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

自适应聚合物网络近表面区域的结构和空间分辨力学以及流变学

• 批准号: 423768931
• 负责人: Professorin Dr. Regine von Klitzing
• 金额: --
• 依托单位: Arbeitsgruppe Weiche Materie an Grenzflächen
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/423768931?language=en
• 关键词: Structure; spatially; resolved; mechanics; well

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.

目的是设计对外部刺激如溶剂组合物（亲水/疏水平衡）、pH、温度和光敏感的两亲共网络（ACN）的反应性涂层。为此，深入了解，从而合理控制结构之间的关系，溶胀性和力学/流变学在近表面区域的ACN将实现在纳米和微观水平。将继续使用共价和离子可逆连接的ACN，其结构单元为4臂星型，并将分别在TP 1和TP 2中合成。此外，在第二个供资期，混合网络的化合物种类将扩大。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，其中一部分四星共价连接，另一部分离子可逆（TP 2）。此外，四臂星形部分地包含热敏聚合物组分（TP 2），其响应于溶剂中的温度变化而可逆地塌陷或溶胀。此外，通过诸如光的外部场的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，其通过等离子体激元加热快速塌陷或膨胀凝胶中的温度敏感区域。必须为每个系统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。在这里，表面形貌确定与高空间分辨率和机械和流变性能进行了研究，通过压痕实验与外部刺激的变化。除了原子力显微镜，GISAXS和GISANS测量也将有助于阐明近表面区域的结构。将在近表面区域获得的结构信息与TP 3的体相（SAXS）进行比较。在TP 6中，模拟了通过相分离形成图案。由此，可以确定图案形成的相关长度，并与AFM实验进行比较。TP 5将阐明宏观长度尺度（TP 4）上的力学/流变学如何由小长度尺度（10 nm至10 μ m）上的力学性能组成。使用TP 7，将实验确定的和理论预测的E模量进行比较。与TP 8合作，将研究是否可以生产适合作为生物医学应用的细胞相容性和可能的反应性涂层的准2D网络。