Structure and spatially resolved mechanics as well as rheology of near-surface regions of adaptive polymer networks

目的是设计两亲共网络（ACN）的反应涂层，该涂层对外部刺激敏感，如溶剂成分（亲疏水平衡）、pH、温度和光线。为此，将在纳米和微观水平上对ACN近表面区域的结构、膨胀性和力学/流变学之间的关系进行深入的理解和合理的控制。共价和离子可逆连接的acn将继续使用，其构建块是4臂星，将分别在TP1和TP2中合成。此外，关于混合网络，化合物的种类将在第二个供资期间扩大。一方面，将研究共价可逆网络，另一方面，将构建共价静电网络，其中四星的一部分是共价连接，另一部分是离子可逆连接（TP2）。此外，四臂恒星将部分包含热敏聚合物组分（TP2），这些组分会随着溶剂温度的变化而可逆地坍缩或膨胀。此外，通过外部场（如光）进行快速切换应该是可能的。为此，将金纳米颗粒（AuNP）添加到凝胶中，通过等离子体加热使凝胶中的温度敏感区域迅速坍塌或膨胀。必须为每个体系找到合适的制备技术。对于近表面区域的结构研究，原子力显微镜仍然是主要的方法。本文采用高空间分辨率确定了表面形貌，并通过压痕实验研究了外部刺激变化下的机械和流变特性。除了原子力显微镜，GISAXS和GISANS的测量也将有助于阐明近地表区域的结构。将在近地表区域获得的结构信息与TP3的体相（SAXS）信息进行比较。在TP6中，模拟了相分离形成的模式。由此，可以确定图案形成的相关长度，并与AFM实验进行比较。tp5将阐明宏观长度尺度（TP4）上的力学/流变学是如何由小长度尺度（10纳米至10微米）上的力学性能组成的。与tp7，实验确定和理论预测的e模比较。与TP8合作，将研究是否可以生产准二维网络，适合作为细胞兼容和可能的生物医学应用的反应性涂层。

The aim is to design reactive coatings of amphiphilic co-networks (ACN) that are sensitive to external stimuli such as solvent composition (hydrophilic/hydrophobic balance), pH, temperature and light. To this end, a deep understanding and thus rational control of the relationship between structure, swellability and mechanics/rheology in the near-surface region of ACN will be achieved at nanoscopic and microscopic levels. Both covalently and ionically-reversibly linked ACNs will continue to be used, whose building blocks are 4-armed stars and which will be synthesised in TP1 and TP2, respectively. In addition, the variety of compounds will be expanded in the second funding period with regard to hybrid networks. On the one hand, covalent-reversible networks will be investigated, and on the other hand, covalent-electrostatic networks will be constructed in which one part of the tetra-stars is linked covalently and the other part ionically-reversibly (TP2). In addition, the tetra-armed stars are to partially contain thermosensitive polymer components (TP2) that reversibly collapse or swell in response to temperature variation in the solvent. In addition, rapid switching by external fields such as light should be possible. For this purpose, gold nanoparticles (AuNP) are to be added to the gel, which rapidly collapse or swell temperature-sensitive areas in the gel by plasmonic heating. A suitable preparation technique must be found for each system. For structural investigations in the near-surface area, atomic force microscopy is still the main method. Here, both the surface topography is determined with high spatial resolution and the mechanical and rheological properties are investigated by indentation experiments with variation of the external stimuli. In addition to atomic force microscopy, GISAXS and GISANS measurements will also help to elucidate the structure in the near-surface region. The structural information obtained in the near-surface regions will be compared with that of the bulk phase (SAXS) from TP3. In TP6, pattern formation by phase separation is simulated. From this, correlation lengths of the pattern formation can be determined and compared with the AFM experiments. TP 5 will clarify how the mechanics/rheology on macroscopic length scales (TP4) is composed of the mechanical properties on small length scales (10 nm to 10 micrometer). With TP 7, experimentally determined and theoretically predicted E-moduli are to be compared. In collaboration with TP8, it will be investigated whether quasi-2D networks can be produced that are suitable as cell-compatible and possibly reactive coatings for biomedical applications.