Abstract
Gating membranes that are sensitive to ethanol concentration were prepared by plasma-graft filling polymerization
and their gating function was investigated by permeation experiments using ethanol/water mixture containing glucose and yeast, and using fermentation solution. When ethanol/water mixture containing glucose and yeast was
used, permeation rate (when gate was open) decreased significantly with operating time. This result suggests that
gating function was being deteriorated by fouling, probably by small fragments of yeast. Flux decline was suppressed
to some extent by controlling operating conditions. Furthermore, use of prefilter having proper pore size on the gating membrane could suppress the flux decline significantly.
Continuous fermentation/permeation experiment was conducted using gating membrane covered with a prefilter.
Although permeation rate decreased with operating time when the gate was open, it was confirmed that the gating
membrane could open and close its pores responding to ethanol concentration. This result showed that it is possible
to apply the gating membrane to the fermentation process.
