Electrophoretic studies of nylon

The surface electrical properties of "unoriented" and of highly "oriented" nylon fibers were investigated by a microelectrophoretic technique. Both types of fibers exhibited definite r eversals of charge but at different pH values-the un oriented fib er at pH 3.9 and the oriented at pH 2.7. Since nylon consists of hydrocarbon chains linked together by amide groups, it appears that reversal of charge is principally dependent on the presence of the amide groups, especially since hydrocarbons do not exhibit reversal of sign of charge under comparable conditions. This suggests that amide groups may also influence the electrophoretic behavior of other substances, such as proteins. The difference in the electrophoretic behavior of the two types of nylon is attributed to the difference in their degrees of "crystallinity."