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The study of polymers in geometrically confined states by the thermal analysis, the spectroscopic study, and the morphological investigation.

机译：通过热分析，光谱学研究和形态研究对处于几何约束状态的聚合物进行研究。

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This thesis focuses on the study of the different geometrically confined states of polyacrylamide (PAL) in bulk film, single chain globules, and thin films. The thermal analysis, the spectroscopic study, and the morphological investigation were carried out. The main contribution of this thesis is that we have acquired a better understanding about the glass transition (T g) behavior of polymers. Although the glass transition is a well known phenomenon for liquids with strong covalently bonded structures, and is especially noteworthy for amorphous polymers, understanding the glass transition still remains one of the most intriguing puzzles in condensed matter physics at present. The solution of the glass transition puzzle will ultimately influence different fields in polymer science, particularly biophysics and biochemistry. Our approach to this complicated assignment, the glass transition phenomenon, is to examine the glass transition behavior of polymer chains in 3 dimensional confinement for single molecular single chain globules, 1 dimensional confinement for polymer thin films, and 0 dimensional confinement for bulk state polymer. We found that the glass transition temperature of a polymer depends on several factors, such as the inter-chain interlock entanglement, the inter-chain molecular interactions, the intra-chain cohesional entanglement, and the local chain orientation and conformational entropy. These factors have been systematically investigated by carefully preparing the polymer samples in different confined states. The main conclusion is that, although the glass transition is a non-equilibrium dynamic property, the true glass transition can be reached when polymer chains are free of the inter-chain entanglement. A better example is illustrated, in this thesis, of the glass transition behavior for the well-annealed single chain globules.; PAL single chain globules are prepared by spray drying from the dilute solution. The size and morphology of the single chain globules are characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). DSC characterization reveals that the Tg of the single chain globules, upon annealing, is higher than that of the bulk film. (Abstract shortened by UMI.)
机译：本文主要研究块状薄膜，单链小球和薄膜中聚丙烯酰胺（PAL）的不同几何约束状态。进行了热分析，光谱研究和形态研究。本论文的主要贡献是我们对聚合物的玻璃化转变（T g）行为有了更好的了解。尽管对于具有强共价键合结构的液体来说，玻璃化转变是众所周知的现象，但对于非晶态聚合物而言，玻璃化转变尤其值得注意，但了解玻璃化转变仍然是当前凝聚态物理中最令人着迷的难题之一。玻璃化难题的解决方案最终将影响聚合物科学的不同领域，尤其是生物物理学和生物化学。我们对这种复杂分配的方法，即玻璃化转变现象，是研究聚合物链在单分子单链小球的3维限制，聚合物薄膜的1维限制和本体聚合物的0维限制中的玻璃化转变行为。我们发现聚合物的玻璃化转变温度取决于几个因素，例如链间互锁缠结，链间分子相互作用，链内内聚缠结以及局部链取向和构象熵。通过仔细制备处于不同限制状态的聚合物样品，系统地研究了这些因素。主要结论是，尽管玻璃化转变是一种非平衡动力学性质，但当聚合物链没有链间缠结时，可以达到真正的玻璃化转变。在本文中，一个更好的例子说明了退火良好的单链小球的玻璃化转变行为。 PAL单链小球是通过从稀溶液中喷雾干燥制得的。单链球的大小和形态通过扫描电子显微镜（SEM）和透射电子显微镜（TEM）表征。 DSC表征表明，退火后，单链小球的Tg高于块状薄膜的Tg。 （摘要由UMI缩短。）

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