Rice Straw Cellulose Research Articles

Organosolv delignification of rice straw cellulose fiber for functional food packaging

Organosolv delignification of rice straw cellulose fiber for functional food packaging

Tailoring the structural and physicochemical properties of rice straw cellulose-based cryogels by cell-mediated polyhydroxyalkanoate deposition

This study presents a novel biotechnological approach for creating water vapor-resistant cryogels with improved integrity. Rice straw cellulose was transformed into nanofibrils through TEMPO-mediated oxidation and high-pressure homogenization. The resulting cryogels remained firm even when immersed in aqueous media, whose pores were used by live cell to deposit polyhydroxyalkanoate (PHA) particles inside them. This novel method allowed the compatibilization of PHA within the cellulosic fibers. As a consequence, the water sorption capacity was decreased by up to 6 times having just 4 % of PHA compared to untreated cryogels, preserving the cryogel density and elasticity. Additionally, this technique can be adapted to various bacterial strains and PHA types, allowing for further optimization. It was demonstrated that the amount and type of PHA (medium chain length and small chain length-PHA) used affects the properties for the cryogels, especially the water vapor sorption behavior and the compressive strength. Compared to traditional coating methods, this cell-mediated approach not only allows to distribute PHA on the surface of the cryogel, but also ensures polymer penetration throughout the cryogel due to bacterial self-movement. This study opens doors for creating cryogels with tunable water vapor sorption and other additional functionalities through the use of specialized PHA variants.

FACILE SYNTHESIS OF CARBOXYMETHYL CELLULOSE (CMC) FROM AGRICULTURAL RESIDUES

Cellulose derivative products, such as carboxymethyl cellulose (CMC), which are used in the food, cosmetics, and pharmaceutical industries, but still rely on cotton-derived cellulose, can be made from oil palm fruit empty bunches (OPEFB) and rice straw. This study examined how sodium monochloroacetic acid (NaMCA) concentration (3, 6, and 9 g) affected the simple synthesis and characteristics of CMC from OPEFB and rice straw cellulose. OPEFB-derived CMC produced with NaMCA (9 g) had the lowest of brightness, while rice straw CMC was brighter. NaMCA modifications altered the onset temperature (Tonset), but not maximum degradation temperature (Tmax), according to thermal analysis. The onset temperatures of OPEFB and rice straw CMC were 40–62 °C and 67–183 °C, respectively. Commercial CMC has an onset temperature of about 27 °C. The EDX analysis showed that rice straw CMC had a higher degree of substitution (DS) of 0.34–1.37 than OPEFB CMC, which had 0.30-0.70. Oil palm empty fruit bunch (OPEFB) cellulose and rice straw cellulose offer a viable carboxymethyl cellulose (CMC) alternative. This process turns agricultural waste into valuable products and enables for their usage in numerous applications.

PH-responsive and mechanical strong chitosan-based hydrogel reinforced with rice straw cellulose micro-fibrils for efficient removal of cu(II)

Straw and chitosan are underutilized raw materials, which could make a significant contribution to sustainable development. Herein, a novel chitosan-based hydrogel incorporating rice straw cellulose micro-fibrils (SCMF) was prepared to effectively remove Cu(II). FTIR and SEM showed that straw cellulose-g-poly (acrylic acid)/chitosan-g-poly (acrylic acid) interpenetrating polymer networks were prepared and the hydrogel SCCH had a 3D porous structure after cross-linking with AA. The swelling properties of SCCH were studied and compared in various pH solution. The results indicated that SCCH replayed pH responsibility, which had the largest and smallest swelling capacity at pH9.18 and pH4.00 respectively. The pseudo-second-order kinetic model can be effectively used to evaluate swelling kinetics of hydrogels. The effects of contact time and initial concentration on Cu(II) ion removal were investigated. The equilibrium adsorption capacity (Qe) was 209.2 mg/g and the obtained results indicated that the adsorption kinetics conformed to the pseudo-second-order. Chemical adsorption combined with porous physical adsorption endowed SCCH excellent swelling and adsorption properties. Tensile, compression, bending and twisting test convinced that SCMF played a significant role on the improvement of mechanical strength. This novel 3D porous chitosan-based hydrogel was identified to be a promising sorbent with advantages of excellent sorption and mechanical properties.

Preparation and Characterization of Cellulose Derivatives from Agricultural Wastes

Background: Rice straw was pretreated with dilute alkaline and acid solutions to extract cellulose, which was then converted into cellulose acetate with acetic anhydride and phosphotungstic acid (H3PW12O40·6H2O). The concentration of KOH and the duration of immersion in acetic acid solution affected the removal of hemicellulose and lignin, and after pretreatment with 4% KOH and immersion in acetic acid for 5 hours, the treated rice straw contained 83wt.% cellulose. Phosphotungstic acid has been shown to be an excellent catalyst for the acetylation of rice straw cellulose. The degree of substitution (DS) values had a substantial effect on the solubility of cellulose acetate, and acetone-soluble cellulose acetate with DS values about 2.2 can be generated by varying the amount of phosphotungstic acid and acetylation duration. Objectives: The aim of the study was to evaluate the preparation and characterization of cellulose derivatives from agricultural wastes. Methods: This cross-sectional study was carried out in the Department of Communicable Diseases Control, Director General of Health Services, Dhaka, Bangladesh. For this investigation the rice plant straw was collected from Magura district region. The collected straws were then treated with 3 wt% nitric acid and 1.5 wt% NaOH solution separately. Statistical analyses of the results were be obtained by using window-based Microsoft Excel and Statistical Packages for Social Sciences (SPSS-24). Results: This study observed that the rice straw contained about 35.67% cellulose, 5.50% hemicellulose and 30.18 % α-cellulose. And the wheat straw contained about 43.99% cellulose, 7.30% hemicellulose and 36.70% α-cellulose. The degree of acetylation and degree of substitution of the synthesized cellulose acetate from rice straw were 39.046% and 2.413 respectively. On the other hand, the degree of acetylation and degree of substitution of the synthesized cellulose acetate from wheat straw were 40.79% and 2.59 respectively. ....

Comparative Examination of Cellulose Nanosphere from Corn Husk and Rice Straw

Cellulose nanosphere (CNS) is a novel material isolated through delignification, bleaching, acid hydrolysis, dialysis, and sonication of cellulose fibers from agricultural wastes such as corn husk and rice straw. Comparative examination through multiple characterizations of CNS from these cellulose sources was conducted to investigate its potential applications. Corn husk cellulose nanospheres (CHCNS) and rice straw cellulose nanospheres (RSCNS) were characterized by its chemical characteristics, crystallinity, surface morphology and thermal stability. FTIR showed the same transmittance patterns for both CNS samples. The peaks for CHCNS and RSCNS in the NMR analysis were comparable, and the presence of toluene enabled the CNS dissolve better in DMSO-d6. Higher crystallinity index was calculated in CHCNS than in RSCNS according to XRD analysis. TEM analysis demonstrated that CHCNS has shorter diameter than RSCNS. Lower onset degradation temperature relative to their corresponding bleached cellulose fiber was determined through TG Analysis. Biomedical applications such as drug delivery, wound dressings and tissue engineering are the most suitable applications based on the profiles of both CNS samples.

Cellulose extraction from rice straw waste for biodegradable ethyl cellulose films preparation using green chemical technology

A green process was devised to effectively extract cellulose from recycled rice straw waste, subsequently ethylating and modifying it into ethyl cellulose (EC), and ultimately blending the EC with ethanol to obtain biodegradable films. The optimal process conditions at each stage were investigated. An assessment was conducted on the crystallinity and thermal stability of rice straw cellulose (RSC), the degree of substitution of EC, and the biodegradability and mechanical properties of EC-ethanol films. The results demonstrated the following: The optimal process conditions resulted in a 95.73 % yield of extracted RSC, a type I crystalline structure, a 31.20 % increase in relative crystallinity, and thermal stability with a main weight loss peak at 340 °C. Under ideal ethylation conditions, the EC production reached 79.60 %, while the degree of substitution ranged from 2.0 to 2.5. After being landfilled in soil for 100 days, the EC-ethanol films degraded at rates of 6.77 %, 4.78 %, and 3.13 % (film concentrations were 0.02, 0.04, and 0.06 g/mL (w/v, EC/ethanol), respectively). Based on the analysis of the films' FT-IR and SEM images, it was concluded that the EC-ethanol films exhibit favorable biodegradability. Moreover, the tensile strength of 0.04 g/mL film reaches up to 44.60 MPa. Hence, the EC-ethanol films in this research could be an environmentally friendly and sustainable alternative to plastic films.

Characterization of biodegradable plastic from jackfruit seed waste with the addition of rice straw cellulose

Biodegradable plastic is an environmentally friendly plastic; most of the components come from renewable raw materials. Biodegradable plastic can be made from starch derived from waste such as jackfruit seeds. Biodegradable plastics made only from starch have poor physical and mechanical properties, so adding reinforcement such as cellulose is necessary. One of the wastes that contain cellulose is rice straw waste. This study aimed to obtain the best ratio of jackfruit seed starch and rice straw cellulose to biodegradable plastic’s physical and mechanical properties. This research was carried out experimentally using a Completely Randomized Design (CRD) with five treatments, namely the ratio of starch and cellulose PS1 (1:0,3), PS2 (1:0,4), PS3 (1:0,5) PS4 (1:0,6), and PS5 (1:0,7) with three repetitions, 15 experimental units were obtained. The data obtained was analyzed statistically using analysis of variance (ANOVA). If Fcount ≥ Ftable data is obtained, it will be continued with Duncan’s Multiple Range Test (DMRT) at the 5% level. The selected treatment was PS5 (starch ratio 1:0,7 cellulose) with had water absorption rate of 34,82%, water vapor transfer rate of 19,12 g/m2hour, tensile strength of 20,21 MPa, elongation of 5,33%, and biodegradation for 6 days. The results showed that the addition of rice straw cellulose had a significant effect on the value of water absorption, water vapor transfer rate, tensile strength, elongation and biodegradation of the resulting biodegradable plastic.

FEASIBILITY STUDY ON PREPARATION OF RICE STRAW NONWOVEN COATED WITH CHITOSAN FOR REACTIVE DYE ADSORPTION

Rice straw is the most abundant agricultural waste material in Thailand. Therefore, this research was interested in utilizing rice straw and adding value by preparing a reactive dye bioadsorbant. The aims of this research were to prepare rice straw nonwovens by the wet-laid process, study chitosan-coated nonwovens by the dip coating method, and evaluate the reactive dye adsorption capacity of the coated nonwovens. The ratio of weight per unit area of the prepared nonwovens was controlled. The nonwovens were dipped in chitosan solutions (0.5, 1, and 1.5 wt% of chitosan) to prepare chitosan coated nonwovens. Reactive dye adsorption capacity, chemical structure, morphology, and physical properties of the nonwovens were investigated. It was found that rice straw nonwoven coated with chitosan increased in thickness, hardness, and water resistance properties with increasing chitosan concentration. Chitosan-coated nonwoven, at 15% chitosan concentration and a contact time of 72 hours, was able to adsorb 38.40% of the reactive azo dye, C.I. Reactive Blue 194 (50 mg/L). The dye absorbency of the chitosan-coated nonwovens increased with the increase in the chitosan-coated concentration and the contact time. In addition, the chitosan-coated nonwovens could remain on rice straw cellulose nonwoven surfaces under reactive dye immersion for at least 72 hours without change. The results indicated that rice straw nonwovens coated with chitosan by the dip coating method had reactive dye adsorption abilities.

Chemical Composition And Surface Images Of Untreated And Urea-Treated Rice Straw As Inf uenced By Days After Threshing

The purpose of this study was to evaluate the chemical composition and changes in the surface structure of rice straw as affected by the number of days of exposure to the field prior to processing. A total of 24 packs of rice straw samples collected at 1 day after threshing (DAT), 4 DAT, and 7 DAT field exposure untreated and treated with urea for 10 days were analyzed for its chemical changes using proximate analysis and surface structure of the fiber compounds through scanning electron microscopy (SEM). Results (%DM basis) showed that 1DAT untreated rice straw obtained the highest dry matter (DM) concentration at 94.61%. Seven DAT untreated rice straw contain the highest amount of Ash at 20.92%. Likewise, 1 DAT and 7 DAT untreated rice straw contains higher levels of crude protein (CP) at 9.60% and 9.79%, respectively. Ether extract (EE) was observed highest in 1DAT untreated rice straw at 1.97%. Considerable breakdown of cellulose, hemicellulose, and lignin fractions of rice straw was attained in 4DAT and 7DAT untreated, and 1 to 7 DAT urea-treated rice straw (UTRS) as evident by its lower NDF, ADF, and ADL values. Changes in the surface structures of microfibers efficiently captured using SEM showed the differences in the morphology of the fibers as influenced by number of days exposed to the field prior to treatment. Therefore, in order to optimize the protocol to improve the feeding and nutritional quality of rice straw, it is suggested that the number of days of exposure to the field be considered prior to processing. Likewise, UTRS is an effective method to disintegrate the complex fibrous compounds of the cell wall of rice straw.

Analisis Sifat Fisis dan Mekanik Biodegradable Foam Berbahan Dasar Selulosa Jerami Padi dan Polivinyl Alcohol

Research has been carried out on analyzing the physical and mechanical properties of biodegradable foam made from rice straw cellulose with a polyvinyl alcohol binding matrix. This study aims to produce a substitute for styrofoam, which is considered not environmentally friendly and harmful to health. The composition of straw fiber and polyvinyl alcohol was varied by the mass ratio of the mixture of rice straw fiber and PVA (%) 40:20%, 30:30%, 20:40%, 50:10%, with the size of the fiber passing through the 80 mesh sieve. The results of the characterization using FT-IR showed that the highest content of functional groups was carbon (C), which corresponds to the content of conventional biofoam, which consists of the elements carbon (C) and hydrogen (H). The highest biofoam tensile strength value is in the comparison fraction (20:40%) of 18.11 MPa. The highest percentage of biofoam water absorption was obtained in the fraction ratio (50:10%) of 0.8928% in the treated sample and 1.1928% in the untreated sample. The percentage of biofoam water content closest to conventional biofoam water content is obtained at a fraction ratio (40:20%) of 0.78%. The highest degradation rate was obtained in samples with a comparative fraction (50:10%) of 0.04237%/day in treated and 0.06403%/day in untreated samples. The results of this study stated that the resulting biofoam did not contain harmful substances. After identifying the functional groups using the FT-IR test, the tensile strength of biofoam still did not meet the SNI 7188.7: 2016 bioplastic standard.

Characterization of lignin and hemicellulose degrading bacteria isolated from cow rumen and forest soil: Unveiling a novel enzymatic model for rice straw deconstruction

Application of greener pretreatment technology using robust ligninolytic bacteria for short duration to deconstruct rice straw and enhance bioethanol production is currently lacking. The objective of this study is to characterize three bacterial strains isolated from the milieux of cow rumen and forest soil and explore their capabilities of breaking down lignocellulose – an essential process in bioethanol production. Using biochemical and genomic analyses these strains were identified as Bacillus sp. HSTU-bmb18, Bacillus sp. HSTU-bmb19, and Citrobacter sp. HSTU-bmb20. Genomic analysis of the strains unveiled validated model hemicellulases, multicopper oxidases, and pectate lyases. These enzymes exhibited interactions with distinct lignocellulose substrates, further affirmed by their stability in molecular dynamic simulations. A comprehensive expression of ligninolytic pathways, including β-ketoadipate, phenyl acetate, and benzoate, was observed within the HSTU-bmb20 genome. The strains secreted approximately 75–82 U/mL of cellulase, xylase, pectinase, and lignin peroxidase. FT-IR analysis of the bacterial treated rice straw fibers revealed that the intensity of lignin-related peaks decreased, while cellulose-related peaks sharpened. The values of crystallinity index for the untreated control and the treated rice straw with either HSTU-bmb18, or HSTU-bmb19, or HSTU-bmb20 were recorded to be 34.48, 28.49, 29.36, 31.75, respectively, which are much higher than that of 13.53 noted for those treated with the bacterial consortium. The ratio of fermentable cellulose in rice straw increased by 1.25-, 1.79-, 1.93- and 2.17-fold following treatments with HSTU-bmb18, HSTU-bmb20, HSTU-bmb19, and a mixed consortium of these three strains, respectively. These aggregative results suggested a novel model for rice straw deconstruction utilizing hydrolytic enzymes of the consortium, revealing superior efficacy compared to individual strains, and advancing cost-effective, affordable, and sustainable green technology.

Controlled release fertilizer delivery system derived from rice straw cellulose nanofibres: a circular economy based solution for sustainable development

ABSTRACTRecently, the development of sustainable and environmentally friendly biomaterials has gained the attention of researchers as potential alternatives to petroleum-based materials. Biomaterials are a promising candidate to mitigate sustainability issues due to their renewability, biodegradability, and cost-effectiveness. Thus, the purpose of this study is to explore a cost-effective biomaterial-based delivery system for delivering fertilizers to plants. To achieve this, rice straw (agro-waste) was selected as a raw material for the extraction of cellulose. The cellulose was extracted through alkali treatment (12% NaOH), followed by TEMPO-based oxidation. The cellulose nanofibers were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, and transmission electron microscopy. In scanning electron microscopy, a loosening of the fibrillar structure in cellulose nanofibers (CNFs) was observed with a diameter of 17 ± 4 nm. The CNFs were loaded with nitrogen-based fertilizer (ammonium chloride) in 1:1, 1:2, and 2:1 (w/w) proportions. The loading was estimated through surface charge variation; in the case of the 1:1 sample, maximum reductions in surface charge were seen from −42.0 mV to −12.8 mV due to the binding of positive ammonium ions. In the release kinetics study, a controlled release pattern was observed at 1:1, which showed a 58% cumulative release of ammonium ions within 8 days. Thus, the study paves the way for value-added uses of rice straw as an alternative to the current environmentally harmful practices.

Differentiated Fractionation of Various Biomass Resources by p-Toluenesulfonic Acid at Mild Conditions.

Biomass is the ideal substitute for petrochemical resources because of its renewable and abundant sources. p-Toluenesulfonic acid (p-TsOH) can effectively separate lignin from biomass under mild conditions, so it is highly expected in biomass fractionation to improve the utilization efficiency. In this study, we investigated the effect of p-TsOH differentiated fractionation of poplar sawdust, eucalyptus sawdust, and rice straw below 100 °C. According to the experimental results, upon pretreatment by p-TsOH of the three kinds of raw biomass, most of the lignin and hemicellulose of poplar sawdust and eucalyptus sawdust were removed, whereas the cellulose was retained, but most of the hemicellulose and cellulose of rice straw were kept, whereas the lignin was removed at similar conditions. The structures and compositions of pretreatment residues, lignin, and hemicellulose extracted from raw biomass were characterized by XRD, FTIR, HSQC-NMR, XPS, and SEM. The differentiated fractionation mechanism of biomass was analyzed. A better recognition and understanding of the factors affecting biomatrix opening and fractionation will allow for the identification of new pretreatment strategies that improve biomass utilization and permit the rational enzymatic hydrolysis of cellulose.

Protonation of Surface Carboxyls on Rice Straw Cellulose Nanofibrils: Effect on the Aerogel Structure, Modulus, Strength, and Wet Resiliency.

Rice straw cellulose nanofibrils from the optimal 2,2,6,6-tetramethylpiperidine-1-oxyl oxidation/blending process carrying 1.17 mmol/g surface carboxyls were protonated to varying charged (COO-Na+) and uncharged (COOH) surfaces. Reducing the electrostatic repulsion of surface charges by protonation with hydrochloric acid from 11 to 45 and 100% surface carboxylic acid most prominently reduced the aerogel densities from 8.0 to 6.6 and 5.2 mg/cm3 while increasing the mostly open cell pore volumes from 125 to 152 and 196 mL/g. Irrespective of charge levels, all aerogels were amphiphilic, super-absorptive, stable at pH 2 for up to 30 days, and resilient for up to 10 repetitive squeezing-absorption cycles. While these aerogels exhibited density-dependent dry [11.3 to 1.5 kPa/(mg/cm3)] and reduced wet [3.3 to 1.4 kPa/(mg/cm3)] moduli, the absorption of organic liquids stiffened the saturated aerogels. These data support protonation as a critical yet simple approach toward precise control of aerogels' dry and wet properties.

Integrated Biobased Processes for Nanocellulose Preparation from Rice Straw Cellulose

High-potential nanomaterials were derived from rice straw using the integrated biobased processes of enzymatic hydrolysis with green organic acid hydrolysis assisted with ultrasonication pretreatment. The optimization condition of nanocellulose preparation by enzymatic hydrolysis via central composite design (CCD) achieved a maximum nanocellulose content of 32.37 ± 0.47% using a cellulase concentration of 107.06 U/mL and 0.13% (w/w) of rice straw cellulose. The ultrasonication-assisted pretreatment prior to enzymatic hydrolysis improved nanocellulose preparation to 52.28 ± 1.55%. Integration with oxalic acid hydrolysis increased the nanocellulose content to 64.99 ± 0.16%. Granular nanocellulose was obtained and consisted of a 105–825 nm nanosize with a zeta potential value of −34.5 mV, and nanocellulose suspension showed high stability without aggregation. In addition, the remaining rice straw cellulose after oxalic acid was microcrystalline nanocellulose. All prepared nanocellulose represented a functional group as original cellulose but had a low crystallinity index (CrI) of 15.68% that could be classified as amorphous nanocellulose. Based on their characteristics, all nanocellose could be further applied in food, cosmetics, and pharmaceuticals. Moreover, the results indicated that the rice straw could be an alternative non-edible cellulose source for preparing potential nanocellulose via a controlled hydrolysis process.

Influence of the cellulose purification process on the properties of aerogels obtained from rice straw

Cellulose aerogels were obtained from purified rice straw cellulose fibres (CF) by applying different extraction methods: the conventional alkaline treatment (ALK) and alternative aqueous extraction based on the ultrasound combined with reflux heating (USHT) and subcritical water extraction (SWE) (160 and 180 °C). The composition and properties of the CFs were significantly affected by the purification process. The USHT treatment was as efficient as the ALK at eliminating the silica content, but the fibres maintained a notable ratio of hemicellulose (∼16 %). The SWE treatments were not so effective at removing silica (15 %) but greatly promoted the selective extraction of hemicellulose, especially at 180 °C (3 %). The CF compositional differences affected their hydrogel formation capacity and the properties of aerogels. A higher hemicellulose content in the CF led to better-structured hydrogels with better water-holding capacity, while the aerogels exhibited a more cohesive structure with thicker walls, higher porosity (99 %) and water vapour sorption capacity, but lower liquid water retention capacity (0.2 g/g). The residual silica content also interfered with the hydrogel and aerogel formation, giving rise to less structured hydrogels and more fibrous aerogels, with lower porosity (97–98 %).

Analysis of Mechanical Properties of Bioplastics Based on Banana Peel Starch with Variations of Rice Straw Cellulose

Analysis of Mechanical Properties of Bioplastics Based on Banana Peel Starch with Variations of Rice Straw Cellulose

Synthesis of Bioplastics on Rice Straw Cellulose Using Orange Peel Extract, Chitosan, and Sorbitol

With the use of several plasticizers (orange peel extract, chitosan, and sorbitol), rice straw cellulose has been used to synthesize and characterize bioplastics. This study aims to synthesize and characterize bioplastics from rice straw cellulose with various additions of plasticizers, namely orange-peel extract, chitosan, and sorbitol, each with a certain concentration so that quality improvement can occur. The methods used in this study include testing the tensile strength value, testing the percentage elongation, and testing the percentage of biodegradation. In addition, functional group characterization tests were also carried out using FTIR. The results obtained in this study were the best values for tensile strength and percentage elongation in treatment A, namely 10.2611 MPa and 13.88%. The percentage of biodegradation for 7 days reached 50.58%. Functional group absorptions were found in various plasticizers, namely C-H, O-H, C-O, C-N, and C=C. Based on existing data, bioplastics synthesized using rice straw cellulose in various plasticizers meet JIS (Japan Industrial Standards).

Gamma-induced grafting of rice straw cellulose with polyvinylpyrrolidone

Cellulose obtained from rice straw was grafted with polyvinylpyrrolidone (Cell-g-PVP). The process was induced by simultaneous gamma iradiation (Co-60). The presence of the grafted PVP chains was confirmed by FT-IR, XRD and EDS methods. The influence of the iradiation dose (20 and 30 kGy) on the reaction efficiency and thermal stability of Cell-g-PVP was investigated. The grafting yield at the dose of 30 kGy was about 56%. The higher dose of radiation resulted in better thermal stability. The AAS results showed that Ni(II), Cu(II), and Cr(II) ions can be adsorbed by Cell-g-PVP. The order of ion metals adsorption capacity of Cell-g-PVP was Cu(II) > Ni(II) > Cr(II). The adsorption isotherm of Cu(II) metal ion using the Cell-g-PVP followed the Langmuir adsorption isotherm whereas the chemical adsorption and the adsorption energy were constant on all sides of the copolymer.