Review of the recent developments in all-cellulose nanocomposites: Properties and applications

Preparation of graphene/carbon nanotube-cellulose composites assisted by ionic liquids: A review

As is well known, cellulose, as a natural polymer material with abundant reserves, plays an irreplaceable role as the major raw material in energy and chemical-related fields. With the continuous advancement of technology, native single-component cellulose is often unsatisfactory for practical applications, constructing composites is an effective means of expanding the applications. When compounded with other ingredients to prepare composites, cellulose usually needs to be dissolved and regenerated to obtain good dispersion. Current studies have revealed that cellulose is insoluble in conventional solvents, and the limited types of solvent systems that can dissolve cellulose tend to degrade the cellulose during the dissolution process, altering the cellulose properties. Ionic liquids (ILs) are a class of solvents that are capable of dissolving cellulose without adversely affecting the cellulose during the dissolution process, such as degradation. Graphene and carbon nanotubes (CNTs) are poorly dispersed and easily agglomerated by π-π stacking in general solvents, whereas ILs can effectively shield them from π-π stacking, resulting in a favorable and steady dispersion. Thus, the cellulose composites of graphene/CNTs can be prepared with the assistance of ILs. In this paper, the solubilization of cellulose by ILs and the solubilization mechanism to the preparation of cellulose composites with graphene/CNTs are reviewed, the interactions between graphene, CNTs and cellulose in the composites are elucidated, and the preparation of cellulose composites with graphene/CNTs is introduced in terms of their structure, properties and application potential.

Dual magnetization and amination of cellulosic chains for the efficient adsorption of heavy metals

Compounds functionalized with hydroxyl and amino groups were found to have good potential for the adsorption of different ions. In this work, a new system of cellulosic chains was amended with amine substitutions and bonded to a magnetic core of NiFe2O4@SiO2 to form NiFe2O4@SiO2-cellulose-NH2 system. The prepared sample showed suitable magnetic separation and was characterized via XRD, FT-IR, SEM, EDS, and TGA-DTA analyses. The adsorption potential of NiFe2O4@SiO2-cellulose-NH2 system has been investigated on the heavy metals (Cd, Ni, and Pb) removal from a synthetic wastewater environment. The results show that the magnetic property created by the magnetic core increased the recycling potential of the adsorbent and the magnetic core has a positive effect on the absorption potential of the polymer. The adsorption removal of Cd(II), Ni(II), and Pb(II) ions was studied using NiFe2O4@SiO2-cellulose-NH2 systems in different pH, temperatures, metal ion concentrations, and adsorbent dosages. The maximum adsorption capacities of single heavy metal ions were obtained as 406.44 mg/g (for Cd(II) ions), 411.63 mg/g (for Ni(II) ions), and 414.68 mg/g (for Pb(II) ions) under optimized conditions as pH = 6.5, ion concentration: 500 mg/L, adsorbent dosage: 1.2 g/L and room temperature.

Carboxymethyl cellulose-based photothermal film: A sustainable packaging with high barrier and tensile strength for food long-term antibacterial protection

Traditional packaging materials feed the growing global food protection. However, these packaging materials are not conducive to environment and have not the ability to kill bacteria. Herein, a green and simple strategy is reported for food packaging protection and long-term antibacterial using carboxymethylcellulose-based photothermal film (CMC@CuS NPs/PVA) that consists of carboxymethyl cellulose (CMC) immobilized copper sulfide nanoparticles (CuS NPs) and polyvinyl alcohol (PVA). With satisfied oxygen transmittance (0.03 cc/m2/day) and water vapor transmittance (163.3 g/m2/day), the tensile strength, tear strength and burst strength reached to 3401.2 N/m, 845.7 mN and 363.6 kPa, respectively, which could lift 4.5 L of water. The composite film had excellent photothermal conversion efficiency and photothermal stability. Under the irradiation of near infrared (NIR), it can rapidly heated up to 197 °C within 25 s. The antibacterial analysis showed that the inhibition rate of composite film against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) could all reach >99 %. Furthermore, the synthesized CuS NPs was well immobilized and the residual rate of copper kept 98.7 % after 10 days. Noticeably, the composite film can preserve freshness of strawberries for up to 6 days. Therefore, the composite film has potential application for food antibacterial protection.

Preparation of multifunctional and mechanically-reliable smart wood infiltrated with cellulose nanocrystal-reinforced polyvinyl alcohol nanocomposite

Multifunctional transparent woods have recently attracted a great interest as efficient products for many applications, such as smart window and smart packaging. Herein, a transparent wood with several desirable properties, including flame-retardant activity, ultraviolet shielding, superhydrophobicity, good roughness, durability and photostability was developed. The current photoluminescent wood showed a remarkable capacity to keep releasing light in the dark for extended durations. Multifunctional transparent wood was prepared by infiltrating a delignified wooden bulk with a combination of polyvinyl alcohol (PVA), ammonium polyphosphate (APP), cellulose nanocrystals, and rare-earth strontium aluminate nanoparticles (RSAN). Cellulose nanocrystals were prepared from microcrystalline cellulose, and used as reinforcement nanofiller to enhance the mechanical strength of the polyvinyl alcohol matrix and a dispersant agent to avoid agglomeration of RSAN. RSAN displayed diameters of 8-16 nm, while cellulose nanocrystals displayed lengths of 75-150 nm and diameters of 5-10 nm. According to photoluminescence spectra and the colorimetric space coordinates reported by the CIE Lab parameters, the transparent wood changed color to bright green when exposed to UV irradiation. For the produced phosphorescent wood surfaces, an absorption band was detected at 365 nm to generate an emission band at 519 nm.

Nanocellulose-mediated bilayer hydrogel actuators with thermo-responsive, shape memory and self-sensing performances

Inspired by creatures, abundant stimulus-responsive hydrogel actuators with diverse functionalities have been manufactured for applications in soft robotics. However, constructing a shape memory and self-sensing bilayer hydrogel actuator with high mechanical strength and strong interfacial bonding still remains a challenge. Herein, a novel bilayer hydrogel with a stimulus-responsive TEMPO-oxidized cellulose nanofibers/poly(N-isopropylacrylamide) (TOCN/PNIPAM) layer and a non-responsive TOCN/polyacrylamide (TOCN/PAM) layer is proposed as a thermosensitive actuator. TOCNs as a nano-reinforced phase provide a high mechanical strength and endow the hydrogel actuator with a strong interfacial bonding. Due to the incorporation of TOCNs, the TOCN/PNIPAM hydrogel exhibits a high compressive strength (~89.2 kPa), elongation at break (~170.7 %) and tensile strength (~24.0 kPa). The prepared PNIPAM/TOCN/PAM hydrogel actuator performs the roles of an encapsulation, jack, temperature-controlled fluid valve and temperature-control manipulator. The incorporation of Fe3+ further endows the bilayer hydrogel actuator with a synergistic performance of shape memory and temperature-driven, which can be used as a temperature-responsive switch to detect ambient temperature. The PNIPAM/TOCN/PAM-Fe3+ conductive hydrogel can be assembled into a flexible sensor and generate sensing signals when driven by temperature changes to achieve real-time feedback. This research may lead to new insights into the design and manufacturing of intelligent flexible soft robots.

Nano-Micron Combined Hydrogel Microspheres: Novel Answer for Minimal Invasive Biomedical Applications

Hydrogels, key in biomedical research for their hydrophilicity and versatility, have evolved with hydrogel microspheres (HMs) of micron-scale dimensions, enhancing their role in minimally invasive therapeutic delivery, tissue repair, and regeneration. The recent emergence of nanomaterials has ushered in a revolutionary transformation in the biomedical field, which demonstrates tremendous potential in targeted therapies, biological imaging, and disease diagnostics. Consequently, the integration of advanced nanotechnology promises to trigger a new revolution in the realm of hydrogels. HMs loaded with nanomaterials combine the advantages of both hydrogels and nanomaterials, which enables multifaceted functionalities such as efficient drug delivery, sustained release, targeted therapy, biological lubrication, biochemical detection, medical imaging, biosensing monitoring, and micro-robotics. Here, this review comprehensively expounds upon commonly used nanomaterials and their classifications. Then, it provides comprehensive insights into the raw materials and preparation methods of HMs. Besides, the common strategies employed to achieve nano-micron combinations are summarized, and the latest applications of these advanced nano-micron combined HMs in the biomedical field are elucidated. Finally, valuable insights into the future design and development of nano-micron combined HMs are provided.

Novel insights on room temperature-induced cellulose dissolution mechanism via ZnCl2 aqueous solution: Migration, penetration, interaction, and dispersion

The unique molecular structure of cellulose makes it challenging to dissolve at room temperature (R.T.), and the dissolution mechanism remains unclear. In this study, we employed ZnCl2 aqueous solution for cellulose dissolution at R.T., proposing a novel four-stage dissolution mechanism. The efficient dissolution of cellulose in ZnCl2 aqueous solution at R.T. involves four indispensable stages: rapid migration of hydrated Zn2+ ions towards cellulose, sufficient penetration between cellulose sheets, strong interaction with cellulose hydroxyl groups, and effective dispersion of separated cellulose chains. The proposed four-stage dissolution mechanism was validated through theoretical calculations and experimental evidence. The hydrated Zn2+ ions in ZnCl2 + 3.5H2O solvent exhibited ideal migration, penetration, interaction, and dispersion abilities, resulting in efficient cellulose dissolution at R.T. Moreover, only slight degradation of cellulose occurred in ZnCl2 + 3.5H2O at R.T. Consequently, the regenerated cellulose materials obtained from ZnCl2 + 3.5H2O (R.T.) exhibited better mechanical properties. Notably, the solvent recovery rate reached about 95 % based on previous usage during five cycles. The solvent is outstanding for its green, low-cost, efficiency, simplicity, R.T. conditions and recyclability. This work contributes to a better understanding of the cellulose dissolution mechanisms within inorganic salt solvents at R.T., thereby guiding future development efforts towards greener and more efficient cellulosic solvents.

The Influence of TiO2-Lignin Hybrid Fillers in Low-Density Polyethylene Composites on Photocatalytic Performance and UV-Barrier Properties

The main objective of this study was to discover new packaging materials that could integrate one of the most expected properties, such as UV protection, with a self-cleaning ability defined as photocatalytic performance. Accordingly, new hybrid additives were used to transform LDPE films into materials with complex performance properties. In this study, titanium dioxide-lignin (TL) hybrid systems with a weight ratio of inorganic to organic precursors of 5-1, 1-1, and 1-5 were prepared using a mechanical method. The obtained materials and pristine components were characterized using measurement techniques and research methods, such as Fourier-transform infrared spectroscopy (FTIR), thermal stability analysis (TGA/DTG), measurement of the electrokinetic potential as a function of pH, scanning electron microscopy (SEM), and particle size distribution measurement. It was found that hydrogen bonds were formed between the organic and inorganic components, based on which the obtained systems were classified as class I hybrid materials. In the next step, inorganic-organic hybrid systems and pristine components were used as fillers for a low-density polyethylene (LDPE) composite, 5 and 10% by weight, in order to determine their impact on parameters such as tensile elongation at break. Polymer composites containing titanium dioxide in their matrix were then subjected to a test of photocatalytic properties, based on which it was found that all materials with TiO2 in their structure exhibit photocatalytic properties, whereby the best results were obtained for samples containing the TiO2-lignin hybrid system (1-1). The mechanical tests showed that the thin sheet films had a strong anisotropy due to chill-roll extrusion, ranging from 1.98 to 3.32. UV-Vis spectroscopy revealed four times higher light absorption for composites in which lignin was present than for pure LDPE, in the 250-450 nm range. On the other hand, the temperature at 5% and 30% weight loss revealed by TGA testing increased the highest performance for LDPE/TiO2 materials (by 20.4 °C and 8.7 °C, respectively).

Fully Bio-Based Ionic Liquids for Green Chemical Modification of Cellulose in the Activated-State

Biopolymers, especially cellulose, are vital to transitioning to a circular economy and reducing our reliance on fossil fuels. However, for many applications a high degree of cellulose hydroxyl modification is necessary. The challenge is that the chemical features of the hydroxyls of cellulose and water are similar. Therefore, chemical modification of cellulose is often explored under non-aqueous conditions with systems that result in high hydroxyl accessibility and reduce cellulose aggregation. Unfortunately, these systems depend on hazardous and complex solvents from fossil resources, which diverge from the initial sustainability objectives. To address this, we developed three new betaine-based ionic liquids that are fully bio-based, scalable, and green. We found that a specific ionic liquid had the perfect chemical features for the chemical activation of cellulose without disturbing its crystalline ordering. The high activation in heterogeneous conditions was exemplified by reacting cellulose with succinic anhydride, resulting in more than 30 % conversion of all hydroxyls on cellulose. Overall, this work opens new perspectives for the derivatization of cellulosic materials while simultaneously "keeping it green".

Modulating digestibility and stability of Pickering emulsions based on cellulose nanofibers

Cellulose nanofibers (CNF) have been widely studied for their biodegradability and for their unique advantages as a stabilizer in Pickering-type emulsions. However, it is challenging to produce cellulose nanofibers from agroindustry waste with good techno-functional properties, without the use of harsh process conditions. Green alternatives (eco-friendly) have been studied to obtain nanofibers, such as enzymatic hydrolysis and/or application of mechanical processes. In this work, we used acid hydrolysis (as a control and example of an efficient method), enzymatic hydrolysis and a mechanical process (ultrasound) to obtain cellulose nanofibers. We also evaluated the effect of the presence of ethyl groups in the cellulosic matrix (ethylcellulose) on the stabilizing mechanism of emulsions. All cellulose nanofibers were able to produce Pickering emulsions at concentrations of 0.01-0.05% (w/w), although showing differences in emulsion stability and digestibility. Morphology of the different cellulose nanofibers affected the viscosity of the aqueous suspensions used as continuous phase. Emulsions with nanofibers obtained from cassava peel (without the presence of ethyl groups) were stabilized only by the Pickering-type mechanism, while ethylcellulose nanofibers also showed surface activity that contributed to the stability of the emulsion. Furthermore, these latter emulsions showed greater release of free fatty acids in in vitro digestion compared to emulsions stabilized by cellulose nanofibers. Despite these differences, in vitro digestion showed the potential of applying cellulose-stabilized emulsions to control the rate of lipid digestion, due to the low amount of free fatty acids released (<20%).

Biomedical applications of natural and synthetic polymer based nanocomposites

Various nanomaterials have been studied for their biomedical application in recent years. Among them, nanocomposites have a prominent medical application in the prevention, diagnosis, and treatment of various diseases. Nanocomposites are made up of polymeric matrix layers composed of synthetic or natural polymers like chitosan, polyethylene glycol, etc. Polymer nanocomposites are inorganic nanoparticles dispersed in a polymer matrix. There are two types of polymeric nanocomposites which include natural and synthetic polymer nanocomposites. These nanocomposites have various biomedical applications, such as medical implants, wound healing, wound dressing, bone repair and replacement, and dental filling. Polymeric nanocomposites have a wide range of biomedical applications due to their high stability, non-immunogenic nature, sustained drug delivery, non-toxic, and can escape reticuloendothelial system uptake along with drug bioavailability improvement. In this review, we have discussed various types of natural and synthetic polymer nanocomposites and their biomedical applications.

Modified Biomass-Reinforced Polylactic Acid Composites

Polylactic acid (PLA), as a renewable and biodegradable green polymer material, is hailed as one of the most promising biopolymers capable of replacing petroleum-derived polymers for industrial applications. Nevertheless, its limited toughness, thermal stability, and barrier properties have restricted its extensive application. To address these drawbacks in PLA, research efforts have primarily focused on enhancing its properties through copolymerization, blending, and plasticization. Notably, the blending of modified biomass with PLA is expected not only to effectively improve its deficiencies but also to maintain its biodegradability, creating a fully green composite with substantial developmental prospects. This review provides a comprehensive overview of modified biomass-reinforced PLA, with an emphasis on the improvements in PLA's mechanical properties, thermal stability, and barrier properties achieved through modified cellulose, lignin, and starch. At the end of the article, a brief exploration of plasma modification of biomass is presented and provides a promising outlook for the application of reinforced PLA composite materials in the future. This review provides valuable insights regarding the path towards enhancing PLA.

Green Preparation and Functional Properties of Reinforced All-Cellulose Membranes Made from Corn Straw

In this study, all-cellulose nanocomposite (ACNC) was successfully prepared through a green and sustainable approach by using corn stalk as raw material, water as regeneration solvent, and recyclable two-component ionic liquid/DMSO as the solvent to dissolve cellulose. The morphology and structural properties of ACNC were determined by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis, indicating homogeneity and good crystallinity. In addition, a comprehensive characterization of ACNC showed that CNF not only improved the thermal stability and mechanical characteristics of ACNC, but also significantly improved the oxygen barrier performance. The ACNC prepared in this work has a good appearance, smooth surface, and good optical transparency, which provides a potential application prospect for converting cellulose wastes such as corn straws into biodegradable packaging materials and electronic device encapsulation materials.

Oriented bacterial cellulose microfibers with tunable mechanical performance fabricated via green reassembly avenue

Bacterial cellulose has garnered remarkable interest from researchers, particularly those working in the biomedical field. In this work, BC microfibers were fabricated via green dissolution (ZnCl2) and regeneration (ethanol). The orientation of cellulose chains was investigated during extrusion and simple post-processing via polarized optical microscopy and small-angle X-ray scattering. The results implied that the mechanical properties of BC microfibers can be tuned by rational pre-stretching. The BC microfibers can be programmable, and be used to suture hard or soft tissues. The as-designed paralleled BC microfibers have good biocompatibility and can regulate the directional growth of cells on their surface. The as-obtained BC microfiber with a high tensile strength of up to ∼115 MPa is suitable for surgical sutures. The tunable BC microfibers may be utilized as an adequate fiber-derived biomedical material product.

Recent advances in cellulose-based sustainable materials for wastewater treatment: An overview

Water pollution presents a significant challenge, impacting ecosystems and human health. The necessity for solutions to address water pollution arises from the critical need to preserve and protect the quality of water resources. Effective solutions are crucial to safeguarding ecosystems, human health, and ensuring sustainable access to clean water for current and future generations. Generally, cellulose and its derivatives are considered potential substrates for wastewater treatment. The various cellulose processing methods including acid, alkali, organic & inorganic components treatment, chemical treatment and spinning methods are highlighted. Additionally, we reviewed effective use of the cellulose derivatives (CD), including cellulose nanocrystals (CNCs), cellulose nano-fibrils (CNFs), CNPs, and bacterial nano-cellulose (BNC) on waste water (WW) treatment. The various cellulose processing methods, including spinning, mechanical, chemical, and biological approaches are also highlighted. Additionally, cellulose-based materials, including adsorbents, membranes and hydrogels are critically discussed. The review also highlighted the mechanism of adsorption, kinetics, thermodynamics, and sorption isotherm studies of adsorbents. The review concluded that the cellulose-derived materials are effective substrates for removing heavy metals, dyes, pathogenic microorganisms, and other pollutants from WW. Similarly, cellulose based materials are used for flocculants and water filtration membranes. Cellulose composites are widely used in the separation of oil and water emulsions as well as in removing dyes from wastewater. Cellulose's natural hydrophilicity makes it easier for it to interact with water molecules, making it appropriate for use in water treatment processes. Furthermore, the materials derived from cellulose have wider application in WW treatment due to their inexhaustible sources, low energy consumption, cost-effectiveness, sustainability, and renewable nature.

Strong, Lightweight, and Shape-Memory Bamboo-Derived All-Cellulose Aerogels for Versatile Scaffolds of Sustainable Multifunctional Materials

Strong, lightweight, and shape-memory cellulose aerogels have great potential in multifunctional applications. However, achieving the integration of these features into a cellulose aerogel without harsh chemical modifications and the addition of mechanical enhancers remains challenging. In this study, a strong, lightweight, and water-stimulated shape-memory all-cellulose aerogel (ACA) is created using a combination strategy of partial dissolution and unidirectional freezing from bamboo. Benefiting from the firm architecture of cellulose microfibers bridging cellulose nanofibers /regenerated cellulose aggregated layers and the bonding of different cellulose crystal components (cellulose Iβ and cellulose II), the ACA, with low density (60.74 mg cm-3 ), possesses high compressive modulus (radial section: 1.2 MPa, axial section: 0.96 MPa). Additionally, when stimulated with water, the ACA exhibits excellent shape-memory features, including highly reversible compression-resilience and instantaneous fold-expansion behaviors. As a versatile scaffold, ACA can be integrated with hydroxyapatite, carboxyl carbon nanotubes, and LiCl, respectively, via a simple impregnation method to yield functionalized cellulose composites for applications in thermal insulation, electromagnetic interference shielding, and piezoresistive sensors. This study provides inspiration and a reliable strategy for the elaborately structural design of functional cellulose aerogels endows application prospects in various multifunction opportunities.

Modification of nanocellulose via atom transfer radical polymerization and its reinforcing effect in waterborne UV-curable resin

Cellulose nanocrystals (CNCs) are green reinforcing materials, and their potential has been evaluated in the preparation of waterborne UV-curable resin composites with high-performance. Herein, we present a novel and scalable approach for preparing surface-modified CNCs with acrylic-based polymers to strengthen the compatibility and interaction between CNCs and UV-curable resins. Using tert-butyl acrylate as the monomer, the nanocellulose grafted copolymer CNC-g-PtBA was successfully synthesized via atom transfer radical polymerization (ATRP) in the presence of a macromolecular initiator. Then, the CNC-g-PtBA is blended into the acrylic resin as a nanofiller to prepare the UV-curable nanocomposite. The results indicated that the contact angle of the CNCs increased from 38.7° to approximately 74.8°, and their thermal stability was significantly improved after graft modification. This contributed to the effective alleviation of the agglomeration phenomenon of nanocomposites due to the high hydrophilicity of pure CNCs. Notably, not only was the UV curing efficiency of the nanocomposites greatly increased but the mechanical properties were also further enhanced. Specifically, with the addition of 0.5 wt% CNC-g-PtBA, the curing time of the nanocomposite was shortened from >30 mins down to approximately 6 mins, and the bending strength was increased from 10 MPa for the original resin and 5 MPa for the addition of pure CNCs to 14.3 MPa, and the bending modulus was also greatly increased (up to approximately 730 MPa). Compared to pure CNCs, they are compatible with the resin, exhibiting high mechanical strength and flexibility, and have virtually no effect on the light transmission of the nanocomposites. Additionally, dielectric analysis (DEA) was used to monitor the dielectric constant and conductivity of the UV-curable nanocomposites in real time to further characterize their curing kinetics. The permittivity of these nanocomposites increased by 125 % compared to pristine resin, which shows potential for applications in high dielectric composites or for improving electrical conductivity. This work provides a feasible method for preparing UV-curable nanocomposites with high curing efficiency and permittivity, realizing a wider application of this high-performance nanocomposite.

Superhydrophilic and Underwater Superoleophobic Copper Mesh Coated with Bamboo Cellulose Hydrogel for Efficient Oil/Water Separation

Super-wetting interface materials have shown great potential for applications in oil-water separation. Hydrogel-based materials, in particular, have been extensively studied for separating water from oily wastewater due to their unique hydrophilicity and excellent anti-oil effect. In this study, a superhydrophilic and underwater superoleophobic bamboo cellulose hydrogel-coated mesh was fabricated using a feasible and eco-friendly dip-coating method. The process involved dissolving bamboo cellulose in a green alkaline/urea aqueous solvent system, followed by regeneration in ethanol solvent, without the addition of surface modifiers. The resulting membrane exhibited excellent special wettability, with superhydrophilicity and underwater superoleophobicity, enabling oil-water separation through a gravity-driven "water-removing" mode. The super-wetting composite membrane demonstrated a high separation efficiency of higher than 98% and a permeate flux of up to 9168 L·m-2·h-1 for numerous oil/water mixtures. It also maintained a separation efficiency of >95% even after 10 cycles of separation, indicating its long-term stability. This study presents a green, simple, cost-effective, and environmentally friendly approach for fabricating superhydrophilic surfaces to achieve oil-water separation. It also highlights the potential of bamboo-based materials in the field of oil-water separation.

A hybrid microcrystalline cellulose/metal-organic framework for dispersive solid phase microextraction of selected pharmaceuticals: A proof-of-concept

Solid phase microextraction (SPME) is considered simple, ecofriendly, sustainable, cost-effective and timesaving sample preparation mode in comparison with other sample preparation procedures. The researchers always try to develop new sorbents with higher surface area in comparison with other conventional sorbents aiming to enhance the extraction efficiency. In this work for the first time, a comparative study was performed between Ca-BTC MOF (1,3,5-benzenetricarboxylic acid, BTC; metal-organic framework, MOF) and a hybrid Ca-BTC-MCC MOF (microcrystalline cellulose, MCC) by using as model compounds seven drugs with different physicochemical properties. The evaluation of the extraction efficiency of both sorbents were obtained by means of an HPLC/DAD instrument configuration in reversed phase mode under isocratic elution mode. The results indicate that Ca-BTC MOF showed superior extraction efficiency than Ca-BTC-MCC MOF in the case of all analytes except nirmatrelvir and ritonavir. The results highlight that not only the surface area of adsorbents controlled the adsorption capacity, but also other factors have a role in extraction efficiency including morphology of adsorbent and physico-chemical properties of the analytes. It is worth mentioning that this is the first time that a comparative study was performed between Ca-BTC MOF and Ca-BTC-MCC MOF hybrid material.

Microplastics in marine-derived traditional Chinese medicine, potential threat to patients

Microplastics (MPs) contamination is widely found in marine organisms. Marine traditional Chinese medicines (MTCM) are derived from marine organisms, but there are no relevant reports on detecting MPs in MTCM. This study selected samples of MTCM from two representative pharmaceutical companies, Brand F and Brand Z, including mother-of-pearl, stone cassia, seaweed, pumice, oyster, kombu, calcined Concha Arcae, cuttlebone, and clam shell to detect and analyze the presence of MPs. The abundance, type, color, size, and composition of MPs were investigated. Varying degrees of MPs contamination was present in all MTCM. The abundance of MPs in different MTCM ranged from 0.07 to 9.53 items/g. Their type, color, and size are similar, mainly fiber, transparent and size <2 mm. The composition of MPs is primarily made of cotton, cellulose and rayon. This study contributes to the first record of MPs in MTCM. Our results show that microplastic pollution is common in MTCM, which may cause potential risk to patients consuming MTCM.

Cellulose Fibers-Based Porous Lightweight Foams for Noise Insulation

This paper examines effective and environmentally friendly materials intended for noise insulation and soundproofing applications, starting with materials that have gained significant attention within last years. Foam-formed materials based on cellulose fibers have emerged as a promising solution. The aim of this study was to obtain a set of foam-formed, porous, lightweight materials based on cellulose fibers from a resinous slurry pulp source, and to investigate the impact of surfactant percentage of the foam mixtures on their noise insulation characterisitcs. The basic foam-forming technique was used for sample assembly, with three percentages of sodium dodecyl sulphate (as anionic surfactant) related to fiber weight, and a standardised sound transmission loss tube procedure was used to evaluate noise insulation performance. Results were obtained as observations of internal structural configurations and material characteristics, and as measurements of sound absorption/reflection, sound transmission loss, and surface acoustic impedance. Based on the findings within this study, the conclusions highlight the strong potential of these cellulosic foams to replace widely used synthetic materials, at least into the area of practical noise insulation applications.

Valorisation of crude glycerol in the production of liquefied lignin bio-polyols for polyurethane formulations

Bio-polyols, produced by liquefying lignin with polyhydric alcohols, offer a promising alternative to conventional polyols for polyurethane production. To enhance the sustainability on the production of these bio-polyols, this study proposes the use of crude glycerol and microwave-assisted liquefaction as substitutes for conventional methods and commercial glycerol. This approach reduces the energy requirements of the reaction while also adding value to this by-product. The synthesis of bio-polyols with suitable properties to produce elastic and rigid polyurethane was carried out using previously optimised reaction conditions. Organosolv lignins obtained from Eucalyptus globulus and Pinus radiata were employed, using polyethylene glycol and crude glycerol as solvents and sulphuric acid as a catalyst. Several parameters of the bio-polyols were analysed, including hydroxyl number (IOH), acid number (An), and functionality (f), suggesting that the bio-polyols were suitable for polyurethane synthesis. Bio-polyols formulated to produce rigid polyurethanes exhibited IOH values of 554 and 383 (mg KOH/g), An values of 1.91 and 4.21 (mg KOH/g), and functionalities of 4.16 and 3.14 for Eucalyptus globulus and Pinus radiata lignin. In the case of bio-polyols for elastic polyurethanes, the values were 228 and 173 (mg KOH/g) (IOH), 20.94 and 25.09 (mg KOH/g) (An), and functionalities of 3.51 and 2.08.

Polypyrrole-Modified Nanocellulose Exhibits Superior Performance for Hg(II) Adsorption

Cellulose, a kind of polymer containing abundant functional groups, has widespread use in the adsorptive removal of environmental pollutants. An efficient and environmental friendly polypyrrole (PPy) coating approach is employed to modify the agricultural by-product straw derived cellulose nanocrystal (CNC) into excellent property adsorbents for removing the heavy metal ion of Hg(II). The FT-IR and SEM-EDS results demonstrated that PPy is formed on the surface of CNC. Consequently, the adsorption measurements proved that the obtained PPy-modified CNC (CNC@PPy) possesses a remarkably enhanced Hg(II) adsorption capacity of 1095 mg g^-1, owing to a plentiful functional group of doped Cl element on the surface of CNC@PPy by forming Hg₂Cl₂ precipitate. The results of the study suggest that the Freundlich model is more effective than the Langmuir model at describing the isotherms, while the pseudo-second order kinetic model is better suited to correlating with the experimental data compared to the pseudo-first order model. Further, the CNC@PPy exhibits an outstanding reusability, capable of maintaining 82.3% of its original Hg(II) adsorption capacity after five successive adsorption cycles. The findings of this work reveal a method to convert the agricultural by-product into high performance environmental remediation materials.

Challenges associated with cellulose composite material: Facet engineering and prospective

Cellulose is the most abundant polysaccharide on earth. It has a large number of desirable properties. Its low toxicity makes it more useful for a variety of applications. Nowadays, its composites are used in most engineering fields. Composite consists of a polymer matrix and use as a reinforcing material. By reducing the cost of traditional fibers, it has an increasing demand for environment-friendly purposes. The use of these types of composites is inherent in moisture absorption with hindered natural fibers. This determines the reduction of polymer composite material. By appropriate chemical surface treatment of cellulose composite materials, the effect could be diminished. The most modern and advanced techniques and methods for the preparation of cellulose and polymer composites are discussed here. Cellulosic composites show a reinforcing effect on the polymer matrix as pointed out by mechanical characterization. Researchers tried their hard work to study different ways of converting various agricultural by-products into useful eco-friendly polymer composites for sustainable production. Cellulose plays building blocks, that are critical for polymer products and their engineering applications. The most common method used to prepare composites is in-situ polymerization. This help to increase the yields of cellulosic composites with a significant enhancement in thermal stability and mechanical properties. Recently, cellulose composites used as enhancing the incorporation of inorganic materials in multi-functional properties. Furthermore, we have summarized in this review the potential applications of cellulose composites in different fields like packaging, aerogels, hydrogels, and fibers.

Development of water-resistant paper using chitosan and plant-based wax extracted from banana leaves

On being exposed to water, cellulose paper swells and its mechanical properties become weak. In this study, natural wax with an average particle size of 12.3 μm extracted from banana leaves was mixed with chitosan to prepare coatings applied on paper surfaces. Chitosan efficiently dispersed banana leaf-extracted wax on paper surfaces. The mixed chitosan and wax coatings considerably influenced paper properties, including yellowness, whiteness, thickness, wettability, water and oil sorption, and mechanical properties. The coating induced hydrophobicity in the paper, resulting in a significant increase in the water contact angle from 65.1 ± 7.7° (uncoated paper) to 123.2 ± 2.1°, and a decrease in water absorption by ⁓64 % to 52.6 ± 1.9 %. The coated paper demonstrated an oil sorption capacity of 212.2 ± 2.8 %, which was ⁓43 % greater than that of the uncoated paper, and the tensile strength of the coated paper improved by 43 % under wet conditions compared to the uncoated paper. Additionally, a separation of oil in water was observed for the chitosan/wax coated paper. Based on these promising results, the paper coated with chitosan and wax could be used for direct-contact packaging applications.

Fibrous Aerogels with Tunable Superwettability for High-Performance Solar-Driven Interfacial Evaporation

Solar-driven interfacial evaporation is an emerging technology for water desalination. Generally, double-layered structure with separate surface wettability properties is usually employed for evaporator construction. However, creating materials with tunable properties is a great challenge because the wettability of existing materials is usually monotonous. Herein, we report vinyltrimethoxysilane as a single molecular unit to hybrid with bacterial cellulose (BC) fibrous network, which can be built into robust aerogel with entirely distinct wettability through controlling assembly pathways. Siloxane groups or carbon atoms are exposed on the surface of BC nanofibers, resulting in either superhydrophilic or superhydrophobic aerogels. With this special property, single component-modified aerogels could be integrated into a double-layered evaporator for water desalination. Under 1 sun, our evaporator achieves high water evaporation rates of 1.91 and 4.20 kg m-2 h-1 under laboratory and outdoor solar conditions, respectively. Moreover, this aerogel evaporator shows unprecedented lightweight, structural robustness, long-term stability under extreme conditions, and excellent salt-resistance, highlighting the advantages in synthesis of aerogel materials from the single molecular unit.

Facile preparation of all cellulose composite with excellent mechanical and antibacterial properties via partial dissolution of corn-stalk biomass

All-cellulose composite (ACC) was directly fabricated by the partial-dissolution welding of cellulose microfibers from agro-residual corn stalks treated with low-concentration ZnCl₂ solvent (10-40 %). The solvent infiltrated deeply into nano/micro-scaled pores of cellulose fibers to facilitate the free migration of the disordered chains among the cellulose network while leaving the fiber core undissolved. Then, these disordered chains would entangle and regenerate to serve as a welded layer to bond the undissolved microfibril core in the solvent removal process. Such welding achieved exceptional mechanical (the tensile strength and Young's modulus of 49.9 MPa and 6.6 GPa, respectively), antibacterial (log removal value (LRV) of 4.8 and 3.0 for E. coli and S. aureus, respectively) and biodegradable properties of the multifunctional ACCs. It is worthwhile noting that the excellent antimicrobial effect is attributed to the sufficient contact of these microbes with ZnO NPs that were converted from the residual Zn²⁺ in ACCs. After five recycling processes, the elimination efficiency could still maintain a high LRV of 2.0-3.8. This high durability of ACC microbicidal activity was originated from strong twining interactions of cellulosic fibrils with in-situ synthesized ZnO NPs. This strategy was proven to be a facile and economical pathway to fabricate functional all-cellulose composites.

Polysaccharides for Medical Technology: Properties and Applications

Over the past decade, the use of polysaccharides has gained tremendous attention in the field of medical technology. They have been applied in various sectors such as tissue engineering, drug delivery system, face mask, and bio-sensing. This review article provides an overview and background of polysaccharides for biomedical uses. Different types of polysaccharides, for example, cellulose and its derivatives, chitin and chitosan, hyaluronic acid, alginate, and pectin are presented. They are fabricated in various forms such as hydrogels, nanoparticles, membranes, and as porous mediums. Successful development and improvement of polysaccharide-based materials will effectively help users to enhance their quality of personal health, decrease cost, and eventually increase the quality of life with respect to sustainability.

Reengineering Waste Boxwood Powder into Light and High-Strength Biodegradable Composites to Replace Petroleum-Based Synthetic Materials

The preparation of biocomposites from renewable and sustainable forestry residues is an effective method to significantly reduce the environmental pollution caused by synthetic materials such as plastics and synthetic fibers. This study is aimed at developing a clean process for the large-scale production of high-performance green biocomposites without involving any chemical adhesive. Adhesive-free biocomposites with superior mechanical properties were prepared using HCl ball milling pretreatment and in situ synthesis. The nano-Fe₃O₄ was uniformly dispersed in the cellulose matrix, and when the matrix was subjected to external forces, the stress concentration effect around the particles absorbed energy, thus effectively improving the mechanical strength of the matrix. The flexural strength and tensile strength of BWP(Fe₃O₄) samples were increased by 159.04 and 175.34%, compared to that of regular wood powder control samples. The lignin melts under high temperature and pressure and then forms a carbonized layer on the surface of the biocomposites during the cooling process, which prevents the rapid penetration of water from the surface and also gives the biocomposites good thermal stability. The results of this research can avoid the harmful volatiles generated by chemical adhesive than that of the traditional fiberboard process and effectively replace petroleum-based synthetic materials prepared using the addition of various chemical additives, making it conform to the concept of environmental protection and sustainability.

Intelligent temperature-pH dual responsive nanocellulose hydrogels and the application of drug release towards 5-fluorouracil

As the typical bio-macromolecules, cellulose and its derivates are widely studied due to the fact that they are green and renewable resources in nature. In this work, intelligent temperature-pH sensitive nanohydrogels consisting of nanocellulose, thermal responsive monomer (N-isopropylacrylamide, NIPAM), and pH responsive monomer (acrylic acid, AA; acrylamide, AM) were prepared [NFC-g-(AA/AM)]-g-NIPAM, the [NFC-g-(AA/AM)]-g-NIPAM was characterized by FTIR, scanning electron microscope (SEM), thermogravimetric analysis (TGA) and automatic gas adsorption analysis (BET). The results showed that the copolymerization of AA, AM and NIPAM were carried out successfully. The specific surface area, total pore volume, average pore diameter and thermal stability of the modified nano-cellulose were increased. In addition, the as-prepared nanohydrogels with 5-fluorouracil (5-FU) released more 5-FU at 40 °C and acidic condition compared to the room temperature and neutral pH, showing the characteristics of the temperature-PH dual response functionalization. The [NFC-g-(AA/AM)]-g-NIPAM have been proved to be the promising drug release nanohydrogels towards 5-FU, and the valuable findings might provide an idea for maximizing the potential of the nanocellulose-based nanohydrogels for the application of environmental pollution control.

Green Preparation of Durian Rind-Based Cellulose Nanofiber and Its Application in Aerogel

In this study, a green, highly efficient and low energy consumption preparation method of cellulose nanofiber (CNF) was developed by using agricultural and forestry waste durian rinds as raw materials. The power of ultrasonic treatment was successfully reduced to only 360 W with low molecular weight liquid DMSO. The obtained durian rind-based CNF had a diameter of 8–20 nm and a length of several micrometers. It had good dispersion and stability in water, and could spontaneously cross-link to form hydrogel at room temperature when the concentration was more than 0.5%. The microscopic morphology and compressive properties of CNF aerogels and composite cellulose aerogels prepared from durian rind-based CNF were evaluated. It was found that CNF could effectively prevent the volume shrinkage of aerogel, and the concentration of CNF had a significant effect on the microstructure and mechanical properties of aerogel. The CNF aerogel with 1% CNF exhibited a sheet structure braced by fibers, which had the strongest compression performance. The porosity of CNF aerogels was high to 99%. The compressive strength of the composite cellulose aerogel with durian rind-based CNF was effectively enhanced.

All-Cellulose Composite Laminates Made from Wood-Based Textiles: Effects of Process Conditions and the Addition of TEMPO-Oxidized Nanocellulose

All-cellulose composites (ACCs) are manufactured using only cellulose as a raw material. Biobased materials are more sustainable alternatives to the petroleum-based composites that are used in many technical and life-science applications. In this study, an aquatic NaOH-urea solvent system was used to produce sustainable ACCs from wood-based woven textiles with and without the addition of TEMPO-oxidized nanocellulose (at 1 wt.-%). This study investigated the effects of dissolution time, temperature during hot press, and the addition of TEMPO-oxidized nanocellulose on the mechanical and thermal properties of the composites. The results showed a significant change in the tensile properties of the layered textile composite at dissolution times of 30 s and 1 min, while ACC elongation was the highest after 2 and 5 min. Changes in hot press temperature from 70 °C to 150 °C had a significant effect: with an increase in hot press temperature, the tensile strength increased and the elongation at break decreased. Incorporating TEMPO-oxidized nanocellulose into the interface of textile layers before partial dissolution improved tensile strength and, even more markedly, the elongation at break. According to thermal analyses, textile-based ACCs have a higher storage modulus (0.6 GPa) and thermal stabilization than ACCs with nanocellulose additives. This study highlights the important roles of process conditions and raw material characteristics on the structure and properties of ACCs.

Bio-Nanocomposite Based on Edible Gelatin Film as Active Packaging from Clarias gariepinus Fish Skin with the Addition of Cellulose Nanocrystalline and Nanopropolis

This study develops bio-nano composite gelatin-based edible film (NEF) by combining nanogelatin, cellulose nanocrystal (CNC), and nanopropolis (NP) fillers to improve the resulting film characteristics. The NEF was characterized in terms of thickness, swelling, pH, water content, solubility, vapor and oxygen permeability, mechanical properties, heat resistance, morphology, transparency, and color. The results showed that the thickness and swelling increased significantly, whilst the pH did not significantly differ in each treatment. The water content and the water solubility also showed no significant changes with loadings of both fillers. At the same time, vapor and oxygen permeability decreased with addition of the fillers but were not significantly affected by the loading amounts. The heat resistance properties increased with the filler addition. Tensile strength and Young’s modulus increased for the films loaded with >3% CNC. The elongation at break showed a significant difference together with transparency and color change. The greater the CNC concentration and NP loading were, the darker the resulting transparency and the color of the NEF. Overall results show a considerable improvement in the properties of the resulting NEFs with the incorporation of CNC and NP fillers.

A hybrid biocomposite of Thamnidium elegans/olive pomace/chitosan for efficient bioremoval of toxic copper

Immobilized biomaterials have recently attracted researchers' attention in the field of environmental biotechnology due to their effective biosorption performances. In this respect, a novel hybrid biocomposite based on Thamnidium elegans cells, olive pomace, and chitosan (TE-OP@C) was produced and tested for the first time to remove a target pollutant. It was successfully employed to eliminate toxic Cu (II) ions. Uptake efficiency of the biocomposite was significantly greater than that of T. elegans and T. elegans-olive pomace, despite the much lesser amount of biocomposite used. Freundlich model best fitted the equilibrium data, and the pseudo-second-order kinetic model followed uptake. The maximum removal efficiencies in batch and continuous systems were determined to be 96 % and 98 %, respectively. After eight cycles, the biosorption and recovery efficiencies of TE-OP@C were higher than 90 %. Biocomposite was able to remove approximately 90 % and 88 % of Cu(II) from real wastewater in batch and continuous systems, respectively. FTIR analysis, zeta potential measurements, EDX, and SEM findings confirmed the Cu(II) uptake. XRD and BET analysis were also performed for biocomposite characterization. Breakthrough and exhausted points were determined as 80 and 150 min, respectively. The findings potentially lead to a new perspective for the treatment of copper contamination.

The Improved Properties of Carboxymethyl Bacterial Cellulose Films with Thickening and Plasticizing

This study aims to improve the thermal stability and mechanical properties of carboxymethyl bacterial cellulose (CMBC) composite films. Experiments were conducted by preparing bacterial cellulose (BC) into CMBC, then parametrically mixing sodium alginate/starch/xanthan gum/gelatin and glycerin/sorbitol/PEG 400/PEG 6000 with CMBC to form the film. Scanning electron microscopy, X-ray diffractometry, infrared spectroscopy, mechanical tests, and thermogravimetric analysis showed that the composite films had better mechanical properties and thermal stability with the addition of 1.5% CMBC (% v/v), 1% sodium alginate, and 0.4% glycerin. Tensile strength was 38.13 MPa, the elongation at break was 13.4%, the kinematic viscosity of the film solution was 257.3 mm²/s, the opacity was 4.76 A/mm, the water vapor permeability was 11.85%, and the pyrolysis residue was 45%. The potential causes for the differences in the performance of the composite films were discussed and compared, leading to the conclusion that CMBC/Sodium alginate (SA)/glycerin (GL) had the best thermal stability and mechanical properties.

Magnetic porous cellulose surface-imprinted polymers synthetized with assistance of deep eutectic solvent for specific recognition and purification of bisphenols

Magnetic porous cellulose molecularly imprinted polymers-based bisphenols have been developed using Fe₃O₄ as the magnetic material, a deep eutectic solvent as the assisted solvent, and N-isopropylacrylamide as the functional monomer. The resulting magnetic porous cellulose molecularly imprinted polymers were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometry, thermal gravimetric analysis, and Brunauer-Emmett-Teller analysis. Moreover, the adsorption properties of the magnetic porous cellulose molecularly imprinted polymers toward bisphenol A, bisphenol F, and bisphenol AF were investigated using static, dynamic, and selective adsorption experiments. The introduction of porous cellulose materials significantly improves the capabilities of the material. The adsorption capacity, mass transfer efficiency, and selectivity of the magnetic porous cellulose molecularly imprinted polymers toward bisphenol A were 5.9, 4.0, and 4.4 times those of traditional molecularly imprinted polymers. Moreover, the adsorption stability of the magnetic porous cellulose molecularly imprinted polymers was investigated under different temperature and pH conditions. The adsorption characteristics of the magnetic porous cellulose molecularly imprinted polymers toward the target molecules were investigated using adsorption isotherm, kinetic, and thermodynamic models. Hydrogen bonding is the main interaction formed between the magnetic porous cellulose molecularly imprinted polymers and the target molecules. Magnetic porous cellulose molecularly imprinted polymers have great application value with excellent stability and reusability. Finally, the combination of the magnetic porous cellulose molecularly imprinted polymers and high-performance liquid chromatography or ultra-performance liquid chromatography-mass spectrometry was successfully used for the purification and detection of bisphenols in milk (1.349 ng/mL bisphenol F and 3.014 ng/mL bisphenol AF), canned fruits (1129 ng/mL bisphenol A, 10.11 ng/mL bisphenol F, and 91.87 ng/mL bisphenol AF), and fish (11.91 ng/mL bisphenol AF) samples. Furthermore, the magnetic porous cellulose molecularly imprinted polymer method is more selective, sensitive, and accurate than the traditional precipitation method.

Chitosan coating for the preparation of multilayer coated paper for food-contact packaging: Wettability, mechanical properties, and overall migration

Cellulose-based paper is an alternative substitution for petroleum-based polymers for packaging applications, but its mechanical performance is poor when in contact with water. Herein, chitosan was applied on cellulose-based paper via a coating approach. The effects of chitosan coatings between none and five layers on the color properties, wettability, thermal properties, mechanical performance, and overall migration in food simulants of the paper were evaluated. After the application of chitosan, chitosan first filled cavities between cellulose fibers within a network, and the chitosan film was formed on the paper surface later. This resulted in a pronounced increase in wettability and mechanical properties associated with a loss of whiteness and an increase in yellowness of the coated paper. The chitosan-coated paper became hydrophobic with a water contact angle of 94.7 ± 2.8°, and a robust improvement of 156.4% for tensile strength and 114.8% for strain at break was observed for the paper coated with three layers of chitosan in wet conditions in comparison to the uncoated paper. A reduction in the migration of the low molecular residuals from the paper could be hindered by the chitosan coating. These enhanced features revealed that chitosan-coated paper could be used as a food-contact material.

Superabsorbent cellulose-based hydrogels cross-liked with borax

Cellulose, the most abundant biopolymer on Earth, has been widely attracted owing to availability, intoxicity, and biodegradability. Environmentally friendly hydrogels were successfully prepared from water hyacinth-extracted cellulose using a dissolution approach with sodium hydroxide and urea, and sodium tetraborate decahydrate (borax) was used to generate cross-linking between hydroxyl groups of cellulose chains. The incorporation of borax could provide the superabsorbent feature into the cellulose hydrogels. The uncross-linked cellulose hydrogels had a swelling ratio of 325%, while the swelling ratio of the cross-linked hydrogels could achieve ~ 900%. With increasing borax concentrations, gel fraction of the cross-linked hydrogels increased considerably. Borax also formed char on cellulose surfaces and generated water with direct contact with flame, resulting in flame ignition and propagation delay. Moreover, the cross-linked cellulose-based hydrogels showed antibacterial activity for gram-positive bacteria (S. aureus). The superabsorbent cross-linked cellulose-based hydrogels prepared in this work could possibly be used for wound dressing, agricultural, and flame retardant coating applications.

Poly(3-hydroxybutyrate) Nanocomposites with Cellulose Nanocrystals

Poly(3-hydroxybutyrate) (PHB) is one of the most promising substitutes for the petroleum-based polymers used in the packaging and biomedical fields due to its biodegradability, biocompatibility, good stiffness, and strength, along with its good gas-barrier properties. One route to overcome some of the PHB’s weaknesses, such as its slow crystallization, brittleness, modest thermal stability, and low melt strength is the addition of cellulose nanocrystals (CNCs) and the production of PHB/CNCs nanocomposites. Choosing the adequate processing technology for the fabrication of the PHB/CNCs nanocomposites and a suitable surface treatment for the CNCs are key factors in obtaining a good interfacial adhesion, superior thermal stability, and mechanical performances for the resulting nanocomposites. The information provided in this review related to the preparation routes, thermal, mechanical, and barrier properties of the PHB/CNCs nanocomposites may represent a starting point in finding new strategies to reduce the manufacturing costs or to design better technological solutions for the production of these materials at industrial scale. It is outlined in this review that the use of low-value biomass resources in the obtaining of both PHB and CNCs might be a safe track for a circular and bio-based economy. Undoubtedly, the PHB/CNCs nanocomposites will be an important part of a greener future in terms of successful replacement of the conventional plastic materials in many engineering and biomedical applications.

Recent Advancements in MOF/Biomass and Bio-MOF Multifunctional Materials: A Review

Metal–organic frameworks (MOFs) and their derivatives have delivered perfect answers in detection, separation, solving water and electromagnetic pollution and improving catalysis and energy storage efficiency due to their advantages including their highly tunable porosity, structure and versatility. Recently, MOF/biomass, bio-MOFs and their derivatives have gradually become a shining star in the MOF family due to the improvement in the application performance of MOFs using biomass and biomolecules. However, current studies lack a systematic summary of the synthesis and advancements of MOF/biomass, bio-MOFs and their derivatives. In this review, we describe their research progress in detail from the following two aspects: (1) synthesis of MOF/biomass using biomass as a template to achieve good dispersion and connectivity at the same time; (2) preparing bio-MOFs by replacing traditional organic linkers with biomolecules to enhance the connection stability between metal ions/clusters and ligands and avoid the formation of toxic by-products. This enables MOFs to possess additional unique advantages, such as improved biocompatibility and mechanical strength, ideal reusability and stability and lower production costs. Most importantly, this is a further step towards green and sustainable development. Additionally, we showcase some typical application examples to show their great potential, including in the fields of environmental remediation, energy storage and electromagnetic wave absorption.