Cellulose nanofibrils aerogels generated from jute fibers

From farm to function: Exploring new possibilities with jute nanocellulose applications

Recent scientific interest has surged in the application of bioresources within nanotechnology, primarily because of their eco-friendly nature, wide availability, and cost-effectiveness. Jute is globally recognized as the second most prevalent source of natural cellulose fibers, and it produces a significant quantity of jute sticks as a byproduct. Nanocellulose (NC), which includes cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC), exhibits exceptional properties such as high strength, toughness, crystallinity, thermal stability, and stiffness. These attributes enable its versatile use across various sectors. The extensive surface areas and abundant hydroxyl groups of nanocellulose allow for diverse surface modifications, facilitating the design of advanced functional materials. This comprehensive review provides an overview of recent advancements in the synthesis, characterization, and potential applications of nanocellulose derived from jute. As a versatile natural fiber, jute holds immense potential across various research domains, including nanocellulose synthesis, scaffold fabrication, nanocarbon material preparation, life sciences, electronics and energy storage devices, drug delivery systems, nanomaterial synthesis, food packaging and paper industries. Additionally, its use extends to polymeric nanocomposites, sensors, and coatings. This study summarizes the extensive utilization of jute, emphasizing its versatility and potential across diverse research fields.

Biofabrication of aminated nanocellulose reinforced polyvinyl alcohol/chitosan nanofibrous scaffold for sustained release of diltiazem hydrochloride

In the modern environment conscious era, there has been a huge demand for the effective green method to fabricate biomaterials for sustained transdermal release of diltiazem hydrochloride to treat hypertension and cardiac failure. In this vein, the present study explores the amination of waste jute sourced nanocellulose (ANC) and its effect as a reinforcing filler to design electrospun polyvinyl alcohol (PVA)/chitosan based polymeric nanofibrous scaffold for drug delivery. The characterization results of FTIR (Fourier Transform Infrared Spectroscopy) confirm the successful chemical modification of nanocellulose (NCC). SEM (Scanning Electron Microscopy) results indicate the morphological modifications in ANC due to grafting. ANC enhances the mechanical properties of scaffold and sustains the release of the loaded drug to 67.89±3.39% as compared to the pure PVA/chitosan scaffold of 92.63±4.63% over a period of 72 h as shown by the results of in-vitro drug release study. Moreover, the incorporation of 0.5 % ANC improves the anti-bacterial activity against both gram-positive (97.4±4.87%, reduction in viable cells count) and gram-negative bacteria (98.5±4.93%, reduction in viable cells count). Further, the skin irritation and MTT assay authenticate the biocompatibility of the developed scaffold. The overall findings hence prove the efficacy of the engineered scaffold as a potential transdermal patch for sustained drug delivery applications.

Exploring nanocellulose's role in revolutionizing the pharmaceutical and biomedical fields

The increasing global demand for eco-friendly products derived from natural resources has spurred intensive research into biomaterials. Among these materials, nanocellulose stands out as a highly efficient option, consisting of tightly packed cellulose fibrils derived from lignocellulosic biomass. Nanocellulose boasts a remarkable combination of attributes, including a high specific surface area, impressive mechanical strength, abundant hydroxyl groups for easy modification, as well as non-toxic, biodegradable, and environmentally friendly properties. Consequently, nanocellulose has been extensively studied for advanced applications. This paper provides a comprehensive overview of the various sources of nanocellulose derived from diverse natural sources and outlines the wide array of production methods available. Furthermore, it delves into the extensive utility of nanocellulose within the biomedical and pharmaceutical industries, shedding light on its potential role in these fields. Additionally, it highlights the significance of nanocellulose composites and their applications, while also addressing key challenges that must be overcome to enable widespread utilization of nanocellulose.

A Brief Review on Advanced Sandwich Structures with Customized Design Core and Composite Face Sheet

Sandwich structures are a class of multifunctional high-performance structural composites that have the advantages of being lightweight, of a high strength-to-weight ratio, and of high specific energy absorption capabilities. The creative design of the core along with the apposite material selection for the fabrication of the face sheet and core are the two prerequisites with encouraging areas for further expedition towards the fabrication of advanced composite sandwich structures. The current review work focused on different types of core designs, such as truss, foam, corrugated, honeycomb, derivative, hybrid, hollow, hierarchical, gradient, folded, and smart core along with different composite materials accessible for face sheet fabrication, including fiber-reinforced composite, metal matrix composite, and polymer matrix composite are considered. The joining method plays a major role for the performance evolution of sandwich structures, which were also investigated. Further discussions are aligned to address major challenges in the fabrication of sandwich structures and further enlighten the future direction of the advanced composite sandwich structure. Finally, the work is summarized with a brief conclusion. This review article provides wider guidelines for researchers in designing and manufacturing next-generation lightweight multilayer core sandwich structures.

Nanocellulose implantation enriched the pore structure of aerogel for effective particulate matter removal

Particulate matter (PM) pollution poses a serious threat to public health, disposable and degradable filter materials are expected to handle the problem in the future. Here, polyvinyl alcohol (PVA)/borax/cellulose nanofibrils (CNF) aerogels were implanted on a biodegradable corrugated paper to form composite air filters for the first time via freeze-drying the coated composite hydrogels. The low content of CNF and PVA could be cross-linked by borax to form hydrogels, which enhanced its maneuverability for surface implanting on the substrate. More importantly, the addition of CNF greatly enriched the pore structure of aerogels, which provided a structural basis for PM capture. The as-prepared composite air filters exhibited excellent filtration efficiencies of 92 % and 96 % toward PM1.0 and PM3.0, respectively. Moreover, the addition of dimethylol-5,5-dimethylhydantoin endowed the filters with an antibacterial property. This work shows a new possibility for the design of degradable and functional filter materials.

Progress, Challenge and Perspective of Fabricating Cellulose

Cellulose as the most abundant biopolymers on Earth, presents appealing performance in mechanical properties, thermal management, and versatile functionalization. The development of fabrication methods closely relates to enrich its functionality and reduce manufacture cost. However, cellulose is hard to be dissolved by most common solvents or melt due to its recalcitrant property. Herein, the recent progress of fabricating cellulose is summarized. First, the unique hierarchical structure of cellulose is fully investigated and the resulted processability is highlighted in directions of down to nanocellulose, dissolution, and thermoplastic processing. Then, the reported fabrication methods are summarized in three aspects: (1) self-assembly from nano/micro cellulose suspensions, especially the self-assembly of cellulose nanocrystals; (2) dissolution-regeneration-drying, covering spinning and solvent infusion processing; and (3) thermoplastic processing, focusing on analysis of the setup and the morphology changes of the prepared products. In each aspect, the flowchart of the fabrication process, the behind mechanism, fabricated products, and effects of processing parameters are explored. Finally, this review provides a perspective on the further direction of fabricating cellulose, especially the challenges toward mass production of cellulose. This article is protected by copyright. All rights reserved.

Strength Enhancement of Regenerated Cellulose Fibers by Adjustment of Hydrogen Bond Distribution in Ionic Liquid

To improve the physical strength of regenerated cellulose fibers, cellulose dissolution was analyzed with a conductor-like screening model for real solvents in which 1-allyl-3-methylimidazolium chloride (AMIMCl) worked only as a hydrogen bond acceptor while dissolving the cellulose. This process could be promoted by the addition of urea, glycerol, and choline chloride. The dissolution and regeneration of cellulose was achieved through dry-jet and wet-spinning. The results demonstrated that the addition of hydrogen bond donors and acceptors either on their own or in combination can enhance the tensile strength, but their effects on the crystallinity of the regenerated fibers were quite limited. Compared with the regenerated fibers without any additives, the tensile strength was improved from 54.43 MPa to 139.62 MPa after introducing the choline chloride and glycerol, while related the crystallinity was only changed from 60.06% to 62.97%. By contrast, a more compact structure and fewer pores on the fiber surface were identified in samples with additives along with well-preserved cellulose frameworks. Besides, it should be noted that an optimization in the overall thermal stability was obtained in samples with additives. The significant effect of regenerated cellulose with the addition of glycerol was attributed to the reduction of cellulose damage by slowing down the dissolution and cross-linking in the cellulose viscose. The enhancement of the physical strength of regenerated cellulose fiber can be realized by the appropriate adjustment of the hydrogen bond distribution in the ionic liquid system with additives.

Experimental Study on the Efficiency Improvement of Flat Plate Solar Collectors Using Hybrid Nanofluids Graphene/Waste Cotton

Flat plate solar collectors can easily be termed as the most vastly studied alternative energy transforming and generating technology of the twenty-first century. As the world is racing towards the fourth industrial revolution (Industry 4.0), more and more energy is being consumed for mega projects to be materialized. Electronic devices are not only confined to conventional intermittent and costlier electric energy, but also fuel. Solar energy is now being shared to work smart devices, transform electric energy, and operate automobiles, aeronautics, water heating, and space heating. Traditional flat plate solar collectors can only occupy 50–60% of their thermal efficiency, resulting in less heat generation and a low thermal performance because of using a common absorber made of copper tubing compared to a high conductive metal sheet (copper or aluminum). To ameliorate the thermal efficiency of the solar collector, it is imperative to find a superior alternative heat exchanger that will result in improved thermal performance of the solar collector. In this study, light has been shed in terms of substituting conventional heat absorbers with crystal nano-cellulose (CNC) and a graphene hybrid. An empirical comparison has been drawn by comparing the familiar 0.3% base fluid, 0.5% graphene, and CNC separately, as well as 0.3%, 0.5% CNC, and graphene hybrids at different temperatures. Remarkably, this work has proven that a CNC and graphene hybrid fluid with a volumetric fraction of 0.5% concentration and at a high temperature of 80 °C, gave astounding results for improved thermal conductivity, viscosity, and other parameters. CNC and graphene hybrid nanofluid can be a superior substitute for a conventional base fluid, resulting in prolific thermal performance.

Self-Assembled Behavior of Ultralightweight Aerogel from a Mixture of CNC/CNF from Oil Palm Empty Fruit Bunches

This study aims to explore the use of cellulose nanocrystals (CNC) and cellulose nanofiber (CNF), obtained from unbleached fiber of oil palm empty fruit bunches (EFB), as raw materials in fabricating aerogel, using the facile technique without solvent displacement. The CNC was isolated from sulfuric acid hydrolysis, and the CNF was fibrillated using Ultra Turrax. The CNC and CNF were mixed by ultrasonication in different ratios to produce aerogel using slow freezing (−20 °C), followed by freeze-drying. The obtained aerogel was characterized as ultralightweight and highly porous material, at the density range of 0.0227 to 0.0364 g/cm³ and porosity of 98.027 to 98.667%. Interestingly, the ratio of CNC and CNF significantly affected the characteristics of the obtained aerogel. The mixed aerogel exhibited a higher specific surface area than pure CNC or CNF, with the highest value of 202.72 m²/g for the ratio of 1:3 (CNC/CNF). In addition, the crystallinity degree of obtained aerogel showed a higher value in the range of 76.49 to 69.02%, with the highest value being obtained for higher CNC content. This study is expected to provide insight into nanocellulose-based aerogel, with a promising potential for various applications.

Present Status and Future Prospects of Jute in Nanotechnology: A Review

Nanotechnology has transformed the world with its diverse applications, ranging from industrial developments to impacting our daily lives. It has multiple applications throughout financial sectors and enables the development of facilitating scientific endeavors with extensive commercial potentials. Nanomaterials, especially the ones which have shown biomedical and other health-related properties, have added new dimensions to the field of nanotechnology. Recently, the use of bioresources in nanotechnology has gained significant attention from the scientific community due to its 100 % eco-friendly features, availability, and low costs. In this context, jute offers a considerable potential. Globally, its plant produces the second most common natural cellulose fibers and a large amount of jute sticks as a byproduct. The main chemical compositions of jute fibers and sticks, which have a trace amount of ash content, are cellulose, hemicellulose, and lignin. This makes jute as an ideal source of pure nanocellulose, nano-lignin, and nanocarbon preparation. It has also been used as a source in the evolution of nanomaterials used in various applications. In addition, hemicellulose and lignin, which are extractable from jute fibers and sticks, could be utilized as a reductant/stabilizer for preparing other nanomaterials. This review highlights the status and prospects of jute in nanotechnology. Different research areas in which jute can be applied, such as in nanocellulose preparation, as scaffolds for other nanomaterials, catalysis, carbon preparation, life sciences, coatings, polymers, energy storage, drug delivery, fertilizer delivery, electrochemistry, reductant, and stabilizer for synthesizing other nanomaterials, petroleum industry, paper industry, polymeric nanocomposites, sensors, coatings, and electronics, have been summarized in detail. We hope that these prospects will serve as a precursor of jute-based nanotechnology research in the future.

Hierarchically Structured Nanocellulose-Implanted Air Filters for High-Efficiency Particulate Matter Removal

Fine particulate matter (PM) air pollution has increasingly become a global problem; thus, high-performance air filtration materials are in great demand. Herein, we first prepared a biodegradable hierarchically structured nanocellulose-implanted air filter with a high filtration capacity using a freeze-drying technique. In this hierarchically structured air filter, porous structures of corrugated paper and cellulose nanofibrils (CNFs) were used as a frame and functional fillers, respectively. The self-assembled structure of the CNF fillers could be controlled by changing the freezing temperature, CNF sizes, concentrations, and base weights. Only the CNFs with a smaller size and concentration of 0.05 wt % were able to self-assemble to well-dispersed fibril networks. With constant optimization of conditions, when the base weight went up to only 0.25 g/m², the coverage of the corrugated paper fibers with CNF networks became perfect, and a high efficiency of 94.6% for PM0.3 removal was achieved, while maintaining a relatively low pressure drop of 174.2 Pa. All of the raw materials we used are biodegradable, nonpetroleum-based materials, contributing to sustainable development. We believe that such excellent biodegradable high-performance cellulose-based air filtration materials will provide a new direction for the application of nanocellulose in air filtration.

Isolation of hierarchical cellulose building blocks from natural flax fibers as a separation membrane barrier

Cellulose nanofibrils (CNF) is a natural nanomaterial composed of biomacromolecules that can be extracted from plants and has great potential applications in many fields due to its excellent regenerative, sustainable, and biodegradable properties. In this work, the flax CNF with hierarchical scales was obtained by using the flax fibers (FF) treated with different concentrations of alkaline solution, followed by the TEMPO-mediated ternary oxidation and mechanical treatment. Subsequently, the resultant CNF was implanted on the commercial filter paper as a surface barrier for oil/water preparation. The changes of cellulose crystal form and crystallinity caused by alkali treatment on FF were studied by Fourier transform infrared spectroscopy and X-ray diffraction. Morphological changes of FF before and after alkali treatment were observed. The morphology of obtained CNF was examined. Moreover, the transmittance of the prepared CNF suspension and films was also investigated by a UV spectroscopy. The prepared modified filter paper can effectively separate the oil/water mixture, which gives themselves promise as candidates in practical applications of oil/water separation.

Insight into the nanostructure of anisotropic cellulose aerogels upon compression

Cellulose II aerogels are a highly porous class of biobased ultra-light-weight materials. They consist of interlinked networks of loosely aggregated cellulose fibrils. The latter typically have random orientation due to spontaneous phase separation triggered by addition of antisolvent to moleculardisperse cellulose solutions. Deceleration of phase separation has been recently proposed as a novel approach towards aerogels featuring preferred cellulose orientation. Here, we investigate the mechanical response of such oriented cellulose aerogels towards load up to 80% compression. Stress-strain curves were recorded and in situ small angle X-ray scattering (SAXS) was performed during compression test to obtain information about the structural alterations of the aerogel fibril networks on the nano-scale related to deformation. Using SAXS in addition, structural changes can be followed in much more detail than by recording stress-strain curves alone. Buckling and coalescence of fibers and a change in fibril orientation can be related to certain regimes in the stress-strain curve. If the loading axis is oriented parallel to the network orientation the aerogels show higher resilience towards the compression.

Complex Aerogels Generated from Nano-Polysaccharides and Its Derivatives for Oil-Water Separation

The complex aerogel generated from nano-polysaccharides, chitin nanocrystals (ChiNC) and TEMPO-oxidized cellulose nanofibers (TCNF), and its derivative cationic guar gum (CGG) is successfully prepared via a facile freeze-drying method with glutaraldehyde (GA) as cross-linkers. The complexation of ChiNC, TCNF, and CGG is shown to be helpful in creating a porous structure in the three-dimensional aerogel, which creates within the aerogel with large pore volume and excellent compressive properties. The ChiNC/TCNF/CGG aerogel is then modified with methyltrichlorosilane (MTCS) to obtain superhydrophobicity/superoleophilicity and used for oil–water separation. The successful modification is demonstrated through FTIR, XPS, and surface wettability studies. A water contact angle of 155° on the aerogel surface and 150° on the surface of the inside part of aerogel are obtained for the MTCS-modified ChiNC/TCNF/CGG aerogel, resulting in its effective absorption of corn oil and organic solvents (toluene, n-hexane, and trichloromethane) from both beneath and at the surface of water with excellent absorption capacity (i.e., 21.9 g/g for trichloromethane). More importantly, the modified aerogel can be used to continuously separate oil from water with the assistance of a vacuum setup and maintains a high absorption capacity after being used for 10 cycles. The as-prepared superhydrophobic/superoleophilic ChiNC/TCNF/CGG aerogel can be used as a promising absorbent material for the removal of oil from aqueous media.

Effects of pH on Nanofibrillation of TEMPO-Oxidized Paper Mulberry Bast Fibers

TEMPO oxidation was conducted as a pretreatment to achieve efficient nanofibrillation of long paper mulberry bast fibers (PMBFs). The pH dependency of nanofibrillation efficiency and the characteristics of the resulting cellulose nanofibrils (CNFs) were investigated. As the pH increased, the negative value of the zeta potential of TEMPO-oxidized fibers increased. The increase in electrostatic repulsion at pH values of greater than 9 prevented the entanglement of long PMBFs, which was a drawback for defibrillation at acidic pH. With increasing pH, the CNF production yield was increased. The crystallinity index of TEMPO-oxidized CNFs from PMBFs was 83.5%, which was higher than that of TEMPO-oxidized CNFs from softwood fibers in the same conditions. The tensile strength of nanopaper from TEMPO-oxidized PMBF CNFs was 110.18 MPa, which was approximately 30% higher than that (84.19 MPa) of the TEMPO-oxidized CNFs from softwood fibers.

A facile approach to light weight, high porosity cellulose aerogels

This work reported a facile approach to make cellulose-based aerogels in NaOH/urea aqueous solution via freeze-drying hydrogels, which were obtained by mixing N,N'-methylene bisacrylamide (MBA) with cellulose solution at room temperature. The cellulose solution showed pronounced MBA-induced gelation behaviors. The obtained cellulose aerogels possessed a three dimensional network with macroporous structure (20-600 μm), low density (0.0820-0.0083 g/cm3), high porosity (90.3%-99.02%), moderate thermal stability (275 °C) and certain absorbency to Cu (II) (85 mg/g) and methylene blue (MB) (115 mg/g). Cellulose aerogels with different morphologies can be obtained by adjusting the cross-linking degree and the concentration of cellulose. This kind of aerogel provides an excellent matrix for the functionalization of cellulose-based aerogel.

A review on processing techniques of bast fibers nanocellulose and its polylactic acid (PLA) nanocomposites

The utilization of nanocellulose has increasingly gained attentions from various research fields, especially the field of polymer nanocomposites owing to the growing environmental hazardous of petroleum based fiber products. Meanwhile, the searching of alternative cellulose sources from different plants has become the interests for producing nanocellulose with varying characterizations that expectedly suit in specific field of applications. In this content the long and strong bast fibers from plant species was gradually getting its remarkable position in the field of nanocellulose extraction and nanocomposites fabrications. This review article intended to present an overview of the chemical structure of cellulose, different types of nanocellulose, bast fibers compositions, structure, polylactic acid (PLA) and the most probable processing techniques on the developments of nanocellulose from different bast fibers especially jute, kenaf, hemp, flax, ramie and roselle and its nanocomposites. This article however more focused on the fabrication of PLA based nanocomposites due to its high firmness, biodegradability and sustainability properties in developed products towards the environment. Along with this it also explored a couple of issues to improve the processing techniques of bast fibers nanocellulose and its reinforcement in the PLA biopolymer as final products.

Advanced Materials through Assembly of Nanocelluloses

There is an emerging quest for lightweight materials with excellent mechanical properties and economic production, while still being sustainable and functionalizable. They could form the basis of the future bioeconomy for energy and material efficiency. Cellulose has long been recognized as an abundant polymer. Modified celluloses were, in fact, among the first polymers used in technical applications; however, they were later replaced by petroleum-based synthetic polymers. Currently, there is a resurgence of interest to utilize renewable resources, where cellulose is foreseen to make again a major impact, this time in the development of advanced materials. This is because of its availability and properties, as well as economic and sustainable production. Among cellulose-based structures, cellulose nanofibrils and nanocrystals display nanoscale lateral dimensions and lengths ranging from nanometers to micrometers. Their excellent mechanical properties are, in part, due to their crystalline assembly via hydrogen bonds. Owing to their abundant surface hydroxyl groups, they can be easily modified with nanoparticles, (bio)polymers, inorganics, or nanocarbons to form functional fibers, films, bulk matter, and porous aerogels and foams. Here, some of the recent progress in the development of advanced materials within this rapidly growing field is reviewed.

Efficient heavy metal removal from industrial melting effluent using fixed-bed process based on porous hydrogel adsorbents

High adsorption capacity, fast adsorption kinetics, good reusability and low cost are highly demanded for adsorbents used in practical adsorption process. In this study, a porous double network Jute/Polyacrylic acid (Jute/PAA) gel was prepared using simple free-radical polymerization of acrylic acid in Jute aqueous solution. The high permeability of Jute/PAA hydrogel with about 80 wt% water made internal adsorption sites fully expose to metal ions. The Jute/PAA gel adsorbent could efficiently adsorb heavy metals in melting wastewater, especially Cd²⁺ and Pb²⁺. The adsorbent showed very high adsorption capacities of 401.7 mg/g for Cd²⁺ and 542.9 mg/g for Pb²⁺. Moreover, the adsorption equilibrium reached within only 10 min for 40 mg/L of Cd²⁺ and Pb²⁺ using 1 g/L adsorbent. Meanwhile, the removal efficiencies reached 81.0% for Pb (C₀ = 3.825 mg/L), 79.3% for Cd (C₀ = 6.075 mg/L), 83.4% for Cu (C₀ = 9.325 mg/L), 29.8% for Zn (C₀ = 188.6 mg/L), 22.3% for Mn (C₀ = 17.05 mg/L), 96.2% for Cr (C₀ = 0.25 mg/L) and 99.8% for Fe (C₀ = 9.75 mg/L) in melting wastewater using 1 g/L adsorbent in 2 h. In particular, the concentrations of Pb, Cd and Cr decreased below 0.001 mg/L using 4 g/L adsorbent. In the fixed-bed column experiments, the treatment volume of melting wastewater reached 2900 BV (32.8 L) only producing 50 BV (565 mL) eluent. This work develops a highly practical adsorption process based on hydrogel adsorbents for the removal of heavy metals in actual wastewater.

Homogenous isolation of individualized bacterial nanofibrillated cellulose by high pressure homogenization

Varying levels of high pressure homogenization (HPH) were applied to disintegrate bacterial nanofibrillated cellulose (BNFC) from bacterial cellulose (BC). HPH was considered as a simple, non-toxic and highly efficient physical method for nanofibrillated cellulose extraction. The blended BC passed through chambers at high pressures of 68, 138 and 207MPa for 30 cycles. The particle size confirmed disintegration of the BC network fibers to bundles of BNFC and the atomic force microscopy images showed the decreased diameter of individual BNFC in the range 36-67nm. Fourier transform infrared spectroscopy measurement indicated there were no change in the chemical functional groups of the BNFC compared with BC. The decreased crystallinity index and crystallite size of BNFC with increased pressure confirmed the effect of HPH on the BNFC. Nevertheless, BNFC at 207MPa had the lowest thermal stability due to having the highest surface area, which resulted in the minimum nanofiber diameter.

Tuning the mechanical properties of cellulose nanofibrils reinforced polyvinyl alcohol composites via altering the cellulose polymorphs

Cellulose nanofibrils (CNF) with polymorphs of cellulose I and II are different in morphology, aspect ratio, density of functional groups and mechanical properties, which influence the reinforcement effect for polymer composites.

Polymer/Carbon-Based Hybrid Aerogels: Preparation, Properties and Applications

Aerogels are synthetic porous materials derived from sol-gel materials in which the liquid component has been replaced with gas to leave intact solid nanostructures without pore collapse. Recently, aerogels based on natural or synthetic polymers, called polymer or organic aerogels, have been widely explored due to their porous structures and unique properties, such as high specific surface area, low density, low thermal conductivity and dielectric constant. This paper gives a comprehensive review about the most recent progresses in preparation, structures and properties of polymer and their derived carbon-based aerogels, as well as their potential applications in various fields including energy storage, adsorption, thermal insulation and flame retardancy. To facilitate further research and development, the technical challenges are discussed, and several future research directions are also suggested in this review.

Effect of selective oxidation of bacterial cellulose on degradability in phosphate buffer solution and their affinity for epidermal cell attachment

Oxidized bacterial cellulose showed the 3D nano-fibrils structure of BC. The mass loss and degradation rate of OBC were much higher than those of BC. When immersed in PBS, OBC degraded gradually. Cell-adhesion and proliferation studies revealed that OBC had excellent cellular affinity.