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SFB 985 - Functional Microgels and Microgel Systems


Functional Microgels and Microgel Systems

The SFB brings together research groups from polymer science, chemical engineering and life sciences and focuses on microgels as a group of highly functional macromolecules. Microgels combine openness with interactive responsiveness and thereby form a synthetic base for novel functionality. The SFB enables microgel research in a comprehensive approach, comprising the individual particle as well as the technical-scale production and formulation process. This will finally lead to new applications considering the microgel within the context of a complex interactive system. The comprehensive approach starts already within the individual research projects, all of which are supervised by two or more principal investigators with complementary expertise. The research projects are organized within four integrated research areas.
  • Microgels with new structures and/or functionalities will be developed in research area A. While some projects have already a target application in mind that requires new microgels to be designed by new synthetic routes, others will predominantly explore the limits of possible microgel functionalities.
  • Research area B is concerned with the quantitative understanding and modelling of microgel formation and properties as well as the design of reactors and separation units. It is based on the combination of experimental and modelling techniques in order to quantitatively describe microgel systems that are developed and used in project areas A and C, respectively.
  • Research area C is devoted to functional microgel systems for specific applications. It comprises projects in biotechnology, medicine and separation technology, respectively. On the one hand, the applications are based on microgels already available at RWTH Aachen; on the other hand, the projects define essential properties microgels must have in order to meet the requirements of the application.
  • The projects in research area G will develop experimental techniques that are of general relevance for the entire SFB: (i) visualization of microgels by electron microscopy in the frozen state as well as in-situ and (ii) in-line monitoring of microgel production processes.

How do microgels collapse?

The structural adaption of microgels to the environment involves a unique transition from a flexible, swollen finite-size macromolecular network, characterized by a fuzzy surface, to a colloidal particle with homogeneous density and a sharp surface. In this contribution, we determine, for the first time, the structural evolution during the microgel-to-particle transition. Time-resolved small-angle x-ray scattering experiments and computer simulations unambiguously reveal a two-stage process: In a first, very fast process, collapsed clusters form at the periphery, leading to an intermediate, hollowish core-shell structure that slowly transforms to a globule. This structural evolution is independent of the type of stimulus and thus applies to instantaneous transitions as in a temperature jump or to slower stimuli that rely on the uptake of active molecules from and/or exchange with the environment. The fast transitions of size and shape provide unique opportunities for various applications as, for example, in uptake and release, catalysis, or sensing.


The full paper is available open-access via the DOI 10.1126/sciadv.aao7086.

Prof. Walter Richerting also gave an interview (in German) in "Welt der Physik".


SFB 985 on the cover of Langmuir

Nanogels and microgels: From model colloids to applications, recent developments and future trends

Cover image by Matthias Karg. The cover image illustrates different research directions associated with nanogels and microgels that were recently discussed in an Invited Feature Article: strategies for the synthesis of (multi)functional nano- and microgels; their use in biological applications, for example, as carrier systems for the controlled release of active species; the structure and properties of nano- and microgels in dense packings including crystallization; nano- and microgels at air/liquid and liquid/liquid interfaces; and the theory and computer simulation of nano- and microgels.

DOI of the associated paper by Karg et al.: 10.1021/acs.langmuir.8b04304


SFB 985 paper on the cover of ChemSusChem

New Kids in Lactide Polymerization: Highly Active and Robust Iron Guanidine Complexes as Superior Catalysts

The image shows iron guanidine complexes as applied for ring‐opening polymerization of lactide, with tin(II)octanoate [Sn(Oct2)] in the background. More information can be found in the communication linked below.

DOI of the cover:

DOI of the associated communication by Rittinghaus et al.:


New SFB 985 paper in Nature Communications

Exploring the colloid-to-polymer transition for ultra-low crosslinked microgels from three to two dimensions

In this work we study ultra-low crosslinked poly(N-isopropylacrylamide) microgels (ULC), which can behave like colloids or flexible polymers depending on their environment, e.g. dimensionality, compression or other external stimuli. Small-angle neutron scattering shows that the structure of the ULC microgels in bulk aqueous solution is characterized by a density profile that decays smoothly from the center to a fuzzy surface. Their phase behavior and rheological properties are those of colloids interacting with a soft potential. However, when these microgels are confined at an oil-water interface, their behavior resembles that of flexible macromolecules. Once monolayers of ultra-low crosslinked microgels are compressed, deposited on solid substrate and studied with atomic-force microscopy, a concentration-dependent topography is observed. Depending on the compression, these microgels can behave as flexible polymers, covering the substrate with a uniform film, or as colloidal microgels leading to a monolayer of particles.

This article is also featured on Nature Communications Editors’ Highlights webpage of recent research on Organic Chemistry and Chemical Biology​.​

SFB 985 on the cover of Applied Materials & Interfaces

Cover image by Andrey A. Rudov

Amphiphilic arborescent block copolymers generate different structures in selective solvents as revealed in computer simulations. The macromolecules do not aggregate in the solution and form monomolecular micelles. Both single- and multicore micelles can be stable. Adsorption of such macromolecules on liquid (oil−water) interface leads to their flattening and segregation of the blocks: hydrophilic and hydrophobic blocks are exposed toward water and oil, respectively. Even in a dense monolayer, the macromolecules do not interpenetrate, resembling leaves of water lilies. Pretty fast adsorption kinetics of the macromolecules makes them efficient stabilizers of emulsions.


Our Pacman is advertising Stimuli-Responsive Hydrogels now

As seen in the advertisement for the Special issue on Stimuli-Responsive Hydrogels

Check out the entire special issue at

Open Access Article on "Functional Microgels and Microgel Systems"

New publication in Accounts of Chemical Research

A new publication by Felix A. Plamper and Prof. Walter Richtering was just made publicly available. Check out their review of "Functional Microgels and Microgel Systems" in the latest special issue of Accounts in Chemical Research "Stimuli-Responsive Hydrogels":

SFB 985 on the cover of PCCP

Cover image by Lucio Isa

Compression and deposition of microgel monolayers from fluid interfaces: particle size effects on interface microstructure and nanolithography

SFB 985 on the cover of Advanced Materials Interfaces

Cover image by Antonio Sechi

Antonio Sechi and co-workers describe the fabrication of highly functional and stimuli-responsive nanogel arrays grafted onto glass surfaces by a printing process using wrinkled PDMS templates in article 1600455. These nanogels influence size and dynamics of focal adhesions as well as cell motility forcing cells to move along highly directional trajectories. The modulation of nanogel topographical and mechanical properties by temperature or spacing serves as an effective tool for the regulation of cell motility.

SFB 985 on the cover of Langmuir

Cover image by Andrey A. Rudov


We compare the behavior of hollow microgels and microgels with a rigid silica core at water–oil interfaces. Compression isotherms and computer simulations demonstrate an enhanced deformation for the hollow microgels at the interface. Interestingly, a lower cross-link density leads to a higher compression modulus at low compression, whereas this behavior is reversed at high compression. This is related to an enhanced spreading of network strands at the interface. The cross-link density of the polymer shell defines the degree of deformation at the interface. Additionally, the core restricts the spreading of polymer chains at the interface. These results illustrate the special behavior of soft microgels at liquid interfaces.

For more information, see "Hollow and Core–Shell Microgels at Oil–Water Interfaces: Spreading of Soft Particles Reduces the Compressibility of the Monolayer" by Karen Geisel, Andrey A. Rudov, Igor I. Potemkin and Walter Richtering

JARA-SOFT: Soft Matter Science made in Aachen und Jülich

Sechste JARA-Sektion startet mit großartigem Auftakt

Am 13. Mai 2015 wurde die Gründung der neuen Sektion JARA-SOFT (Soft Matter Science) mit einem Festakt gefeiert. JARA-SOFT widmet sich der multidisziplinaren Erforschung der Weichen Materie. Weiche Materie umfasst sowohl synthetische und biologische Makromoleküle als auch kolloidale und amphiphile Systeme. Ihre Einsatzmöglichkeiten reichen vom Medikamententransport im Körper bis zur verbesserten Straßenhaftung von Autoreifen. Die im Soft Matter Bereich vorhandenen Expertisen am Forschungszentrum Jülich, dem Leibniz-Institut DWI sowie der RWTH Aachen University ergänzen sich hervorragend und liefern das Fundament für die erfolgreiche Forschung in JARA-SOFT.




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SFB Colloquium - Prof. Christine Selhuber-UnkelMonday, 03 February 2020 17:15