[Detection of pores in plastic membranes. 74: Contributions to problems concerning the use of plastic receptacles for...

The presence of pores in plastic membranes is detected by the permeability of the latter to electrolytes in the electric field. The plastics are not damaged by the electric field intensities applied. Lithium chloride and crystal violet are employed as electrolytes. In this way, pore-size differentiation becomes faesible. A dialyzing membrane is used for the purpose of comparison. The electrical resistance of the membrane permits conclusions to the amount of its porosity. On using crystal violet, the migration through the pores can be followed visually or colorimetrically.