Pagnotta S E, Cerveny S, Alegría A, Colmenero J
Centro de Fisica de Materiales (CSIC-UPV/EHU)-Materials Physics Center MPC, Universidad del Pais Vasco (UPV/EHU), Apartado 1072, 20018 San Sebastian, Spain.
J Chem Phys. 2009 Aug 28;131(8):085102. doi: 10.1063/1.3202215.
The relaxation dynamic of ribose and deoxyribose water solutions at different concentrations has been studied by broadband dielectric spectroscopy and differential scanning calorimetry in the temperature range of 150-250 K. Two relaxation processes are observed for all the hydration levels; the slower (process I) is related to the relaxation of the whole solution whereas the faster one (process II) is associated with the reorientation of water molecules in the mixture. As for other polymeric water solutions, dielectric data for process II indicate the existence of a critical water concentration above which water mobility is less restricted. According to these results, attenuated total reflectance Fourier transform infrared spectroscopy measurements of the same sugar solutions showed an increment in the intensity of the OH stretching sub-band close to 3200 cm(-1) as water content increases.
通过宽带介电谱和差示扫描量热法，在150 - 250 K的温度范围内研究了不同浓度核糖和脱氧核糖水溶液的弛豫动力学。对于所有水合水平，均观察到两个弛豫过程；较慢的（过程I）与整个溶液的弛豫有关，而较快的（过程II）与混合物中水分子的重新取向有关。与其他聚合物水溶液一样，过程II的介电数据表明存在一个临界水浓度，高于该浓度时水的流动性受限制较小。根据这些结果，相同糖溶液的衰减全反射傅里叶变换红外光谱测量表明，随着含水量增加，靠近3200 cm(-1)的OH伸缩子带强度增加。
