To functionalize poly(vinyl chloride)(PVC) for various applications, monomers containing tertiary amine group are incorporated into PVC via atom transfer radical polymerization(ATRP) initiated by the labile chlorines in their backbones. The kinetics of synthesis was carefully investigated, and it is proven that the grafting polymerization process can be effectively controlled by regulating the reaction time. The membranes are fabricated using PVC and copolymers by non-solvent induced phase separation(NIPS) process. The hydrophilicity and pore structure of copolymer membranes were enhanced as well, these membranes are endowed with positive charge. When PDMA%(i.e., the PDMA weight percentage in copolymer) is 31.1%, the flux and Victoria blue B rejection are 26.0 L?m?2?h?1(0.5 MPa) and 91.2%, respectively. Thus, the newly synthesized polymer is proven to be a promising material for dye separation with positive charges.
Li-feng FangNa-chuan WangMing-yong Zhou朱宝库Li-ping ZhuAngelin Ebanezar John
To improve the performances of HDPE-based separators, polyether chains were incorporated into HDPE membranes by blending with poly(ethylene-block-ethylene glycol) (PE-b-PEG) via thermally induced phase separation (TIPS) process. By measuring the composition, morphology, crystallinity, ion conductivity, etc, the influence of PE-b-PEG on structures and properties of the blend separator were investigated. It was found that the incorporated PEG chains yielded higher surface energy for HDPE separator and improved affinity to liquid electrolyte. Thus, the stability of liquid electrolyte trapped in separator was increased while the interfacial resistance between separator and electrode was reduced effectively. The ionic conductivity of liquid electrolyte soaked separator could reach 1.28 × 10-3 S.cm-1 at 25℃, and the electrochemical stability window was up to 4.5 V (versus Li + /Li). These results revealed that blending PE-b-PEG into porous HDPE membranes could efficiently improve the performances of PE separators for lithium batteries.
