(121i) Effect of Inorganic Multivalent Nanocluster on the Complexation and Electric Charging of Neutral Polymer in Solution

Unusual electric charging and conformational behavior of neutral polymers, such as poly (ethylene oxide) (PEO), in polar solvents have been reported in the past. Recently, we have observed unusual biphasic coacervate complexation between uncharged PEO and inorganic polyoxometalate polyanions in aqueous solution, distinct from conventional coacervate formation between oppositely charged polyelectrolyte in salted water. To understand the interaction underlying PEO-POM binding, we examine the effect of POM macroion on the electrical potential and conformational structure of PEO in solutions of varied polarity in comparison to that of simple ions. Measured electrical potential indicates that multivalent macroions can effectively bind with PEO to cause significant increase of the effective charges of a PEO chain, which is accompanied with the collapse of PEO chain in polar solvents as determined by single-molecule laser spectroscopy. In contrast, little change of PEO electrical potential and conformation is observed with lithium salt added solutions. These results give insight to develop a facile process of PEO-based ionomers.