Thermal and mechanical properties of poly(N‐isopropylacrylamide)‐based hydrogels as a function of porosity and medium change. Issue 45 (6th August 2015)

• Record Type: Journal Article
• Authors: Chatterjee, Prithwish; Dai, Annie; Yu, Hongyu; Jiang, Hanqing; Dai, Lenore L.
• Is Part Of: Journal of applied polymer science. Volume 132:Issue 45(2015)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2015-08-06
• Subjects: Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.42776
• Languages: English
• ISSNs: 0021-8995

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>Poly(<italic>N</italic>‐isopropylacrylamide) (PNIPAAm) has been a well‐known stimuli–responsive material and has been used in multiple novel applications. One of the key attributes to make the hydrogel more attractive is to control the response time and temperature. This work focused on comparing the physical properties, such as response time, transition temperature, heat of fusion, and mechanical strength, of macroporous and microporous PNIPAAm hydrogels, respectively. It was found that the macroporous hydrogels synthesized from a low‐temperature polymerization with addition of tetramethyl orthosilicate exhibited a faster response time and superior mechanical strength. Furthermore, to modulate the transition temperature, both the macroporous and microporous hydrogels were subjected to different qualities of media by introducing a cosolvent (methanol) or an anionic surfactant (sodium dodecyl sulfate). Interestingly, addition of a cosolvent demonstrated a more pronounced effect on the macroporous hydrogel, whereas the surfactant resulted in a more pronounced effect on the microporous hydrogel. Such results revealed that based on their porosity; there were appreciable differences when the PNIPAAm hydrogels interacted with media molecules. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. <bold>2015</bold>, <italic>132</italic>, 42776.</p> </abstract>