Hollow Metal-Organic Framework/MXene/Nanocellulose Composite Films for Giga/Terahertz Electromagnetic Shielding and Photothermal Conversion

With the continuous advancement of communication technology,the escalating demand for electromagnetic shielding interference(EMI)materials with multifunctional and wideband EMI performance has become urgent.Controlling the electrical and magnetic components and designing the EMI material structure have attracted extensive interest,but remain a huge challenge.Herein,we reported the alternating electromagnetic structure composite films composed of hollow metal-organic frameworks/layered MXene/nanocellulose(HMN)by alternating vacuum-assisted filtration process.The HMN composite films exhibit excellent EMI shielding effectiveness performance in the GHz frequency(66.8 dB at Kaband)and THz frequency(114.6 dB at 0.1-4.0 THz).Besides,the HMN composite films also exhibit a high reflection loss of 39.7 dB at 0.7 THz with an effective absorption bandwidth up to 2.1 THz.Moreover,HMN composite films show remarkable photothermal conversion performance,which can reach 104.6℃under 2.0 Sun and 235.4℃under 0.8 W cm^(−2),respectively.The unique micro-and macrostructural design structures will absorb more incident electromagnetic waves via interfacial polarization/multiple scattering and produce more heat energy via the local surface plasmon resonance effect.These features make the HMN composite film a promising candidate for advanced EMI devices for future 6G communication and the protection of electronic equipment in cold environments.

Fabrication of Free Standing Nanocellulose Film via Spray Coating and its Biomedical Application: A Review

Spraying nanocellulose onto films provides a quick and scalable way to create free-standing films with exceptional consistency and customizable thickness. This method increases the application of nanocellulose films in various industries and satisfies the requirements of large-scale production. In the field of biomedicine, spray-coated free-standing nanocellulose films hold great promise for applications such as drug delivery, tissue engineering, wound healing, device coatings, and biosensing. They are excellent nanomaterials for a variety of biomedical applications due to their special qualities, including biocompatibility, high mechanical strength, porous structure, large surface area, and adaptability. This paper reviewed the detailed exposure of the spray coating process of nanocellulose suspension onto free- standing films and its biomedical applications.

Nanocellulose-Assisted Construction of Multifunctional MXene-Based Aerogels with Engineering Biomimetic Texture for Pressure Sensor and Compressible Electrode

Multifunctional architecture with intriguing structural design is highly desired for realizing the promising performances in wearable sensors and flexible energy storage devices.Cellulose nanofiber(CNF)is employed for assisting in building conductive,hyperelastic,and ultralight Ti_(3)C_(2)T_(x)MXene hybrid aerogels with oriented tracheid-like texture.The biomimetic hybrid aerogels are constructed by a facile bidirectional freezing strategy with CNF,carbon nanotube(CNT),and MXene based on synergistic electrostatic interaction and hydrogen bonding.Entangled CNF and CNT“mortars”bonded with MXene“bricks”of the tracheid structure produce good interfacial binding,and superior mechanical strength(up to 80%compressibility and extraordinary fatigue resistance of 1000 cycles at 50%strain).Benefiting from the biomimetic texture,CNF/CNT/MXene aerogel shows ultralow density of 7.48 mg cm^(-3)and excellent electrical conductivity(~2400 S m^(-1)).Used as pressure sensors,such aerogels exhibit appealing sensitivity performance with the linear sensitivity up to 817.3 kPa^(-1),which affords their application in monitoring body surface information and detecting human motion.Furthermore,the aerogels can also act as electrode materials of compressive solid-state supercapacitors that reveal satisfactory electrochemical performance(849.2 mF cm^(-2)at 0.8 mA cm^(-2))and superior long cycle compression performance(88%after 10,000 cycles at a compressive strain of 30%).

Aging Resistance Evaluation of Aged Paper Reinforced with Different Nanocelluloses

Paper documents experience severe acidification and embrittlement.Nanocellulose is an excellent reinforcement material for paper documents owing to its compatibility and excellent mechanical strength.However,little research has been conducted on the aging resistance of nanocellulose-reinforced paper.In this study,six types of nanocelluloses were used to reinforce aged paper.The reinforcement and anti-aging performances were evaluated,and the anti-aging mechanism was further clarified.Nanocellulose with a high degree of polymerization can better enhance aged paper,and non-chemical nanocellulose also shows better anti-aging performance,such as nanocellulose prepared by mechanical or biological methods.However,nanocellulose prepared using chemical methods exhibits poor reinforcement and anti-aging performance.This is because it has a small particle size that is not beneficial for physical crosslinking with paper fibers.More importantly,the introduction of acidic or oxidizing groups on nanocellulose accelerates the acid hydrolysis and oxidation rate of paper fibers,especially nanocellulose prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl oxidation,which should not be used to protect paper documents.

Bismuth-Complex-Incorporated Nanocellulose Sheet for Biomedical Application:A Review on New Nanocellulose Composites

Antibiotic resistance is one of the major issues in the medical field and a potential threat to human health.However,newly emerging antimicrobial compounds failed to combat antimicrobial resistance developed by bacterial pathogens.Recently,a bismuth-based complex has been developed to eradicate antimicrobial-resistant microorganism infections.The complex is known as organobismuth(III)phosphinate,which is said to be a potential broad-spectrum antimicrobial agent.This complex has been incorporated into the nanocellulose suspension to fabricate a biomedical composite for various applications.The composite can be fabricated by two methods namely vacuum filtration and spray coating.In this paper,the surface and topography of the composite are investigated and discussed in terms of SEM micrographs and their antimicrobial potential.This review focuses on the organo-bismuth nanocellulose composite and its biomedical application in the future.

Nanocellulose-Graphene Hybrids: Advanced Functional Materials as Multifunctional Sensing Platform

Naturally derived nanocellulose with unique physiochemical properties and giant potentials as renewable smart nanomaterials opens up endless novel advanced functional materials for multi-sensing applications.However,integrating inorganic functional two-dimensional carbon materials such as graphene has realized hybrid organic-inorganic nanocomposite materials with precisely tailored properties and multi-sensing abilities.Altogether,the affinity,stability,dispersibility,modification,and functionalization are some of the key merits permitting their synergistic interfacial interactions,which exhibited highly advanced multifunctional hybrid nanocomposites with desirable properties.Moreover,the high performance of such hybrids could be achievable through green and straightforward approaches.In this context,the review covered the most advanced nanocellulose-graphene hybrids,focusing on their synthetization,functionalization,fabrication,and multi-sensing applications.These hybrid films exhibited great potentials as a multifunctional sensing platform for numerous mechanical,environmental,and human bio-signals detections,mimicking,and in-situ monitoring.

Research progress of nanocellulose for electrochemical energy storage:A review

Recently, in response to the major challenges in energy development and environmental issues, tremendous efforts are being devoted to developing electrochemical energy storage devices based on green sustainable resources. As a class of green materials, nanocellulose(NC) has received extensive attention. In this review, we summarize the research progress of NC derived materials in electrochemical energy storage. Specifically, we first introduce various synthesis methods based on NC and the pretreatment process to increase the conductivity. Then we focus on the specific application of NC in electrochemical energy storage devices. Finally, we summarize the previously reported work and put forward views on the further development of NC in the field of electrochemical energy storage.

State of the Art Manufacturing and Engineering of Nanocellulose: A Review of Available Data and Industrial Applications

This review provides a critical overview of the recent methods and processes developed for the production of cellulose nanoparticles with controlled morphology, structure and properties, and also sums up (1) the processes for the chemical modifications of these particles in order to prevent their re-aggregation during spray-drying procedures and to increase their reactivity, (2) the recent processes involved in the production of nanostructured biomaterials and composites. The structural and physical properties of those nanocelluloses, combined with their biodegradability, make them materials of choice in the very promising area of nanotechnology, likely subject to major commercial successes in the context of green chemistry. With a prospective and pioneering approach to the subject matter, various laboratories involved in this domain have developed bio-products now almost suitable to industrial applications;although some important steps remain to be overcome, those are worth been reviewed and supplemented. At this stage, several pilot units and demonstration plants have been built to improve, optimize and scale-up the processes developed at laboratory scale. Industrial reactors with suitable environment and modern control equipment are to be expected within that context. This review shall bring the suitable processing dimension that may be needed now, given the numerous reviews outlining the product potential attributes. An abundant literature database, close to 250 publications and patents, is provided, consolidating the various research and more practical angles.

Nanocellulose isolation characterization and applications:a journey from non-remedial to biomedical claims

Cellulose is a renewable,biodegradable,ecofriendly and sustainable biomaterial.Global market of nanocellulose is comprehensively very high due to its utility.Extraction of nanocellulose from bacteria and plant results in different morphology and size of nanocellulose.Biocompatibility,mechanical strength,biofabrication,crystallinity,high surface area per unit mass,hydrophilicity,porosity,transparency and non-toxicity of bacterial cellulose make it more attractive.The extravagant nanoscaled three-dimensional network of cellulosic structures possess extraordinary properties for biomedical application,evidencing its usage in skin therapy,cardiovascular implants,cartilage meniscus implants,tissue engineering,bone tissue and neural implants,wound care products,drug delivery agents,tablet modification,tissue engineered urinary conduits,and synthesis of artificial cornea.Hence due to potential benefits associated with nanocellulose effective and efficient techniques are required for the isolation of nanocellulose that should be economical,ecofriendly and non-toxic.

Progress in Nanocellulose Preparation and Application

Nanocellulose is a biodegradable, renewable, nonmeltable polymeric material that is insoluble in most solvents due to hydrogen bonding and crystallinity. Nanocellulose has attracted considerable attention in recent decades owing to its environmental friendliness, wide availability, good biocompatibility, high crystallinity, and high Young's modulus. This review presents the recent achievements in preparation and applications of nanocellulose, including a discussion of the advantages and disadvantages of various preparation methods and a summary of the applications of nanocellulose in composite materials research. Finally, we examine the mounting evidence of more widespread potential applications of nanocellulose.

Nanocomposite membranes with high-charge and size-screened phosphorylated nanocellulose fibrils for CO_(2)separation

In this study,cellulose nanofibrils(CNF)of high charge(H-P-CNF)and screened size(H-P-CNF-S)were fabricated by increasing the charge of phosphorylated cellulose nanofibrils(P-CNFs)during the pre-treatment step of CNF production.Results show that the H-P-CNF have a significantly higher charge(3.41 mmol g^(-1))compared with P-CNF(1.86 mmol g^(-1)).Centrifugation of H-P-CNF gave a supernatant with higher charge(5.4 mmol g^(-1))and a reduced size(H-P-CNF-S).These tailored nanocelluloses were added to polyvinyl alcohol(PVA)solutions and the suspensions were successfully coated on porous polysulfone(PSf)supports to produce thin-film nanocomposite membranes.The humid mixed gas permeation tests show that CO_(2)permeability increases for membranes with the addition of H-P-CNF-S by 52%and 160%,compared with the P-CNF/PVA membrane and neat PVA membrane,respectively.

Bacterial nanocellulose production and biomedical applications

Bacterial nanocellulose(BNC)is a homopolymer ofβ-1,4 linked glycose,which is synthesized by Acetobacter using simple culturing methods to allow inexpensive and environmentally friendly small-and large-scale production.Depending on the growth media and types of fermentation methods,ultra-pure cellulose can be obtained with different physio-chemical characteristics.Upon biosynthesis,bacterial cellulose is assembled in the medium into a nanostructured network of glucan polymers that are semitransparent,mechanically highly resistant,but soft and elastic,and with a high capacity to store water and exchange gasses.BNC,generally recognized as safe as well as one of the most biocompatible materials,has been found numerous medical applications in wound dressing,drug delivery systems,and implants of heart valves,blood vessels,tympanic membranes,bones,teeth,cartilages,cornea,and urinary tracts.

A Review of Hydrophobic Nanocellulose and Its Applications

Nanocellulose is of great interest in various areas nowadays as a natural nanostructured biomaterial.However,in many applications,the high hydrophilicity due to a large number of hydroxyl groups is not desired.The hydrophobic modification of nanocellulose can thus increase its application.This work reviewed recent developments of methods for nanocellulose hydrophobic modification,through physical adsorption and chemical grafting.The applications of hydrophobic nanocellulose were also reviewed.

High-value Applications of Nanocellulose

Nanocelluloses, obtained from the biopolymer cellulose, are a class of renewable functional nanomaterials with excellent properties and a broad range of applications. This review mainly illustrates practical and advanced applications of nanocellulose-based materials in the following categories.(1) Fire-resistant materials: in the section on these types of materials, the fireprotection property of nanocellulose/clay hybrid composites(clay nanopaper) is illustrated; oriented montmorillonite(MTM) provides barrier properties and low thermal conductivity whereas cellulose nanofibers(CNFs) impart favorable charring.(2) Thermal insulation materials: the best way to obtain materials with good heat insulation performance is to decrease the thermal conductivity of such materials.(3) Template materials: nanocellulose can direct the deposition and patterning of materials to form nanoparticles, nanowires, or nanotubes with improved properties.

Enzymatic Conversion of Sugarcane Lignocellulosic Biomass as a Platform for the Production of Ethanol,Enzymes and Nanocellulose

The conversion of sugarcane lignocellulosic biomass into fuels,chemicals and high-value materials using the biochemical pathway is considered the most sustainable alternative for the implementation of future biorefineries.Actually,the first large-scale cellulosic ethanol plants that have started operating worldwide apply the enzymatic hydrolysis process to convert biomass into simple sugars that are fermented to ethanol by yeasts.However,several technological challenges still need to be addressed in order to obtain commercially competitive products.This review describes current challenges and perspectives regarding the enzymatic hydrolysis step for processing sugarcane lignocellulosic biomass within the biorefinery.Recent developments in terms of process configuration strategies and opportunities for the implementation of a sugarcane biorefinery,in which the production of ethanol is integrated into the production of high-value products such as enzymes and nanocellulose,are discussed in view of the demands of the current bioeconomy.

Removal of Cu(II),Pb(II),Mg(II),and Fe(II) by Adsorption onto Alginate/Nanocellulose Beads as Bio-Sorbent

Alginate blended with cellulose nanocrystals(CNC),cellulose nanofibers(CNF),and tri-carboxylate cellulose nanofibers(TPC-CNF)prepared and encapsulated in the form of microcapsules(bio-polymeric beads).The cellulosic nanomaterials that used in this study were investigated as nanomaterials for wastewater treatment applications.Batch experiments were performed to study the removal of copper,lead,magnesium,and iron from aqueous solutions by the prepared beads.The effects of the sorbent dosage and the modified polymers on the removing efficiency of the metal cations were examined.Atomic absorption was used to measure the metal ions concentrations.The modified bio-polymeric beads(Alg-CNF,Alg-CNC,and Alg-TPC-CNF)exhibited high-efficiency towards removing of the metal cations;Cu^(2+),Pb^(2+),Mg^(2+),and Fe^(2+).The Alg-TPC-CNF composite was exhibited excellent removing efficiency which around 95%for Pb,92%for Cu,43%for Fe and 54%for Mg.These outcomes affirm that the utilization of nanomaterials giving higher adsorption capacities contrasted with similar material in its micro or macrostructure form.

Nanocellulose Applications in Wood Adhesives—Review

Bio-based materials open a new world of possibilities in every field due to its independence from the petrochemical origin. Moreover, concerns on environmental footprints and toxicity of synthetic adhesives made scientists investigate the utilization of biomaterials for wood adhesives. In this perspective, nanocellulose as a sustainable and cheap bio-nanomaterial provides a better alternative to conventional adhesive based on formaldehyde-containing condensation resins. Property of nanocellulose to act as both binders and as structural reinforcement in various adhesive systems adds to its potential. Besides by reducing the harmful emission of formaldehyde, it also can improve the mechanical properties and enhance performance of adhesives. This review paper aims to point out the potential application of nanocellulose based wood adhesives compared to petroleum-based conventional systems beyond renewability. New functionalities through structural modification in nanocellulose could bring a replacement with the synthetic adhesive systems which will play a significant role in future bio-economy.

Performance Assessment of Nanocellulose Hydroxypropyl Methyl Cellulose Composite on Role of Nano-CaCO_(3) for the Preservation of Paper Documents

Deacidification and self-cleaning are important for the preservation of paper documents.In this study,nano-CaCO_(3) was used as a deacidification agent and stabilized by nanocellulose(CNC)and hydroxypropyl methylcellulose(HPMC)to form a uniform dispersion.Followed by polydimethylsiloxane(PDMS)treatment and chemical vapor deposition(CVD)of methyltrimethoxysilane(MTMS),a hydrophobic coating was constructed for self-cleaning purposes.The pH value of the treated paper was approximately 8.20,and the static contact angle was as high as 152.29°.Compared to the untreated paper,the tensile strength of the treated paper increased by 12.6%.This treatment method endows the paper with a good deacidification effect and self-cleaning property,which are beneficial for its long-term preservation.

Preparation and Functional Design of Polyethyleneimine Reinforced Nanocellulose-based Aerogel

An aerogel electrode composed of conductive active materials based on nanocellulose aerogels can absorb more electrolytes,as well as enhance electron transport and ion diffusion channels.In the present study,aerogels with high strength were successfully prepared using 2,2,6,6-tetramethyl-1-piperidinyloxy free radical(TEMPO)-oxidized cellulose nanofibrils(CNF)as a raw material and polyethyleneimine(PEI)as a crosslinking agent.Simultaneously,functional electrode materials were prepared via self-assembly.Based on our findings,PEI can significantly improve the water and solvent solubility and enhance the wet strength and shape recovery ability of CNF aerogels.Meanwhile,the minimum density of the aerogel reached 0.0160 g/cm3,the maximum porosity was approximately 98.5%,and the maximum stress approximated 0.02 MPa.Furthermore,electrochemical tests revealed that after self-assembly of reduced graphene oxide(RGO)and polyaniline(PANI)solution,the mass specific capacitance of the functional composite aerogel was approximately 92 F/g and exhibited good chargedischarge performance.

Co-effect of Mechanical Ball-milling and Microenvironmental Polarity on Morphology and Properties of Nanocellulose

Cellulose is a linear polymer consisting of D-anhydroglucose units joined by β-1,4-glycosidic linkages. The densely packed cellulose molecular chain forms crystalline cellulose through strong hydrogen bonding. Owing to its chemical tunability and excellent mechanical resistance, nanocellulose is widely used in everyday life and the industrial sector. In this work, cellulose materials were nanoprocessed by mechanical ball-milling(1) in polar solvents(N,N-dimethylformamide or dimethyl sulfoxide) with esterification or(2) in hydrophobic agents(polydimethylsiloxane or polytetrafluoroethylene) with different molecular weights. Cellulose nanofibers and nanosheets with different hydrophilic and hydrophobic properties were obtained, and the mechanism of cellulose disintegration along a crystallographic plane induced by mechanical force and the polarity condition were discussed. This work affords a new way to manipulate the morphology and properties of nanocellulose.