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Home  >  Journal list  >  Polymer Journal  >  Vol.20  No.9 (1988)  >  pp.761-769

Polymer Journal
<<Previous article Vol.20  No.9 (1988)   pp.761 - 769 Next article>>

Permeability Changes of a Porous Membrane by an Adsorbed Photoresponsive Polypeptide

Morimasa Sato1), Takatoshi Kinoshita1), Akira Takizawa1), Yoshiharu Tsujita1) and Ryuji Ito1)
1) Department of Materials Science & Engineering, Nagoya Institute of Technology

ABSTRACT:  Photoresposive polypeptides, poly(L-glutamic acid)s containing azobenzene-4-sulfonic acid residues in the side chains (azo·S-X-PGA, X is the mol% of the azobenzene sulfonate residue), were adsorbed onto a porous support membrane and photoinduced permeation changes of the membrane obtained were studied. The maximum amount of adsorption, nmax (g g−1), of azo·S-PGA in the membrane was shown to decrease by increasing the azobenzene sulfonate groups, X, resulting from decrease in the content of the L-glutamic acid residues which interact with the adsorption sites on the pore wall through hydrogen bonds. It was estimated that the value of nmax of the azo·S-14.1-PGA adsorbed membrane used for the permeation measurements was 1.40×10−2 g of the polymer per g of the support membrane. The filtration coefficient of the azo·S-14.1-PGA adsorbed membrane largely decreased at the pH where α-helix to coil transition of the polymer occurred, indicating that permeation of the membrane was mainly determined by the conformation of the adsorbed azo·S-PGA on the pore wall. Moreover, it was observed that photoirradiation of the membrane at adequate pHS could induce rapid decrease in Lp of the membrane within a few minute. The photoresposive behavior of the membrane can be explained in terms of the photoinduced helix to coil transition of the azo·S-14.1-PGA in the membrane. The permeability of the membrane containing azo·S-46.3-PGA, which was in the random coil state at any given pH value in the aqueous solution, was independent on pH and photoirradiation.

Photoresponsive Polypeptide/ Azobenzene Sulfonate Side Chain/ Poly(L-glutamic acid)/ Adsorption/ Porous Membrane/ Photoinduced Conformational Change/ Photoinduced Permeation Change

Published online: April 08, 2005
© Copyright, 2005 by The Society of Polymer Science, Japan



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