CRC 1767 Paper
Fluid and ion transport in paper is a crucial parameter in (microfluidic) paper-based sensing, digital printing, soft robotics, or for paper membranes with controlled vapor permeability in construction applications. So far, the adjustment of fluid transport and vapor condensation can only be controlled to a limited extent or requires large amounts of coating material. Questions also remain regarding modeling, such as the influence of nanoscale porosity and fiber swelling on these fluidic properties. A combination of swellable cellulose fibers in paper with ceramic hard silica coatings allows a controlled setting of the fluid transport as well as the fluid distribution in paper, depending on nanoscale porosity, coating composition, and fiber assembly into a paper architecture. To exploit the potential of this hybrid material, the influence of fiber properties on the silica coating formation should be thoroughly understood, a library of mesopore structures and wettability, adjustable on coated single fibers, should be generated, and from this, paper composition and architecture (e.g., layer-by-layer wetting gradients or 3D printed papers) should be specifically built in a bottom-up approach. In perspective, a rational design of structure-property relation and a temporally controllable and switchable fluidics and vapor condensation as well as recycling is envisioned.
Involved team members: T. Gaydoul
