低温保护剂微液滴在液氮表面的Leidenfrost效应及分析

发布时间：2018-03-13 12:21

本文选题：微液滴　切入点：低温保护剂　出处：《中国科学:技术科学》2017年02期 　论文类型：期刊论文

【摘要】：借助红外摄像和图像分析技术,并结合非等温结晶动力学模型理论分析,系统研究了微量低温保护剂溶液在液氮表面的Leidenfrost效应及其影响因素.研究结果表明:微水滴的相变温度最高(约273K),最大结晶度变化率达到3×10~(-2),最大运动速度值为100~130mm/s,但其Leidenfrost时间最短;随着低温保护剂浓度的增大,其相变温度降低(20%和50%甘油分别约为250和225K),结晶变化率显著减小(20%和50%甘油分别约为1.4×10~(-3)和7×10~(-7)),其最大运动速度值也会降低(20%和50%甘油分别为90~120和85~105mm/s),且Leidenfrost时间会随着浓度增大而增长;Vs55的相变温度最低(约158K),结晶度变化率最小(约2.8×10~(-16)),最大运动速度值降低到75~95mm/s,且其Leidenfrost时间最长(约是水的2~3倍);微液滴体积越大,其Leidengfrost时间越长,但对低浓度溶液(水和20%甘油)最大运动速度的影响不大,而对于高浓度溶液(50%甘油和Vs55)则是呈现出"体积越大,速度越快"的变化趋势.这些结论对于微液滴玻璃化保存生物样本方案的优化设计具有重要的指导意义.
[Abstract]:With the help of infrared camera and image analysis technology, combined with the theoretical analysis of non-isothermal crystallization kinetic model, The Leidenfrost effect of microamount cryogenic protectant solution on the surface of liquid nitrogen and its influencing factors are systematically studied. The results show that the phase transition temperature of microdroplet is the highest (about 273Kg), the maximum crystallinity change rate is 3 脳 10 ~ (10) ~ (-1) ~ (-2), and the maximum motion velocity is 100 ~ (13) mm / s. But its Leidenfrost time is the shortest; With the increase of the concentration of low temperature protectant, The phase transition temperature is reduced by 20% and 50% glycerol is about 250 and 225 KG respectively, and the crystal change rate is significantly reduced by 20% and 50% glycerol respectively (1.4 脳 10 ~ (-3)) and 7 脳 10 ~ (10) ~ (-7). The maximum motion velocity values are also reduced by 20% and 50% glycerol (90 ~ 120 mm / s and 8510 ~ 5 mm / s ~ (-1)), respectively, and the Leidenfrost time will be increased with the increase of Leidenfrost time. When the concentration increases, the phase transition temperature is the lowest (about 158 KG), the crystallinity change rate is the least (about 2.8 脳 10 ~ (-1) -16 ~ (-1)), the maximum velocity decreases to 7595 mm / s, and the Leidenfrost time is the longest (about 2 ~ 3 times as much as water). The longer the Leidengfrost time, but the less the effect on the maximum movement velocity of low concentration solution (water and 20% glycerol), but the larger the volume of 50% glycerol and Vs55 in high concentration solution. These conclusions have important guiding significance for the optimization design of microdroplet vitrification biological sample scheme.
【作者单位】：上海理工大学生物系统热科学研究所;
【基金】：国家自然科学基金(批准号:51576132) 上海市自然科学基金(批准号:13ZR1428600)资助项目
【分类号】：R318.52

【相似文献】