Green Solvent Processed Cellulose/Graphene Oxide Nanocomposite Films with Superior Mechanical, Thermal, and Ultraviolet Shielding Properties

Cellulose nanocrystal/graphene oxide one-dimensional photonic crystal film with excellent UV-blocking and transparency

Achieving excellent ultraviolet (UV) blocking properties and maintaining high light transmittance are highly challenging. In this study, a facile and green polymer-assisted vacuum filtration strategy was used to prepare cellulose nanocrystal (CNC) one-dimensional photonic crystal (1DPhC) films with excellent UV-blocking performance and good transparency. The polymer-assisted self-assembly behaviors of CNC and the hydrogen bonding interaction between CNC, polyethylene glycol (PEG), and graphene oxide (GO) drive the homogeneous distribution and parallel alignment of GO. The UV absorption of GO and high reflection of UV resulting from the chiral nematic structure of CNCs result in excellent UV-blocking and high visible light transmission. Besides, the strong hydrogen bonding interaction among CNC, PEG, and GO endows the films with obviously increased mechanical properties. The UV-blocking and the transparency of the CNC composite films could reach 98.3 % and 60.5 %, respectively. Besides, the strain at break of the composite film reached 1.72 ± 0.11 %, which was 535.94 % of neat CNC films. The CNC composite films present great potential in the field of UV-blocking glass, sensors, anti-counterfeiting measures, radiation protection, and so on.

Bioinspired multiscale cellulose/lignin-silver composite films with robust mechanical, antioxidant and antibacterial properties for ultraviolet shielding

Constructing a high-performance ultraviolet shielding film is an effective way for addressing the growing problem of ultraviolet radiation. However, it is still a great challenge to achieve a combination of multifunctional, excellent mechanical properties and low cost. Here, inspired by the multiscale structure of biomaterials and features of lignin, a multifunctional composite film (CNF/CMF/Lig-Ag) is constructed via a facile vacuum-filtration method by introducing micron-sized cellulose fibers (CMF) and lignin-silver nanoparticles (Lig-Ag NPs) into the cellulose nanofibers (CNF) film network. In this composite film, the microfibers interweave with nanofibers to form a multiscale three-dimensional network, which ensures satisfactory mechanical properties of the composite film. Meanwhile, the Lig-Ag NPs are employed as a multifunctional filler to enhance the composite film's antioxidant, antibacterial and ultraviolet shielding abilities. As a result, the prepared CNF/CMF/Lig-Ag composite film demonstrates excellent mechanical properties (with tensile strength of 133.8 MPa and fracture strain of 7.4 %), good biocompatibility, high thermal stability, potent antioxidant and antibacterial properties. More importantly, such composite film achieves a high ultraviolet shielding rate of 98.2 % for ultraviolet radiation A (UVA) and 99.4 % for ultraviolet radiation B (UVB), respectively. Therefore, the prepared CNF/CMF/Lig-Ag composite film shows great potential in application of ultraviolet protection.

Metal Particle Pencil Beam Spray-Coating Method for High-Density Polymer-Resin Composites: Evaluation of Radiation-Shielding Sheet Properties

Medical shielding suits must be lightweight and satisfy the requirements of thin films to guarantee user mobility and safety. The thin film weight is related to the density and thickness, which are associated with the particle dispersion in shielding materials. An even distribution of metal particles in a polymer can maintain the spacing among them. This paper proposes a pencil beam spray-coating method that involves spraying a constant amount of a polyethylene and tungsten mixture in a thin beam onto a nonwoven fabric at a constant speed. This technique yields higher productivity than does the electrospinning method and is expected to produce materials with better shielding performance than that of materials obtained using the calender method. The shielding performance was evaluated by manufacturing shielding sheets (thickness: 0.48-0.54 mm) using the calender and pencil beam spray-coating methods under the same conditions. The densities and performances of the sheets differed significantly. The sheet manufactured using the proposed method had an even particle dispersion and exhibited 2-4% better shielding performance than did that manufactured using the calender method. Therefore, the pencil beam spray-coating method can effectively satisfy the requirements of thin films for medical radiation-shielding materials while increasing the material flexibility.

Boosting the ultraviolet shielding and thermal retardancy properties of unsaturated polyester resin by employing electrochemically exfoliated e-GO nanosheets

In this work, a series of unsaturated polyester resin (UPRs)/electrochemically exfoliated graphene oxide (e-GO) polymer nanocomposites with different ratios of e-GO (0.05, 0.1, 0.15, and 0.2 wt%) were prepared via an in situ polymerization method. The surface morphology and structural and chemical properties of the original UPR and UPR/e-GO nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). The positive influence of e-GO nanosheets on the mechanical properties, thermal stability, and anti-UV aging performance of UPR/e-GO nanocomposites was demonstrated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The obtained results showed that the incorporation of e-GO nanosheets within the UPR matrix, despite the addition of e-GO at as low as 0.2 wt% comprehensively improves the advanced functional properties of UPR/e-GO nanocomposites as compared to the original UPR. In addition, artificial weathering testing of quartz-based artificial stone using UPR/e-GO 0.2 wt% showed excellent UV-resistant efficiency, supporting the use of e-GO nanosheets as an additive in manufacturing the industrial-scale UPRs-based artificial quartz stone samples for real outdoor applications.

From Forces to Assemblies: van der Waals Forces-Driven Assemblies in Anisotropic Quasi-2D Graphene and Quasi-1D Nanocellulose Heterointerfaces towards Quasi-3D Nanoarchitecture

In the pursuit of advanced functional materials, the role of low-dimensional van der Waals (vdW) heterointerfaces has recently ignited noteworthy scientific interest, particularly in assemblies that incorporate quasi-2D graphene and quasi-1D nanocellulose derivatives. The growing interest predominantly stems from the potential to fabricate distinct genres of quasi-2D/1D nanoarchitecture governed by vdW forces. Despite the possibilities, the inherent properties of these nanoscale entities are limited by in-plane covalent bonding and the existence of dangling π-bonds, constraints that inhibit emergent behavior at heterointerfaces. An innovative response to these limitations proposes a mechanism that binds multilayered quasi-2D nanosheets with quasi-1D nanochains, capitalizing on out-of-plane non-covalent interactions. The approach facilitates the generation of dangling bond-free iso-surfaces and promotes the functionalization of multilayered materials with exceptional properties. However, a gap still persists in understanding transition and alignment mechanisms in disordered multilayered structures, despite the extensive exploration of monolayer and asymmetric bilayer arrangements. In this perspective, we comprehensively review the sophisticated aspects of multidimensional vdW heterointerfaces composed of quasi-2D/1D graphene and nanocellulose derivatives. Further, we discuss the profound impacts of anisotropy nature and geometric configurations, including in-plane and out-of-plane dynamics on multiscale vdW heterointerfaces. Ultimately, we shed light on the emerging prospects and challenges linked to constructing advanced functional materials in the burgeoning domain of quasi-3D nanoarchitecture.

Fluorinated Polyimide/Allomelanin Nanocomposites for UV-Shielding Applications

A series of highly fluorinated polyimide/allomelanin nanoparticles (FPI/AMNPs) films were prepared with FPI as the matrix and AMNPs as the filler. Due to the formation of hydrogen bonds, significantly reinforced mechanical and UV-shielding properties are acquired. Stress-strain curves demonstrated a maximum tensile strength of 150.59 MPa and a fracture elongation of 1.40% (0.7 wt.% AMNPs), respectively, 1.78 and 1.56× that of pure FPI. The measurements of the UV-vis spectrum, photodegradation of curcumin and repeated running tests confirmed the splendid UV-shielding capabilities of FPI/AMNPs films. The enhancement mechanisms, such as synergistic UV absorption of the charge transfer complexes in FPI and AMNPs and photothermal conversion, were the reasons for its exceptional UV shielding. The excellent comprehensive properties above enable FPI/AMNPs nanocomposites to be potential candidates in the field of UV shielding.

Recent Advances in Cellulose-Based Hydrogels Prepared by Ionic Liquid-Based Processes

This review summarizes the recent advances in preparing cellulose hydrogels via ionic liquid-based processes and the applications of regenerated cellulose hydrogels/iongels in electrochemical materials, separation membranes, and 3D printing bioinks. Cellulose is the most abundant natural polymer, which has attracted great attention due to the demand for eco-friendly and sustainable materials. The sustainability of cellulose products also depends on the selection of the dissolution solvent. The current state of knowledge in cellulose preparation, performed by directly dissolving in ionic liquids and then regenerating in antisolvents, as described in this review, provides innovative ideas from the new findings presented in recent research papers and with the perspective of the current challenges.

Graphene oxide reinforced chitosan/polyvinyl alcohol antibacterial coatings on stainless steel surfaces exhibit superior bioactivity without human cell cytotoxicity

The study proposes an alternative therapeutics to diminish bacterial attachment in biomedical implants by modifying their surface with passive coatings. A uniform, thin-film of chitosan/polyvinyl alcohol/graphene oxide (CS/PVA/GO) was coated on 316 L stainless steel (SS) surface through spread casting followed by solvent evaporation. The abundant anchoring sites available at macromolecular interfaces of chitosan/PVA matrix facilitated a smooth, dense loading of GO. The effect of GO content on physicochemical features, antibacterial potential, and biocompatibility of coatings was thoroughly studied. The hybrid films displayed good adhesion behavior, and UV-protection ability with desired mechanical and thermal stability when coated on SS surface. Coatings manifested a 1.5-1.7 fold rise in antibacterial efficacy against Staphylococcus epidermidis and Staphylococcus aureus and exhibited a permanent biocidal response after 6 h of contact-active behaviour. We investigated a 3-fold generation of reactive oxygen species as the predominant antibacterial mechanism, which diminishes bacterial integrity by inducing protein leakage (8.5-9 fold higher) and suppressing respiratory chain activity as two secondary mechanisms. All coatings with varying GO content appeared non-haemolytic (<2%) with ultra-low cytotoxicity (<29.08%) against human hepatocellular carcinoma (HepG2) and peripheral blood mononuclear cells. The degradation rate of coatings in simulated body fluid exhibited a higher stability, indicated by a lower weight loss (69-78%) and a decrease in pH values as the GO content in coatings increased from 0.05 to 0.15 wt%. Such anti-infective coating is a step forward in inhibiting bacterial colonization on SS surfaces to extend its lifespan.

Sugarcane leave-derived cellulose nanocrystal/graphene oxide filter membrane for efficient removal of particulate matter

The goal of this study is to isolate cellulose nanocrystals (CNC) from sugarcane leaves (SCL) and fabricate filter membranes. Filter membranes consisting of the CNC and varying amount graphene oxide (GO) were fabricated using vacuum filtration technique. The α-cellulose content increased from 53.56 ± 0.49 % in untreated SCL to 78.44 ± 0.56 % and 84.99 ± 0.44 % in steam-exploded and bleached fibers, respectively. Atomic force microscopy (AFM) and transmission electron microscope (TEM) of CNC isolated from SCL indicated nanosized particles in the range of 7.3 nm and 150 nm for diameter and length, respectively. Morphologies of the fiber and CNC/GO membranes were determined by scanning electron microscopy (SEM) and crystallinity by X-ray diffraction (XRD) analysis of crystal lattice. The crystallinity index of CNC decreased with the addition of GO into the membranes. The CNC/GO-2 recorded the highest tensile index of 3.001 MPa. The removal efficiency increases with increasing GO content. The highest removal efficiency of 98.08 % was recorded for CNC/GO-2. CNC/GO-2 membrane reduced growth of Escherichia coli to 65 CFU compared to >300 CFU of control sample. SCL is a potential bioresource for isolation of cellulose nanocrystals and fabrication of high-efficiency filter membrane for particulate matter removal and inhibition of bacteria.

Recoverable cellulose composite adsorbents for anionic/cationic dyes removal

GO/HEC/PGDE/Fe₃O₄ materials were successfully fabricated using environmentally-friendly hydroxyethyl cellulose (HEC), poly(ethylene glycol) diglycidyl ether (PGDE), graphene oxide (GO) and magnetic Fe₃O₄. Systematic investigations were completed to explore the influences of GO content in GO/HEC/PGDE/Fe₃O₄ and adsorption conditions on the adsorptions of cationic dyes (methylene blue (MB), crystal violet (CV)) and anionic dye acid blue 25 (AB-25). The increase of GO content can remarkably improve the adsorption capacity of GO/HEC/PGDE/Fe₃O₄ for the dyes. The three kinetic, four isothermic and three thermodynamic models were investigated to reveal the adsorption behaviors of the dyes. The formation of HEC/PGDE/Fe₃O₄ and adsorption mechanisms of the dyes by GO/HEC/PGDE/Fe₃O₄ were suggested. The GO/HEC/PGDE/Fe₃O₄ endowed with easy-fabrication, eco-friendly feature, efficient adsorption capacity of anionic/cationic dyes, convenient separation and reusability has potential applications in wastewater purification industry.

Arresting Aqueous Swelling of Layered Graphene-Oxide Membranes with H3O+ and OH- Ions

Over the past decade, graphene oxide (GO) has emerged as a promising membrane material with superior separation performance and intriguing mechanical/chemical stability. However, its practical implementation remains very challenging primarily because of its undesirable swelling in an aqueous environment. Here, we demonstrated that dissociation of water molecules into H₃O⁺ and OH^- ions inside the interlayer gallery of a layered GO membrane can strongly affect its stability and performance. We reveal that H₃O⁺ and OH^- ions form clusters inside the GO laminates that impede the permeance of water and salt ions through the membrane. Dynamics of those clusters is sensitive to an external ac electric field, which can be used to tailor the membrane performance. The presence of H₃O⁺ and OH^- ions also leads to increased stability of the hydrogen bond (H-bond) network among the water molecules and the GO layers, which further reduces water permeance through the membrane, while crucially imparting stability to the layered GO membrane against undesirable swelling.

Transparent Cellulose-based Film with High UV-blocking Performance Fabricated by Surface Modification using Biginelli Reaction

Efficient and sustainable ultraviolet (UV)-blocking materials are of great interest in many fields. Herein, novel cellulose-based UV-blocking films were developed via surface modification using Biginelli reaction. The resulting films exhibited excellent visible transparency (80%) at 550 nm and superhigh UV-blocking performance, which can shield almost 100% UVA and UVB. These features are very stable even the materials being subjected to solvents, UV irradiation, and thermal treatment. This work provides a novel and facile strategy to fabricate functional cellulose-based films with superhigh anti-ultraviolet performance. This article is protected by copyright. All rights reserved.

Biomimetic Chiral Photonic Materials with Tunable Metallic Colorations Prepared from Chiral Melanin-like Nanorods for UV Shielding, Humidity Sensing, and Cosmetics

Many biological species combine the helical organization of cellulose or chitin microfibrils with broadband light absorption of black melanin to produce brilliant structural colors with metallic and glossy effects and other diverse functions. In this work, based on core-shell CNC@PDA chiral nanorods consisting of cellulose nanocrystals (CNCs) as the core and melanin-like polydopamine (PDA) as the shell that can form well-defined chiral liquid crystal phases, we report chiral photonic materials that closely mimic the unique coloration mechanisms and functionalities mastered by several biological species. The photonic films formed by such single CNC@PDA nanorods have brilliant iridescent structural colors originating from selective reflection of circularly polarized lights by the helical organization of CNC@PDAs across the films. Furthermore, the colors of such films have background-independent brightness, high visibility, and metallic effects that arise from the light absorption of the PDA component. Especially, the color ranges and metallic effects of the films can be conveniently tuned by varying the thickness of the PDA shell. In addition, the UV absorption and hygroscopic properties of PDA endow these CNC@PDA films with efficient broadband UV shielding and sensitive humidity-induced dynamic color changes. Due to the mussel-like superior adhesion of PDA, CNC@PDA-based photonic coatings can be formed conformably onto diverse kinds of substrates. A shiny eye shadow with viewing angle-dependent colorful patterns was used to demonstrate the potential applications. With combinations of multiple unique properties in one photonic material fabricated from a single building block, these CNC@PDA-based films are expected to have potential applications in cosmetics, UV protection, anticounterfeiting, chiral reflectors, etc.

Nano-MIL-88A(Fe) Enabled Clear Cellulose Films with Excellent UV-Shielding Performance and Robust Environment Resistance

While tremendous efforts have been dedicated to developing cellulose-based ultraviolet (UV)-blocking films, challenges still remain in simultaneously achieving high transparency, low haze and excellent UV shielding properties via simple and green strategy. Here, we present a facile and eco-friendly route to fabricate flexible, biodegradable and clear UV-shielding nano-MIL-88A(Fe)@carboxymethylated cellulose films (M(Fe)CCFs) via in situ synthesis of nano-MIL-88A(Fe) in carboxymethylated cellulose hydrogel followed by natural drying. The carboxymethylated cellulose film has high transmittance (93.2%) and low haze (1.8%). The introduction of nano-MIL-88A(Fe) endowed M(Fe)CCFs superior UV-shielding ability, while retaining high transmittance (81.5-85.3%) and low haze (2.5-4.9%). Moreover, M(Fe)CCFs showed stable UV blocking performance under UV irradiation, high temperature, acidic or alkaline conditions. Quite encouragingly, the UV-shielding ability of M(Fe)CCFs did not deteriorate, even after 30 days of immersion in aqueous solution, providing films with a long-term use capacity. Thus, M(Fe)CCFs show high potential in the UV protection field. Overall, these UV-blocking films with outstanding performances are a promising candidate to replace conventional film materials made from synthetic polymers in fields such as packaging and flexible electronics.

Nanostructured Carbons: towards Soft-Bioelectronics, Biosensing and Theraputic Applications

Recently, nanostructured carbon-based soft bioelectronics and biosensors have received tremendous attention due to their outstanding physical and chemical properties. The ultrahigh specific surface area, high flexibility, lightweight, high electrical conductivity, and biocompatibility of 1D and 2D nanocarbons, such as carbon nanotubes (CNT) and graphene, are advantageous for bioelectronics applications. These materials improve human life by delivering therapeutic advancements in gene, tumor, chemo, photothermal, immune, radio, and precision therapies. They are also utilized in biosensing platforms, including optical and electrochemical biosensors to detect cholesterol, glucose, pathogenic bacteria (e. g., coronavirus), and avian leucosis virus. This review summarizes the most recent advancements in bioelectronics and biosensors by exploiting the outstanding characteristics of nanocarbon materials. The synthesis and biocompatibility of nanocarbon materials are briefly discussed. In the following sections, applications of graphene and CNTs for different therapies and biosensing are elaborated. Finally, the key challenges and future perspectives of nanocarbon materials for biomedical applications are highlighted.

Facile fabrication of a polyvinyl alcohol-based hydrophobic fluorescent film via the Hantzsch reaction for broadband UV protection

Excessive exposure to ultraviolet (UV) light is harmful to human health. However, the traditional preparation of anti-UV films through the doping of UV absorbers leads to unstable products. Chemical modification of polyvinyl alcohol (PVA) to fabricate functional derivatives expand the application of these materials. Herein, a 1,4-dihydropyridine (DHP) fluorescent ring with a conjugated structure as a strong UV-absorber group was introduced onto a polyvinyl alcohol acetoacetate (PVAA) film to improve its UV-blocking performance. Firstly, PVAA was prepared via transesterification using tert-butyl acetoacetate (t-BAA). Then, the Hantzsch reaction was carried out on the surface of the PVAA film at room temperature. The resulting film showed high transparency, bright fluorescence emission, good mechanical properties, and outstanding stability. The introduction of the hydrophobic carbon chain reduced the hydrophilicity and swelling capacity of the PVAA film. In addition, the conjugated structure endowed the fluorescent film with excellent UV-blocking performance, where almost 100% UVA and UVB spectra could be shielded. The UV-blocking properties of the prepared films were persistent when they were exposed to UV irradiation, solvents, and subjected to thermal treatment. This work presents a facile and environmentally-friendly strategy by which to fabricate a multifunctional PVA-based film, which holds great potential for application in the anti-counterfeiting and UV-blocking fields.

Green and cost-effective synthesis of flexible, highly conductive cellulose nanofiber/reduced graphene oxide composite film with deep eutectic solvent

Developing efficient strategy for nanomaterials dispersion is the key for promoting the utilization of cellulose-based composite in energy storage devices. In this study, an instant synthesis method for cellulose nanofiber (CNF)/reduced graphene oxide (rGO) composite film with a deep eutectic solvent (DES) based on choline chloride and urea as a media is developed. This DES shows favorable abilities of recyclability, materials dispersion, and could adjust the pH value for reaction systems of neutral to alkaline which in favor of electrostatic repulsion arising from deprotonated carboxyl groups at the composite surface. As-obtained films feature excellent flexibility, high electrical conductivity (as high as 26.47 S∙cm^-1) and well electrochemical properties. Furthermore, a little amount of nitrogen atoms (~3.0 at%) could be introduced in the composite at a mild condition. Overall, this approach offers the potential for cost-effective, environmentally friendly and large-scale production of cellulose-based electrode and numerous advanced applications.

Nanocellulose-Graphene Derivative Hybrids: Advanced Structure-Based Functionality from Top-down Synthesis to Bottom-up Assembly

There is an emerging endeavor of advanced structure-based functionality in the next-generation advanced functional materials inspired by hierarchical architecture for future technical applications. This review provides an impressive range roadmap for constructing advanced functional materials based on the nanocellulose-graphene derivative hybrids, from the top-down synthesis of their hierarchical materials to the bottom-up assembly of their nanoscale building blocks. First, the roadmap started from the top-down synthesis routes of nanocellulose-graphene hierarchical materials into their derivatives, where the pristine properties of nanoscale building blocks are still accessible and processable. Then, the stable-strong synergistic interfacial interactions between nanocellulose chains and graphene derivative nanosheets are uniquely well-suited in this roadmap for constructing scalable hybrid materials with interesting emergent properties. After that, the roadmap presented the bottom-up assembly approaches of these versatile nanoscale building blocks through self-assembly, templating, and mimicking of the bioinspired hierarchical structures toward advanced functional materials. Thereafter, toward understanding the specificity, superiority, and functionality of such hybrid materials, the roadmap discussed the properties and potential applications so far. Finally, the roadmap pointed out the key challenges and future outlooks, paving the way for comprehensive understanding and ideal designing of hybrid structures from nanocellulose and graphene derivatives.

Graphene- and Nanoparticle-Embedded Antimicrobial and Biocompatible Cotton/Silk Fabrics for Protective Clothing

Protection against pathogens using personal protective equipment is essential yet challenging in healthcare settings. Concerns over emerging biothreats and outbreaks of infectious diseases underscore the need for antimicrobial and biocompatible protective clothing to protect patients and staff. Herein, we report the antimicrobial efficacy and cytotoxicity of cotton/silk fabrics containing embedded reduced graphene oxide (RGO) and Ag/Cu nanoparticles (NPs), prepared using a 3-glycidyloxypropyl trimethoxy silane coupling agent followed by chemical reduction and vacuum heat treatment. Embedding NPs on top of the RGO layer substantially increased the antimicrobial activity. All RGO-Ag NPs or RGO-Cu NPs embedded in cotton or silk fabrics reduced the viability of approximately 99% of the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. RGO-Ag NPs embedded into cotton or silk fabrics reduced the viability of the Gram-positive bacterium Staphylococcus aureus by 78-99%, which was higher than the growth inhibition by RGO-Cu NPs samples against S. aureus. Both silk and cotton containing RGO-Cu NPs produced a greater reduction in the viability of the yeast Candida albicans compared to RGO-Ag NPs fabrics. All RGO-Ag NPs or RGO-Cu NPs embedded in cotton or silk fabrics showed good washing durability by sustaining good bactericidal activity, even on washing up to 10 times. Moreover, none of the RGO-Ag or RGO-Cu fabrics reduced mammalian cells' (HEK293) viability by >30%, suggesting low cytotoxicity and good biocompatibility. These findings show that RGO-NPs embedded in cotton or silk fabrics have great potential for use in protective clothing and medical textiles.

Self-Compounded Nanocomposites: toward Multifunctional Membranes with Superior Mechanical, Gas/Oil Barrier, UV-Shielding, and Photothermal Conversion Properties

Nanocomposites combine multiple favorable properties to achieve intriguing functionalities, but the formation of nanocomposites with only one constituent with the inclusion of multiple superior properties is still not known. Herein, novel self-compounded nanocomposite membranes from one single polymer-cellulose cinnamate (CCi)-with multiple outstanding properties are reported. The self-compounded membranes contain two distinct morphologies as CCi nanoparticles (CCi-NPs) and a CCi polymer matrix, while CCi-NPs are either firmly embedded in the CCi matrix or fused with adjacent CCi-NPs. The unique self-compounded nanostructure endows the membranes with a tensile strength of 94 MPa and Young's modulus of 3.1 GPa. The water vapor permeability, oxygen permeability, and oil permeability reach as low as (0.94 ± 0.03) × 10^-11 g m^-1 s^-1 Pa^-1, (8.48 ± 2.39) ×10^-13 cm³·cm/cm²·s·cmHg, and 0.008 ± 0.003 g mm m^-2 day^-1, respectively. Moreover, self-compounded CCi nanocomposite membranes also demonstrate UV-shielding and photothermal conversion properties. UVB and UVC light are entirely blocked, while UVA light is partly blocked. The temperature increases from room temperature to 120 °C within 1 min under UV irradiation. In addition, CCi membranes also show remarkable thermal and humidity resistance. Based on these outstanding properties, CCi membranes are applied as food packaging materials. This work offers a new avenue to construct nanocomposites with multiple superior properties from one constituent, which is promising for diverse applications.

Green Approaches to Carbon Nanostructure-Based Biomaterials

The family of carbon nanostructures comprises several members, such as fullerenes, nano-onions, nanodots, nanodiamonds, nanohorns, nanotubes, and graphene-based materials. Their unique electronic properties have attracted great interest for their highly innovative potential in nanomedicine. However, their hydrophobic nature often requires organic solvents for their dispersibility and processing. In this review, we describe the green approaches that have been developed to produce and functionalize carbon nanomaterials for biomedical applications, with a special focus on the very latest reports.

Improved mechanical and ultraviolet shielding performances of hydroxyethyl cellulose film by using aramid nanofibers as additives

Recently, aramid nanofibers (ANFs) have drawn the attention of scientist due to the high mechanical strength, high-temperature resistance, and high electrical and thermal insulation properties. In this work, we aimed at improving the mechanical and ultraviolet shielding properties of hydroxyethyl cellulose (HEC) film by using ANFs as additives. Mechanical results show that the 1.0 % ANFs could improve the tensile strength of pure HEC film by 176.6 %. Meanwhile, the ANFs additives can also enable the HEC film excellent ultraviolet (UV) shielding and visible light transmittance, as well as high UV radiation resistance ability. It is believed that the high mechanical strength of the HEC/ANFs composites is derived from the rearrangement of HEC chains along the tensile direction after the addition of hard ANFs and the enhanced hydrogen bonds between HEC and ANFs.

Elimination of Uremic Toxins by Functionalized Graphene-Based Composite Beads for Direct Hemoperfusion

Conventional absorbents for hemoperfusions suffer from low efficiency and slow absorption with numerous side effects. In this research, we developed cellulose acetate (CA) functionalized graphene oxide (GO) beads (∼1.5-2 mm) that can be used for direct hemoperfusion, aiming at the treatment of kidney dysfunction. The CA-functionalized GO bead facilitates adsorption of toxins with high biocompatibility and high-efficiency of hemoperfusion while maintaining high retention for red blood cell, white blood cells, and platelets. Our in vitro results show that the toxin concentration for creatinine reduced from 0.21 to 0.12 μM (p < 0.005), uric acid from 0.31 to 0.15 mM (p < 0.005), and bilirubin from 0.36 to 0.09 mM (p < 0.005), restoring to normal levels within 2 h. Our in vivo study on rats (Sprague-Dawley, n = 30) showed that the concentration for creatinine reduced from 83.23 to 54.87 μmol L^-1 (p < 0.0001) and uric acid from 93.4 to 54.14 μmol L^-1 (p < 0.0001), restoring to normal levels within 30 min. Results from molecular dynamics (MD) simulations using free-energy calculations reveal that the presence of CA on GO increases the surface area for adsorption and enhances penetration of toxins in the binding cavities because of the increased electrostatic and van der Waals force (vdW) interactions. These results provide critical insight to fabricate graphene-based beads for hemoperfusion and to have the potential for the treatment of blood-related disease.

Unique and outstanding quantum dots (QD)/tunicate cellulose nanofibrils (TCNF) nanohybrid platform material for use as 1D ink and 2D film

Quantum dots (QD)/polymer materials have wide applications in biological imaging, clinical diagnostics, anti-counterfeiting materials, light-emitting devices and solar cells. The development of QD/cellulose nanofibrils (CNF) hybrids with a more perfect structure and excellent properties is important for improving known applications. A unique tunicate CNF (TCNF) was homogeneously blended with outstanding CdSe/CdS core/shell QD to prepare a novel QD/TCNF hybrid. The QD were monodispersed on a single TCNF fibril surface as an evenly distributed monolayer with an extremely high packing density and no visible aggregation. The prepared hybrid is an excellent platform nanomaterial which was demonstrated by its good writing fidelity when applied as a 1D ink and by its good processability in the preparation of 2D films with acceptable transparency and flexibility. This one-step direct blending approach provides a facile shortcut to effectively fabricate cellulose-based high-performance functional QD nanomaterials at the single-fibril level.