STABILITY OF THE TWO-PHASE COEXISTENCE AND THE STRUCTURE OF PHASE BOUNDARIES NEAR THE FIRST-ORDER PHASE TRANSITION

两相共存的稳定性和一阶相变附近的相界结构

基本信息

批准号：
05640437
负责人：
HIROTSU Shunsuke
金额：
$ 1.34万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640437/
关键词：
Polymer gels Phase transition Phase equilibria Domein boundary Phase separation Gel water Viscoelasticity Coherent solid ゲル体積相転移分域構造高分子物理学相境界パターン形成 2相共存領域

项目摘要

Summary of Research ResultsOn the experimental side, the behavior of domain boundaries in a transition region of gels, and formation of peculiar cellular patterns inside gels embedded in a mixed solvent have been investigated in detail. On the theoretical side, on the other hand, behavior of gel water at the volume phase transition has been analyzed in terms of the experimental data and the phenomenological considerations.(1)Realization of the tri-phasic equilibrium and the temperature behavior of domain boundaries.Fast and precise measurements of the movement of domain boundaries were made possible by requires higher magnification of a microscope to observe the detailed behavior of the domain. Because an objective lense of smaller working distance had to be used, temperature regulation of the sample had become more difficult. We overcame this difficulty by improving the temperature controller as well as the sample holder. It has been confirmed by this experiment that the more advanced … More theoretical considerations than the previous phenomenological one is needed to understand fully the volume phase transition of gels.(2)Observation of the peculiar cellular pattern at the phase separation of gels.It was first demonstrated that, a characteristic cellular pattern developls when the solvent outside the N-isopropylacrylamide gel is changed from pure water to water-ethanol mixture. The fibers constituting this pattern have been found to be birefringent, which suggests that the aggregates has some sort of crystalline order. It is also deduced that NIPA chains are fairly rigid.(3)Behavior of gel water at the volume phase transition.A most significant result emerged from this year's study is that the real volume phase transition occurs in a fairly different fashion from the model predicted by the coventiona Flory's theory. Combining various experimental facts accumulated so far, it has become evident that the shrunken phase of gel does not contain free water, and some kind of ordered structure is present, which is made up from bound water molecules and polymer chains. This fact is important because even a gel made from homopolymer and pure water has some kind of secondary or tertially structure, and thus can be regarded as a model system of much more complex biopolymer systems. Less

研究结果的摘要已详细研究了凝胶过渡区域中域边界的行为以及嵌入混合溶液中凝胶内部特殊细胞模式的形成。在理论方面，另一方面，已经根据实验数据和现象学考虑对凝胶水的行为进行了分析。（1）实现三重强调平衡的实现和域边界的温度行为。快速固定和精确测量域边界的运动的精确测量，可以通过较高的细节来详细介绍一个细节，以使较高的详细信息的详细信息详细说明。由于必须使用较小的工作距离的客观镜头，因此样品的温度调节变得更加困难。我们通过改善温度控制器和样品持有器来克服这一困难。该实验已经证实，比先前的现象学更为先进的考虑因素更高级的考虑，需要充分了解凝胶的体积相位过渡。（2）观察凝胶相分离处特殊的细胞模式。这首先证明，当n-异丙基氨基酰基透明的质量水中溶解了一种特征性的细胞模式开发者，从而从纯净的水中溶解了纯净的水。已经发现构成这种模式的纤维是双折的，也是驱动NIPA链相当刚性的。（3）（3）凝胶水在体积相位过渡时的行为。今年的研究中最重要的结果是，实际体积相位过渡与Consultationa Flory的模型相当不同的方式发生了相当不同的方式。迄今为止，结合了各种实验事实，已经证明了凝胶的缩小相不含自由水，并且存在某种有序结构，这是由结合的水分子和聚合物链组成的。这一事实很重要，因为即使是由均聚物和纯水制成的凝胶具有某种二次或第二个性结构，因此可以被视为更复杂的生物聚合物系统的模型系统。较少的