| Summary: | 碩士 === 中原大學 === 化學工程研究所 === 93 === Abstract
In this study, the effect of vapor induced phase separation (VIPS) on the morphology and formation mechanism of Polysulfone (PSf) hollow fiber membranes were investigated. PSf hollow fiber membranes were fabricated via dry/wet spinning process with different air gap under various relative humidity. N-methyl pyrrolidinone (NMP) was used as the solvent. The results show that by introducing the dry/wet spun PSf hollow fiber membranes into water bath, the macrovoids morphology of hollow fiber membrane can be suppressed, recreated, and resuppressed as increasing the air gap regardless of relative humidity. The macrovoids suppressed, recreated, as well as resuppressed air gap decreased with increasing the relative humidity. The results also show that the microstructure of PSf hollow fiber membranes can formed from dense to lacy structure and coarsened to form sponge-like structure as increasing the air gap. By introducing the as-spun hollow fiber membranes into liquid nitrogen directly after went through air gap zone, micro phase separation structure, lacy structure, and sponge-like structure can be found as increasing the air gap. These results can tell us that the micro phase separation structure and lacy structure induced by water vapor during air gap zone can further grow to form lacy and sponge structure by introducing the nascent hollow fiber membranes into water bath. Moreover, the effect of spinning speed on the formation mechanism of PSf hollow fiber membranes spun via VIPS was also investigated. The data show that by increasing the spinning speed, the exchange rate of water vapor and solvent was increased and induced the phase separation.
|
|---|
