Abstract

Poly(N-isopropylacrylamide) i.e. PNIPAAm is a temperature sensitive smart material which displays a lower critical solution temperature (LCST) at 33–35°C. At the lower critical solution temperature, the gel changes from hydrophilic to hydrophobic which has significant consequences in cell culturing. The first known measurements of the optical properties i.e. absorption (μ_a) and reduced scattering (μ′_s) coefficients, as a function of temperature, of a series of crosslinked PNIPAAm gels, using an Integrating Sphere setup, is presented at a wavelength of 632.8 nm. These properties showed a direct correlation between the scattering coefficient and the crosslinker density for the gels. The absorption properties correlated well with the known absorption characteristics of these gels.

© 2009 OSA/SPIE