Novel Ion‐Exchange Membranes for Electrodialysis Prepared by Radiation‐Induced Graft Polymerization

1995 ◽  
Vol 142 (11) ◽  
pp. 3659-3663 ◽  
Author(s):  
Satoshi Tsuneda ◽  
Kyoichi Saito ◽  
Hisashi Mitsuhara ◽  
Takanobu Sugo
Keyword(s):  
Ion Exchange ◽  
Graft Polymerization ◽  
Ion Exchange Membranes ◽  
Radiation Induced

Preparation of Highly Stable Ion Exchange Membranes by Radiation-Induced Graft Copolymerization of Styrene and Bis(vinyl phenyl)ethane Into Crosslinked Polytetrafluoroethylene Films

2006 ◽  
Vol 4 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Tetsuya Yamaki ◽  
Junichi Tsukada ◽  
Masaharu Asano ◽  
Ryoichi Katakai ◽  
Masaru Yoshida
Keyword(s):  
Ion Exchange ◽  
Proton Conductivity ◽  
Water Uptake ◽  
Graft Copolymerization ◽  
Exchange Capacity ◽  
Polymer Electrolyte Fuel Cells ◽  
Ion Exchange Membranes ◽  
Aromatic Rings ◽  
Ion Exchange Capacity ◽  
Radiation Induced

We prepared novel ion exchange membranes for possible use in polymer electrolyte fuel cells (PEFCs) by the radiation-induced graft copolymerization of styrene and new crosslinker bis(vinyl phenyl)ethane (BVPE) into crosslinked polytetrafluoroethylene (cPTFE) films and subsequent sulfonation and then investigated their water uptake, proton conductivity, and stability in an oxidizing environment. In contrast to the conventional crosslinker, divinylbenzene (DVB), the degree of grafting of styrene∕BVPE increased in spite of high crosslinker concentrations in the reacting solution (up to 70mol%). Quantitative sulfonation of the aromatic rings in the crosslinked graft chains resulted in the preparation of membranes with a high ion exchange capacity that reached 2.9meq∕g. The bulk properties of the membranes were found to exceed those of Nafion membranes except for chemical stability. The emphasis was on the fact that the BVPE-crosslinked membranes exhibited the higher stability in the H2O2 solution at 60°C compared to the noncrosslinked and DVB-crosslinked ones, as well as decreased water uptake and reasonable proton conductivity. These results are rationalized by considering the reactivity between styrene and the crosslinker, which is an important factor determining the distribution of the crosslinks in the graft component. In the case of BVPE, the crosslinks at a high density were homogeneously incorporated even into the interior of the membrane because of its compatibility with styrene while the far too reactive DVB led to a crosslink formation only near the surface. The combination of both the cPTFE main chain and BVPE-based grafts, i.e., a perfect “double” crosslinking structure, is likely to effectively improve the membrane performances for PEFC applications.

Removal of Fluorine and Boron From Groundwater Using Radiation-Induced Graft Polymerization Adsorbent at Mizunami Underground Research Laboratory

2010 ◽  
Author(s):  
Yosuke Iyatomi ◽  
Hiroyuki Hoshina ◽  
Noriaki Seko ◽  
Noboru Kasai ◽  
Yuji Ueki ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Research Laboratory ◽  
Graft Polymerization ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Boron Removal ◽  
Radiation Induced ◽  
Flow Through ◽  
Underground Research Laboratory ◽  
Better Than

High fluorine and boron contents in groundwater are commonly reduced using coagulation and ion-exchange treatments. As an alternative, we tested the efficiency of fluorine and boron removal from groundwater using radiation-induced graft polymerization adsorbent. The durability of the adsorbent was also determined by varying groundwater flow-through rates and repetitive use of the adsorbent. The results indicated that it was possible for the adsorbent to remove more than 95% of boron and fluorine from the groundwater, and that the performance of the adsorbent for boron removal was better than commonly used ion-exchange resin. The adsorbent used several times was able to remove boron, indicating that the adsorbent can be used for efficient boron removal.

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