Radiation-induced Graft Copolymerization Research Articles

Radiation-induced graft copolymerization of a phosphonate monomer onto short flax fibers and Miscanthus x giganteus stem fragments: Influence of substrate composition

The functionalization of Miscanthus x giganteus stems fragments (R-MSF) by dimethyl(methacryloyloxy)methyl phosphonate (MAPC1) using pre-irradiation was studied. The influence of the composition and the structure of the substrate on the grafting efficiency was investigated by comparing the results with short flax fibers (SFF) and bleached Miscanthus x giganteus stems fragments (B-MSF). The lignocellulosic substrates were irradiated at several target doses ranging from 11 to 108.1 kGy using e-Beam. Electron Paramagnetic Resonance spectroscopy (EPR) highlighted major differences in terms of radical nature between R-MSF, SFF, and B-MSF samples. Following the polymerization reactions, washing, and drying steps, the phosphorus contents were measured by X-ray fluorescence spectrometry (XRF). Unlike Flax, pre-irradiation grafting was not efficient on R-MSF. The role of lignin content on grafting reactions was then evaluated by comparing R-MSF with SFFand B-MSF), showing only a minor impact. Using a reducing agent, it was possible to reach a phosphorus content of about 1.4 wt% for R-MSF and up to 4.0 wt% for B-MSF for a 100 kGy dose. Furthermore, phosphorus mapping using scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM-EDX) highlighted a homogeneous dispersion of the grafted macromolecules. This demonstrates the possibility of conducting pre-irradiation grafting on lignin-rich substrates without bleaching. Efforts were then made to optimize the operating conditions in terms of storage temperature, reaction temperature and Fe2+ concentration. Finally, the fire behavior of treated Miscanthus x giganteus stem fragments was evaluated by pyrolysis-combustion flow calorimetry (PCFC).

Radiation-Induced Graft Copolymerization of Methacrylonitrile onto Poly (Tetrafluoroethylene-co-ethylene) Film by Discontinuous Method

An attempt has been made to graft copolymerize the vinyl monomer methacrylonitrile onto poly tetrafluoroethylene-co-ethylene, known as Tefzel film, by the double-irradiation method in aqueous medium. Optimum conditions for attaining the maximum percentage of grafting were evaluated. The maximum percentage of grafting for methacrylonitrile was obtained 128.7 % at an optimum dose of 24.9 kGy using 2.98 mol L-1 of methacrylonitrile. Investigations on the effects of different chain-length aliphatic alcohols, methanol, ethanol, n-butanol, cyclohexanol and amyl alcohol on the grafting percentages of methacrylonitrile have been performed. Characterization of Tefzel and grafted Tefzel films have been performed by infrared spectroscopy and Thermogravimetric Analysis. Methacrylonitrile grafted Tefzel films showed better thermal stability.

Separation of 64+67Cu(II) from irradiated natural zinc target by sodium alginate-polyacrylic acid/nanohalloysite composite

A sodium alginate-polyacrylic acid/nanohalloysite (Alg-PAA/NHA) composite was used to develop a fast and effective method for separating 64+67Cu(II) from a neutron-irradiated natural zinc target. Gamma radiation-induced graft copolymerization was used to prepare the Alg-PAA/NHA composite. Under ideal conditions, the grafting efficiency (GE%) of acrylic acid (AA) on the alginate/nanohalloysite (Alg/NHA) surface reached 99%. To validate the structural morphology and the mechanical properties of the synthesized composite, various analyses including FT-IR, SEM, TGA, and DTA were used. It is worth noting that the Alg-PAA/NHA composite demonstrated selective adsorption of Cu(II) ions over Zn(II) ions at pH 3 with an adsorption efficiency of approximately 86%. Using an acidic solution of 0.1 M HCl, the ionic exchange separation of 64+67Cu(II) from the irradiated Zn(II) target on an the Alg-PAA/NHA composite packed column effectively eluted 64+67Cu(II). For further purification, the eluted 64+67Cu(II) was loaded onto another cationic exchange column packed with Dowex 50 W X8. The radionuclidic, radiochemical, and chemical quality control tests confirmed that the obtained 64+67Cu(II) solution was highly pure and can be safely applied in cancer theranostics Applications.

Bibliometrics of Functional Polymeric Biomaterials with Bioactive Properties Prepared by Radiation-Induced Graft Copolymerisation: A Review.

Functional polymeric biomaterials (FPBMs) with bioactive characteristics obtained by radiation-induced graft copolymerisation (RIGC) have been subjected to intensive research and developed into many commercial products. Various studies have reported the development of a variety of radiation-grafted FPBMs. However, no reports dealing with the quantitative evaluations of these studies from a global bibliographic perspective have been published. Such bibliographic analysis can provide information to overcome the limitations of the databases and identify the main research trends, together with challenges and future directions. This review aims to provide an unprecedented bibliometric analysis of the published literature on the use of RIGC for the preparation of FPBMs and their applications in medical, biomedical, biotechnological, and health care fields. A total of 235 publications obtained from the Web of Science (WoS) in the period of 1985-2021 were retrieved, screened, and evaluated. The records were used to manifest the contributions to each field and underline not only the top authors, journals, citations, years of publication, and countries but also to highlight the core research topics and the hubs for research excellence on these materials. The obtained data overviews are likely to provide guides to early-career scientists and their research institutions and promote the development of new, timely needed radiation-grafted FPBMs, in addition to extending their applications.

Modified Surface Polymer Prepared by using Radiation-Induced Grafting Co-polymerization Method and Its Application: A Mini Review

The use of radiation-induced grafting (RIG) polymerization techniques is an appealing way to create and develop polymerization of polymer. The method of copolymerization preparation was evaluated in this paper based on the types of radiation-induced grafting polymerization and their prospective applications. Based on the method of preparation, the optimum grafting yield of the monomer in the polymer backbone is described. The approach used to summarise this review was to go through polymer-related papers from the science direct online database from 2010 to 2021. Then, from those selected journals, the technique of preparation, the grafting yield, and the application were reviewed. Furthermore, the majority of researchers from reviewed journals employed gamma irradiation to prepare the modified polymer, followed by electron beam irradiation, plasma irradiation and UV irradiation. Gamma irradiation is popular because it has a better penetration rate and generates a purer result. As a result of this review paper, the radiation-induced graft polymer from the conducted study is ideal for use in biomedical applications, as a material for wastewater treatment fibre membranes, as an absorbent, and as a gas remover.

A porous fabric-based molecularly imprinted polymer for specific recognition of tetracycline by radiation-induced RAFT-mediated graft copolymerization

Despite technical and methodological advances, the selective separation of antibiotics from aqueous media remains a challenge. In this work, a novel molecularly imprinting polymer (MIP) with specific recognition sites was constructed by radiation-induced RAFT-mediated graft copolymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) from PE/PP nonwoven fabric for tetracycline hydrochloride (TC) removal. Binding isotherm and kinetics were found to follow Freundlich and pseudo-second-order model, respectively. The as-synthesized molecularly-imprinted fabric exhibited excellent binding performance towards TC, with the maximum adsorption capacity and imprinting factor of 46.7 mg g−1 and 3.6, respectively. Moreover, it removed approximately 95% of TC from the aqueous media, also performed well in real environmental samples. For comparison purposes, MIPs obtained with conventional grafting performed significantly lower than those attained by RAFT-mediated grafting. After ten consecutive adsorption and desorption cycles, the fabric-based molecularly-imprinted material retained excellent stability and reusability with a performance loss of only 3.6%, which could facilitate its potential application on an industrial scale.

Effect of amine head group imparted to poly (glycidyl methacrylate) grafted fibrous adsorbent for CO2 adsorption

Abstract The demand to develop adsorbents for CO2 capture with high performance continued to grow extensively. Adsorbents with covalently bonded amine groups based on fibrous substrate modified by radiation-induced grafting copolymerization (RIGC) of glycidyl methacrylate (GMA) and amination treatment have emerged recently. In this study, GMA was grafted onto a polyethylene/polypropylene (PE/PP) fibrous sheet and the grafted intermediate was used to incorporate two different amine-containing agents, namely polyethyleneimine (PEI) and ethylenediamine (EDA) for CO2 adsorption. The chemical structural and morphological changes in the two aminated adsorbents were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. A low and equal amination level of 20% was achieved in PEI-containing and EDA-containing adsorbents. The CO2 adsorption from a binary mixture of CO2/N2 (40:60 v/v) was not satisfactory despite a 30% higher adsorption capacity (50.44 mg/g) demonstrated by EDA-containing adsorbent compared to 34.51 mg/g for PEI-containing counterpart at 30 bar and at room temperature. More work is needed to elevate the CO2 adsorption capacity levels in such adsorbents by increasing the amination level via optimization of reaction parameters.

Radiation Grafted Ion Conducting Membranes for Electrochemical Energy Systems: Status of Developmental and Upscaled Membranes

Ion conducting membranes (ICMs) play a crucial role in the development of electrochemical energy systems supporting the conversion, storage, and management of renewable energy in various fields. Thus, this class of materials has received continuous intensive research efforts to obtain membranes/separators with superior properties, including high conductivity, durability, and cost-attractiveness. Radiation induced graft copolymerization (RIGC) techniques have been found to be most effective in developing a variety of IEMs due to their efficient endowment of the desired type and level of ionic functionality to preformed films to form hybrid materials with integrated physico-chemical properties. Various articles have reviewed the fundamental research aspects of radiation grafted ICMs’ and battery separators’ developments in many laboratories with little attention given to research activities at the developmental scale paving the way to commercialization of such materials. This article reviews the status of the development of emerging radiation grafted ICMs and separators for various types of fuel cells, batteries, and water electrolysers with a special focus on those undergoing developmental research activities and others successfully commercialized.

Fouling Prevention in Polymeric Membranes by Radiation Induced Graft Copolymerization.

The application of membrane processes in various fields has now undergone accelerated developments, despite the presence of some hurdles impacting the process efficiency. Fouling is arguably the main hindrance for a wider implementation of polymeric membranes, particularly in pressure-driven membrane processes, causing higher costs of energy, operation, and maintenance. Radiation induced graft copolymerization (RIGC) is a powerful versatile technique for covalently imparting selected chemical functionalities to membranes’ surfaces, providing a potential solution to fouling problems. This article aims to systematically review the progress in modifications of polymeric membranes by RIGC of polar monomers onto membranes using various low- and high-energy radiation sources (UV, plasma, γ-rays, and electron beam) for fouling prevention. The feasibility of the modification method with respect to physico-chemical and antifouling properties of the membrane is discussed. Furthermore, the major challenges to the modified membranes in terms of sustainability are outlined and the future research directions are also highlighted. It is expected that this review would attract the attention of membrane developers, users, researchers, and scientists to appreciate the merits of using RIGC for modifying polymeric membranes to mitigate the fouling issue, increase membrane lifespan, and enhance the membrane system efficiency.

Engineered Bioactive Polymeric Surfaces by Radiation Induced Graft Copolymerization: Strategies and Applications.

The interest in developing antimicrobial surfaces is currently surging with the rise in global infectious disease events. Radiation-induced graft copolymerization (RIGC) is a powerful technique enabling permanent tunable and desired surface modifications imparting antimicrobial properties to polymer substrates to prevent disease transmission and provide safer biomaterials and healthcare products. This review aims to provide a broader perspective of the progress taking place in strategies for designing various antimicrobial polymeric surfaces using RIGC methods and their applications in medical devices, healthcare, textile, tissue engineering and food packing. Particularly, the use of UV, plasma, electron beam (EB) and γ-rays for biocides covalent immobilization to various polymers surfaces including nonwoven fabrics, films, nanofibers, nanocomposites, catheters, sutures, wound dressing patches and contact lenses is reviewed. The different strategies to enhance the grafted antimicrobial properties are discussed with an emphasis on the emerging approach of in-situ formation of metal nanoparticles (NPs) in radiation grafted substrates. The current applications of the polymers with antimicrobial surfaces are discussed together with their future research directions. It is expected that this review would attract attention of researchers and scientists to realize the merits of RIGC in developing timely, necessary antimicrobial materials to mitigate the fast-growing microbial activities and promote hygienic lifestyles.

Facile preparation of fibrous glycidol-containing adsorbent for boron removal from solutions by radiation-induced grafting of poly(vinylamine) and functionalisation

In this study, a facile method was developed to prepare fibrous boron-selective adsorbent through introduction of poly(vinylamine) (PVAm) onto polyethylene/polypropylene (PE/PP) non-woven sheet by radiation induced graft copolymerization (RIGC) of N-vinylformamide (NVF) followed by hydrolysis, and glycidol immobilisation. The dependence of the degree of grafting (DG) on the reaction parameters (absorbed dose, monomer concentration, temperature, and reaction time) was investigated to control the content of hydrolysed poly(N-vinylformamide) (PNVF) grafts. The properties of the adsorbent were evaluated by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC), and thermal gravimetric analyser (TGA). The boron adsorption from solution on the prepared adsorbent was investigated under various pHs, contact times, initial boron concentrations, adsorbent dosages, and adsorption/desorption cycles. The adsorbent with a DG of 120% showed an adsorption capacity of 21.4 mg-B/g-adsorbent at pH 7 with an appealing stability. The overall properties and adsorption behaviour suggest that RIGC is highly effective method for preparation of glycidol-containing fibrous adsorbent with highly attractive properties for boron removal from aqueous solutions.

Effects of natural rubber latex fraction to glycidyl methacrylate on grafting polymerization and its application as Th4+ and UO2 2+ ions bio adsorbent

Natural rubber (NR) latex was modified by in situ gamma radiation-induced grafting copolymerization of glycidyl methacrylate (GMA). NR latex to GMA emulsion ratio of 100:0, 50:50, 40:60, 30:70 and 20:80 have been investigated at the absorbed dose of 150kGy. The grafted GMA natural rubber-based follow the subsequent chemical modification to anchor phosphate group by open up the epoxy ring. The modified NR was characterized by Fourier transform infrared. Demonstration of modified NR on Th4+ and UO2 2+ ions adsorption in 25ml of 10ppm standard solution gave 95% and 28% percentage removal respectively.

Radiation induced graft copolymerization of amine-containing monomer onto polyethylene coated propylene for CO2 adsorption

Modification of polyethylene coated polypropylene by radiation-induced graft copolymerization (RIGP) of N-vinylformamide film followed by hydrolysis was studied to produce polyvinylamine (PVAm) containing adsorbent for CO2 adsorption. A number of grafting parameters such as irradiation dose, monomer concentration, and reaction temperature were investigated to obtain desired degree of grafting (DOG) prior to hydrolysis. The DOG was found to be a function of reaction parameters and achieved a desired value of 131% at 40 wt% NVF concentration in toluene, 300 kGy dose, 70°C temperature and 1h reaction time. Subsequently the hydrolysis of formamide groups in the grafted films into amine functionalities was carried out in basic medium. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) confirmed the NVF monomer was successfully grafted on PE/PP and consequently the hydrolysis of amide into amine functionalities has occurred in the grafted substrates. The CO2 adsorption capacity of PVAm modified adsorbent was brought to be a function of DOG, which is corresponding to the amine content after hydrolysis. The adsorbent showed the highest CO2 adsorption capacity of 1.32 mmol/g when tested with gas composition of 40% CO2 and 60% nitrogen at room temperature.

Fabrication and Characterization of PU-g-poly(HEMA) Film for Clotting Time and Platelet Adhesion

This paper describes a fabrication of poly (2-hydroxylethyl methacrylate) poly(HEMA) grafted on polyurethane (PU) film prepared by radiation-induced grafting (RIG) copolymerization method using electron beam irradiation for the first time. This method was well known to be fast technique, clean method without involve any chemical initiator, chemically bond the materials, and at the same time is a sterile technique suitable for further potential of biomedical application. This poly(HEMA) grafted on PU film or called as PU-g-poly(HEMA) films was analysed using Fourier-transform infrared (FTIR), scanning electron microscope (SEM), water contact angle analyser (WCA), platelet adhesion and clotting time measurement. As the results, poly(HEMA) was confirmed successful grafted on PU based on the shifting of the functional group, no significant changes in surface morphology, lowering the water contact angle from 78.28° to 70.02°, nearly no platelet adhesion and no excessive disturbance of the clotting time was observed. This means that PU-g-poly(HEMA) was improved its hydrophilicity, thus significantly reduced the platelet adhesion and maintain the normal range of time taken for blood to clot. Therefore, the present PU-g-poly(HEMA) films not only improved hydrophilicity, however, was also compatible with blood. Thus, it may be potential candidates in the biomedical devices or new biomaterial useful for future tissue engineering fields.

Radiation induced graft copolymerization of graphene oxide and carbopol onto sterculia gum polysaccharide to develop hydrogels for biomedical applications

In order to explore the potential of graphene oxide (GOx) in the field of biomedical applications, in the present work, GOx containing polymers were prepared using carbopol (CARBO) and sterculia gum (STRG) polysaccharide by graft-copolymerization method. These polymers were used for evaluation of the release profile of an antibiotic drug ciprofloxacin. The polymers were characterized by SEMs, XRD, FTIR, TGA, DTG and DSC techniques. It has been found that the presence of GOx in the polymer matrix has influenced various properties including drug loading and drug release. Both drug loading and drug release was improved in case of GOx containing polymer matrix. The release of the ciprofloxacin drug occurred in a controlled manner without burst effect and release profile followed the non-Fickian diffusion mechanism and it was best fitted in the Korsmeyer-Peppas kinetic release model.

Preparation and Candida rugosa Lipase Immobilization on Nylon-6 Grafted and Aminated (Polyvinyl Benzyl Chloride) Microfibers

This paper demonstrates a simplified procedure for the preparation of a nylon-6 microfibers based support for the immobilization of Candida rugosa lipase via covalent attachment to enhance the stability and reusability of lipase. The preparation of the support was done by radiation induced graft copolymerization (RIGC) of vinyl benzyl chloride (VBC) onto nylon-6 microfibers followed by amination with ethanolamine to facilitate the immobilization of lipase. Fourier transfer infra red (FTIR) and scanning electron microscope (SEM) were used to study the chemical and physical changes following grafting, amination and immobilization. Response surface methodology (RSM) was applied for the optimization of lipase immobilization on the aminated microfibers. The optimization parameters were incubation time, pH, and lipase concentration. Moreover, this study investigated the effect of temperature, pH, and storage stability and reusability on the lipase in its immobilized and free forms. The developed model from RSM showed an R2 value of 0.9823 and P-value < 0.001 indicating that the model is significant. The optimum temperatures for both immobilized and free lipases were 45 °C, whereas the best pH values for lipase activity were at pH 8 and pH 7, respectively. This study also identifies values for KM and Vmax for both immobilized and free lipase accordingly. Based on the results, immobilized lipase had significantly improved the stability and reusability of lipase compared to that in free forms.

Single-Step Synthesis of Atmospheric CO2 Sorbents through Radiation-Induced Graft Polymerization on Commercial-Grade Fabrics.

Primary amines form a key component of a well-studied mechanism for capturing carbon dioxide (CO2) from the atmosphere. This study comprises a single-step synthesis of a novel sorbent for CO2 by grafting monomers rich in primary amines to three commercial-grade fabrics: polyethylene terephthalate, high-density polyethylene and nylon 6. An initial evaluation of the sorbency of the chosen monomers, allylamine and butenylamine, qualitatively confirmed their ability to extract CO2 from the atmosphere. Six novel copolymers, comprised of each of the three fabrics grafted with one of each monomer, were synthesized using radiation-induced graft copolymerization through electron beam irradiation. All fabrics achieved greater grafting with butenylamine compared to allylamine, likely given the closer proximity of the primary amine to the radical on the latter's structure. Primary amines can stabilize radicals, preventing copolymerization reactions. Characterization of sorbency revealed that the majority of the grafted amines likely reacted to adsorb CO2. Therefore, the amount of amine grafted comprises the primary limiting factor on the sorbents' CO2 capacity.

Removal of Cs-137 and Sr-90 from reactor actual liquid waste samples using a new synthesized bionanocomposite-based carboxymethylcellulose

Abstract A new biosorbent containing vinylsulphonic acid and 2-acryloamido-2-methyl-1-propanesulphonic acid in the presence of magnetic nanoparticles, iron (III) oxide, grafted to carboxymethylcellulose sodium salt P(VSA/AMPSO3H/MNPs)-g-CMC bionanocomposite material (BNC) has been synthesized by γ radiation induced grafting copolymerization technique. The effect of comonomer, crosslinker, CMC concentration and the absorbed dose (kGy) on the grafting efficiency and swelling degree was studied. The BNC has been successfully synthesized and the structure of the prepared BNC was confirmed by Fourier transform infrared (FTIR), thermal analysis (TGA and DTA), X-ray powder diffraction (XRD), high-resolution 1H NMR spectroscopy and scanning electron microscopy (SEM) micrograph. Batch studies relevant to adsorption of Cs-137 and Sr-90 from the reactor actual liquid waste samples by the BNC were performed as a function of contact time, solution pH, metal ion concentration, and temperature in simulation studies using the γ emitting isotopes Cs-134 and Sr-85 as representatives of Cs-137 and Sr-90, respectively. Those studies were used to find out the best conditions for isolation of Cs-137 and Sr-90 from reactor actual liquid waste. The isotherms and kinetics were analyzed using different models at 25 °C. The maximum capacity of BNC was found to be 297 and 330 mg g−1 for Cs(I) and Sr(II) metal ions, respectively.

Surface Modification of Teflonated Carbon Fabric by Ultrasound-Assisted Radiation Induced Grafting Copolymerization

A simple and effective modification method was carried out to improve the surface properties of teflon-impregnated carbon fabric (TICF) by radiation induced grafting (RIG) of glycidyl methacrylate (GMA). The grafting reaction was carried out using an ultrasound-assisted technique in comparison with a conventional grafting technique. The degree of grafting was investigated at various reaction times for both systems. The grafting efficiency for ultrasonic-aided technique reached 85% compared to 53% in conventional grafting technique. This significant improvement is probably due to the emergence of monomers diffusion on the grafting sites caused by ultrasonically assisted grafting reaction. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy have provided evidences for incorporation of poly(GMA) grafts. The grafting under ultrasonic condition was proven to be more efficient and economical as indicated by the increase in DG and reduction in the homopolymer contamination accompanied by homogenous grafting and smoother surfaces in TICF.

Preparation of Polymer Electrolyte Membranes via Radiation-Induced Graft Copolymerization on Poly(ethylene-alt-tetrafluoroethylene) (ETFE) Using the Crosslinker N,N'-Methylenebis(acrylamide).

Polymer electrolyte membranes (PEM) prepared by radiation-induced graft copolymerization are investigated. For this purpose, commercial poly(ethylene-alt-tetrafluoroethylene) (ETFE) films were activated by electron beam treatment and subsequently grafted with the monomers glycidyl methacrylate (GMA), hydroxyethyl methacrylate (HEMA) and N,N′-methylenebis(acrylamide) (MBAA) as crosslinker. The target is to achieve a high degree of grafting (DG) and high proton conductivity. To evaluate the electrochemical performance, the PEMs were tested in a fuel cell and in a vanadium redox-flow battery (VRFB). High power densities of 134 mW∙cm−2 and 474 mW∙cm−2 were observed, respectively.