The Effects of Polydispersity on Self Assembly in Block Copolymers.

众所周知，制造业非常依赖由聚合物分子组成的塑料材料。典型的现成聚合物是通过将大量（例如，数以千计）的化学相同的单元（称为单体）形成长链分子。正如人们所料，一块塑料中的单个分子长度不同。事实上，这种链长的多分散性在商业材料中是非常大的，这是合成分子的简单但具有成本效益的方法的结果。幸运的是，事实证明，在将聚合物成型或加工成各种产品时，高度的多分散性实际上是有利的。现在出现了涉及新一代更精细的聚合物的潜在应用，所述聚合物被称为二嵌段共聚物，其中链的第一部分（即，嵌段）由一种类型的单体形成，第二嵌段由另一种类型的单体形成。化学上不同的嵌段分离的一般趋势导致材料内共聚物的自组织，从而产生独特的性质和行为。为了研究的目的，科学家们已经做出了巨大的努力来生产模型材料，其中多分散度非常低。虽然这在试图理解它们的复杂行为时提供了巨大的优势，但合成单分散二嵌段共聚物的成本是潜在商业应用的严重障碍。本项目的目的是了解多分散性的引入如何影响二嵌段共聚物材料的行为。这将涉及实施新的合成方法，用于生产多分散二嵌段共聚物，其具有良好的特征链长分布，并结合广泛的实验技术，用于探测分子的自组织。然后将实验观察结果与最先进的理论预测进行比较。与简单聚合物材料的情况一样，希望多分散性不仅降低生产成本，而且提供有利的性能。

As everyone is well aware, the manufacturing sector has a huge reliance on plastic materials composed of polymeric molecules. A typical off-the-shelf polymer is created by linking together a large number (e.g., thousands) of chemically-identical units (called monomers) to form long-chain molecules. As one might expect, the individual molecules within a piece of plastic differ in length. In fact, this polydispersity of chain lengths is extremely large in commercial materials, as a consequence of the simple but cost-effective methods of synthesising the molecules. Fortunately, it turns out that a high-degree of polydispersity is, in fact, advantageous when shaping or processing the polymers into various products.There are now emerging potential applications involving a new generation of more elaborate polymers called diblock copolymers, where the first part of the chain (i.e., block) is formed from one type of monomer and the second block is created from another type of monomer. The general tendency for the chemically-distinct blocks to separate causes self-organisation of the copolymers within the material, resulting in unique properties and behaviour. For research purposes, scientists have made great efforts to produce model materials, where the degree of polydispersity is very low. Although this provides a huge advantage when trying to understand their complicated behaviour, the cost of synthesising monodisperse diblock copolymers is a serious impediment to potential commercial applications. The aim of the current project is to understand how the introduction of polydispersity affects the behaviour of diblock-copolymer materials. This will involve the implementation of novel synthetic methods for producing polydisperse diblock copolymers with well-characterised chain-length distributions combined with a wide-range of experimental techniques for probing the self-organisation of the molecules. The experimental observations will then be compared with state-of-the-art theoretical predictions. The hope is, as in the case of simple polymeric materials, that polydispersity not only reduces production costs but also provides advantageous properties.