Filtration Properties of a Two-Sided Irradiated Track-Etched Membrane with a Thickness Exceeding the Ion Range

Filtration properties of a new two-sided irradiated membrane with a thickness of 20 µm (exceeding the range of the incident ion), a pore diameter of 0.20 µm, and a pore density of 1.5 × 108 cm−2 have been studied in comparison with a one-sided irradiated 12-µm membrane having the same pore size and a somewhat higher pore density of 2.3 × 108 cm−2. An aqueous dispersion of a dye with a stable particle size distribution has been used in the experiments, with most of the particles being not larger than the pore size of the membranes. Close permeability values have been found for both membranes operating in the dead-end filtration mode, with the two-sided irradiated membrane being slightly better, and their close selective properties with some advantage of the one-sided irradiated membrane have been shown using dynamic light scattering and spectrophotometry techniques. For different dye dispersion concentrations, the mechanism of reduction in the productivity of the filtration process has been determined and differences in the limiting size of the rejected particles have been shown. It has been found that in the crossflow mode, the two-sided irradiated membrane has a certain advantage in permeability, whereas the one-sided irradiated membrane has higher rejection ability. In general, it has been concluded that the new two-sided irradiated membrane can be used in water treatment processes on a par with a one-sided irradiated membrane.