Tunable morphologies in charged multiblock polymers in thin film geometry

该研究项目解决了ABCBA型多嵌段聚合物在薄膜几何结构中形成的形态。在此基础上，研究了一种以疏水聚甲基丙烯酸甲酯（PMMA）端段a、聚(2-（二甲氨基）甲基丙烯酸乙酯（PDMAEMA）和聚（2-乙烯基吡啶）（P2VP）中间段B和C为中心的五嵌段三元共聚物。PDMAEMA和P2VP的电荷状态可以通过制备膜所用溶液的pH值来控制，并且对膜中的结构有很强的影响。该项目的目的是使用选择性溶剂（水，甲醇）的循环蒸汽处理来安装多种形态，这些形态是块之间相互作用和纳米结构域桥接之间相互作用的结果。用不同pH值的水溶液进行旋涂法制备膜。通过吸收溶剂，端块的移动性和中间块的柔韧性将被改变，这可能导致平衡状态，并使不同块的混合。将利用光学显微镜、原子力显微镜和掠射小角x射线散射（GISAXS）对薄膜形态进行原位研究。GISAXS数据的建模将不仅使用薄膜内部的结构，还将使用表面地形的贡献。选择的样品将使用掠入射共振软x射线散射进行研究，也在溶剂蒸气处理期间，以区分化学上不同的纳米畴。为了阐明五嵌段三元共聚物中电荷顺序分布的作用，将对参考样品pmma -b- pdmama -b- pmma进行单次测量。复杂聚合物、先进的原位结构研究方法和定量建模的独特结合，将为带电荷块的多嵌段聚合物的行为和构建薄膜的可能性提供全面的见解。

The research project addresses the morphologies formed by multiblock polymers of the type ABCBA in thin film geometry. At this, a pentablock terpolymer featuring hydrophobic poly(methyl methacrylate) (PMMA) end blocks A together with poly(2-(dimethylamino)ethyl methacrylat) (PDMAEMA) and poly(2-vinylpyridine) (P2VP) middle blocks B and C will be investigated. The charge state of the PDMAEMA and P2VP blocks can be controlled by the pH value of the solution used for preparation of the films and has a strong influence on the structures in the film. Aim of the project is to use cyclic vapor treatment with selective solvents (water, methanol) to install a multitude of morphologies, which are a result of the interplay between the interactions between the blocks and the bridging of the nanodomains. The films are prepared by spin-coating from aqueous solution having different pH values. By taking up solvent, the mobility of the end blocks as well as the flexibility of the middle blocks will be altered, which possibly results in equilibrium states and enables the mixing of different blocks. The film morphologies will be investigated, also in situ, using optical microscopy, atomic force microscopy and grazing-incidence small-angle X-ray scattering (GISAXS). Modeling of the GISAXS data will be carried out using not only structures inside the film, but also contributions from the surface topography. Selected sample will be investigated using grazing-incidence resonant soft X-ray scattering, also during solvent vapor treatment, to discriminate the chemically different nanodomains. To elucidate the role of the sequential distribution of charges in the pentablock terpolymer, single measurements will be carried out on a reference sample PMMA-b-PDMAEMA-b-PMMA. The unique combination of a complex polymer, advanced in-situ methods for structural investigations and quantitative modeling will provide comprehensive insight into the behavior of multiblock polymers with charged blocks and the possibilities for structuring thin films.