Picture of boy being examining by doctor at a tuberculosis sanatorium

Understanding our future through Open Access research about our past...

Strathprints makes available scholarly Open Access content by researchers in the Centre for the Social History of Health & Healthcare (CSHHH), based within the School of Humanities, and considered Scotland's leading centre for the history of health and medicine.

Research at CSHHH explores the modern world since 1800 in locations as diverse as the UK, Asia, Africa, North America, and Europe. Areas of specialism include contraception and sexuality; family health and medical services; occupational health and medicine; disability; the history of psychiatry; conflict and warfare; and, drugs, pharmaceuticals and intoxicants.

Explore the Open Access research of the Centre for the Social History of Health and Healthcare. Or explore all of Strathclyde's Open Access research...

Image: Heart of England NHS Foundation Trust. Wellcome Collection - CC-BY.

Super-selective polysulfone hollow fiber membranes for gas separation: rheological assessment of the spinning solution

Gordeyev, S.A. and Lees, G.B. and Dunkin, I.R. and Shilton, S.J. (2001) Super-selective polysulfone hollow fiber membranes for gas separation: rheological assessment of the spinning solution. Polymer, 42 (9). pp. 4347-4352. ISSN 0032-3861

Full text not available in this repository. Request a copy from the Strathclyde author

Abstract

A polysulfone spinning solution used recently to produce enhanced selectivity gas separation hollow fiber membranes was rheologically assessed using a rotational rheometer and an optical shear cell. Effects of temperature and shear rate on viscosity, power law behavior and normal force provided some clues regarding phase inversion and molecular orientation. At relatively low temperatures, phase inversion may occur in the absence of a shear field. At moderately low temperatures, phase inversion may be induced by applied shear. At higher temperatures, phase inversion is not induced by shear but rather shear induces molecular orientation. The results suggest that, unless spinning at low temperature, extrusion shear does not directly induce demixing during membrane formation but, instead, is linked indirectly to phase inversion through induced molecular orientation which, in turn, affects the subsequent dry or wet precipitation stages in spinning. This work is a step towards the construction of phase diagrams and determining their distortion in shear fields. Such knowledge, coupled with deeper insights into induced polymer molecule orientation, would enable further improvements in spinning techniques and membrane performance.