Preparation and characterization of DLC/SiO2/Al2O3 nanofiltration membrane

High quality ceramic thin films were fabricated by thin film deposition process in semiconductor field in order to fabricate high performance carbon/SiO (2) /Al (2) O-3 membrane. alpha-Al (2) O (3) substrate was used as a supporting material. A severe thermal stress and rough surface for active ceramic top layer such as zeolite were observed. To overcome thermal stress, intermediate layer of SiO2 and diamond-like carbon (DLC) thin film were used. SiO (2) and DLC thin films on porous alumina support were deposited using plasma-enhanced chemical vapour deposition (PECVD). Homogeneous and smooth surfaces and interfaces of DLC/SiO (2) /Al (2) O (3) membrane were observed by FESEM. The phases of DLC and SiO (2) thin films were identified by X-ray diffraction pattern. Gas permeabilities of the nanofiltration membrane with DLC/SiO (2) /Al (2) O (3) were observed at various annealing temperatures. Mixed gas permeability of the membrane with 1 mu m-thick SiO2 and 2 mu m-thick DLC thin film annealed at 200 A degrees C was similar to 18 ccm at 1018 mb back pressure.