Building Colloidal Surfaces with Responsive Pores

In her current research project, Carina Karner is investigating porous materials with micro-pores that can adaptively open and close at the microscopic level in response to external influences. As so often, biology provides the inspiration: the cell walls in our bodies precisely regulate which substances can enter or exit a cell. Whether a substance can pass through the cell membrane depends not only on the size and composition of its molecules but also on external conditions. For example, temperature or pH changes can significantly alter the permeability of a cell membrane, allowing the fine regulation of essential biological processes. In her project Building Colloidal Surfaces with Responsive Pores, Carina Karner applies this principle to artificial materials. She is developing surfaces that can flexibly adapt to their environment. Depending on the temperature or pH value, they can precisely adjust their permeability. This is made possible by the composition of these surfaces: they are constructed from tiny, micrometer-sized building blocks called colloidal particles, which are connected through specialized, movable binding sitesreferred to as patches. These patches respond to external influences by shifting position or acting as anchor points for rotational movements of the particles, thereby controlling the pore structure of the surface. One of the biggest challenges is ensuring that this process occurs uniformly across the entire surface. Only if the pores open and close in a controlled and stable manner can the material remain functional and reliable. To achieve this, Karner relies on state-of-the-art research methods. Using molecular dynamics simulations and machine learning techniques, she precisely analyzes how the particles behave and identifies the external conditions that yield optimal results. Through her work, Carina Karner bridges the gap between fundamental research and practical applications. Her findings could pave the way for intelligent filters that selectively allow or block particles depending on external influences. Such materials have the potential to enable a range of new technologiesfrom tailored filtration systems to adaptive surfaces for environmental engineering and medical technology.