Given the demand for plastic products, solving the problem of plastic waste is urgent. To alleviate this, biodegradable plastics are replacing conventional plastics; however, their biodegradation rates are often low. While engineering plastics with low-surface-energy silicon-containing lubricants provide broad liquid repellency, the limited moisture permeability slows biodegradation. A long-standing challenge is to combine the conflicting requirements of waterproofness and breathability within a single platform. Here, for the first time, we propose a new class of self-lubricative, omniphobic, covalently attached liquid coating that harnesses the dual mechanisms of both physical and chemical cross-linking. This coating was achieved by the cohydrolysis and co-condensation of linear polydimethylsiloxane (PDMS) blocks and silicone oil onto noncommercial plastics via a facile, cost-effective, and industrially feasible spray-coating technique. The superior smoothness and the interfacial slippage arising from the synergistic lubrication effects between the PDMS and silicone oil enable a wide range of both polar and nonpolar liquids to slide easily. Diffusion of silicone oil into the porous PDMS skeleton improved the breathability (180 g m-2 per day) and led to pronounced biodegradation (33% mass loss in 10 weeks). This work provides proof-of-concept data for constructing biodegradable coatings on plastics, which may have significant applications in biomedical settings.

Uncrewed Aerial Vehicles (UAVs) offer a promising solution for efficient and cost-effective reforestation, particularly on challenging terrains inaccessible by traditional methods. This study explores soft hydrogel technology as a seed encapsulant for UAV dispersal, emphasizing criteria such as on-site preparation feasibility, a limited (5-hour) processing window, and deployment capabilities from a UAV at 3 m height. The research utilising a Psyllium Husk Mucilage (PHM) hydrogel was deemed to be impractical due to rapid degradation and prolonged stabilisation requirements. Hence, the current study employed a blend of bentonite micro-clay, carboxymethyl cellulose (CMC), and sodium alginate (SA), simplifying processing requirements, and potentially improving the permeability with the degradation process, due to cracking. Growth and germination of all seeds were evaluated under 50% and 90% soil field capacity (FC), mimicking dry and moist soil conditions, and compared with conventional planting (C-Planted) and surface sowing (C-Surface). While the encapsulants successfully germinated agricultural seeds overall they were worse than C-Planted at 50% FC, and C-Surface at 90% FC. Encapsulant growth performance for beans was also concluded to be reduced compared to C-Planted at 50% FC. Cucumbers exhibited improved growth with encapsulants at both moisture levels. For non-agricultural native species like C. refractus and E. coolabah, CMC encapsulants initially showed low germination rates, though the addition of additives and microparticles (CMC-AB) notably enhanced germination outcomes. For A. stenophylla the application of microparticles (CMC-B) and CMC-AB reduced growth properties, whilst CMC-AB largely had no effect on the growth properties of C. refractus. The reduced germination rates with encapsulants were attributed to potential seed entrapment within the gel matrix, limiting emergence. In conclusion, while bentonite clay-based hydrogel encapsulants show promise for agricultural and non-agricultural seed germination and growth enhancement, their efficacy varies across species and soil moisture conditions. The study underscores the need for further optimization to maximize their potential in UAV-based reforestation efforts. Graphical Abstract

Efforts to develop biodegradable plastics are ongoing in response to growing environmental concerns. However, the post-use fate of these materials is not always well understood. This study aimed to evaluate the biodegradation behavior of poly(butylene adipate-co-terephthalate) (PBAT) and its composites. The aim of this study was to determine the biodegradation of poly(butylene adipate-co-terephthalate) (PBAT) and its composites. The nanocomposites were produced by melt blending PBAT with either 5 wt% unmodified cellulose nanocrystals (PBAT-CNC) or 5 wt% phenyl silane modified cellulose nanocrystals (PBAT-CNCPhS). The aerobic biodegradation of the composite films was studied for their physical disintegration behavior under simulated industrial composting conditions (58 degrees C +/- 2 degrees C) for 120 days. Additionally, respirometric biodegradation tests were separately carried out to assess CO2 evolution and the extent of mineralization under the identical conditions. Surface morphology and thermal degradation of representative partially degraded samples were also analyzed. The effect of unmodified and silane modified cellulose nanocrystals (CNCs) on the biodegradation of the composites was evaluated. Both PBAT-CNC and PBAT-CNCPhS composite films exhibited faster fragmentation and mass loss compared to that of PBAT. The hydrolysis of the nanocomposite was moderately restricted by phenyl silane modified CNCs, but this effect was only observed for the first 28 days. The composites demonstrated the following order in terms of fragmentation and CO2 evolution: PBAT-CNC > PBAT-CNCPhS > PBAT. The composite materials produced using silane-modified CNCs are suitable for use as biodegradable plastics.

To meet global food demand, reduce waste, and minimise environmental impact, the agricultural sector must improve its current practices on soil amendment, fertiliser encapsulation, and seed and crop protection. Super absorbent polymers (SAPs) are a class of polymeric materials that can absorb and retain large quantities of liquids/aqueous solutions compared to their own mass. Typically, SAPs are cross-linked to form three-dimensional hydrophilic networks, commonly known as hydrogels. Although SAPs can be synthesised from both synthetic and naturally sourced materials, for agricultural applications they are generally composed of synthetic polymers, due to their advantageous properties. These include higher water absorption rate and capacity, low cost, availability, durability, and mechanical performance. However, many of these systems utilise polyacrylic acid (PAA) and polyacrylamide (PAM) monomers which may have toxic effects on the nervous and respiratory systems of humans and animals. To ensure sustainable agricultural practices and maintain healthy long-term crop output, synthetic SAP usage must be greatly reduced. This review article aims to investigate alternative natural SAPs for agriculture and critically rationalise their adoption into the industry. Specific applications investigated include (i) soil amendment, (ii) fertiliser encapsulation, (iii) seed coating, and (iv) crop protection.

Abstract Introduction An efficient, economical, and flexible reforestation system capable of uncrewed aerial vehicle (UAV) deployment is a global necessity. Hydrogels have been previously investigated for their use in agriculture, however, research is limited in terms of UAV deployment. Psyllium Husk Mucilage (PHM) a natural hydrogel seed mucilage, has been previously investigated in other agricultural settings and shows promise in fulfilling the needs of UAV seeding. Materials and Methods A greenhouse trial was conducted under controlled laboratory conditions using two soil conditions 50% and 90% field capacity. PHM and bentonite clay blends containing dextran (DEX) and sodium alginate (SA) were tested for efficacy for two agricultural crops Green beans (Phaseolus vulgaris) and Lebanese cucumber (Cucumis sativus), as well as three Australian native species Acacia stenophylla, Cymbopogon refractus, and Eucalyptus coolabah. Agricultural Trials were conducted across a 4‐week period, whilst A. stenophylla was 8 weeks, and C. refractus and E. coolabah was 12 weeks. Results Utilisation of PHM had varying effectiveness based on seed and soil moisture. In nonagricultural seed trials, PHM hydrogel succeeded with A. stenophylla but dried out and rotted in the extended trials with C. refractus and E. Coolabah, leading to plant death. The encapsulated agricultural seeds were largely outperformed in growth trials by C‐Planted at 50% FC, and C‐Surface at 90% FC. Conclusion PHM exhibits potential for successful UAV seeding in low‐moisture agricultural conditions and is promising for fast‐germinating plants or other riverbank species with high water content requirements. Without extending degradation time PHM is not suitable for slow‐growing species.

In the pursuit of a sustainable and pollution free environment, the need for bioplastic alternatives that satisfy many of the performance demands of persistent petroleum-derived plastics is paramount. Biopolymer films reinforced with nanostructures have become an interesting area of research. Poly(butylene adipate-co-terephthalate) (PBAT) is a synthetic polymer capable of biodegrading at ambient temperature. The polar nature of cellulose nanocrystals (CNCs) used as additive in PBAT matrix makes its dispersion challenging. In this work silylation was achieved by partial substitution of surface hydroxyl groups of nanocellulose with hydrophobic silicone moieties. The surface of nanocellulose was initially modified by 5 wt.

The purpose of this work is to improve mechanical properties of rigid polyurethane (RPU) composites used in traditional ceramic casting industry. Therefore, monofilament (mono) and fibermesh (fibril) polypropylene (PP) fibers with various lengths (3, 6, 12 and 18 mm) were incorporated to polymer matrix at different rates (0.5, 1.0, 1.5 and 2% by weight). Effects of fiber type and content on flexural strength, bending strength and compressive strength of composites were investigated. Surface morphology and thermal characteristics of composites were evaluated by SEM and TGA analysis, respectively. Bulk densities of specimens with and without PP fibers vary between 72,15-146 kg/m3. Compared to pure rigid polyurethane foam, bulk density of monofilament PP reinforced composites significantly increased and the highest density value (146,86 kg/m3) was reached in M6/2.0 sample. On the other hand, incorporation of fibrilmesh caused a decrease in bulk density. While the increase in percentage of mono PP increased flexural strength, the presence of fibril PP had a negative effect on strength. Compressive strength of all mono PP reinforced composites is higher than that of pure RPU, except for M6/0.5 sample. Besides, SEM analysis revealed that the presence of PP fibers generally reduced number of closed cells in composite structure. Experimental findings indicate that fiber type, content and length affect mechanical performance of RPU composites. In addition, it is possible to use mono PP fiber reinforced RPU composites as support apparatus in ceramic casting industry.

This study deals with the improvement of light barrier properties and stress cracking strength of polyethylene terephthalate (PET) packaging materials by incorporating calcium metaborate (CaB2O4). CaB2O4 powders were synthesized by the sol-gel method. After the extrusion process produced PET/ CaB2O4 granules, the preform arid bottle production was carried out by injection molding and blow molding. Compared to pure PET, UV transmittance is reduced (similar to 88%), and it is more effective at lower wavelengths (<800 nm). Similarly, the presence of CaB2O4 improved the environmental stress cracking performance of PET packaging materials. While the burst strength increased in the range of 0.05%-0.2% CaB2O4 concentration, it decreased at higher concentrations. The load-carrying capacity is approximately 109% higher than pure PET. Acetic acid (COOH) degradation increased with the incorporation of CaB2O4 particles, while isophthalic acid and diethylene glycol degradations did not change. The experimental data indicate that the photocatalytic degradation of the PET bottle is prevented significantly, and its mechanical performance is also improved with the incorporation of CaB2O4. Thanks to this novel product, the quality of food and beverages in PET packaging materials can be protected from the harmful effects of light, and the deformation of PET packaging materials can be prevented for various reasons.

This study is on polyethylene terephthalate (PET) compounded with magnesium borate (MB) (Mg 2 B 2 O 5 ) powders between (0.2–3.2% by weight) which were synthesized via sol-gel technique at laboratory-scale. The MB/PET composites were characterized in terms of chemical, thermal degradation, and mechanical properties. Their phases and chemical structures were identified by X-ray Diffraction and Fourier Transform Infrared analyses. The MB added into PET matrix significantly reduced PET degrading to acetaldehyde, carboxylic acids and diethylene glycol. However, while at 0.2 wt.% MB isophthalic acid (IPA) decreased and at higher MB concentrations there were higher IPA levels. The added MB increased the composites intrinsic viscosity (IV) compared to the pure PET. The highest IV (0.701 dL/g) was at the 0.2 wt.% MB/PET composite. Both T g and T m temperatures trended down up to 3.2 wt.% MB. Compared to pure PET, glass transition temperature (T g ) decreased to 80.4°C (at 3.2 wt.% MB) from 81°C, whereas melt temperature (T m ) decreased to 248.5°C (at 3.2 wt.% MB) from 249.4°C. The MB/PET composite tensile strength increased by 11.31% to a 60 MPa maximum at 0.2 wt.% MB compared to neat PET (53.9 MPa). However, at 0.4 wt. % and higher MB the dispersion was insufficient causing the MB powders to aggregate in the PET matrix, resulting in reduced tensile strength.

Incompatibility of nanocellulose with non-polar polymer matrices disrupts the interfacial interaction and results in aggregation and phase separation. In this study a facile and environmentally friendly method was used to partially substitute the surface hydroxyl groups by attaching polysiloxane to impart hydrophobic properties. The silanization reaction proceeded with hydrolysis of triethoxyvinylsilane (TEVS) into reactive silanols followed by condensation to form the branched polymer. These polysiloxane oligomers were chemically grafted to form alkoxy silane bonds on the surface of CNCs. A suitable degree of hydrophilic-hydrophobic balance of the modified CNCs was achieved which improved their dispersion in hydrophobic matrix poly(butylene adipate-co-terephthalate) (PBAT). FTIR, NMR (13C and 29Si) and XPS demonstrated successful surface chemical modification and confirmed extent of silanization as a function of silane concentration. XRD showed successful grafting of the vinyl silane agent and confirmed polymorph structure of the nanocellulose was retained. The results from TEM and AFM demonstrated successful coating of nano whiskers at 5 wt% silane loading. The successful grafting of the silane agent with pendant vinyl groups improved surface hydrophobicity. These results show that this facile method produces adequately surface modified CNC which can be used as filler in hydrophobic matrices of bioplastics.

Plastic pollution is recognized as a major environmental problem in many countries. Over the last decade, academics have embraced research on bioplastics to discover newer high-end green materials. However, the end-of-life environmental fate of such materials is not adequately understood. Non-isocyanate polyhydroxyurethanes (PHUs) are green engineering materials with huge potential to replace traditional polyurethanes. Despite this immense potential, a number of questions about their environmental fate remain unanswered. The present study investigated the extent and mechanisms underlying soil biodegradation of PHUs and determined whether the deterioration of PHUs within starch bioplastics (ST) can improve the biodegradation of starch (ST)-PHU hybrids. Soil microbiomes managed to effectively and quickly digest not only PHUs but also ST-PHU hybrids. All ST-PHU hybrids were characterized by exceptional biodegradability with mass losses of up to ~88% following a soil burial time of only 120 days. The biodegradation of ST-alone bioplastics was 69% under identical conditions. The presence of cellulose nanocrystals (CNC) reduced the potential for the soil microbial community to degrade nanohybrids (ST-PHU-CNC). Microbially digested bioplastics with PHU presented less stages of thermal degradation, and reduced intensities of FTIR, NMR and XPS signals compared to the original films, indicating improvement of the biodegradation mechanism. These findings suggested the positive environmental implications of PHU in improving the bioplastic's degradation and their potential for future applications.

The current study aimed to produce polyethylene terephthalate (PET)/takedaite (Ca3B2O6) composite bottles, an innovative packaging material with better performance. For this, Ca3B2O6 was firstly synthesized by sol-gel route and then it was incorporated to PET at five rates by extrusion. Finally, preform and PET bottles were produced by injection and stretch-blow-molding processes, respectively. The results showed that the use of Ca3B2O6 significantly improved the mechanical performance and UV transmittance of PET. Compared to pure PET, the load-carrying capacity and burst strength enhanced by 133.66% and 54.16%, respectively. Environmental stress cracking (ESC) time increased from 0.3 to 18 min at 0.8% Ca3B2O6 concentration. Moreover, UV transmittance (similar to 85%) of PET decreased to approximately similar to 18% in the visible region with the incorporation of 0.8 wt% Ca3B2O6. In terms of chemical degradation, Ca3B2O6 incorporation did not change the diethylene glycol (DEG) and isophthalic acid (IPA) rates, however it played an enhancing and reductive role in acetaldehyde (AA) and carboxylic acid (COOH) degradations, respectively. Accordingly, this novel product offers the opportunity to minimize the problems that may occur due to transportation/storage and photocatalytic degradation of food and beverages in PET packaging.

Graphene oxide quantum dots (GOQDs) hold great promise as a new class of high-performance carbonaceous nanomaterials due to their numerous functional properties, such as tunable photoluminescence (PL), excellent thermal and chemical stability, and superior biocompatibility. In this study, we developed a facile, one-pot, and effective strategy to engineer the interface of GOQDs through covalent doping with silicon. The successful covalent attachment of the silane dopant with pendant vinyl groups to the edges of the GOQDs was confirmed by an in-depth investigation of the structural and morphological characteristics. The Si-GOQD nanoconjugates had an average dimension of ∼8 nm, with a graphite-structured core and amorphous carbon on their shell. We further used the infrared nanoimaging based on scattering-type scanning near-field optical microscopy to unveil the spectral near-field response of GOQD samples and to measure the nanoscale IR response of its network; we then demonstrated their distinct domains with strongly enhanced near fields. The doping of Si atoms into the sp2-hybridized graphitic framework of GOQDs also led to tailored PL emissions. We then sought to explore the potential applications of Si-GOQDs on the surface of plastic films where poly(dimethylsiloxane) (PDMS) served as a bridge to tightly anchor the Si-GOQDs to the surface. The bi-layered coated films which were built with co-assembly of Si-GOQDs and PDMS contributed to suppressing the transmission of water molecules due to the generation of compact and less accessible passing sites, achieving a nearly twofold reduction in water permeability compared to the single-layered coated films. The nanoindentation and PeakForce quantitative nanomechanical mapping showed that Si-GOQD-coated substrates were softer and more deformable than those coated only with PDMS. The co-assembly of PDMS and Si-GOQDs yielded films that were less stiff than those made from PDMS alone. Our findings provided conceptual insights into the importance of nanoscale surface engineering of GOQDs in conferring excellent dispersibility and enhancing the performance of nanocomposite films.

This work describes a simple yet effective pathway for extracting cellulose nanomaterials from jute bast fibers by chemical pretreatment to isolate microfibrillated cellulose followed by either mechanical or acid hydrolysis to ultimately isolate cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), respectively. Analyses carried out through Fourier transform infrared spectroscopy (FTIR), X-ray photon spectroscopy (XPS) and solid state C-13 nuclear magnetic resonance (NMR) demonstrated that the pretreatments gradually removed lignins and hemi-celluloses from the fibers. The yield of microfibrillated cellulose was 56.5% with respect to the initial dry mass of untreated fibers. Scanning electron microscopy (SEM) evaluated the morphological variation in the fiber dimension during the initial chemical pretreatment stages leading to extraction of microfibril 12-15 mu m in average width. Transmission electron microscopy (TEM) images confirmed the nano-scale dimension of these nanocelluloses. The thermal stability of jute fibers at different stages of treatment was studied by thermogra-vimetric analysis. The high yield and high crystallinity of the nanocelluloses demonstrated effective isolation protocol confirming that jute bast fibers can be a valuable source for generation of nanomaterials.

Graphene-polyamide-6 composite (GC) filament was 3D-printed via melt extrusion (ME). The influence of specimen thickness and internal geometric designs on electromagnetic interference shielding effectiveness (EMI SE) and dielectric properties in the X-band frequency range (8.2-12.4 GHz) was investigated. Increasing specimen thickness from 1 to 5 mm did not improve EMI SE due to impedance matching and the associated reductions in electromagnetic (EM) wave reflection. It was demonstrated that the introduction of suitable internal geometric assemblies avoided impedance matching and significantly improved EMI SE. A material model for simulating EM response of 3D-printed GC was developed and experimentally verified. It was found that different internal geometric designs each displayed unique EM responses. However, geometrical inaccuracies in printed specimens resulted in differences between experimental EM response and that predicted by simulations. These inaccuracies stem from the small size of the features relative to the printer resolution and the ME printing methodology. Therefore, the limitations of a printer when replicating complex geometries must be considered to effectively apply internal geometric designs for enhancing EMI SE of 3D-printed components.

Graphene-polyamide-6 composite (GC) filament with 9%center dot v/v graphene concentration was applied as feedstock in filament-based material extrusion (ME) additive manufacturing. The materials are characterized by melt flow index (MFI), mechanical properties, dielectric properties, and electromagnetic interference shielding effectiveness (EMI SE) in the X-band frequency range. Despite high graphene concentration, MFI is unaffected. In ME test specimens; GC has both superior elastic modulus and tensile strength at yield when compared with the neat polymer. Enhanced mechanical properties at high graphene concentration without diminished processability highlight the suitability of polyamide-6 (PA6) as matrix material for graphene composite filaments. Scanning electron microscopy (SEM) imaging indicates graphene alignment in GC after printing. In both compression molded (CM) and ME test specimens, dielectric properties and EMI SE of PA6 are enhanced by graphene inclusion. Further analysis reveals that ME has a negative influence on absorption of electromagnetic waves, while reflection is virtually unaffected.

The use of superhydrophobic surfaces in a broad range of applications is receiving a great deal of attention due to their numerous functionalities. However, fabricating these surfaces using low-cost raw materials through green and fluorine-free routes has been a bottleneck in their industrial deployment. This work presents a facile and environmentally friendly strategy to prepare mechanically robust superhydrophobic surfaces with engineered lotus leaf mimetic multiscale hierarchical structures via a hybrid route combining soft imprinting and spin-coating. Direct soft-imprinting lithography onto starch/polyhydroxyurethane/cellulose nanocrystal (SPC) films formed micro-scaled features resembling the pillar architecture of lotus leaf. Spin-coating was then used to assemble a thin layer of low-surface-energy poly(dimethylsiloxane) (PDMS) over these microstructures. Silica nanoparticles (SNPs) were grafted with vinyltriethoxysilane (VTES) to form functional silica nanoparticles (V-SNPs) and subsequently used for the fabrication of superhydrophobic coatings. A further modification of PDMS@SPC film with V-SNPs enabled the interlocking of V-SNPs microparticles within the cross-linked PDMS network. The simultaneous introduction of hierarchical microscale surface topography, the low surface tension of the PDMS layer, and the nanoscale roughness induced by V-SNPs contributed to the fabrication of a superhydrophobic interface with a water contact angle (WCA) of ∼150° and a sliding angle (SA) of <10°. The PDMS/V-SNP@SPC films showed an ∼52% reduction in water vapor transmission rate compared to that of uncoated films. These results indicated that the coating served as an excellent moisture barrier and imparted good hydrophobicity to the film substrate. The coated film surfaces were able to withstand extensive knife scratches, finger-rubbing, jet-water impact, a sandpaper-abrasion test for 20 cycles, and a tape-peeling test for ∼10 repetitions without losing superhydrophobicity, suggesting superior mechanical durability. Self-cleaning behavior was also demonstrated when the surfaces were cleared of artificial dust and various food liquids. The green and innovative approach presented in the current study can potentially serve as an attractive new tool for the development of robust superhydrophobic surfaces without adverse environmental consequences.

Globally, around 87% of discarded textiles ended up in landfill, of which more than 90% are reusable and recyclable. Recycling textile waste to other value-added products is economically feasible. To integrate recycling into the apparel waste stream, it is important to know the environmental benefit and impact of the different recycling options. This study presents the environmental performance of apparel recycling and landfill using the life cycle assessment methodology in terms of climate change, acidification, agricultural land occupation and water depletion. Landfill scenarios and recycling scenarios of post-consumer household discarded apparel waste have been developed in the context of Australia. This study finds that the landfill process of natural apparel waste contributes more environmental impact credit compared to synthetic apparel, and this is mainly credited from the power generation from landfill methane gas captured. This study also specifies that the environmental benefit from the landfill process of discarded apparel depends on the ratio of natural fibre and synthetic fibre in discarded apparel. Integration of recycling into the apparel waste stream can potentially generate environmental benefits. A recycling scenario of cleaning wipes shows the highest impact benefits, followed by cotton fibre, insulation material and polyester raw material recycling. Net impact savings of recycling depend on the avoided landfill impact and avoided virgin production impact. The results generated from this study can be useful for future policy recommendations on apparel waste management through recycling. It is clear that increased collection of apparel by recyclers can significantly reduce environmental impact.

Synthetic polymers, commonly referred to as plastics, are anthropogenic contaminants that adversely affect the natural ecosystems. The continuous disposal of long lifespan plastics has resulted in the accumulation of plastic waste, leading to significant pollution of both marine and terrestrial habitats. Scientific pursuit to seek environment-friendly materials from renewable resources has focused on cellulose, the primary reinforcement component of the cell wall of plants, as it is the most abundantly available biopolymer on earth. This paper provides an overview on the current state of science on nanocellulose research; highlighting its extraction procedures from lignocellulosic biomass. Literature shows that the process used to obtain nanocellulose from lignocellulosic biomass greatly influences its morphology, properties and surface chemistry. The efficacy of chemical methods that use alkali, acid, bleaching agents, ionic liquids, deep eutectic solvent for pre-treatment of biomass is discussed. There has been a continuous endeavour to optimize the pre-treatment protocol as it is specific to lignocellulosic biomass and also depends on factors such as nature of the biomass, process and environmental parameters and economic viability. Nanofibers are primarily isolated through mechanical fibrillation while nanocrystals are predominantly extracted using acid hydrolysis. A concise overview on the ways to improve the yield of nanocellulose from cellulosic biomass is also presented in this review. This work also reviews the techniques used to modify the surface properties of nanocellulose by functionalizing surface hydroxyl groups to impart desirable hydrophilic-hydrophobic balance. An assessment on the emerging application of nanocellulose with an emphasis on development of nanocomposite materials for designing environmentally sustainable products is incorporated. Finally, the status of the industrial production of nanocellulose presented, which indicates that there is a continuously increased demand for cellulose nanomaterials. The demand for cellulose is expected to increase further due to its increasing and broadening applications.

Nanocellulose is at the cutting edge of current research owing to its highly useful features, such as abundance and renewability of its source, biocompatibility, nanoscale dimension, high specific surface area, and tunable surface chemistry. Its multifunctional characteristics present opportunities for novel applications across a wide range of emerging fields. However, despite of its many beneficial features, its inherent hydrophilicity is posing a substantial challenge for the application of nanocellulose as reinforcing filler in conventional plastics as it complicates its dispersion in hydrophobic host polymers and often results in aggregated structures that detriment properties. The formation of aggregates is a significant barrier to achieving outstanding mechanical performance in composites. Manipulation and fine-tuning of the interfacial properties of nanocellulose has thus been recognized as a crucial step in exploiting its full potential in the development of new materials. Diverse surface-modification routes are now being developed to improve the miscibility and interfacial compatibility of nanocellulose with hosting matrices and also to confer new functionalities. We present a comprehensive overview of the fundamental aspects of a broad range of surface-modification strategies, from basic grafting of small molecules to sophisticated development of responsive platforms. We have emphasized the quantification of these modifications in terms of degree of substitution and their possible relationship with level of dispersion in organic solvents. We also reviewed the polymer reinforcement as it is one of the most prominent areas of nanocellulose research. We cover various domains of nanocellulose-reinforced polymer composites that are reported in the current literature and provide insights into technical breakthroughs and the scientific underpinnings of reinforcement mechanisms of nanocellulose in various polymer matrices with the aid of easy-to-understand illustrations. Finally, we critically evaluate the challenges encountered in the current research and highlight future opportunities for research to enable tunable and high-performance nanostructured cellulosic materials for applications across engineering and biomedical sciences.