Soft Nanoscience

Mimicking functional natural materials

Soft materials have a modular structure and the ability to repair themselves if damaged. These natural materials are self-organizing and characterized by a wide range of properties which inert, synthetic materials such as steel or aluminum do not have. Control over these natural functions in synthetic, biomimetic nanosystems is key to the nanosciences of the future.

Research fields in soft nanoscience

The SoN research program aims to investigate and understand the fundamental preparation processes of biomimetic functional natural materials according to the molecular “bottom-up” fabrication principle. Our primary focus is on 3D nanomaterials and (nano)containers. We aim to integrate experimental findings with theoretical models in order to understand both the molecular level and the nonlinear processes of self-assembly.

Following are the research fields and relevant projects carried out at the SoN:

© S.Engel

Self-assembly and dynamics

Nanostructured surfaces are versatile platforms for attaching locally functional molecules using various bottom-up processes. Locally functional molecules are often attached via self-assembly processes, either on planar surfaces or in zeolite cages.

SoN researchers investigate the basic processes underlying self-assembly and its kinetics, both experimentally and theoretically. Self-assembly also plays an important role in the functionalization of surfaces with chiral and helical molecules, which act as sources for spin-oriented electrons in future molecular spintronic devices. Using AFM and localization microscopy (STORM), researchers study self-assembled ensembles and domains in cell membranes. Also of interest is the dimensionality of the surrounding, whether 2D or 3D, where the electron interaction between various constituents is studied.

Atomically defined and structurally rigid copper-oxide tip in nc-AFM
© Harry Mönig / Macmillan Publishers Limited, part of Springer Nature

Nanotools

The SoN has state-of-the art nanoanalytic and nanostructuring instruments, including an AFM and a STM, He ion microscopy, a ToF-SIMS, and a Fourier-transform tip-enhanced SNOM in the IR (for details see the MNF pages). Also available for use are He and Ga ion beam machines for top-down structuring. With our dip pen lithography instruments it is possible to use bottom-up techniques to grow advanced functional nanostructures.

Our infrastructure and methodologies are continuously updated to satisfy future needs and enable new insights into nanosystems. We also apply methodologies for integrating functional films into optoelectronic devices on a chip, e.g. for optical quantum operations.

© Cristian Strassert

Synthesis

The synthesis of novel molecules with novel functions is an important endeavor. Novel stereoselective synthesis not only leads to carbenes and ionic metal-doped DNA, but also to polymeric radicals and addressable and switchable moieties on nanoparticles. Furthermore, on-surface reactions provide a new environment that can generate products which cannot be synthesized in conventional liquid-phase reactions. SoN researchers treat electronic properties of new molecules at various levels of precision using theoretical chemistry and ultrafast spectroscopy.

© J. Neugebauer

Responsive systems

Functional surface coatings such as polymer brushes or gels have the potential to facilitate the adhesion of molecules and nanoparticles. Researchers at the SoN develop strategies for modulating surface coatings with an external trigger in a simple form with light stimulation. Using multiscale simulations, our researchers aim to gain insight from a theoretical point of view: the properties of functional, bioactive films or nanoparticles can influence the growth of cells and even molecular defined leucocytes, serving as model systems of synaptic activity and inflammatory reactions.

© Marc Wolf, Johannes Roth

Bioactive hybrid interfaces

In this field SoN researchers specifically design and synthesize functional organic molecules to interact with various biosystems. In a first and simple step, we investigate optimized combinations for photoactivation. Some of our more complex schemes involve porous nanoparticles with functionalized bioactive pores, often with Janus density gradients between two active moieties. Nanoscopic approaches at chirally modified surfaces reveal first steps of cell – material interactions. Our research benefits from a general theoretical approach which addresses questions of active motion of bioactive particles through their environment.

© M. Schönhoff

Addressable nanocontainers

Nanocontainers have immense potential for advanced reaction schemes in mutliple scientific fields. They can be used for drug delivery, biomedical research and localized chemical reactions. Common to all schemes is the localization of a desired reaction. A successful delivery is dependent on the triggered release of contained reaction educts. At the SoN we study various potential release mechanisms, from pH sensitive containers to light-induced opening in polyionic containers and dextrin-based systems.