Elastic Paper with Mechanically Switchable Fiber and Pore Structure

具有机械可转换纤维和孔结构的弹性纸

• 批准号: 405549418
• 负责人: Professor Dr. Matthias Rehahn
• 金额: --
• 依托单位: Helmholtz-Zentrum hereon GmbH
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/405549418?language=en
• 关键词: Elastic; Paper; Mechanically; Switchable; Fiber

The aim of the project is to develop papers that can be reversibly stretched by more than 100%. With increasing elongation, a higher order of fiber alignment should result in an increasing orientation of the pore structure of the sheet. Deformation and preferential orientation, driven by entropy elasticity, on the one hand should immediately regress when the applied tensile, compressive or shear stress ends. On the other hand, elastic papers are to be developed, which initially retain a distinct state of elongation/compression without application of force and only return to an initial, permanent shape after application of a stimulus from this temporary deformation (i.e. shape-memory papers).With regard to their chemical and physical properties, the fibers of the desired elastic paper should be similar to those of conventional papers, hence, the only difference will be an elastic deformability of the novel paper. Likewise, its production should be based on well-known components and processes of paper making technology. The main challenge is to prevent the otherwise common direct linking of the pulp fibers by means of hydrogen bonding, and instead to achieve their cohesion indirectly via elastomeric, highly deformable colloidal particles in between the fibers.On the one hand, a major challenge is to build up the colloid particles with respect to suitable size, elasticity, deformation/relaxation characteristics and chemical structure (sufficient number of cationic functionalities on the shell). On the other hand, the fibers should be equipped with a chemical structure for preferential formation of the ionic bonds (e.g. attachment of anionic groups).Finally, it is necessary to develop a method of mixing the likewise electrostatically stabilized suspensions of the cationic elastomer particles with the anionic pulp fibers and converting them into homogeneous papers while forming the fiber-bridging ionic bonds between the particles and the surface of the fibers.In the later stage of the project, additional colloid particles are to be produced, which exhibit stretch crystallization or glass transition temperatures near room temperature. By this, elastic shape memory papers can be generated. Furthermore, it should be validated whether elastic papers with preferential orientation of the fibers can be developed for anisotropic extensibilities. Perspectively, a fundamental understanding as well as in ideal case the modeling of the structure-property relationship will be developed. Thereby, the variability of the hierarchical pore structure and its orientation during stretching is of particular importance.

该项目的目的是开发可以可逆地拉伸超过100％的论文。随着伸长率的增加，更高的纤维比对应导致板孔结构的提高。一方面，当施加的拉伸，压缩应力或剪切应力末端时，由熵弹性驱动的变形和优先取向应立即退缩。另一方面，要开发弹性论文，该论文最初保留了不使用力的伸长/压缩的独特状态）。关于它们的化学和物理特性，所需的弹性纸的纤维应与传统纸的纤维相似，因此，唯一的差异将是新论文的弹性变形性。同样，其生产应基于著名的造纸技术组成部分和过程。主要的挑战是通过氢键来防止原本常见的纸浆纤维连接，而是通过弹性体，高度可变形的胶体颗粒在纤维之间间接地实现其内聚力。相对于合适的尺寸，弹性，变形/松弛特性和化学结构（壳上足够数量的阳离子功能），建立了胶体颗粒。另一方面，应配备纤维的化学结构，以优先形成离子键（例如，阴离子组的附着）。在本文中，有必要开发一种混合阳离子弹性颗粒的静电稳定悬浮液的方法使用阴离子纸浆纤维并将其转化为均匀的纸张，同时形成颗粒和纤维表面之间的纤维桥接离子键。玻璃过渡温度在室温附近。这样，可以生成弹性形状记忆纸。此外，应该验证是否可以为各向异性扩张性开发具有优先纤维方向的弹性论文。从透视上，将开发基本的理解以及理想情况下的结构 - 托管关系的建模。因此，分层孔结构及其在拉伸过程中的方向的变异性尤其重要。