Use of plasma polymerization for preparing silicone-coated membranes for possible use in blood oxygenators.

The plasma polymerization of hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4) over the microporous polypropylene membrane Celgard 2400, over polypropylene filter membranes, and over glass slides was investigated. The rate of polymer deposition was dependent upon the location of the substrate materials in the reaction vessel. The increase in weight of all the substrates was linear with the time of reaction, indicating a uniform polymerization rate. The rate of polymer deposition over polypropylene filters was found to be 2.27 micrograms/cm(2)/min for both D3, and D4, whereas over the glass slides it was 1.53 and 1.87 microgram/cm(2)/min for D3 and D4, respectively. The coated Celgard membranes showed better blood compatibility that Silastic sheeting or glass.