| 초록 |
Conventionally, there are three major categories for manufacturing microfiltration membranes with organic polymers. First there is the phase inversion method of which pore size and porosity are mainly controlled by the interaction of three components: polymer, solvent and nonsolvent. Second is the thermally induced phase separation method. In this method, only two phases of polymer and diluent are involved in making pores via liquid-liquid or solid-liquid phase separation. The last is the stretching method which was employed in this work. The stretching method is the simplest method of three, which do not require any other material except the polymer. There are many advantages of using stretching method over the other two methods. High take-up speed of hollow fiber results in high production rate and fewer components make products cheaper. Because this process does not require any solvents, diluents and additives, it is a very clean and economical process. The membranes prepared by this method have very high mechanical strength. Also, the membranes show high flux, high removal efficiency and outstanding fouling resistance due to its high aspect ratio. In this study, we prepared the hollow fiber membranes by stretching method having a variety of advantages stated above. We investigated the relationship of pore formation to the morphology of the semi-crystalline polymers. HDPE (high density polyethylene) was used as a membrane material. Also, FE-SEM and Wide-angle x-ray diffraction (WAXD) were used in analyzing the morphology and the chain orientation. |
