanks to the precision, time-effectiveness, and cost-effectiveness of advanced microfluidic systems. This paper reviews state-of-the-art microfluidic technologies for environmental applications, such as on-site environmental monitoring and detection. Microdevices are extensively used in collecting environmental samples as a means to facilitate detection and quantification of targeted components with minimal quantities of samples. Likewise, microfluidic-inspired approaches for separation and treatment of contaminated water and air, such as the removal of heavy metals and waterborne pathogens from wastewater and carbon capture are also investigated.