Murase Norio, Abe Satoru, Takahashi Hiroshi, Katagiri Chihiro, Kikegawa Takumi
Department of Biotechnology, School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama 350-0394, Japan.
Cryo Letters. 2004 May-Jun;25(3):227-34.
Ice crystallisation in crosslinked dextran (Sephadex) gels was studied by the method of two-dimensional X-ray diffraction (XRD) in combination with the simultaneous measurement of differential scanning calorimetry (DSC). With a Sephadex G25 gel where an exotherm due to ice crystallisation is observed in the DSC rewarming trace, it was indicated by the XRD pattern that small ice crystals less than approximately 10 microns in diameter are readily formed during freezing, and that the endothermic trend prior to the exotherm is not due to the glass transition but due to the melting of the small ice crystals. Moreover, the diffraction pattern observed with frozen Sephadex gels depended on the density of crosslink indicating that ice crystals of different size and dimension are formed in the gels.
通过二维X射线衍射（XRD）方法结合差示扫描量热法（DSC）的同步测量，研究了交联葡聚糖（葡聚糖凝胶）凝胶中的冰晶形成。对于葡聚糖凝胶G25，在DSC复温曲线上观察到由于冰晶形成而产生的放热峰，XRD图谱表明在冷冻过程中容易形成直径小于约10微米的小冰晶，并且在放热峰之前的吸热趋势不是由于玻璃化转变，而是由于小冰晶的融化。此外，冷冻葡聚糖凝胶观察到的衍射图谱取决于交联密度，表明在凝胶中形成了不同尺寸和维度的冰晶。
