Temperature dependence of thermal diffusion for aqueous solutions of monosaccharides, oligosaccharides, and polysaccharides
Yuki Kishikawa,Haruka Shinohara,Kousaku Maeda,Yoshiyuki Nakamura,Simone Wiegand,Rio Kita
Physical Chemistry Chemical Physics Pub Date : 05/24/2012 00:00:00 , DOI:10.1039/C2CP41183K
Abstract

We studied the thermal diffusion behavior for binary aqueous solutions of glucose, maltotriose, maltohexaose, pullulan, and dextran by means of thermal diffusion forced Rayleigh scattering (TDFRS). The investigated saccharides with molar masses between 0.180 and 440 kg mol−1 were studied in the temperature range between 15 and 55 °C. The thermal diffusion coefficient DT and the Soret coefficient ST of all solutions increase with increasing temperature. For maltohexaose and the polymers the thermal diffusion coefficient changes sign from negative to positive with increasing temperature, whereas glucose and maltotriose show only positive values in the entire investigated temperature range. While we were able to find a master curve to describe the temperature dependence of DT, we were not able to find a similar expression for ST. This comprehensive study allows for the first time the determination of the interaction parameters for the polymer and the solvent within the theoretical framework suggested by Würger [Phys. Rev. Lett., 2009, 102, 078302].

Graphical abstract: Temperature dependence of thermal diffusion for aqueous solutions of monosaccharides, oligosaccharides, and polysaccharides