Das Jayajit, Yoshida Masaru, Fresco Zachary M, Choi Tae-Lim, Fréchet J M J, Chakraborty Arup K
Department of Chemical Engineering and Chemistry, University of California-Berkeley, Berkeley, California 94720, USA.
J Phys Chem B. 2005 Apr 14;109(14):6535-43. doi: 10.1021/jp058081e.
The molecular architecture of dendronized polymers can be tuned to obtain nanoscale objects with desired properties. In this paper, we bring together experiments and computer simulations to study the thermodynamic and dynamic properties of a single dendronized polymer chain. We find that, upon changing certain architectural features, dynamic correlations characterizing backbone conformational fluctuations of a dendronized polymer exhibit dynamics akin to glass-forming bulk liquids. Thus, a dendronized polymer chain is a novel macromolecule that is a single-molecule glass. Over a range of conditions that lead to glassy dynamics, there does not appear to be any thermodynamic singularities. We discuss how a dendronized polymer is a molecular system that can directly test different models of glassy dynamics. We also show that defect densities characteristic of typical synthesis conditions do not alter the material properties of dendronized polymers.
树枝状聚合物的分子结构可以进行调整，以获得具有所需特性的纳米级物体。在本文中，我们结合实验和计算机模拟来研究单个树枝状聚合物链的热力学和动力学性质。我们发现，在改变某些结构特征时，表征树枝状聚合物主链构象波动的动态相关性呈现出类似于形成玻璃的本体液体的动力学。因此，树枝状聚合物链是一种新型大分子，即单分子玻璃。在一系列导致玻璃态动力学的条件下，似乎不存在任何热力学奇点。我们讨论了树枝状聚合物如何成为一个能够直接测试不同玻璃态动力学模型的分子系统。我们还表明，典型合成条件下的缺陷密度不会改变树枝状聚合物的材料性质。
