In situ monitoring of hydrogel polymerization using speckle interferometry

Electronic speckle pattern interferometry (ESPI) was proposed to study the polymerization kinetics of hydrogels in water. The potentials of the technique were demonstrated by studying the asymmetrical hydrogel formation between a hydrophobic template and a hydrophilic template. By ESPI, the spatial distribution of gelation was successfully followed in real time, and the concentration distribution of polymer gel was evaluated. By use of this technique, it was for the first time found that the gelation was suppressed at the hydrophobic surface and resulted in an inhomogeneous distribution of the polymer network density between two templates.