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 techni que were demonstrated by studying the asymmetrical hydrogel formation betwe en a hydrophobic template and a hydrophilic template. By ESPI, the spatial distribution of gelation was successfully followed in real time, and the co ncentration distribution of polymer gel was evaluated. By use of this techn ique, it was for the first time found that the gelation was suppressed at t he hydrophobic surface and resulted in an inhomogeneous distribution of the polymer network density between two templates.