Leibniz Institute of Polymer Research Dresden e. V., 01069 Dresden, Germany and Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland.
Leibniz Institute of Polymer Research Dresden e. V., 01069 Dresden, Germany and Institute for Theoretical Physics, Technische Universität Dresden, 01069 Dresden, Germany.
Soft Matter. 2016 Nov 9;12(44):9007-9013. doi: 10.1039/c6sm02164f.
We study the conformational properties of dendrimers with flexible spacers in solutions over a wide range of concentrations from dilute solutions to melts. By combining large scale computer simulations using the bond fluctuation model with scaling arguments we identify the semi-dilute regime of dendrimers which is controlled by the concentration behavior of the linear spacers. Associated with this observation we find that the decrease in the size of flexible dendrimers is accompanied by increasing interpenetration between the molecules with increasing concentration of the solution. In the melt state we show that the size of individual dendrimers follows the scaling prediction for isolated dendrimers at the θ-point rather than that of collapsed dendrimers. The pair correlation functions between the centers of dendrimers indicate that for short spacers dendrimer solutions retain the morphological characteristics of simple liquids. For long spacers the functions reveal high penetration of neighboring dendrimers in the melt state. Our studies show that flexible dendrimers in solution can be understood with arguments similar to those of linear polymers. The role of generation is to influence the particular form of the crossover-function.
我们研究了在从稀溶液到熔体的很宽浓度范围内，具有柔性间隔物的树状聚合物在溶液中的构象性质。通过使用键波动模型的大规模计算机模拟和标度分析，我们确定了树状聚合物的半浓溶液区，该溶液区由线性间隔物的浓度行为控制。与这一观察结果相关，我们发现，随着溶液浓度的增加，柔性树状聚合物的尺寸减小，分子之间的相互渗透增加。在熔体状态下，我们表明，单个树状聚合物的尺寸遵循孤立树状聚合物在θ点的标度预测，而不是塌陷树状聚合物的标度预测。树状聚合物中心之间的对关联函数表明，对于短间隔物，树状聚合物溶液保留了简单液体的形态特征。对于长间隔物，这些函数揭示了在熔体状态下相邻树状聚合物的高穿透性。我们的研究表明，溶液中的柔性树状聚合物可以用类似于线性聚合物的论点来理解。代的作用是影响交叉函数的特定形式。
