Cellulose Composites Research Articles

Evaluation of the adsorption capacity of glyphosate in a microbial cellulose composite

The objective of this project was to develop a composite based on microbial cellulose (CM), chitosan (Qs) and citric acid (AC) as a crosslinker at two different concentrations (4 and 6% w/v). The CM was obtained from the fermentation of fruit residues with a SCOBY (symbiotic consortium of bacteria and yeast). The composites were morphologically characterized by SEM and spectroscopy techniques (FTIR-ATR) as well as UV-VIS spectrophotometry with ninhydrin were used to evaluate the composite as an adsorbent for glyphosate in water; in the spectra obtained by FTIR, the representative vibrational bands of the functional groups belonging to chitosan and microbial cellulose were observed; for cellulose and chitosan composites with 4% citric acid in 1579 cm-1 , 1386 cm-1 , 1046 cm-1 and 853 cm-1 ; and for the 6% cellulose-chitosan-citric acid composite at 1573 cm-1 , 1380 cm-1 , 1056 cm-1 and 503 cm-1 , thus attributing cross linkage between the biopolymers. Post- adsorption FTIR-ATR analysis revealed significant changes possibly attributable to the adsorption of glyphosate in the cellulose composites. Further research is still being conducted to better understand this interaction and the involved mechanism; the goal is to comprehend how microbial cellulose can effectively adsorb glyphosate, which could have practical and efficient applications in the remediation of environments contaminated with this herbicide.

Physicochemical Modifications on Fibre Reinforced Polymer Composites for Mining Applications

Polymer composites are mainly employed as an industrial material because of their chemical and corrosion resistance, especially in mining applications. As a result of the growing demand for biodegradable, ecological, and recyclable materials, organic fibres are widely used as reinforcement in polymer composites in recent years. The challenges arising from polymer composites, like environmental impact, moisture absorption, Thermomechanical property deterioration, lower durability in mining applications are discussed in this review. This work analyses the influence of certain physicochemical modifications on the reinforcement and matrix in polymer composites for mining purpose. This investigation was to understand the effectiveness of physicochemical modifications, specifically cryogenic treatment, on reinforcements and matrix to overcome the above mentioned challenges. This study also highlights the morphological and thermal changes due to the modifications. Results show the effect of these modifications on the composite and its constituents, cryogenic treatment on the organic fibre reinforcements showed increased moisture resistance, higher cellulose composition and mechanical properties, exposing the potential of using organic fibre-reinforced polymer composite in Mining applications.

A comparative study on porous activated carbon derived from waste biomass with varying oxygen functionalities as supercapacitor electrodes

AbstractActivated carbon derived from biomasses with different oxygen‐bearing chemical constituents has been explored as supercapacitor electrode. The rice straw (RS) and eucalyptus wood biomasses were selected owing to their contrasting composition of cellulose, hemicellulose, and lignin contents. The activated carbons of these biomasses are obtained by pyrolysis at 550°C followed by thermal activation (700°C) after treatment with optimized KOH. The specific capacitance of RS‐based activated carbon (ACRS‐700), measured from galvanostatic charging‐discharging studies at 0.5 A g−1, is much higher (eg, 365 F g−1) than that of ACEW‐700 (168 F g−1). The higher specific capacitance of ACRS‐700 is attributable to: (i) significantly higher surface area (3345 m2 g−1) comprising of interconnected micro‐ and mesoporous structure; (ii) porosity of about 2.0 cm3/g; and (iii) oxygen‐rich hemicellulose contents. The possible charge storage mechanism in ACRS‐700 has been discussed. The real‐time application of ACRS‐700 has been demonstrated by lighting up red LEDs using ACRS‐700//ACRS‐700 symmetric supercapacitor device, operated with aqueous and freshly synthesized [Bu4N+][NO3−] ionic liquid as electrolytes. The maximum energy density (42.7 Wh kg−1) and the power density (1.9 kW kg−1) for ionic liquid electrolyte are favourable for supercapacitor applications.

Cellulose-embedded polyacrylonitrile/amidoxime for the removal of cadmium (II) from wastewater: Adsorption performance and proposed mechanism

The adsorption of metals using unmodified cellulose is often unsatisfactory owing to insufficient active functional groups on its surface. The objective of this work is to modify cellulose to enhance its adsorption capacity for cadmium (II). In this work, a chelating polyacrylonitrile/amidoxime-functionalized cellulose (Cel/PAN/AO) composite was successfully synthesized as modified cellulose and applied as a novel adsorbent to efficiently remove Cd2+ from aqueous solution. Cel/PAN/AO composite was synthesized by Michael's addition between cellulose and acrylonitrile, followed by amidoximation. Tools including SEM, EDS, FTIR, XRD, TGA, XPS, BET, and zeta potential were exploited to give insights about the Cel/PAN/AO adsorbent nature as well as the adsorption mechanism. The numerous available adsorption active sites embedded into modified cellulose contribute to enhancing the adsorption capacity of Cel/PAN/AO (in comparison to unmodified cellulose) toward Cd2+. Using the produced composite, cadmium was removed from the water at 50 mg/L Cd2+ by reacting 0.1 g Cel/PAN/AO with Cd2+ at pH 5 for 90 min at 298 K. The maximum adsorption capacity of Cel/PAN/AO toward Cd2+ was 123.23 mg/g. Cel/PAN/AO adsorbent exhibits competitive adsorption capacity as compared with other reported adsorbents. Pseudo-first-order and Langmuir's isotherm fit the sorption mechanism quite well. Cd2+ sorption onto the Cel/PAN/AO composite was found to be an exothermic, random, and spontaneous process in the thermodynamic analyses. Moreover, Cd2+ adsorption was also confirmed through SEM, EDS, FTIR, and XPS analysis of Cd2+-loaded adsorbent. Using 0.9 M KCl and 1:70 S:L ratio for 90 min, Cd2+ was also desorbed from Cd-loaded Cel/PAN/AO. In addition, after six cycles of Cd2+ adsorption-elution, the Cel/PAN/AO sorbent was regenerated and showed excellent reusability. It appears from the adsorption performance results of this work that the Cel/PAN/AO formulation has promise as an adsorbent for extracting Cd2+ from wastewater.

Infrared-based machine learning models for the rapid quantification of lignocellulosic multi-feedstock composition

Machine learning models to rapidly quantify lignocellulosic multi-feedstock composition were developed using partial least squares regression (PLSR) and artificial neural networks (ANN) trained using augmented spectroscopic dataset (ASD). ASD helps to overcome spectral sample size limitations. ANN model outperformed PLSR models in predicting biomass composition. Moreover, the optimized ANN models, developed using ASD on lignocellulosic biofingerprint region with 1051 variables, demonstrated exceptional performance with a coefficient of determination (R2) of 99.21, 99.27 and 99.23 % for predicting cellulose, hemicellulose, and lignin composition. Interestingly, ANN models developed with only 68 spectral peaks in the same spectral region identified based on a peak identification algorithm developed earlier, exhibited very similar performance in predicting cellulose, hemicellulose, and lignin composition with an R2 of 99.16, 98.98, and 99.10 %. These findings demonstrate the applicability of ANN models for rapid composition analysis in multi-feedstock and would aid in biomass conversion to fuels and chemicals.

Enhancing Carbon Fiber Properties through Lignin-Cellulose Composites: A Comparative Study of Hardwood Vs. Softwood Lignin Sources

Carbon fibers are integral to a wide range of applications, including automotive, construction, packaging, textiles, and emerging fields such as energy storage electrodes like flexible supercapacitors. However, concerns related to limited availability and environmental impact associated with fossil-based carbon fiber production have sparked growing interest in sustainable alternatives, particularly those derived from lignin and cellulose composites. This conference work presents a comparative analysis of the mechanical properties of lignin-cellulose composite carbon fibers derived from hardwood and softwood lignin sources, elucidating the significant influence of lignin origin on fiber performance.Our study focuses on the advantages and disadvantages of utilizing a composite of hardwood lignin vs. softwood lignin with cellulose in carbon fiber production, comparing these materials to commercially available carbon fibers. We emphasize the mechanical performance of these composite fibers, specifically highlighting the tensile strength and tensile modulus as a key metric. Notably, our results demonstrate that carbon fibers derived from hardwood lignin/cellulose composites exhibit superior mechanical strength compared to those from softwood lignin/cellulose composites. To gain fundamental insights into the reasons behind this mechanical disparity, we employed Raman spectroscopy to analyze the carbon structures within the fibers. Our findings revealed that carbon fibers produced from hardwood lignin exhibited a higher degree of graphitization, helping in achieving of typically desirable pre-graphite turbostractic carbon structures. These structural enhancements significantly contributed to the improved mechanical characteristics observed. In summary, our research underscores the critical importance of lignin source selection in the production of lignin-cellulose composite carbon fibers. The mechanical performance of these fibers is closely linked to the carbon morphology influenced by the lignin source. Therefore, understanding and controlling the lignin source from hardwood or softwood is pivotal for tailoring carbon fiber properties to meet specific application requirements. This study not only advances the knowledge in sustainable carbon fiber production but also offers valuable insights into achieving desirable properties for a wide range of applications, including advanced energy storage systems and structural materials.

Visualization of latent fingerprints based on composites of dye-doped cellulose with red emissive fluorescence

Visualization of latent fingerprints based on composites of dye-doped cellulose with red emissive fluorescence

Comparative Analysis on Microwave and Pressure Cooker Pre-Treatment of Lignocellulosic Biomass in Glucose Production via Fungal Treatment

Oil Palm Empty Fruit Bunch (OPEFB) is lignocellulosic biomass waste generated from palm oil processing industries. Due to its significant compositions of cellulose, hemicellulose, and lignin, OPEFB can be further utilized and converted into value-added chemical products which can be used as alternative energy. Hence, the focus of this research is to analyze the effect of microwave pre-treatment (MP) and pressure cooker pre-treatment (PCP) parameters on OPEFB lignin reduction. The treated OPEFB was directly processed using two serial fungal treatment processes. The first fungal treatment process (FT-1) was to maximize the OPEFB lignin removal while the second fungal treatment process (FT-2) was to maximize the glucose production. Combination of microbes such as Phanerochaete chrysosporium, Trichoderma harzianum, Aspergillus niger, and Tricodherma viride was used for both fungal treatment processes. The OPEFB passing 25-mesh screening was used as raw materials. The raw materials mixed with 0.05 w/w NaOH pellets and water to achieve a concentration ratio of 3/50 (w/v) were pre-treated with either MP or PCP. Subsequently, the slurry produced from the pre-treatment process was introduced to FT-1 (P. chrysosporium for 5 days) and finally to FT-2 (T. harzianum, A. niger and T. viride for 4 days). The compositions of lignin, cellulose, hemicellulose, and glucose were analyzed at each process transition and the end of the whole process. It was observed that PCP (60 mins) was the best pre-treatment process with 39.23%-w of lignin removed. On the other hand, combination of MP (150 watts, 60 mins) was followed with FT-1 removed 66.67%-w of lignin. Only around 38.37%-w of lignin was removed when using the whole process, e.g., MP (150 watts, 60 mins), FT-1, and FT-2. The highest composition of glucose, ca. 131.02%-w, was obtained when 40-min PCP followed with FT-1 and FT-2 was applied. The obtained results exhibited that large lignin removal did not necessarily promote high glucose yield in the final product as observed in the 60-min PCP, e.g., P. chrysosporium consumed not only lignin but also presumably hemicellulose and cellulose.

Multiscale characterization and design of cellulose composites based on polymers with movable cross-links

To combine the conflicting properties of impact resistance, stiffness, and toughness, we focused on composite materials reinforced with cellulose nanofibers and polymers with movable cross-links using cyclic macromonomers and analyzed their mechanical properties through experiments and computational simulations. Based on the experimental foundation, the mechanical properties of cellulose nanofibers modified with citric acid and flexible crosslinked polymer composites using cyclodextrin were investigated. On the other hand, multi-scale finite element analysis simulation based on homogenization theory was employed to systematically clarify the effects of aspect ratio and content ratio of cellulose fibers by considering polymer blending and modification of molecular structure in the base material. For modification of the matrix polymers and the fiber morphologies, the elastic modulus of the cellulose composite was comprehensively organized by the fiber contribution based on strain energy. A design method for cellulose composites based on fiber contribution proportion was also developed. The design method was applied to a new cellulose composite with a different polymer of the matrix, and it was demonstrated that the elastic modulus can be predicted with an error of less than 10 %.

Synthesis of Extract-Bacterial Cellulose Composite Using Ageratum conyzoides L. and Chromolaena odorata L., Its Antibacterial Activities, and Biodegradability Properties.

Bacterial cellulose is a natural polymer produced by fermentation of coconut water using Acetobacter xylinum bacteria. This study aimed to synthesize a novel composite of bacterial cellulose impregnated with plant extracts that had an antibacterial activity that have the potential to be used as a food packaging material to maintain food quality. Pure bacterial cellulose (pure BC) was impregnated using Ageratum conyzoides L. leaf extract (AC-BC) and Chromolaena odorata L. leaf extract (CO-BC), which contain secondary metabolites with potential as antibacterial. The study began with the synthesis of pure BC, AC-BC, and CO-BC composites then characterized by SEM-EDX and FTIR, continued with antibacterial activity tests against S. aureus, S. typhimurium, E. coli, and their biodegradability tests. The results of SEM and FTIR characterization showed the success of the impregnation process for antibacterial compounds. The results of the antibacterial activity of AC-BC disc diffusion against S. typhimurium and E. coli showed good antibacterial activity of 9.82 mm and 8.41 mm, respectively. The similar result showed with the antibacterial activity of CO-BC disc diffusion against S. typhimurium and E. coli that showed good activity of 9.73 mm and 6.82 mm, respectively. On the other hand, the biodegradability test showed that the impregnation of bacterial cellulose slowed down the degradation process in the soil. This study confirmed the potential application of bacterial cellulose-plant extracts as an active and biodegradable food packaging.

Synergistic enhancement of the mechanical properties of cement-based materials by using microcrystalline cellulose and nano-silica composites

The flexural strength and compressive strength are the two most important parameters that characterize the mechanical properties of cement-based materials, but the two are usually mutually exclusive or negatively correlated. The flexural strength of cement-based materials cannot be effectively improved by a single nanomaterial without reducing their compressive properties. Therefore, compounding various micro–nano materials, fully utilizing their respective advantages, and developing composite materials with new properties and application characteristics are important techniques for enhancing the mechanical properties of cement-based materials. This study aimed to investigate the synergistic enhancement of the mechanical properties of concrete by using microcrystalline cellulose (MCC) and nano-silica (NS) composites. MCC and NS were mixed and modified to synthesize MCCNS materials, which were added to cement slurry for experiments. Results indicated that the flexural strength and compressive strength of the cement paste with MCCNS materials were significantly increased compared with those of the cement pastes without MCCNS or with only NS. The flexural strength of the cement paste with MCCNS-1 was increased by 47%, 20%, 6.3%, and 6.8% after curing for 1, 7, 28, and 56 days, respectively. Meanwhile, compressive strength was also increased by 14.4%, 6.3%, 6.8% and 6.5%, respectively. In addition, the reaction mechanism was speculated through a variety of test results. The addition of MCCNS material facilitated the formation of additional C-S-H, which also contributed to enhancing the mechanical properties of cement paste.

Effect of alkali metals on physical and spectroscopic properties of cellulose

A 3-unit cellulose model molecule was built and optimized using DFT B3LYP/6-31G(d,p). The electronic properties of the optimized structure of cellulose were investigated in terms of total dipole moment (TDM), HOMO–LUMO band gap (ΔE), and molecular electrostatic potential (MESP). Cellulose demonstrated a TDM of 9.106 Debye and ΔE of 7.647 eV. The hydrogen atom of the hydroxyl group of the CH2OH group of each cellulose unit was replaced by an alkali metal atom (X) such that the 3-unit cellulose once had 1X atom, then 2X, then 3X atoms, where X = Li, Na or K, both without and with 2, 4 and 6 water molecules (W), respectively, to study also the effect of hydration. Without hydration, the values of TDM decreased for all of the proposed interaction, but increased with hydration, while ΔE decreased in all interactions, confirming that interaction cellulose-alkali metal interaction, especially with hydration, resulted in more reactive structures. Mapping of HOMO–LUMO and MESP indicated significant change in the electron density distribution around cellulose under the effect of interaction with the alkali metals, both with and without hydration. The plots of projected density of states also clearly demonstrated the contribution of each alkali metal as well as water in the molecular orbitals, reflecting their effect on the electronic properties of cellulose and cellulose-alkali metals composites. The theoretical calculations were experimentally verified using FTIR and FT-Raman spectroscopy.

Preparation and characterization of quaternary bacterial cellulose composites for antimicrobial oil‐absorbing materials

AbstractThe treatment of various types of oily wastewater is paramount for environmental protection. Bacterial cellulose (BC) stands out as a highly promising material for oil/water separation, owing to its exceptional mechanical properties and three‐dimensional porous structures. However, excessive hydroxyl groups on BC make it highly hydrophilic, reducing oil absorption and promoting bacterial growth, affecting its stability. To address these challenges, we developed a straightforward in situ polymerization method for the preparation of BC‐DMC composites. The innovation lies in the concurrent enhancement of BC's hydrophobicity and antimicrobial properties only through the addition of 2‐(Methacryloyloxy)ethyltrimethylammonium chloride (DMC), considerably simplifying the synthesis of materials possessing oil‐absorbing and antimicrobial properties. Morphological and structural characterization results confirmed the successful combination of DMC onto BC while maintaining its porous structure. After process parameter optimization, the BC‐DMC composites exhibited a remarkable increase in contact angle (117.7° compared with pure BC's 19.5°). It also demonstrated excellent oil absorption performance, with maximum capacities exceeding 30 g/g for different oils, maintaining values above 20 g/g even after eight cycles. In addition, the BC‐DMC composites exhibited strong antibacterial activity, with rates of 82.4% against Escherichia coli and 97.5% against Staphylococcus aureus. The antibacterial mechanism of the BC‐DMC composites was also discussed. Our novel BC‐DMC composites provides excellent oil absorption and antibacterial properties, making it highly applicable in the field of oily wastewater treatment and serving as a valuable reference for other researchers.

Green synthesis of elephant manure-derived carbon dots and multifunctional applications: Metal sensing, antioxidant, and rice plant promotion

Carbon dots, the carbon nanomaterials, have been greatly developed for several applications including fluorescent sensors for metal ion detection, antioxidant activity, and plant growth promotion due to their excellent photophysical properties, non-toxicity, and high quantum yield. Therefore, this research focused on the synthesis of multifunctional carbon dots from elephant manure via green hydrothermal synthesis owing to its chemical composition of cellulose, hemicellulose, and lignin. The as-synthesized carbon dots exhibited blue fluorescence emission under UV light and the excitation wavelength-dependent fluorescence enhancement. Carbon dots could be further used as a “turn-off” fluorescence sensor for Hg2+ detection as a part of environmental monitoring. Furthermore, the as-synthesized carbon dots containing high phenolic content showed the antioxidant activity and promoted rice growth with an increase in the characteristic aroma compound (2-acetyl-1-pyrroline), confirmed by GC–MS analysis.

Preparation, characterization, and adsorption kinetics of graphene oxide/chitosan/carboxymethyl cellulose composites for the removal of environmentally relevant toxic metals

This study attempted to develop a low-cost and eco-friendly bio-based composite adsorbent that is highly efficient in capturing potential toxic metals. The bio-composite adsorbent was prepared using graphene oxide (GO), carboxymethyl cellulose (CMC) and chitosan (CS); and characterized using FTIR, SEM-EDX and WAXD techniques. Metal-ion concentration in an aqueous solution was measured by ICP-OES. This article reveals that the adsorption of heavy metal ions varied according to the adsorbent quantity, initial metal concentration, pH, and interaction time. The metal ions' adsorption capacity (mg/g) was observed to increase when the interaction time and metal concentration increased. Conversely, metal ions adsorption was decreased with an increase in adsorbent dosages. The effect of pH on metal ions' adsorption was ion-specific. The substantial adsorption by GO/CMC/CS composite for Co2+, CrO42−, Mn2+ and Cd2+, had the respective values of 43.55, 77.70, 57.78, and 91.38 mg/g under acidic conditions. The metal ions experimental data were best fitted with pseudo-second-order (PSO) kinetics, and Freundlich isotherm model (except Co2+). The separation factors (RL) value in the present investigation were found between 0 and 1, meaning that the metal ions adsorption onto GO/CS/CMC composite is favorable. The RL and sorption intensity (1/n) values fitted well to the adsorption isotherm.

Inorganic composites based on carboxymethyl cellulose: preparation, characterization, sorption, and selectivity behavior for some radionuclides from radioactive solutions

Abstract This work is interested in the sorption and separation of 131Ba, 109Cd, 152+154Eu, and 97Zr from radioactive solutions onto barium molybdenum titanate loaded on carboxy methyl cellulose (BaMoTi@CMC) composites. In this work, different samples of BaMoTi@CMC composites were fabricated by the co-precipitation method and characterized using different analytical tools such as X-ray diffraction (XRD), attenuated total reflectance (ATR), and scanning electron microscope (SEM). The batch sorption investigations on 131Ba, 109Cd, 152+154Eu, and 97Zr include the influence of time, pH, and metal ion concentrations. The data reveal that S-3 has higher sorption efficiency than S-2 under all conditions. Isotherm is studied by Langmuir and Freundlich models. Binary systems data confirm that Cd(ii), Ba(ii), and Zr(iv) can be separated from Cd–Eu, Ba–Eu, and Zr–Eu binary systems using S-2 and S-3 at different pHs. Finally, the data prove that Zr(iv) and Ba(ii) can be easily separated from tertiary systems (Zr–Ba–Cd) onto S-2 and S-3 at pH 2.

The Chemical Characterisation of the Maritime Pine Bark Cultivated in Northern Portugal

Maritime pine, scientifically known as Pinus pinaster, holds a vital role in Iberian Peninsula forests, primarily as a source of wood for panels, paper, and cellulose production. Recently, there has been a growing interest in utilising agroforestry by-products to yield valuable chemicals for applications in various sectors, including the food, pharmaceutical, and bioenergy industries. This study aimed to assess the value of the primary by-product of Pinus pinaster from the Minho region of northwestern Portugal, i.e., the bark. The research extensively examined the bark’s chemical and thermal characteristics, including ash content, extractives, lignin, cellulose, hemicellulose, fatty acids, and mineral composition. Additionally, various analytical techniques like FTIR, SEM, DSC, DTG, and XRD were used to observe chemical structure differences. The results reveal that the Pinus pinaster bark primarily consists of lignin (51.15%) and holocellulose (46.09%), with extractives mainly soluble in toluene–ethanol, followed by water, and a small amount of them are soluble in ethanol. The bark contained around 0.44% ash, and heavy metals such as Cd and Pb were not found. During degradation, Pinus pinaster experienced a 10% mass loss at 140 °C. In terms of crystallinity, holocellulose and cellulose showed similar percentages at approximately 25.5%, while α-cellulose displayed the highest crystallinity index at 41%.

Biodegradation of oil palm empty fruit bunch during cultivation of Volvariella volvacea

AbstractBiodegradation of cellulose, lignin, and hemicellulose from oil palm empty fruit bunches (OPEFB) by straw mushroom (Volvariella volvacea) was investigated. The present research mainly focused on the effects of effective microorganism (EM) treatment (M) and composting duration of OPEFB (C) on straw mushroom production. Two main stages were involved in this research. The first stage was emphasized on the V. volvacea culture process while the second stage was to evaluate the chemical properties of the OPEFB. Zero percent EM solution increased the OPEFB decomposition rate significantly for cellulose and slightly for hemicellulose. The EM solution of 20% increased the OPEFB decomposition rate significantly for hemicellulose after 5 days of composting. In contrast, 10% EM solution increased the OPEFB decomposition rate significantly for cellulose and lignin that were composted for 5 days and for hemicellulose that were composted for 10 and 15 days. The introduction of different EM solutions and varied composting days significantly affected the final compositions of the lignocellulose degraded by the V. volvacea. Most of the lignocellulose composition had positive correlation which depend on the nature of lignocellulose substrates. The final composition of cellulose, lignin, and hemicellulose in the spent OPEFB on average were 44.17 ± 0.04%, 22.66 ± 0.03%, and 11.39 ± 0.04%. Conversely, the raw OPEFB composition were 53.62% + 0.06%, 32.68% + 0.03%, and 15.23% + 0.19%. Based on the reduced percentage of the lignocelluloses, V. volvacea cultivation on OPEFB proved to be a good alternative in degrading biowastes.

Facile synthesis of Co, Fe-bimetallic MIL-88A/microcrystalline cellulose composites for efficient adsorptive and photo-Fenton degradation of RhB dye

Photo-Fenton technology is effective in treatment of dye containing effluents in water under visible light illumination. The present article reports fabrication of a considerably efficient photo-Fenton catalytic system, the Co, Fe-MIL88/MCC composite, by a mild hydrothermal method. The composite containing bimetals Co2+/Co3+ and Fe2+/Fe3+ ions with coordination environments used as activators of H2O2-assited visible light photo-Fenton degradation of RhB. The effects of initial pH, catalyst dosage and H2O2 concentration on RhB decomposition were explored. Nearly 87% of RhB molecule was removed within 100 min in the Co, Fe-MIL88/MCC/H2O2/Visible system ana maintain the recyclability rate of more than 82.2% after five successive cycles. The photoinduced •O2− and •OH plays a major role in efficient removal of RhB. The excellent catalytic performance of the composite can be credited to the proficient electrons transfer by Fe2+/Fe3+ and Co2+/Co3+ redox cycles, activation of H2O2 by photoexcited electrons to generate •OH. As well, the optimal Co, Fe-MIL88 (Co/Fe in ratio 1/2 wt%)/MCC composite exhibited good recyclability and stability.

Humidity‐Responsive Polyvinyl Alcohol/Microcrystalline Cellulose Composites with Shape Memory Features for Hair‐Styling Applications

AbstractThis study investigates the maintenance of humidity‐responsive shape memory polymer composites comprising polyvinyl alcohol (PVA) and cellulose microcrystal for maintaining hair curls in humid environments. The composite films are prepared by a simple blending method using aqueous solutions of different polymer ratios and characterized for thermal properties, chemical structure, and surface morphology. The hydroxyl groups in the PVA and cellulose provided hydrogen‐bonding interactions and improved the miscibility of the composites. Increasing the cellulose content in the composites enhanced mechanical properties and curl‐shape recovery performance, with 20–25 wt.% cellulose achieving maximum recovery. When the PVA/cellulose solution is applied to natural hair, it effectively maintains the shape of curled hair bundles for at least 6 h under 80% humidity and promotes the hair shape recovery rate to 8–10%. Overall, The proposed humidity‐responsive PVA/cellulose composites present promising application potential in the field of hairstyling to withstand humid weather.