MICROPOROUS MATERIAL HAVING FILTRATION AND ADSORPTION PROPERTIES AND THEIR USE IN FLUID PURIFICATION PROCESSES

摘要

The present invention is directed to microfiltration membranes comprising a microporous material, said microporous material comprising: (a) a polyolefin matrix present in an amount of at least 2 percent by weight, (b) finely divided, particulate, substantially water-insoluble silica filler distributed throughout said matrix, said filler constituting from about 10 percent to about 90 percent by weight of said microporous material substrate, wherein the weight ratio of filler to polyolefin is greater than 4:1; and (c) at least 35 percent by volume of a network of interconnecting pores communicating throughout the microporous material. The present invention is also directed to methods of separating suspended or dissolved materials from a fluid stream such as a liquid or gaseous stream, comprising passing the fluid stream through the microfiltration membrane described above.