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Biomimetic engineering surfaces featuring heterogeneous wettability are vital for atmospheric water harvesting applications. Existing research predominantly focuses on the coordinated regulation of surface wettability through structural and chemical modifications, often overlooking the prevalent triboelectric charge effect at the liquid-solid interface. In this work, we designed a heterogeneous wettability surface by strategic masking and activated its latent triboelectric charge using triboelectric brushes, thereby enhancing the removal and renewal of surface droplets. By examining the dynamic evolution of droplets, the mechanism of triboelectric enhancement in the water collection efficiency is elucidated. Leveraging this inherent triboelectric charge interaction, fog collection capacity can be augmented by 29% by activating the system for 5 s every 60 s. Consequently, the advancement of triboelectric charge-enhanced fog collection technology holds both theoretical and practical significance for overcoming the limitations of traditional surface wettability regulation.

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Ubiquitous anti-counterfeiting materials with a rapidly rising annual consumption (over 1010 m2) can pose a serious environmental burden. Biobased cellulosic materials with birefringence offer attractive sustainable alternatives, but their scalable solvent-free processing remain challenging. Here, a dynamic chemical modification strategy is proposed for multi-modal melt-processing of birefringent cellulosic materials for eco-friendly anti-counterfeiting. Relying on the thermal-activated dynamic covalent-locking of the spatial topological structure of preferred oriented cellulose, the strategy balances the contradiction between the strong confinement of long-range ordered structures and the molecular motility required for entropically-driven reconstruction. Equipped with customizable processing forms including mold-pressing, spinning, direct-ink-writing, and blade-coating, the materials exhibit a wide color gamut, self-healing efficiency (94.5%), recyclability, and biodegradability. Moreover, the diversified flexible elements facilitate scalable fabrication and compatibility with universal processing techniques, thereby enabling versatile and programmable anti-counterfeiting. The strategy is expected to provide references for multi-modal melt-processing of cellulose and promote sustainable innovation in the anti-counterfeiting industry.

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Cellulosic materials are attracting increasing research interest because of their abundance, biocompatibility, and biodegradability, making them suitable in multiple industrial and medical applications. Functionalization of cellulose is usually required to improve or expand its properties to meet the requirements of different applications. Cellulose-binding domains (CBDs) found in various proteins have been shown to be powerful tools in the functionalization of cellulose materials. In this review, we firstly introduce the structural characteristics of commonly used CBDs belonging to carbohydrate-binding module families 1, 2 and 3. Then, we summarize four main kinds of methodologies for employing CBDs to modify cellulosic materials (i.e., CBD only, genetic fusion, non-covalent linkage and covalent linkage). Via different approaches, CBDs have been used to improve the material properties of cellulose, immobilize enzymes for biocatalysis, and design various detection tools. To achieve industrial applications, researches for lowering the production cost of CBDs, improving their performance (e.g., stability), and expanding their application scenarios are still in need.

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Membranes are a selective barrier that allows certain species (molecules and ions) to pass through while blocking others. Some rely on size exclusion, where larger molecules get stuck while smaller ones permeate through. Others use differences in charge or polarity to attract and repel specific species. Membranes can purify air and water by allowing only air and water molecules to pass through, while preventing contaminants such as microorganisms and particles, or to separate a target gas or vapor, such as H2 and CO2, from other gases. The higher the flux and selectivity, the better a material is for membranes. The desirable performance can be tuned through material type (polymers, ceramics, and biobased materials), microstructure (porosity and tortuosity), and surface chemistry. Most membranes are made from plastic from petroleum-based resources, contributing to global climate change and plastic pollution. Cellulose can be an alternative sustainable resource for making renewable membranes. Cellulose exists in plant cell walls as natural fibers, which can be broken down into smaller components such as cellulose fibrils, nanofibrils, nanocrystals, and cellulose macromolecules through mechanical and chemical processing. Membranes made from reassembling these particles and molecules have variable pore architecture, porosity, and separation properties and, therefore, have a wide range of applications in nano-, micro-, and ultrafiltration and forward osmosis. Despite their advantages, cellulose membranes face some challenges. Improving the selectivity of membranes for specific molecules often comes at the expense of permeability. The stability of cellulose membranes in harsh environments or under continuous operation needs further improvement. Research is ongoing to address these challenges and develop advanced cellulose membranes with enhanced performance. This article reviews the microstructures, fabrication methods, and potential applications of cellulose membranes, providing some critical insights into processing-structure-property relationships for current state-of-the-art cellulosic membranes that could be used to improve their performance.

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Electromagnetic hydrogels have attracted significant attention due to their vast potential in soft robotics, biomedical engineering, and energy harvesting. To facilitate future commercialization via large-scale industrial processes, we present a facile concept that utilizes the specialized knowledge of papermaking to fabricate hydrogels with multifunctional electromagnetic properties. The principles of papermaking wet end chemistry, which involves the handling of interactions among cellulosic fibers, fines, polymeric additives, and other components in aqueous systems, serves as a key foundation for this concept. Notably, based on these principles, the versatile use of chemical additives in combination with cellulosic materials enables the tailored design of various products. Our methodology exploits the unique hierarchically pitted and hollow tube-like structures of papermaking grade cellulosic fibers with discernible pits, enabling the incorporation of magnetite nanoparticles through lumen loading. By combining microscale softwood-derived cellulosic fibers with additives, we achieve dynamic covalent interactions that transform the cellulosic fiber slurry into an impressive hydrogel. The cellulosic fibers act as a skeleton, providing structural support within the hydrogel framework and facilitating the dispersion of nanoparticles. In accordance with our concept, the typical hydrogel exhibits combined attributes, including electrical conductivity, self-healing properties, pH responsiveness, and dynamic rheologic behavior. Our approach not only yields hydrogels with interesting properties but also aligns with the forefront of advanced cellulosic material applications. These materials hold the promise in remote strain sensing devices, electromagnetic navigation systems, contactless toys, and flexible electronic devices. The concept and findings of the current work may shed light on materials innovation based on traditional pulp and paper processes. Furthermore, the facile processes involved in hydrogel formation can serve as valuable tools for chemistry and materials education, providing easy demonstrations of principles for university students at different levels.

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Cellulose nanofibrils (CNFs) are supramolecular assemblies of cellulose chains that provide outstanding mechanical support and structural functions for cellulosic organisms. However, traditional chemical pretreatments and mechanical defibrillation of natural cellulose produce irreversible surface functionalization and adverse effects of morphology of the CNFs, respectively, which limit the utilization of CNFs in nanoassembly and surface functionalization. Herein, this work presents a facile and energetically efficient surface engineering strategy to completely exfoliate cellulose elementary fibrils from various bioresources, which provides CNFs with ultrahigh aspect ratios (≈1400) and reversible surface. During the mild process of swelling and esterification, the crystallinity and the morphology of the elementary fibrils are retained, resulting in high yields (98%) with low energy consumption (12.4 kJ g-1). In particular, on the CNF surface, the surface hydroxyl groups are restored by removal of the carboxyl moieties via saponification, which offers a significant opportunity for reconstitution of stronger hydrogen bonding interfaces. Therefore, the resultant CNFs can be used as sustainable building blocks for construction of multidimensional advanced cellulosic materials, e.g., 1D filaments, 2D films, and 3D aerogels. The proposed surface engineering strategy provides a new platform for fully utilizing the characteristics of the cellulose elementary fibrils in the development of high-performance cellulosic materials.

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Dyes are emerging as harmful pollutants, which is one of major issues for the environmentalists and there is a urgent need for the removal of dyes from the effluents. In this context, the adsorption technology has been extensively used as an effective tool for the removal of dyes from the aqueous phase. This technique uses low-cost adsorbents and the cellulosic material is a biodegradable, cost-effective and renewable polymer, which is not soluble in the majority of solvents because of its crystalline nature and hydrogen bonding. Currently, the modified cellulosic materials for the removal of dyes from wastewater gained much attention. Moreover, the application of cellulose for water treatment can be utilized for controlling pollution and have high economic viability and availability. This review signifies the use of cellulose-based adsorbent for dyes adsorption from wastewater. The key advancement in the preparation and modification of cellulose-based adsorbents is discussed and their adsorption efficiencies are compared with other adsorbents for removal of dyes and adsorption conditions are also considered for the same. The studies reporting cellulose-based adsorption from 2003 to 2022 are included and their various properties are compared for the efficient removal of dyes. The modified cellulosic materials cellulose is a highly effective adsorbent for the remediation of effluents.

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Technologies are needed to address contamination with energetic compounds at military installations. This research developed and evaluated novel and sustainable materials that can be used to remove munition constituents (MC) from stormwater runoff. Initial work focused on 3-nitro-1,2,4-triazol-5-one (NTO), as it is both highly soluble and ionized at environmentally relevant pH values. Screening cellulosic materials indicated that cationized (CAT) versions of pine shavings (pine, henceforth) and burlap (jute) demonstrated >70% removal of NTO from artificial surface runoff. CAT materials also demonstrated >90% removal of the anionic propellant perchlorate. NTO removal (~80%) by CAT pine was similar across initial pH values from 4 to 8.5 S.U. An inverse relationship was observed between NTO removal and the concentration of the major anions chloride, nitrate, and sulfate due to competition for anion binding sites. Sorption isotherms were performed using a mixture of the three primary legacy explosives (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), hexahydro-1,3,5-trinitro-s-triazine (RDX), 2,4,6-trinitrotoluene (TNT)), the three insensitive MC (nitroguanidine (NQ), NTO, 2,4-dinitroanisole (DNAN)), and perchlorate. Isotherm results indicated that effective removal of both legacy and insensitive MC would best be achieved using a mixture of peat moss plus one or more of the cationized cellulosic materials.

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Sensors and biosensors play a key role as an analytical tool for the rapid, reliable, and early diagnosis of human diseases. Such devices can also be employed for monitoring environmental pollutants in air and water in an expedited way. More recently, nanomaterials have been proposed as an alternative in sensor fabrication to achieve gains in performance in terms of sensitivity, selectivity, and portability. In this direction, the use of cellulose nanomaterials (CNM), such as cellulose nanofibrils (CNF), cellulose nanocrystals (CNC), and bacterial cellulose (BC), has experienced rapid growth in the fabrication of varied types of sensors. The advantageous properties are related to the supramolecular structures that form the distinct CNM, their biocompatibility, and highly reactive functional groups that enable surface functionalization. The CNM can be applied as hydrogels and xerogels, thin films, nanopapers and other structures interesting for sensor design. Besides, CNM can be combined with other materials (e.g., nanoparticles, enzymes, carbon nanomaterials, etc.) and varied substrates to advanced sensors and biosensors fabrication. This review explores recent advances on CNM and composites applied in the fabrication of optical, electrical, electrochemical, and piezoelectric sensors for detecting analytes ranging from environmental pollutants to human physiological parameters. Emphasis is given to how cellulose nanomaterials can contribute to enhance the performance of varied sensors as well as expand novel sensing applications, which could not be easily achieved using standard materials. Finally, challenges and future trends on the use of cellulose-based materials in sensors and biosensors are also discussed.

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This Minireview provides a comprehensive discussion on the potential of using acid hydrotropes for sustainably fractionating lignocelluloses for biorefinery applications. Acid hydrotropes are a class of acids that have hydrotrope properties toward lignin, which helps to solubilize lignin in aqueous systems. With the capability of cleaving ether and ester bonds and even lignin-carbohydrate complex (LCC) linkages, these acid hydrotropes can therefore isolate lignin embedded in the plant biomass cell wall and subsequently solubilize the isolated lignin in aqueous systems. Performances of two acid hydrotropes, that is, an aromatic sulfonic acid [p-toluenesulfonic acid (p-TsOH)] and a dicarboxylic acid [maleic acid (MA)], in terms of delignification and dissolution of hemicelluloses, and reducing lignin condensation, were evaluated and compared. The advantages of lignin esterification by MA for producing cellulosic sugars through enzymatic hydrolysis and lignin-containing cellulose nanofibrils (LCNFs) through mechanical fibrillation from the fractionated water insoluble solids (WIS), and for obtaining less condensed lignin with light color, were demonstrated. The excellent enzymatic digestibility of maleic acid hydrotropic fractionation WISs was also demonstrated by comparing with WISs from other fractionation processes. The recyclability and reusability of acid hydrotropes were also reviewed. Finally, perspectives on future research needs to address key technical issues for commercialization were also provided.

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Hantzsch reaction is one of the typical multicomponent reactions (MCRs), and it is employed herein to endow cellulosic materials with fluorescent properties. For example, acetoacetyl (ACAC)-bearing cotton fabric prepared via transesterification with tert-butyl acetoacetate is subjected to an aqueous Hantzsch reaction with formaldehyde and ammonium acetate at ambient temperature. A strong fluorescent emission around 460 nm is achieved within 10 min. XPS, fluorescent spectroscopy, and elemental analysis are used to confirm the presence of 1,4-dihydropyridine (DHP) rings on the surface of the fabric. TGA, SEM, XRD, and mechanical testing results show that the modification process has minimum impact on intrinsic properties of the fabric. The strategy is also shown to be generally applicable to various forms of cellulosic materials and different aldehydes. This fast and simple approach enriches the application of MCR in modification of cellulose and cellulose derivatives.

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Identifying and quantifying microplastic in marine samples can be facilitated by removing natural organic matter (NOM). Cellulosic material, like chitin, however, are a type of NOM that is resistant to chemical digestion, and difficult to eliminate from samples. To address this, a two-step digestion method was developed to remove or reduce cellulosic materials in diverse marine media. This method was applied to reference microplastics, reference cellulosic materials, and diverse marine samples from the Inner Oslofjord Norway. This included plankton, seabed sediments near a water treatment plant and driftline sand. The method was developed and tested for plastic particles >45 µm. The first-step was to pre-dissolve cellulosic materials using a mixture of urea:thiourea:NaOH. This was followed by an oxidative digestion step, here using H2O2 and NaOH. Most reference plastics were unaffected, except minor effects for PET and nylon. After sufficient repetitions, cellulosic materials in both reference and marine samples were largely removed. This method was compared to other digestion methods used for microplastic quantification, including single-step oxidation, alkaline treatment, acid treatment and enzymatic treatment. The results indicate that the pre-dissolution step greatly facilitates NOM and cellulosic material digestion for the purpose of microplastic quantification.

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This study reports on eco-friendly graft polymerization approach for the modification of a cellulosic material via combination between enzymatic catalysis and reversible addition-fragmentation chain transfer polymerization (RAFT). Polyacrylamide (PAM) was polymerized on a cellulosic filter paper via horseradish peroxidase (HRP)-initiated RAFT polymerization. The results of grafting ratio, conversion, and pseudo-first-order kinetics were proved that the PAM graft polymerization on the filter paper followed RAFT rules. The results of Attenuated total reflection (ATR-FTIR), elemental analysis, and X-ray photoelectron spectroscopy (XPS) confirmed the presence of PAM in PAM-grafted filter paper. The results of water contact angle and Thermogravimetric analysis (TG) evidenced the change in the wetting properties and thermal performance, respectively of the treated filter paper. This work provides a new environmentally approach to graft polymerization on cellulosic materials.

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The guild between higher termites and their partnership with the diverse community of bacteria and archaea in their gut is a marvel evolutionary achievement. Sustained attempts were made worldwide with a quest for identifying viable important biological macromolecule polyhydroxyalkanoate (PHA) accumulating bacteria. Termite gut serve as a novel source for bacteria with dual properties like PHA production as well as cellulose degradation. Among 40 isolates cultivated, 32.5% turned positive for PCR based screening of PhaC gene. The 16S rRNA gene sequencing revealed that elite PHA producer and cellulose degrader which is phylogenetically affiliated to Bacillus cereus. The PHA production was maximized by employing different carbon and nitrogen sources along with altered pH and temperatures. GC-MS, FTIR and 1HNMR analyses confirmed the presence of PHA and the thermal characterization was performed through TGA and DSC for the termite gut isolate. Our results indicated that the combined integrative approach using isolated strains from termite gut would be preferable choice in producing biomolecules from cellulosic materials.

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A simple chemical synthetic route was designed to prepare zinc oxide nanoparticles (ZnO-NPs) by using sodium alginate as anti-agglomeration agent in the presence of sodium hydroxide as alkali. Next, surface modification of ZnO-NPs with SiO2 nanoparticles was achieved as per to sol-gel process. Further enhancing of the multifunctional properties of SiO2@ZnO-NPs was conducted successfully thanks to (aminopropyl)triethoxysilan (APTES) and vinyltriethoxysilan (VTES) which, in turns, increase the affinity of the SiO2@ZnO-NPs nanocomposite towards glycosidic chains of cotton fabrics. Thorough characterizations of synthesized ZnO-NPs, SiO2@ZnO-NPs, SiO2@ZnO-NPs/APTES and SiO2@ZnO-NPs/VTES were conducted by the making use of well advanced techniques such as FT-IR, XRD, TEM, DLS and SEM-EDX. The data obtained clarified the formation of an interfacial chemical bond between ZnO and SiO2 as affirmed by FT-IR and XRD analysis. In addition, the results revealed by TEM, zeta sizer and SEM-EDX techniques, declared that the amorphous layers of SiO2, APTES or VTES evenly coated the surface of ZnO-NPs. For these nanocomposites, the work was extended to render cotton fabrics multifunctional properties such as antibacterial and UV protection with high durability even after 20 washing cycles using pad dry cure method. Taking the advantages of the silane compounds terminated by active groups such as OH, NH2, etc., open the door for further functionalization of the cotton fabrics' surfaces by durable multifunctional agents applied in various applications.

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To address high fire risks of flamable cellulosic materials, that can trigger easy combustion, flame propagation, and release of toxic gases, we report a new fire-retardant approach using synergetic actions combining unique properties of reduced graphene oxide (rGO) and hydrated-sodium metaborates (SMB). The single-step treatment of cellulosic materials by a composite suspension of rGO/SMB was developed to create a barrier layer on sawdust surface providing highly effective fire retardant protection with multiple modes of action. These performances are designed considering synergy between properties of hydrated-SMB crystals working as chemical heat-sink to slow down the thermal degradation of the cellulosic particles and gas impermeable rGO layers that prevents access of oxygen and the release of toxic volatiles. The rGO outer layer also creates a thermal and physical barrier by donating carbon between the flame and unburnt wood particles. The fire-retardant performance of developed graphene-borate composite and mechanism of fire protection are demonstrated by testing of different forms of cellulosic materials such as pine sawdust, particle-board, and fiber-based structures. Results revealed their outstanding self-extinguishing behavior with significant resistance to release of toxic and flammable volatiles suggesting rGO/SMB to be suitable alternative to the conventional toxic halogenated flame-retardant materials.

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Cotton wool, cotton textile, tissue paper and printing paper, all potential waste cellulosic materials, were directly converted to sorbitol using a Ru/CNT catalyst in the presence of H2 and using only water as solvent, without any acids. Conversions up to 38% were attained for the raw substrates, with sorbitol yields below 10%. Ball-milling of the materials disrupted their crystallinity, allowing reaching 100% conversion of cotton wool, cotton textile and tissue paper after 4h, with sorbitol yields around 50%. Mix-milling these materials with the catalyst greatly enhanced their conversion rate, and the materials were efficiently converted to sorbitol with a yield around 50% in 2h. However, ball- and mix-milled printing paper presented a conversion of only 50% after 5h, with sorbitol yields of 7%. Amounts of sorbitol of 0.525, 0.511 and 0.559g could be obtained from 1g of cotton wool, cotton textile and tissue paper, respectively.

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As per to silver nanoparticles/silicon dioxide nanoparticles (SiO2@AgNPs) properties (e.g., conductivity, reactant, adsorption, detachment and antimicrobial), many researchers were focused on its preparation technique. A core/shell of silicon dioxide and silver nanoparticles (SiO2@AgNPs) has been prepared by facile route. The as synthesized core/shell nanoparticles were chemically modified with two different silan compounds, nominated, vinyltriethoxysilan (VTEOS) and (3-aminopropyl)trimethoxysilan (APTEOS). World class facilities such as XRD, FT-IR, TEM, Particle size, DLS, SEM techniques were utilized for the nanoparticles characterization. The nanoparticulate system comprises SiO2@AgNPs, SiO2@AgNPs/APTEOS were applied to cotton fabric using butantetracarboxylic acid (BTCA) as across-linking agent. While UV irradiation by photo initiator was used as crosslinking agent for SiO2@AgNPs/VTEOS on cotton fabrics. The Treated cotton fabrics were evaluated for their surface morphology and heat transfer ability as well as antibacterial activity. The obtained data prove that the core/shell was successfully prepared, with AgNPs in core. In addition, both silan compounds (APTEOS, VTEOS) were successfully reacted with the outer shell SiO2. The results declared also that the treated fabrics exhibit a good antibacterial activity as well as good thermal properties.

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Adsorption behavior in the HyperCel family of cellulosic ion-exchange materials (Pall Corporation) was characterized using methods to assess, quantitatively and qualitatively, the dynamics of protein uptake as well as static adsorption as a function of ionic strength and protein concentration using several model proteins. The three exchangers studied all presented relatively high adsorptive capacities under low ionic strength conditions, comparable to commercially available resins containing polymer functionalization aimed at increasing that particular characteristic. The strong cation- and anion-exchange moieties showed higher sensitivity to increasing salt concentrations, but protein affinity on the salt-tolerant STAR AX HyperCel exchanger remained strong at ionic strengths normally used in downstream processing to elute material fully during ion-exchange chromatography. Very high uptake rates were observed in both batch kinetics experiments and time-series confocal laser scanning microscopy, suggesting low intraparticle transport resistances relative to external film resistance, even at higher bulk protein concentrations where the opposite is typically observed. Electron microscopy imaging of protein adsorbed phases provided additional insight into particle structure that could not be resolved in previous work on the bare resins.

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Silver nanoparticles (AgNPs) have attracted great attention due to its optical, electrical and thermal properties. Cellulosic supports for these nanoparticles are of particular interest because of its availability, flexibility and biocompatibility. In this work, AgNPs were synthesized using two cellulosic materials, cellophane (CP) and filter paper (FP), as matrix support. Cellulosic materials were immersed in an aqueous solution of silver nitrate containing polyvinylpyrrolidone (PVP) and then reduced with hydroxylamine. The obtained nanocomposites (CP-AgNPs and FP-AgNPs) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (DRX) and scanning electron microscopy (SEM). AgNPs of near 15nm anchored onto cellulosic surfaces were detected. The thermal properties of these materials were investigated through thermogravimetry (TG). Their kinetic of thermal decomposition was studied by the Vyasovkin method of dynamic isoconvertion, which indicated a catalytic effect of AgNPs in the cellulose thermal decomposition reaction.