Mixtures of solvents and mixtures of block copolymers as tools for tunable structures in block copolymer thin films

继续项目的目的是(I)了解两嵌段共聚物薄膜在溶剂混合物的蒸气处理过程中的过程，以及(Ii)在两嵌段共聚物混合物的薄膜中使用微观和宏观相分离来制备复杂结构。在项目(I)中，将用选择性和非选择性混合溶剂对圆柱形两嵌段共聚物的薄膜进行蒸气处理。这将导致对重组过程的理解；因此，将确定通过溶剂蒸气退火来退火缺陷和诱导所需圆柱体取向的最佳方案。在项目(II)中，将研究由于微观和宏观相分离的相互作用而形成复杂结构的对称性两嵌段共聚物的二元混合物的薄膜。在对称和不对称两嵌段共聚物的混合物中，我们将研究从片层到圆柱体的转变，包括可能的中间相和外延生长，以及薄膜界面的作用。溶剂蒸气处理将使样品达到平衡。由于聚(苯乙烯-b-二甲基硅氧烷)体系稳定，相互作用参数高，且存在多种选择性不同的溶剂，因此将被选作所有研究的对象。原位实时掠入射小角X射线散射将与原位白光干涉、非原位原子力显微镜和X射线反射技术相结合。选定的样品将使用飞行时间中子反射率进行研究，以突出膨胀薄膜中的溶剂分布。实验研究将得到俄罗斯项目合作伙伴的理论计算和计算机模拟的支持。这样，我们的目的是加深我们对这些多元体系中结构形成的理解。该项目是在RFBR和DFG谅解备忘录的框架内实现的。

The continuation project aims at (i) understanding the processes in diblock copolymer thin films during vapor treatment with solvent mixtures and (ii) at using micro- and macrophase separation in thin films of mixtures of diblock copolymers to prepare complex structures. In project part (i), thin films from cylinder-forming diblock copolymers will be vapor treated with mixtures of selective and non-selective solvents. This will lead to an understanding of the restructuring processes; thus, optimum protocols to anneal defects and to induce the desired cylinder orientations by solvent vapor annealing will be identified. In project part (ii), thin films from binary mixtures of symmetric diblock copolymers will be investigated which form complex structures due to the interplay of micro- and macrophase separation. In mixtures of symmetric and asymmetric diblock copolymers, we will investigate the transition from the lamellar to the cylindrical morphology including possible interphases and epitaxial growth as well as the role of the film interfaces. Solvent vapor treatment will bring the samples into equilibrium. The poly(styrene-b-dimethylsiloxane) system will be chosen for all investigations because it is stable, has a high interaction parameter and because a number of solvents having different selectivity exist. In-situ, real-time grazing-incidence small-angle X-ray scattering will be combined with in-situ white-light interferometry and ex-situ atomic force microscopy and X-ray reflectometry. Selected samples will be investigated using time-of-flight neutron reflectivity to highlight the solvent distribution in the swollen films. The experimental studies will be supported by theoretical calculations and computer simulations by the Russian project partner. This way, we aim at furthering our understanding of structure formation in these multicomponent systems. The project is realized in the framework of the Memorandum of Understanding of the RFBR and DFG.