Depth-Resolved Analyses of Water Penetration During Dynamic Wetting in Solvatochromic Dye-Gradient Polymer Brushes by Time-Resolved Fluorescence

通过时间分辨荧光对溶剂变色染料梯度聚合物刷动态润湿过程中的水渗透进行深度分辨分析

• 批准号: 505838607
• 负责人: Professor Dr. Heiko Ihmels
• 金额: --
• 依托单位: Arbeitsgruppe Physikalische Chemie I
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/505838607?language=en
• 关键词: Depth; Resolved; Analyses; Water; Penetration

The wide and detailed knowledge of processes that occur during dynamic (de)wetting of surfaces with liquids is of fundamental importance in chemistry, physics, biology, and engineering, in particular for the optimization, development and application of innovative, materials. Despite the progress gained with sophisticated experimental and theoretical approaches, however, even the most advanced models for dynamic (de)wetting rely on simplifying assumptions because of the lack of complete experimental data. Specifically, under dynamic wetting conditions, the main parameters of polymer softening, swelling and structural reorientation are thus far not adequately studied in terms of spatial and temporal resolution. In order to fill this knowledge gap, we propose an approach that monitors the dynamic wetting processes on dye-labeled polymer materials with precisely localized, tailor-made fluorophores, aiming at the delivery of complementary and significantly enhanced input for further development and refinement of models for dynamic wetting of adaptive surfaces.The proposed strategy is based on polymer brushes with controlled thickness and grafting density, that enable a controlled one-dimensional polymer swelling stimulated by solvent and/or temperature. As a key feature, these materials contain fluorosolvatochromic probes at defined depths as well as at the interfaces of the polymer with the supporting substrate and the wetting liquid. For that purpose, precisely tuned dyes will be developed whose emission energy, lifetime and quantum yields change significantly with the varying microscopic environment, thus providing a static and dynamic fluorimetric readout of the physical-chemical changes of the polymer during (de)wetting processes. As an important feature, the polymer brushes contain a dye x-gradient along which the distinct depth of the polymer-attached probes within the material varies linearly.In this set-up, the fluorimetric monitoring of wetting dynamics is facilitated and should enable a depth resolution with up to sub-10 nm precision by spatially resolved microscopy analysis. The confocal microscopic analysis of the emission energy and, in particular, the emission lifetime will reveal the diffusion dynamics of liquid into the polymer layer as well as the triggered polymer chain relaxation. Thereby, the dye-labeled gradient polymer brushes constitute a novel system that enables the fluorimetric analysis of dynamic wetting processes and further provide complementary data sets for critical tests and refinement of existing theoretical models, namely by linking the internal dynamics and relaxations of adaptive polymers, as obtained in this project with high local control, to physical quantities, such contact angles, velocity, drop dimension acquired versus sliding velocity.

对液体动态润湿表面过程的广泛而详细的了解在化学、物理、生物学和工程学中具有根本的重要性，特别是对于创新材料的优化、开发和应用。尽管先进的实验和理论方法取得了进展，但是，即使是最先进的动态（去）湿模型依赖于简化的假设，因为缺乏完整的实验数据。具体而言，在动态润湿条件下，聚合物软化，溶胀和结构重取向的主要参数，因此没有充分研究的空间和时间分辨率。为了填补这一知识空白，我们提出了一种方法，监测动态润湿过程的染料标记的聚合物材料与精确定位，定制的荧光团，旨在提供互补的和显着增强的输入，进一步发展和完善的模型，动态润湿的自适应表面。所提出的策略是基于聚合物刷控制的厚度和接枝密度，其能够实现由溶剂和/或温度刺激的受控的一维聚合物溶胀。作为一个关键特征，这些材料在限定的深度以及在聚合物与支撑基底和润湿液体的界面处含有荧光溶剂化显色探针。为此，将开发精确调谐的染料，其发射能量、寿命和量子产率随着变化的微观环境而显著变化，从而提供聚合物在润湿（去润湿）过程期间的物理化学变化的静态和动态荧光读数。作为一个重要的特征，聚合物刷包含一个染料的x梯度沿着，在材料内的聚合物附着的探针的不同深度线性变化。在这种设置中，润湿动力学的荧光监测是便利的，并应使深度分辨率与空间分辨显微镜分析高达10 nm的精度。的发射能量，特别是发射寿命的共聚焦显微镜分析将揭示的扩散动力学的液体到聚合物层，以及触发的聚合物链松弛。因此，染料标记的梯度聚合物刷构成了一种新的系统，其能够进行动态润湿过程的荧光分析，并进一步为现有理论模型的关键测试和改进提供补充数据集，即通过将自适应聚合物的内部动力学和弛豫（如在该项目中获得的，具有高度局部控制）与物理量（例如接触角、速度、获得的液滴尺寸与滑动速度的关系。