Grafting Yield Research Articles

Graft copolymerization of carboxymethylcellulose with solketal acrylate

The objective of this work is to synthesize new materials based on cellulose fiber. In this study, we presented the synthesis of a new biomaterial by conducting graft polymerization of 2,2-dimethyl-1,3-dioxolan-4-yl methyl acrylate (DMDMA solketal acrylate) onto carboxymethylcellulose (CMC), using KPS as an initiator. We conducted several experiments to determine the optimal conditions for preparing this biopolymer, varying the reaction time and the ratio between the initiator and the monomer. The results revealed that the highest grafting yield, 52%, was obtained after 72 min at 65 °C, with 6.26 mmol of KPS/eq OH and 4.43 moles of DMDMA/eq OH, using THF as a solvent. FTIR spectroscopy confirmed the grafting of monomers onto the CMC. Thermogravimetry showed that the degradation of the grafted CMC occurs in two stages, unlike the degradation of the CMC, which occurs in a single stage, confirming the modification of the starting product. SEM images clearly show the morphological difference between the CMC and the grafted CMC. The BET analysis reveals moderate adsorption at low pressure, followed by a marked increase at high pressure, indicating the presence of mesopores. The hysteresis between adsorption and desorption also suggests closed pore structures. The pore size distribution shows a predominance of pores between 30 and 100 Å, providing an optimal specific surface area for small molecule adsorption and catalytic reactions. This mesoporous profile is suitable for adsorption and catalysis applications. To our knowledge, our study represents the first use of the synthesized monomer, DMDMA solketal acrylate, for grafting onto the structure of CMC, highlighting the originality of our research.

Kinetic and isotherm studies on the adsorption of ionic liquids from aqueous solutions by carboxymethyl cellulose modified with sodium methacrylate sulfonate

A novel carboxymethyl cellulose (CMC) graft copolymer (CMC-g-PSMAS) was successfully synthesized by grafting sodium methacrylate sulfonate (SMAS) onto CMC. The resulting CMC-g-PSMAS was used to absorb 1-allyl-3-methylimidazole chloride ([Amim]Cl) ionic liquid. The effects of different experimental factors such as monomer dosage, temperature and time on the grafting yield were systematically studied. Adsorption studies demonstrated that the adsorption equilibrium could be achieved within 60 min. The theoretical maximum adsorption capacity of CMC-g-PSMAS for [Amim]Cl reached 69.2 mg·g−1. Compared to several kinetic and isothermal models, the adsorption process of [Amim]Cl onto CMC-g-PSMAS could be well-described by the pseudo-second-order model (R2 = 0.991) and the Langmuir model (R2 = 0.999), which was a typical chemical adsorption process. Adsorption thermodynamics analyses at 25 °C revealed that the adsorption process was spontaneous (ΔG = −33.37 KJ·mol−1) and exothermic (ΔH = −56.52 KJ·mol−1). The adsorption capacity of CMC-g-PSMAS was 35.3 mg·g−1 after eight cycles, indicating its good stability and recyclability. As a consequence, CMC-g-PSMAS was efficient in the adsorption of [Amim]Cl, which could be a potential candidate for removing ionic liquids in aqueous environments.

Gamma radiation induced optimized synthesis of amine functionalised poly-glycidyl methacrylate grafted poly-propylene non-woven fabric and its adsorption behaviour towards aqueous Pb(II)

Comprehensive optimization of the functionalization of polypropylene (PP) non-woven fabric through gamma irradiation-induced graft polymerization of glycidyl methacrylate (GMA), results in a material having high grafting yield. The technique, utilizing a mutual irradiation method, produced poly-GMA (PGMA) grafted PP fabric with a remarkable grafting yield of 125 % in a 1:1 acetone–water mixture, subjected to 25 kGy of total dose at a dose rate of 5 kGyh−1. The enhancement of the amination process utilizing PGMA-grafted PP was investigated with polyamines. Under the optimized conditions, the diethylene triamine (DETA) functionalized variant was identified as an effective adsorbent for aqueous Pb2+ ions. The optimized adsorbent exhibited a high saturation capacity of approximately 230 mgg−1 for Pb2+ ions, demonstrating rapid kinetics at near-neutral pH and 25 °C. This low cost innovative material holds significant promise for effective lead removal from drinking water and industrial wastewater, offering a sustainable economical solution for environmental remediation.

Interferometric analysis of the opto‐mechanical properties for polyamide‐6 antimicrobial fibers

AbstractPolyamide‐6 fibers were modified for use as antimicrobial fibers using two complementary methods: grafting with polyacrylic acid and silver nanoparticle treatment. The grafted samples exhibited different grafting yields of 7%, 8.8%, 10%, and 20.7%. Subsequently, two grafted samples (7% and 20.7% yields) were treated with silver nanoparticles (Ag NPs). The grafting process and the silver nanotreament were successfully confirmed using FTIR spectroscopy and SEM microscopy. Shake‐ flask method was used to study the cell viability of nanotreated samples. A two‐beam Mach–Zehnder interferometer was used to characterize the opto‐mechnaical and structural properties of the modified samples. For this purpose, a mechanical drawing device was equipped with the interferometer. The results indicated that with increasing grafting yield, optical properties decreased in both directions of light vibration. A fitting method was employed to calculate intrinsic optical properties that help to determine structural properties. Mechanical properties, including tensile strength and elongation at break, were also examined. Treatment of the grafted samples with silver nanoparticles improved their optical, mechanical, and antimicrobial properties. These findings confirmed that the PA‐6‐g‐PAA 20.7%‐t‐Ag NPs sample is suitable for various medical applications. Figures and tables are provided for illustration.Highlights PA‐6 fiber has been modified for medical applications by complementary processes. Grafting process introduced additional functional groups and enhanced ductility. Ag nano‐treatment gives the grafted PA‐6 fiber good antimicrobial activity. Interferometry precisely characterizes structural and opto‐mechanical properties. PA‐6‐g‐PAA20.7%‐t‐Ag NPs sample has good mechanical and antimicrobial properties.

One pot gamma radiation mediated interfacial engineering of P-N synergistic flame retardant and antibacterial cellulose fabric: novel fabrics for future applications

The work describes an ionizing radiation mediated, toxic solvent free interfacial engineering of a novel Phosphorus-Nitrogen functionalized bifunctional cotton cellulose fabric (BCF) endowed with flame retardant (FR) and antibacterial properties. Monomers bis[2-(methacryloyloxy)ethyl] phosphate (B2MEP) and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MAETC) in different proportions were co-grafted onto cellulose fabric via 60Co radiation mediated Simultaneous Irradiation Grafting Process (SIGP) to incorporate Phosphorus and Nitrogen functionalities. Effects of radiation dose, monomer concentration on the grafting yield (GY) were investigated and samples were characterized using TGA, ATR-FTIR, XRD, SEM–EDX, EDXRF, CHN Elemental Analysis and XPS analytical techniques. Limiting oxygen index (IS:13501/ASTM D 2863) and vertical flammability tests (IS11871-1986) were conducted to establish the halogen free, P-N synergistic FR properties of the fabric. All the co-grafted samples were observed to possess LOI values in excess of 30%, while BCF (1:2) (GY = ~ 44%) demonstrated LOI of 32% with the least char length of 74 mm in the vertical flammability tests. Tear strength studies were carried out as per ASTMD 1424-09. Antibacterial assay revealed that the fabric possessed activity against both gram positive (S. aureus) and gram negative (E. coli) organisms, with BCF (1:4) (GY = ~ 48%) demonstrating complete killing of ~ 5 log cycles for both microorganisms in 24 h. BCF retained its FR and antibacterial properties even after multiple washing cycles. With its bonafide green credentials, durability and unique properties, multifunctional BCF fabric prepared under optimized conditions of P/N ratio > 1.7 and GY ~ 45% can be a potential candidate for future applications.

Synthesis of ion exchange film based on chemical grafting of styrene onto polyethylene/EPDM rubber blend for thorium removal.

Chemical grafting of low-density polyethylene film blended with ethylene propylene diene monomer rubber (PE/EPDM) using styrene monomer followed by a sulfonation process was investigated. Different factors affecting the grafting process, such as monomer and initiator concentrations, time of reaction, and grafting temperature, were studied. Sulfonation of the grafted films was carried out using chlorosulfonic acid in dichloromethane. Characterization of the grafted and sulfonated films was performed using ATR-FTIR, SEM, TGA, and XRD instruments. The grafting was successfully performed in aqueous media using sodium bisulfite as initiator, reaching a grafting yield of 130% and an ion exchange capacity of 1.2 meq/g. The removal of thorium ions from aqueous solution was studied using the obtained ion exchange films. The results showed that the maximum adsorption capacity of Th(IV) was 177.5 mg. g-1 (pH = 3, 298 K and 60 min). Removal isotherm and Kinetics were investigated, and the results revealed that the adsorption process was chemisorption homogeneous monolayer adsorption, exothermic, and spontaneous.

Emulsion graft polymerization of glycidyl methacrylate onto bamboo fiber composites for efficient removal of lead ions from aqueous solutions

The emulsion graft polymerization process was used to synthesize a novel polyglycidyl methacrylate grafted silanized bamboo fiber composites. The grafting percentage was assessed by varying surfactant, initiator and monomer concentrations. The surface morphologies and thermal behavior of the biocomposites were analyzed using FTIR, SEM, XRD and TGA techniques. In batch adsorption studies, the effect of adsorption parameters like pH, adsorption time, adsorbent dose and solution temperature were examined on the adsorption efficiency of lead ions. The adsorption capacity of biosorbent composites was enhanced through conversion of epoxy group of Poly glycidyl methacrylate (PGMA) into sulfonic acid groups via sulfonation process. The sulfonic acid groups were incorporated into VMBF-g-PGMA by stirring the grafted sample in H2SO4 (98 %) for 2 h at 90 °C to obtain sulfonated grafted polymer (VMBF-g-PGMA-S). By increasing the concentration of monomers up to 5 %, the maximum grafting percentage (289 %) was achieved. The grafting % increases rapidly from 0.5 to 0.20 g initiator and at 0.20 g of initiator, the highest grafting yield was 512 %. The maximum Pb+2 adsorption capacity of adsorbent was 200 mg/g. The thermodynamic parameters for pb+2 adsorption revealed an exothermic and spontaneous nature of sorption process, and the entropy change showed that there are no substantial structural changes occurred in biosorbent material. The experimental results confirmed that sulfonated biosorbent composites are effective, economical, and promising adsorbent which could be used for removal of lead and other ions from aqueous solution.

Anion exchange membrane with enhanced alkaline stability through radiation grafting of ETFE for solid polymer electrolytes

AbstractSolid polymer electrolyte membranes are considered as the nub of many electrochemical devices. Given the climate crisis and related concerns, the evolution of new membrane materials to support the sustainable systems is inevitable. Building on recent advances with the radiation technique and polymer chemistry, herein, anion exchange membranes (AEMs), ETFE‐g‐1VIm/4VP, were fabricated through graft copolymerization of vinyl heterocyclic monomer binary mixture, such as 1‐vinylimidazole (1‐VIm) and 4‐vinylpyridine (4‐VP) onto ethylene tetrafluoroethylene (ETFE), a main polymer backbone without aryl ether bonds. The grafting reaction was achieved at 60°C and then followed by quaternization as a subsequent step. The effects of various reaction grafting conditions were investigated. The ETFE‐g‐1VIm/4VP AEM were characterized w.r.t the morphological and structural features. The dense surface of the grafted membranes is proved by field emission‐scanning electron microscopy (FE‐SEM) images, which also show that the vinyl entities are clearly distributed in the prepolymer, which may lead to a continuous ion transport channel. AEMs processed from the highest graft yield showed good hydroxide conductivity at 90°C, reaching 16.9 mS/cm due to the presence of more transport sites. The same membrane has a relatively good alkaline stability, which is studied through weight percentage method and FT‐IR. Hence, we assume that the introduction of multi‐cationic moieties, pyridinium and imidazolium, contributes to the performance of anion exchange membranes and makes a perfect balance, especially the hydrophilicity and hydrophobicity. These data highlight the potential of the copolymer as an anion exchange membrane for wide spectra of electrochemical applications.Highlights AEMs based on ETFE‐g‐1VIm/4VP are developed via radiation grafting. The membrane exhibits remarkable alkaline stability. FT‐IR, SEM, and weight percentage methods were used to prove the alkaline stability. The membrane has the potential to be used for different electrochemical applications.

An intensive exploration of plasticization, tensile, flexural and ecotoxicity of styrene-grafted thermoplastic starch (TPS) composite material

Thermoplastic starch (TPS) is a potential alternative to non-biodegradable plastics. Nevertheless, nice hydrophilicity, poor mechanical property and processability restrain use. Herein, pure corn starch was modified by styrene grafting, then, plasticized by glycerol to prepare TPS composite material. Later, plasticizing behavior, thermal-stability, mechanical property, ecotoxicity, etc. were explored. Main results reveal that styrene was successfully grafted to starch achieving a grafting yield (GY) as 45.58 wt% and grafting converted starch crystalline shape transformation from A to V. Glycerol plasticization furtherly altered crystalline structure and surface wettability. To native species, plasticization induced amorphization; to grafted species, it induced crystalline perfection. Compared to native species grafted starch displayed easier plasticization characteristic and better processability, elevated hydrophobicity and mechanical property. Herein, a glycerol content as 20 wt% is proper. From native to grafted TPS composite material tensile, flexural strengths and modulus were elevated from 8.9, 20.9 and 777–24.2, 56.5 and 1924 MPa. A more important issue is that styrene grafted TPS composite material composting products displayed no-visible ecotoxicity. Where, wheat and mung seeds germination rates and plant fresh and dry masses in systems containing 10 wt% previous TPS composting products are all higher than 90 % those of blank compositing systems, which is in line with EN 13432–2000 standard, non-toxic to environment. It seems via some level styrene grafting possessing nice mechanical property and non-visible ecotoxicity starch material can be prepared, possibly having a potential use in plastic industry in real, which is of great significance and attractive.

Optimization of Yucca filamentosa fiber based graft copolymer through response surface methodology and evaluation of physico-chemical properties

The study of the physico-chemical modification of Yucca filamentosa (Yf) natural fiber by graft copolymerization with ethylmethacrylate using ferrous ammonium sulfate-potassium persulfate as a redox initiator has been reported in the article. Initially, six process parameters; reaction duration, reaction temperature, solvent amount, pH, FAS:KPS ratio, and monomer concentration were used in the study in a sequential experimental design technique, and the significant process variables affecting the yield of the graft copolymer were identified. The Resolution-V design method identified the significant parameters as the reaction temperature, amount of solvent, and the concentration of monomer. In second phase of the study, the screened variables were utilized in the development of a model through the technique of response surface methodology (RSM) for the prediction of the yields, and its optimization. The developed RSM model fitted well with the experimental data, and predicted for the optimal conditions of reactions as temperature 50 °C, solvent 100 ml, and the monomer 3.05 × 10−3 mol/L; at which the highest graft yield percentage obtained was 124.2%. The techniques of FTIR, SEM, and XRD were used for the characterization graft copolymers. Studies of the various physico-chemical properties showed that the produced graft copolymers were more resistant than the natural fibers.

Transparent, thermal stable, water resistant and high gas barrier films from cellulose nanocrystals prepared by reactive deep eutectic solvents

Nanocellulose-based film, as a novel new type of film mainly made of nanosized cellulose, has demonstrated an ideal combination of renewability and enhanced or novel properties. Considerable efforts have been made to enhance its intrinsic properties or create new functions to expand its applications, such as in food packaging, water treatment or flexible electronics. In this paper, two different types of deep eutectic solvents (guanidine sulfamate-glycerol and guanidine sulfamate-choline chloride) were formulated and applied to prepare cellulose nanocrystals with dialdehyde cellulose (DAC). The effects of reaction conditions including time, temperature and cellulose-DES ratio on the grafting degree and yield were studied. After ultrasonication, two types of CNCs, with an average diameter of 3–5 nm and an average length of 140.7–204.2 nm, were obtained. The synthesized CNCs displayed an enhanced thermal stability compared to pristine cellulose. Moreover, highly transparent (light transmittance higher than 90 %) and water stable nanocellulose based films (a wet tensile strength of higher than 30 MPa after immersing in water for 24 h) were fabricated. Besides, the obtained films exhibited low oxygen transmission rate, showing a good potential application in food packaging.

Efficient removal of p-nitrophenol from water by imidazolium ionic liquids functionalized cellulose microsphere

Removing p-nitrophenol (PNP) from water resources is crucial due to its significant threat to the environment and human health. Herein, imidazolium ionic liquids with short/long alkyl chain ([C2VIm]Br and [C8VIm]Br) modified cellulose microspheres (MCC-[C2VIm]Br and MCC-[C8VIm]Br) were synthesized by radiation method. To examine the impact of adsorbent hydrophilicity on adsorption performance, batch and column experiments were conducted for PNP adsorption. The MCC-[C2VIm]Br and MCC-[C8VIm]Br, with an equivalent molar import amount of ionic liquids, exhibited maximum adsorption capacities of 190.84 mg/g and 191.20 mg/g for PNP, respectively, and the adsorption equilibrium was reached within 30 min. Both adsorbents displayed exceptional reusability. Integrating the findings from XPS and FTIR analyses, and AgNO3 identification, the suggested adsorption mechanism posited that the adsorbents engaged with PNP through ion exchange, hydrogen bonds and π-π stacking. Remarkably, the hydrophobic MCC-[C8VIm]Br exhibited superior selectivity for PNP than the hydrophilic MCC-[C2VIm]Br, while had little effect on adsorption capacity and rate. MCC-[C8VIm]Br-2 with high grafting yield increased the adsorption capacity to 327.87 mg/g. Moreover, MCC-[C8VIm]Br-2 demonstrated efficient PNP removal from various real water samples, and column experiments illustrated its selective capture of PNP from groundwater. The promising adsorption performance indicates that MCC-[C8VIm]Br-2 holds potential for PNP removal from wastewater.

Better liver transplant outcomes by donor interventions?

Donor risk factors and events surrounding donation impact the quantity and quality of grafts generated to meet liver transplant waitlist demands. Donor interventions represent an opportunity to mitigate injury and risk factors within donors themselves. The purpose of this review is to describe issues to address among donation after brain death, donation after circulatory determination of death, and living donors directly, for the sake of optimizing relevant outcomes among donors and recipients. Studies on donor management practices and high-level evidence supporting specific interventions are scarce. Nonetheless, for donation after brain death (DBD), critical care principles are employed to correct cardiocirculatory compromise, impaired tissue oxygenation and perfusion, and neurohormonal deficits. As well, certain treatments as well as marginally prolonging duration of brain death among otherwise stable donors may help improve posttransplant outcomes. In donation after circulatory determination of death (DCD), interventions are performed to limit warm ischemia and reverse its adverse effects. Finally, dietary and exercise programs have improved donation outcomes for both standard as well as overweight living donor (LD) candidates, while minimally invasive surgical techniques may offer improved outcomes among LD themselves. Donor interventions represent means to improve liver transplant yield and outcomes of liver donors and grafts.

A synthesis of styrene-grafted starch accompanied with reaction condition optimization and microstructural and macroscopic property analysis

Styrene grafting is efficient to alter starch macroscopic property. Nevertheless, reaction mechanism, condition and products structure and properties are blurry. A deep exploration is necessary. Herein, K2S2O8 and styrene were chosen for corn starch modification. Reaction conditions involving K2S2O8 and styrene amounts, temperature and period were explored. Concurrently, microstructural and macroscopic properties of modified starches were explored via FT-IR, XPS, 13C NMR, GPC, XRD, SEM, TGA, DSC, CA and water dispersibility analysis. Main results reveal that K2S2O8 and styrene amounts, temperature and period as 3 and 200 wt%, 50 °C and 3 h is an optimized condition for starch grafting styrene, achieving a grafting yield (GY) as 45.8 wt%. GPC, XPS and 13C NMR analysis certified successful grafting and grafting mainly occurred at C-3 site OH within glucose unit. This variation converted starch crystalline shape transformation from A-typed to V-typed accompanied with crystallinity, thermal-stability and swelling characteristic decrease and surface hydrophobicity elevation. With GY increased from 0 to 45.8 wt% crystallinity decreased from 38.7 to 15.1%, thermal-decomposition temperature decreased by 10 °C, gelatinization temperature and CA increased by 50 °C and 70°, respectively. It seems a small amount styrene grafting can alter starch macroscopic property such as hydrophilicity efficiently, readily to manufacture hydrophobic starch. This hydrophobic starch might have a potential use in plastic industry, enlarging starch use application, meaningful.

Surface-modified PVDF membranes for separation of dye by forward osmosis

Modification of membranes is widely used for altering their separation properties. In this study, the modification of PVDF nanofiber mat by deposition of polyamide layers was evaluated to improve dye recovery by means of forward osmosis process. The polyamide active layer was prepared by a reaction of cyclic aromatic amines, m-phenylenediamine, or piperazine, and trimesoylchloride. The modification progress was monitored by FTIR analysis, water uptake, nitrogen content, and grafting yields. Investigated membranes showed an excellent dye separation features with water flux and dye fluxes strongly related to type of applied amines and reaction time. The best obtained membrane demonstrated outstanding performance in forward osmosis; their water flux was 3.3 LMH and rejection rate of 97% for bromocresol green dye. The membrane allowed increase dye concentration by 50% after 24 h of the process.

Design of Silk Fabric Surface with Enhanced Antiseptic Properties through Graft Modification and Iodophor Integration

AbstractTo improve the hydrophobic character of silk and impart iodine complex ion adsorption, the surface of woven silk fabric is enriched by different functional groups through the grafting of N‐vinylpyrrolidone (NVP), ethylene glycol dimethacrylate (EGDMA), and their mixtures (NVP–EGDMA). The dominant fibrous texture of silk enables an efficient graft copolymerization in terms of high grafting yield (>30%) after applying a mild degumming process. The structural and morphological alterations in the silk surface are evidenced with attenuated total reflectance‐fourier transform infrared spectroscopy (ATR‐FTIR), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. The imparted hydrophilicity property of the samples is revealed by contact angle–wetting time measurements. The usability of the graft‐modified samples as an iodophor polymeric substrate is then examined by treatment with I2/KI solutions, and the results are monitored using UV–vis spectroscopy. It is obtained that the NVP–EGDMA mixture‐grafted sample exhibits satisfactorily high iodine adsorption compared to untreated and NVP‐grafted silk samples, such as 0.05 g per 1 g fabric with high antibacterial activity against various pathogens, including methicillin‐resistant Staphylococcus aureus (MRSA) responsible for hospital‐acquired infections. This finding evidences its potential as an alternative antiseptic tissue for biomedical applications.

Graft Copolymerization of Acrylonitrile onto Banana Cellulose Fiber

The graft co-polymerization of acrylonitrile monomer (AN) onto banana cellulose fiber (BCF) was carried out using ceric ammonium nitrate (CAN)/oxalic acid (OA) as redox pair in the aqueous nitric acid medium at 90 ºC. The effect of different reaction conditions on the grafting has been studied by determining the grafting parameters, i.e. concentration of acrylonitrile, ceric ammonium nitrate, oxalic acid, nitric acid, reaction time and temperature were carefully optimized to achieve the highest rate of grafting polymerization (RG), highest percent grafting yield (%GY) and grafting efficiency (%GE). All the reagents enhanced the RG%, GY% and %GE, with an increase of concentration up to a certain extent and then found to decline, except for the concentration of nitric acid. The grafting parameters were also increased with time/duration and temperature. The water retention value (WRV) of the grafted co-polymer was also measured. Activation parameters such as energy of activation (Ea), enthalpy change (ΔH), entropy change (ΔS) and free energy change (ΔG) can also be reported by using the Arrhenius plot. The evidence of grafting can also be predicted by the FTIR spectral analysis, moreover, the organic reaction mechanism has been proposed.

Drug delivery in thermo-responsive silicone catheters by grafting of N-vinylcaprolactam using gamma radiation

Radiation-induced graft polymerization of poly(N-vinylcaprolactam) onto silicone catheters by direct irradiation method was studied. The effects of the irradiation dose, as well as the monomer concentration, on the grafting efficiency were studied. The conditions for achieving maximum grafting yield were observed at 30% of monomer concentration in toluene at 50 kGy. The graft polymerization was examined by different characterization methods, including measurements such as thermogravimetric analysis, infrared, water contact angle, and swelling. The temperature-responsive behavior of smart grafted copolymer was studied by swelling at different temperatures. Differently from pristine silicone catheter, the N-vinylcaprolactam-grafted catheters were able to load vancomycin and sustain the release for 30 h.Graphical abstract

Synthesis, Characterization, and Evaluation of the Adsorption Behavior of Cellulose-Graft-Poly(Acrylonitrile-co-Acrylic Acid) and Cellulose-Graft-Poly(Acrylonitrile-co-Styrene) towards Ni(II) and Cu(II) Heavy Metals.

In this study, the synthesis and characterization of grafted cellulose fiber with binary monomers mixture obtained using a KMnO4/citric acid redox initiator were investigated. Acrylonitrile (AN) was graft copolymerized with acrylic acid (AA) and styrene (Sty) at different monomer ratios with evaluating percent graft yield (GY%). Cell-g-P(AN-co-AA) and Cell-g-P(AN-co-Sty) were characterized by SEM, FT-IR, 13C CP MAS NMR, TGA, and XRD. An AN monomer was used as principle-acceptor monomer, and GY% increases with AN ratio up to 60% of total monomers mixture volume. The adsorption behaviors of Cell-g-P(AN-co-AA) and Cell-g-P(AN-co-Sty) were studied for the adsorption of Ni(II) and Cu(II) metal ions from aqueous solution. Optimal adsorption conditions were determined, including 8 h contact time, temperature of 30 °C, and pH 5.5. Cell-g-P(AN-co-AA) showed maximum adsorption capacity of 435.07 mg/g and 375.48 mg/g for Ni(II) and Cu(II), respectively, whereas Cell-g-P(AN-co-Sty) showed a maximum adsorption capacity of 379.2 mg/g and 349.68 mg/g for Ni(II) and Cu(II), respectively. Additionally, adsorption equilibrium isotherms were studied, and the results were consistent with the Langmuir model. The Langmuir model's high determinant coefficient (R2) predicted monolayer sorption of metal ions. Consequently, Cell-g-P(AN-co-AA) and Cell-g-P(AN-co-Sty) prepared by a KMnO4/citric acid initiator were found to be efficient adsorbents for heavy metals from wastewater as an affordable and adequate alternative.

Adsorption of Cu (II) ions from aquatic environment using pre-irradiated Ethylene Tetrafluoroethylene Film

Although copper (Cu) is a very beneficial metal, having too much of it in the body can cause lung issues, severe anemia, nausea, and vomiting. In order to extract Cu (II) ions from aqueous solution, an adsorbent was constructed in this study employing pre-irradiation grafted Ethylene tetrafluoroethylene (ETFE) film. The grafting method was used to binary monomers of sodium styrene sulfonate (SSS) and acrylic acid (AA), where NaCl served as an additive. The grafted polymer was also subjected to studies of tensile strength, water uptake, surface area extension, Scanning Electron Microscopy (SEM), and Fourier Transform Infrared spectroscopy (FTIR). The adsorption of Cu (II) was investigated with respect to pH, starting metal ion concentrations, contact time, monomer concentrations, and temperature. With 50 kGy of radiation dose, 4% NaCl, and 30% of monomer solution (SSS:AA = 1:2) in water generated the highest graft yield of 470%. The maximum adsorption capacity (412 mg g−1) was discovered with an initial concentration of 2500 mg L−1, a pH of 4.86, and a contact time of 24 h at room temperature (25 ℃). A monolayer adsorption was recommended by the good linking between experimental data and the Langmuir Isotherm Model. The kinetic adsorption data closely fitted with the pseudo-second-order reaction. Due to its increased adsorption capacity and reusability, the synthesized new grafted polymer can be considered an efficient adsorbent for Cu (II) removal from wastewater.