TY - JOUR
T1 - Microstructures in phase-inversion membranes
T2 - Part I. Formation of macrovoids
AU - Smolders, C.A.
AU - Reuvers, A.J.
AU - Boom, R.M.
AU - Wienk, I.M.
PY - 1992
Y1 - 1992
N2 - A new mechanism for the formation of macrovoids in phase-inversion membranes is proposed. It is based on the observed difference in type of demixing of a thin film of a polymer solution when immersed in a nonsolvent bath: delayed or instantaneous demixing. The explanation for macrovoid formation assumes local conditions of delayed demixing in front of a certain layer of nuclei already formed, due to a change in the interfacial compositions at the advancing coagulation front, as compared to the original composition at the interface film-bath. Effects of variations in membrane formation conditions which can be calculated using the model of diffusive mass transport in thin films of polymeric solutions in combination with phase separation in phase-inversion membranes, completely support the mechanism as proposed.
AB - A new mechanism for the formation of macrovoids in phase-inversion membranes is proposed. It is based on the observed difference in type of demixing of a thin film of a polymer solution when immersed in a nonsolvent bath: delayed or instantaneous demixing. The explanation for macrovoid formation assumes local conditions of delayed demixing in front of a certain layer of nuclei already formed, due to a change in the interfacial compositions at the advancing coagulation front, as compared to the original composition at the interface film-bath. Effects of variations in membrane formation conditions which can be calculated using the model of diffusive mass transport in thin films of polymeric solutions in combination with phase separation in phase-inversion membranes, completely support the mechanism as proposed.
U2 - 10.1016/0376-7388(92)80134-6
DO - 10.1016/0376-7388(92)80134-6
M3 - Article
VL - 73
SP - 259
EP - 275
JO - Journal of membrane science
JF - Journal of membrane science
SN - 0376-7388
IS - 2-3
ER -