Finger-like voids induced by viscous fingering during phase inversion of alumina/PES/NMP suspensions
Type
ArticleAuthors
Wang, BoLai, Zhiping

KAUST Department
Advanced Membranes and Porous Materials Research CenterBiological and Environmental Sciences and Engineering (BESE) Division
Chemical Engineering Program
Physical Science and Engineering (PSE) Division
Date
2012-07Permanent link to this record
http://hdl.handle.net/10754/562226
Metadata
Show full item recordAbstract
The formation mechanism of phase-inversion ceramic hollow fibre membranes has not been well understood. In this paper, we report on the formation of finger-like macrovoids during non-solvent-induced phase inversion of alumina/PES/NMP suspensions. A membrane structure without such finger-like macrovoids was observed when the suspension was slowly immersed into pure ethanol or a mixture of 70. wt% NMP and 30. wt% water, whereas finger-like macrovoids occurred when the suspension was slid into the non-solvents at higher speeds. We found that the formation process of finger-like macrovoids could be fully or partially reversed when nascent membranes were taken out from water shortly after immersion, depending on the duration of the immersion. Splitting of the fingers during the formation of the macrovoids was also observed during the phase inversion of two alumina/PES/NMP suspensions. These experimental observations were not predicted by current theories of finger-like macrovoid formation in polymer membranes, but appear to mimic the well-known viscous fingering phenomenon. We therefore propose that in the phase inversion of ceramic suspensions, the viscous fingering phenomenon is an important mechanism in the formation of finger-like voids. © 2012 Elsevier B.V.Citation
Wang, B., & Lai, Z. (2012). Finger-like voids induced by viscous fingering during phase inversion of alumina/PES/NMP suspensions. Journal of Membrane Science, 405-406, 275–283. doi:10.1016/j.memsci.2012.03.020Sponsors
This work was supported by baselines funds to Z.P. Lai from King Abdullah University of Science and Technology. B. Wang acknowledges support from the Ministry of Education of China (Contract No. 210093). We thank Dr. S.H. Choi for stimulating discussions and Dr. P. Wang for providing access to the microscope.Publisher
Elsevier BVJournal
Journal of Membrane Scienceae974a485f413a2113503eed53cd6c53
10.1016/j.memsci.2012.03.020