Ultrafast optical Kerr effect spectroscopy of water confined in nanopores of the gelatin gel

This paper reports on the investigation of the water structure in the pores of the gelatin gel, gelatin being the biopolymer obtained by denaturation of collagen, in times shorter than the lifetime of molecular complexes. This study utilizes the femtosecond optical Kerr-effect spectroscopy with heterodyne detection, by use of Ar-ion laser pumped sapphire laser with 40 fs pulse duration. The ultrafast responses of water molecules, obtained in bulk liquid and in two concentrations of gelatin gels are shown. Significant changes can be seen in the intermediate-time region, which results from the intermolecular collective vibrations of molecular clusters.