Investigations in the Stranski-Laboratorium of the TU Berlin – Physical Chemistry of Colloidal Systems – Going Towards Complexity and Functionality

Abstract

The research topics of our group are in general from the field of physical chemistry of colloidal systems. Within this rather wide layout a large variety of quite different questions and systems are tackled, where the common bridging factor is the aim of understanding the properties of colloidal systems based on their mesoscopic structure and dynamics, which in turn are controlled by their molecular composition. With such an enhanced understanding of the correlation between mesoscopic structure and the macroscopic properties the goal then is to employ this knowledge in order to formulate increasingly complex colloidal system with correspondingly more variable and interesting functionalities. From this general context of investigations, some representative systems and questions that have been studied in recent time by us are covered in this text.They comprise the phase behaviour and the structures formed in solutions of surfactants and amphiphilic copolymers. Once these static properties are known, we also have a high interest in the dynamic properties and the kinetics of morphological transitions as they are observed under non-equilibrium conditions, since they are frequently encountered in applications. A key property of amphiphilic molecules is their ability to solubilise sparingly soluble compounds thereby forming microemulsions or nanoemulsions, where the ability to form such systems depends strongly on the molecular architecture of the amphiphiles. By turning to polymeric amphiphiles the concept of surfactants and their architecture can be extended largely towards more versatile structures, more complex self-assembly and much larger length and time scales. Another direction is the surfactant assisted formation of nanoparticles or mesoporous inorganic materials. By combining copolymers with other polymers, copolymers, colloids, or surfactants – for instance via electrostatically driven co-assembly – one may then form increasingly complex colloidal aggregates. By doing so one is able to control rheological properties or develop complex delivery systems, whose properties can be tailor-made by appropriate choice of the molecular build-up. This striving towards well controlled complexity achieved by means of self- and co-assembly then leads to increasingly more functional systems and is the key direction for future research activities in our group.

Review of the years 2011/2012

“…This last mentioned contribution was published in the section "Research Group Portrait" which we established in 2011. This new section has been well received by our readers and hence has been continued in 2012 with the presentation of the research group of M. Gradzielski at the TU Berlin [21]. Special interest was also received by the papers, whose contents were presented at the European Detergency Conference 2011 in Fulda.…”

“…Zu den Top-20 der beiden vergangenen Jahren gehçren auch der detaillierte EDC/SEPAWA-Konferenzbericht 2011, der sich mit Biotensiden, neuen Inhaltstoffen in Formulierungen, der Nachhaltigkeit von Tensiden, Waschmitteln und Kosmetika beschäftigt, und die zusammenfassende Präsentation der Forschungsarbeiten der "Colloid & Interface Science Group" an der Universität Stuttgart [12]. Dieser Beitrag wurde unter der neu eingeführten Rubrik "Arbeitgruppenportrait" publiziert, die von unseren Lesern positiv aufgenommen wurde, weshalb wir sie im Jahr 2012 mit dem Beitrag über die Arbeitsgruppe des Stranski-Laboratoriums der TU Berlin [21] …”