Temperature-sensitive switch from composite poly(N-isopropylacrylamide) sponge gels

✍ Scribed by Liang Liang; Xiangdong Feng; Paul F. C. Martin; Loni M. Peurrung

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 131 KB
• Volume: 75
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000401)75:14<1735::aid-app7>3.0.co;2-r

✦ Synopsis

Thermally sensitive polymers change their properties with a change in environmental temperature in a predictable and pronounced way. These changes can be expected in drug delivery systems, solute separation, enzyme immobilization, energytransducer processes, and photosensitive materials. We have demonstrated a thermalsensitive switch module, which is capable of converting thermal into mechanical energy. We employed this module in the control of liquid transfer. The thermally sensitive switch was prepared by crosslinking poly(N-isopropylacrylamide) (PNIPAAm) gel inside the pores of a sponge to generate the composite PNIPAAm/sponge gel. This gel, contained in a polypropylene tube, was inserted into a thermoelectric module equipped with a fine temperature controller. As the water flux through the composite gel changes from 0 to 6.6 ϫ 10 2 L m Ϫ2 h, with a temperature change from 23 to 40°C, we can reversibly turn on and off the thermally sensitive switch.