STUDY OF ION SOLVATION AND ION ASSOCIATION IN POLYMER GEL ELECTROLYTEWITH POLYETHYLENE OXIDE-CO-POLYPROPYLENE OXIDE AS A PLASTICIZER

Using a molal conductance method, ion solvation and ion association in polytriethylene glycol dimethacrylate (PTREGD)-LiClO4 gel electrolyte s with amorphous ethylene oxide-co-propylene oxide (EO-co-PO, <(M)over bar (n)>, = 1750) as the plasticizer were investigated. It was found that the fraction of solute existing as single ions (alpha(i)) and ion pairs (alpha(p)) decreases, while that of triple ions (alpha(t)) incr eases linearly with increasing salt concentration. The dependence of t hese fractions on molecular weight of plasticizer was also examined. I t was shown that alpha(i) and alpha(t) increase and alpha(p) decreases with increasing molecular weight. The result of temperature dependenc e of these fractions was very interesting: when the temperature is low er than 55 degrees C, alpha(i) increases while alpha(p) and alpha(t) d ecrease with increasing temperature; however, when the temperature is higher than 55 degrees C, the reverse is true.