AST PRODUCTS INC

The CA of the SMM-blended membranes was measured to study their hydro-phobicity/hydrophilicity. The CA measurements were made using the VCA-Optima (AST Products, Inc., Billerica, MA, USA). Samples of 4 cm area (2x2 cm) at random positions were prepared from each membrane. The samples were then placed on a glass sample plate and fixed with scotch tape. The equipment syringe, filled with distilled water, was installed to stand vertically. About 2 pi of water was deposited on the membrane surface. The CA was measured at five different spots on both the top and the bottom surfaces of each membrane sample. 

VGA Optima Contact Angle System (AST Products, Inc., U.S.) was used to measure static water contact angles. A water droplet of 0.5-1 pL was used for coutact augle measurement, and at least five to six measurements, on three differait samples, were carried out to obtain an average value. The variation in water contact angle values at various locations of a sample was within 2°, while the measurement error was within F. 

The static contact angle was measured for each membrane before and after carbonization using the VCA optima surface analysis system (AST Products, Inc., Billerica, MA). For each membrane the contact angle was measured at five different spots and the values were averaged. 

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