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This study demonstrated a sustainable, zero-waste approach to produce carboxylated lignin-containing cellulose nanofibers (LCNFs) directly from untreated sugarcane bagasse (SCB) using nitro-oxidation process (NOP) fol lowed by high-pressure homogenization. Systematic optimization of reaction parameters was conducted, including reaction time, HNO3-to-SCB ratio, HNO3 concentration, temperature, and co-oxidant addition (KNO₂). The results revealed that HNO3 concentration played the most dominant role in tailoring LCNF properties. Notably, the resulting LCNFs exhibited high dispersibility, with zeta potential values ranging from 􀀀38 to 􀀀65 mV due to the increasing surface carboxyl content (0.43 to 1.21 mmol/g) even under relatively mild conditions (e.g., 50 ◦C, 5 h). Lowering the acid concentration significantly increased the lignin content, enhancing the thermal stability. All LCNFs exhibited nanoscale diameters (7–13 nm), high crystallinity (54 to 70 %), and shear- thinning behavior. Elemental analysis of NOP effluents confirmed their enrichment with macro- and micro- nutrients, enabling their reuse as biofertilizers. This dual valorization of solid and liquid products positions NOP as a viable nanocellulose production and nutrient recovery pathway from lignocellulosic biomass. Resulting LCNFs, with their amphiphilic, biodegradable, and tunable surface properties, represent a compelling platform to make new materials to replace some synthetic polymers and reduce microplastic and chemical pollution. 

The existence of organic pollutants in our environment is a growing concern. Many processes (e.g., textiles, painting, and printing) release waste effluents with organic pollutants (e.g., synthetic dyes) that harm aquatic systems. However, detecting and removing them efficiently and effectively is challenging. This study addressed this by developing a dual-functional plasmonic membrane using biowaste-derived nanocellulose for both detection and removal. The plasmonic nanomaterial was integrated with surface-enhanced Raman spectroscopy (SERS) to identify and quantify three organic pollutants (basic red 9, BR9; malachite green, MG; and methylene blue, MB). The nanocellulose removed these pollutants through electrostatic attraction. The organic pollutants were detected down to 0.05 mg/L, 0.25 mg/L, and 0.05 mg/L for BR9, MG, and MB, respectively; these concentrations are well below those considered to be environmentally hazardous. SERS analysis was performed in spiked streamwater samples to demonstrate detection in an environmentally relevant matrix. The nanomaterial was also used to remove the pollutants from aqueous matrices; removal efficiencies were 99.54 ± 0.16% for BR9, 99.50 ± 0.25% for MG, and 99.84 ± 0.10% for MB. For pollutant-spiked stream samples, removal efficiencies were 98.76 ± 1.26% for BR9, 97.50 ± 2.29% for MG, and 98.33 ± 1.59% for MB. This study demonstrates the high potential of this nanomaterial for the simultaneous detection and removal of organic contaminants, which provides the first example of using biowaste-derived functional nanomaterial for water testing and remediation concurrently. 

Polyamide membranes are widely used in reverse osmosis (RO) water treatment, yet the mechanism of interfacial polymerization during membrane formation is not fully understood. In this work, we perform atomistic molecular dynamics simulations to explore the cross-linking of trimesoyl chloride (TMC) and m-phenylenediamine (MPD) monomers at the aqueous–organic interface. Our studies show that the solution interface provides a function of “concentration and dispersion” of monomers for cross-linking. The process starts with rapid cross-linking, followed by slower kinetics. Initially, amphiphilic MPD monomers diffuse in water and accumulate at the solution interface to interact with TMC monomers from the organic phase. As cross-linking progresses, a precross-linked thin film forms, reducing monomer diffusion and reaction rates. However, the structural flexibility of the amphiphilic film, influenced by interfacial fluctuations and mixed interactions with water and the organic solvent at the solution interface, promotes further cross-linking. The solubility of MPD and TMC monomers in different organic solvents (cyclohexane versus n-hexane) affects the cross-linking rate and surface homogeneity, leading to slight variations in the structure and size distribution of subnanopores. Our study of the interfacial polymerization process in explicit solvents is essential for understanding membrane formation in various solvents, which will be crucial for optimal polyamide membrane design. 

Charge-stabilized colloidal cellulose nanocrystals (CNCs) can self-assemble into higher-ordered chiral nematic structures by varying the volume fraction. The assembly process exhibits distinct dynamics during the isotropic to liquid crystal phase transition, which can be elucidated using X-ray photon correlation spectroscopy (XPCS). Anionic CNCs were dispersed in propylene glycol (PG) and water spanning a range of volume fractions, encompassing several phase transitions. Coupled with traditional characterization techniques, XPCS was conducted to monitor the dynamic evolution of the different phases. Additionally, simulated XPCS results were obtained using colloidal rods and compared with the experimental data, offering additional insights into the dynamic behavior of the system. The results indicate that the particle dynamics of CNCs undergo a stepped decay in three stages during the self-assembly process in PG, coinciding with the observed phases. The phase transitions are associated with a total drop of Brownian diffusion rates by four orders of magnitude, a decrease of more than a thousand times slower than expected in an ideal system of repulsive Brownian rods. Given the similarity in the phase behaviors in CNCs dispersed in PG and in water, we hypothesize that these dynamic behaviors can be extrapolated to polar solvent environments. Importantly, these findings represent the direct measurement of CNC dynamics using XPCS, underscoring the feasibility of directly assessing the dynamic behavior of other rod-like colloidal suspensions. 

In this study, an eco-friendly and novel hydrogel based on a crosslinked polyvinyl alcohol (PVA), iota carrageenan (IC) and polyvinylpyrrolidone (PVP) scaffold, containing a large amount (10–50 wt%) of nanoscale palm fronds (NPF) as additives, for water purification was demonstrated. A life cycle assessment (LCA) findings on NPF as biomass waste incorporated into PVA_PVP_IC polymer matrix was presented, and the results highlight the necessity of focused actions to reduce environmental impact and support the palm waste utilization in a sustainable manner. The multicomponent nanocomposite hydrogels were examined as adsorbents in a system work in batches for methylene blue (MB) and paracetamol (PCT) removal. The results show that, the presence of NPF, which dispersed in the hydrogel PVA_PVP_IC scaffolds containing both covalent and non-covalent cross-linking bonds, greatly enhanced the MB and PCT adsorption efficiency. A response surface methodology (RSM) model was used to find the best operating parameters of contaminant adsorption, including time, adsorbent dose, and starting concentration of pollutants. By using this statistical model, it was found that the optimal conditions for the adsorption reaction to achieve the complete removal of MB are 66.7 h adsorption time duration, 98.5 mg/L starting concentration, and an adsorbent dose of 5.9 mg, while for the complete removal of PCT, it is 57.6 h adsorption time duration, 80 mg/L starting concentration, and an adsorbent dose of 6 mg. The reusability of the nanocomposite hydrogels were tested for 5 cycles, all showed high adsorption capacity, indicating the potential for practical application of this nanocomposite hydrogel system. This study indicates that the prepared nanocomposite hydrogel raises the standard used for treatment of wastewater and also gives a solution to protect the environment and mitigate global warming. 

The increased demand for agricultural productivity to support the growing population has resulted in the expanded use of pesticides. However, modern pesticide applications contaminate air, water, soil, and unintentional target species. It is necessary to develop effective and sustainable methods to detect different pesticides within our environment. Surface-enhanced Raman spectroscopy (SERS) has garnered significant attention for its ability to detect and quantify environmental contaminants, as it is a rapid and sensitive technique that requires minimal sample preparation. The present study demonstrates the development of a biowaste-derived nanocellulose-based thin-film that, when integrated with gold nanoparticles, produces a sustainable and reproducible SERS nanosubstrate. In this study, three pesticides (carbaryl, ferbam, and thiabendazole) were sensitively and selectively detected by the combined use of this novel nanocellulose-based SERS nanosubstrate and a portable Raman instrument. The limits of detection were determined to be 1.34, 1.01, and 1.41 mg/L for carbaryl, ferbam, and thiabendazole, respectively, all of which are well below the agricultural application concentrations recommended. SERS signals were collected for both prepared ferbam spray solution and collected sprayed droplets, and it was found that there is no major difference in the signals, indicating that this detection method is reliable to detect pesticide droplets. A commercial pesticide was detectable by the biowaste-derived SERS nanosubstrate. This study is among the first to utilize biowaste-derived nanocellulose to create SERS nanosubstrate for pesticide detection in spray droplets. We demonstrate the high potential of biowaste-derived nanocellulose in combination with the portable Raman technique for agricultural pesticide spray detection. 

Anionic carboxylated cellulose nanofibers (CNF) are effective media to remove cationic contaminants from water. In this study, sustainable cationic CNF-based adsorbents capable of removing anionic contaminants were demonstrated using a simple approach. Specifically, the zero-waste nitro-oxidization process was used to produce carboxylated CNF (NOCNF), which was subsequently converted into a cationic scaffold by crosslinking with aluminum ions. The system, termed Al-CNF, is found to be effective for the removal of fluoride ions from water. Using the Langmuir isotherm model, the fluoride adsorption study indicates that Al-CNF has a maximum adsorption capacity of 43.3 mg/g, which is significantly higher than that of alumina-based adsorbents such as activated alumina (16.3 mg/g). The selectivity of fluoride adsorption in the presence of other anionic species (nitrate or sulfate) by Al-CNF at different pH values was also evaluated. The results indicate that Al-CNF can maintain a relatively high selectivity towards the adsorption of fluoride. Finally, the sequential applicability of using spent Al-CNF after the fluoride adsorption to further remove cationic contaminant such as Basic Red 2 dye was demonstrated. The low cost and relatively high adsorption capacity of Al-CNF make it suitable for practical applications in fluoride removal from water. 

Low-cost production of nanocellulose from diverse lignocellulosic feedstocks has become an important topic for developing sustainable nanomaterials. The available feedstocks include both woody and non-woody plants, where the latter are relatively underutilized. Interestingly, the porous structure and low lignin content in most non-woody plants, such as agricultural residues and natural fibers, also makes them ideal sources for lower energy nanocellulose production using simpler methods than those required to process woody plants. To enhance the goal of circularity, this review first provides an overview of the nanocellulose conversion from cellulose and then comprehensively discusses the use of non-woody feedstocks for nanocellulose production. Specifically, the availability of suitable non-woody feedstocks and the use of low-cost processes for pulping and cellulose oxidation treatments, including alkaline, solvent pulping, and nitrogen-oxidation treatments, are discussed. The information in this review can lead to new opportunities to achieve greater sustainability in biobased economies. Additionally, demonstrations of nanocellulose-based water purification technologies using agricultural residues derived remediation materials are highlighted at the end of this review.