Thermosensitive properties of semi-IPN gel composed of amphiphilic gel and zwitterionic thermosensitive polymer in buffer solutions containing high concentration salt

Takahashi Atsushi

Hamai Kenta

Okada Yuko

Sakohara Shuji

Polymer

In this study, a semi-interpenetrating polymer network (semi-IPN) gel, which consists of an amphiphilic N,N-dimethylacrylamide-co-N-isopropylacrylamide (DMAA-co-NIPAM) gel and an interpenetrating zwitterionic thermosensitive poly(N-isopropylacrylamide-co-N,N-dimethyl(acrylamidopropyl)ammonium propane sulfonate) (poly(NIPAM-co-DMAAPS)) was prepared. The thermosensitive behavior of the semi-IPN gel was investigated in a buffer solution composed of a relatively high concentration of sodium chloride and sodium citrate as salts, and sodium dodecyl sulfate as a surfactant, which are generally used as a buffer solution in biochips. At low temperatures, the semi-IPN gel in the buffer solution was absolutely transparent; however, when the gel was heated, the gel became milky white or opaque without a large change in the gel size. The network of the transparent gel is homogeneous, whereas that of the opaque gel consists of coarse and dense parts. Such a structural change in the gel network was confirmed by the temperature dependence of the permeability of the buffer solution through the semi-IPN gel membrane. The permeability increased drastically when the gel became opaque because of heating.

Semi-IPN gel

Zwitterionic polymer

Thermosensitive property

Chemical technology [ 570 ]

eng

Elsevier Science Ltd

(c) 2011 Elsevier Ltd. All rights reserved.

[ISSN] 0032-3861

[DOI] 10.1016/j.polymer.2011.06.014

[NCID] AA11537383

[DOI] http://dx.doi.org/10.1016/j.polymer.2011.06.014