Local Effects of Ring Topology Observed in Polymer Conformation and Dynamics by Neutron Scattering-A Review.
Local Effects of Ring Topology Observed in Polymer Conformation and Dynamics by Neutron Scattering-A Review.
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DOI：
10.3390/polym12091884
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发表时间：
2020-08-21
期刊：
影响因子：
5
通讯作者：
Higgins JS
中科院分区：
文献类型：
--
作者：
Arrighi V;Higgins JS
聚合物的物理性质取决于一系列结构和化学参数，特别是分子拓扑结构。显然，简单的变化，如在一个点连接链形成恒星或简单地连接两端形成一个环，可以深刻地改变分子的构象和动力学，从而改变性质。环状聚合物，因为它们没有自由端，代表了爬行被完全抑制的最简单的模型系统。因此，有相当多的文献和几个评论集中在高分子量的环状化合物，其中长程动力学描述的爬行模型开始发挥作用。然而，这只是感兴趣的一个领域。考虑到环和链的构象和动力学，以及它们的混合物，在分子量范围从几十个重复单元到纠缠的开始和在溶液和熔体中，提供了丰富的理论和模拟文献。实验工作，特别是中子散射，一直受到合成表征良好的环样品和氘代类似物的困难的限制。在这里，在更广泛的文献的背景下，我们审查调查的线性和环状聚合物的局部构象和动力学，集中在聚（二甲基硅氧烷）（PDMS），并涵盖了广泛的一般不太高的摩尔质量。小角中子散射（SANS）和准弹性中子散射（QENS），包括中子自旋回波（NSE）的实验数据进行了比较，理论和计算预测。
The physical properties of polymers depend on a range of both structural and chemical parameters, and in particular, on molecular topology. Apparently simple changes such as joining chains at a point to form stars or simply joining the two ends to form a ring can profoundly alter molecular conformation and dynamics, and hence properties. Cyclic polymers, as they do not have free ends, represent the simplest model system where reptation is completely suppressed. As a consequence, there exists a considerable literature and several reviews focused on high molecular weight cyclics where long range dynamics described by the reptation model comes into play. However, this is only one area of interest. Consideration of the conformation and dynamics of rings and chains, and of their mixtures, over molecular weights ranging from tens of repeat units up to and beyond the onset of entanglements and in both solution and melts has provided a rich literature for theory and simulation. Experimental work, particularly neutron scattering, has been limited by the difficulty of synthesizing well-characterized ring samples, and deuterated analogues. Here in the context of the broader literature we review investigations of local conformation and dynamics of linear and cyclic polymers, concentrating on poly(dimethyl siloxane) (PDMS) and covering a wide range of generally less high molar masses. Experimental data from small angle neutron scattering (SANS) and quasi-elastic neutron scattering (QENS), including Neutron Spin Echo (NSE), are compared to theory and computational predictions.
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影响因子：
5.5
作者：
Arrighi, V;Gagliardi, S;Telling, MTF
通讯作者：
Telling, MTF
影响因子：
4.4
作者：
DEGENNES, PG
通讯作者：
DEGENNES, PG
影响因子：
1.4
作者：
Alatas, Panagiotis V.;Tsalikis, Dimitrios G.;Mavrantzas, Vlasis G.
通讯作者：
Mavrantzas, Vlasis G.
影响因子：
5.5
作者：
Arrighi, Valeria;Gagliardi, Simona;Telling, Mark T. F.
通讯作者：
Telling, Mark T. F.
影响因子：
4.4
作者：
Brown, S;Szamel, G
通讯作者：
Szamel, G