Morphological dependency of polymer electrolyte membranes on transient salt type: effects of anion species

作者：Esmaeili Majid; Madaeni Sayed S^*; Barzin Jalal

来源：Polymer International, 2011, 60(3): 362-370.

DOI：10.1002/pi.2956

• anion
• copper salt
• facilitated transport
• membrane structure
• morphology

Two types of transition metal salts, i.e. Cu(NO3)(2) and CuCl2, with different anion species were used to prepare various polyethersulfone-based poly(N-vinyl pyrrolidone) (PVP) composite membranes. The polymer crystallinity, strength of some of the bonds in the membrane structure and effects of anion species on the membrane morphology were investigated through X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDX), Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy. The XRD results indicated an enhancement of the PVP crystallinity after addition of Cu(NO3)(2). Moreover, addition of copper salt was accompanied by an increase of effective membrane distances. The FTIR analysis revealed that the nitrate ions might be better distributed than the other salt ions. The complexes created between them and carbonyl oxygens on the PVP chains were thus stronger. More powerful interactions caused a crystallinity enhancement following the addition of Cu(NO3)(2). The SEM-EDX experiment gave insight into the copper ion and carbonyl oxygen distributions in the membrane surface and active layer. The uniform distribution of copper ions resulted in a clear distribution of interchain interactions and complexes in the active layer structure and also caused structural order improvement.

• 出版日期2011-3