KANG, YS KIM, HJ KIM, UY 2024-01-21T23:41:55Z 2024-01-21T23:41:55Z 2022-01-11 1991-08-23 0376-7388 https://pubs.kist.re.kr/handle/201004/146753 The kinetic effect of the phase inversion process on the membrane morphology is explored, with emphasis on the diffusion coefficient of the nonsolvent as a measure of the solvent/nonsolvent exchange rate. The diffusion coefficient is closely related to the nonsolvent tolerance of the polymer solution, which was estimated from a pseudo-ternary phase diagram of the following system: polymer: polysulfone; solvent system: a mixture of the solvent 1-methyl-2-pyrrolidinone and a solvent additive (formic acid, water or ethanol); and nonsolvent: ethanol. Regardless of the kind of solvent additive employed, when the diffusion coefficient of the nonsolvent is high for a given gelation medium, then the membrane consists of a smooth, defect-free surface and macrovoid-free cross section, and is highly permeable to oxygen. However, using a polymer solution with a low diffusion coefficient results in a membrane of a rather defective morphology. Therefore, it is concluded that the diffusion coefficient of the nonsolvent is a crucial parameter in controlling membrane morphology. English ELSEVIER SCIENCE BV HOLLOW FIBER MEMBRANES GAS-SEPARATION MEMBRANE LEWIS ACID BASE COMPLEXES FREE-VOLUME POLYSULFONE MECHANISM SOLVENT SPUN ASYMMETRIC MEMBRANE FORMATION VIA IMMERSION PRECIPITATION METHOD .1. KINETIC EFFECT Article 1 JOURNAL OF MEMBRANE SCIENCE, v.60, no.2-3, pp.219 - 232 JOURNAL OF MEMBRANE SCIENCE 60 2-3 219 232 scie scopus A1991GE76300009 2-s2.0-0026204764 Engineering, Chemical Polymer Science Engineering Polymer Science Article HOLLOW FIBER MEMBRANES GAS-SEPARATION MEMBRANE LEWIS ACID BASE COMPLEXES FREE-VOLUME POLYSULFONE MECHANISM SOLVENT SPUN MEMBRANE PREPARATION AND STRUCTURE IMMERSION PRECIPITATION METHOD PHASE INVERSION DIFFUSION COEFFICIENT