Electrical Anisotropy of Xerogels of Hydrophile Colloids Part I

摘要

A number of colloid materials—proteins, plastics, and the like—have been coated in sheet form and ``fibered'' internally by stretching to 100 percent or more elongation. Circular disks were cut from the fibered sheets, and their degree of orientation measured in an (alternating) electric field. Account is given of the relation of the orientation measured to field strength, thickness, humidity, and moisture content. It was observed that induced electrical anisotropy is not shown by all kinds of natural and synthetic colloids; thus it is not shown by organophile xerogels, but only by the hydrophile ones. With most of these the electrical response depends upon the relative humidity and the absorbed water content, but with polyvinyl alcohol the effect was independent of the absorbed water.