• Journal of Radiation Industry
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• v.7 no.1
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• pp.61-67
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• 2013

In this study, we developed ionic permselective membrane as a core material of redox flow battery using radiation grafting method. Two ionic permselective membranes, ETFE-g-PSSA and ETFE-g-PVBSA were prepared by radiation grafting with styrene and VBC followed by sulfonation, respectively. We confirmed that the prepared membranes were successfully prepared via FT-IR. The prepared ionic permselcetive membranes were characterized and the performance of the membranes were evaluated as ionic permselective membranes for vanadium redox flow battery.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.938-945
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• 1996

The present studies are to describe the grafting reaction of styrene in various solvents to polypropylene fabric by the simultaneous method using Co-60. The influence of various factors such as absorbed dose, dose rate, type of solvent, acid and multifunctional monomer were evaluated. At constant absorbed dose, the grafting yield was found to be higher at low dose rate. The initial rate of grafting was found to be proportional to a 0.56 power of dose rate. The inclusion of mineral acid in the grafting solution led to an increase in radiation grafting yield at almost all monomer concentration examined. Multifunctional monomer was also effective to increase grafting yield. The addition of both acid and multifunctional monomer was found to accelerate the grafting yield much more than the separate addition of two additives.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.946-953
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• 1996

The effect of absorbed dose, dose rate, cationic salts and solvent on the grafting yield was evaluated when acrylic acid was grafted onto polypropylene fabric by simultaneous irradiation process. Low dose rate when irradiated with the same absorbed dose led to a high grafting yield. On the other hand, the grafting yield increased with dose rate in case the total irradiation times is equal, and the initial rate of grafting was found to be proportional to be 0.74 power of dose rate. $FeSO_4{\cdot}7H_2O$ was found to be the most effective additive for high grafting yield, while inhibiting homopolymer formation. It was impossible to induce radiation grafting without the addition of the certain amount of salt, but the grafting yield decreased with increasing metallic salt.

• Nuclear Engineering and Technology
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• v.13 no.4
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• pp.245-253
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• 1981

The properties of polyethylene materials exhibit good insulation and radiation resistance, but exhibit poor flame resistance. Flame retardant properties of the polyethylene were improved by the radiation induced grafting or crosslinking. When the various flame retardants were fixed onto polyethylene, the amount of fixation in grafting was increased with the increase of radiation dosages. In the case of grafting, it is necessary for high grafting yield that the polyethylene films were swelled before irradiation with ${\gamma}$-rays or electron beams. It is the suitable method for the fixation of flame retardant that polyethylene samples were blended with various flame retardants at 1$25^{\circ}C$ and then blended polymers were crosslinked by the electron beams at room temperature.

• Polymer(Korea)
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• v.33 no.3
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• pp.268-271
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• 2009

In this study, the distribution behaviors of the polystyrene sulfonic acid (PSSA) grafting polymer across the FEP-g-PSSA membranes prepared by a simultaneous irradiation method, were investigated by analyzing the cross-section of the membranes with a SEM-EDX instrument. The effects of irradiation conditions such as the degree of grafting, FEP film thickness, and grafting solvent on the distribution of the grafting polymer were mainly studied in this experiment. The results indicate that to obtain the evenly grafted FEP-g-PSSA membranes, the higher degree of grafting is required as the film thickness increases, and the lower dose rate are more effective than the higher dose rate at the given dose.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.53-57
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• 2014

The kenaf is quickly developing as a renewable resource. Kenaf can be grown under a wide range of weather conditions. Modification of kenaf fiber by graft polymerization provides a significant route to alter the chemical properties, including surface hydrophilicity or hydrophobicity. In this study, kenaf fiber surfaces were grafted with acrylic acid as a hydrophilic group using electron beam irradiation. The grafting rate increased with an increase in grafting time. The FT-IR results confirmed that acrylic acid was successfully grafted onto the kenaf fibers. The wettability of the kenaf fiber was increased, accompanied by acylic acid grafting on the fiber surface. According to the permeability test result, it was found that acrylic acid grafted kenaf fiber reinforced cement composite was more reduced than non-grafted kenaf fiber reinforced cement composite.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.99-101
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• 1998

1. Introduction : The conventional grafting polymerization technique requires chemically reactive groups on the surface as well as on the polymer chains. For this reason, a series of prefunctionalization steps are necessary for covalent grafting. The surface prefunctionalizational technique for grafting can be used to ionization radiation, UV, plasma, ion beam or chemical initiators. Of these techniques, radiation method is one of the useful methods because of uniform and rapid creation of active radical sites without catalytic contamination in grafted samples. If the diffusion of monomer into polymer is large enough to come to the inside of polymer substrate, a homogeneous and uniform grafting reaction can be carried out throughout the whole polymer substrate. Radiation-induced grafting method may attach specific functional moieties to a polymeric substrate, such as preirradiation and simultaneous irradiation. The former is irradiated at backbone polymer in vacuum or nitrogen gas and air, and then subsequent monomer grafting by trapped or peroxy radicals, while the latter is irradiated at backbone polymer in the presence of the monomer. Therefore, radiation-induced polymerization can be used to modification of the chemical and physical properties of the polymeric materials and has attracted considerable interest because it imparts desirable properties such as blood compatibility. membrane quality, ion excahnge, dyeability, protein adsorption, and immobilization of bioactive materials. Synthesizing biocompatible materials by radiation method such as preirradiation or simultaneous irradiation has often used $\gamma$-rays to graft hydrophilic monomers onto hydrophobic polymer substrates. In this work, in attempt to produce surfaces that show low levels of anti-fouling of bovine serum albumin(BSA) solutions, hydroxyethyl methacrylate(HEMA) was grafted polypropylene membrane surfaces by preirradiation technique. The anti-fouling effect of the polypropylene membrane after grafting was examined by permeation BSA solution.

• Polymer(Korea)
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• v.38 no.3
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• pp.293-298
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• 2014

We prepared hydrophilic porous supporters for the reinforced composite fuel cell membrane by radiation grafting of acrylonitrile (AN) and hydrophilic sodium allylsulfonate (SAS) into a porous polytetrafluoroethylene (PTFE) supporter. The physicochemical properties of the supporters prepared under various reaction conditions such as molar ratio of SAS/AN, monomer concentration, and irradiation dose were evaluated. FTIR was utilized to confirm the successful introduction of SAS/AN copolymer chains into the porous PTFE. The pores of the porous PTFE film were found to be decreased with an increase in the degree of grafting by using FE-SEM and gurley number. Furthermore, by analyzing the degree of grafting, contact angle, and TBO (toluidine blue O) uptake, the hydrophilicity of the prepared supporters was found to increase with an increase in the degree of grafting.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1101-1108
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• 2009

The ocean contains around eighty elements of the periodic table and uranium is also one among them, with a uniform concentration of 3.3 ppb and a relative abundance factor of 23. With a large coastline, India has a large stake in exploiting the 4 billion tonnes of uranium locked in seawater. The development of radiation grafting techniques, which are useful in incorporating the required functional groups, has led to more efficient adsorbent preparations in various geometrical configurations. Separation based on a polymeric adsorbent is becoming an increasingly popular technique for the extraction of trace heavy metals from seawater. Radiation grafting has provided definite advantages over chemical grafting. Studies related to thermally bonded non woven porous polypropylene fiber sheet substrate characterization and parameters to incorporate specific groups such as acrylonitrile (AN) into polymer back bones have been investigated. The grafted polyacrylonitrile chains were chemically modified to convert acrylonitrile group into an amidoxime group, a chelating group responsible for heavy metal uptake from seawater/brine. The present work has been undertaken to concentrate heavy metal ions from lean solutions from constant potential sources only. A scheme was designed and developed for investigation of the recovery of heavy metal ions such as uranium and vanadium from seawater.

• Polymer(Korea)
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• v.31 no.6
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• pp.512-517
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• 2007

The grafting of styrene, glycidylmethacrylate (GMA) or acrylic acid (AAc) onto kapok fiber were performed by $Co_{60}\;{\gamma}-ray$ radiation-induced graft copolymerization. Degree of grafting (DG) of copolymers were increased with increasing monomer concentration and radiation dose. In addition to we confirmed the introduced functional group and measured ion exchange capacity. Morphology of the ion exchange fibers and their structures were analyzed by SEM and FT-IR.