Titre : Multi-Sensitive Microgels: Particles with Special Properties in Solution as well as in Pickering Emulsions.
Cette conférence sera prononcée par le professeur Walter Richtering de l'institut de chimie physique de l'Université RWTH Aachen. Elle est commanditée par le Centre de recherche sur les materiaux auto-assemblés (CRMAA) et sera donnée en anglais.
Résumé : Multi-sensitive microgels have special properties that can be controlled via the chemical composition as well as via the morphology of the particle. Depending on the polymerization procedure one can obtain 'simple' copolymer microgels or particles with core-shell or nanophase separated morphology. The structure of the particles is determined mainly by mean of light, X-ray and neutron scattering experiments. We will discuss, how charge interaction can be exploited for uptake and release of polyelectrolytes and show that both adsorption and absorption can occur. The hydrogen bonding pattern of polyacrlyamides can be used to influence the temperature dependent particle swelling in aqueous solution but also the cononsolvency behavior in water-methanol mixtures. Finally we will report on the unique behavior of microgels at fluid interfaces. Microgels are used to prepare stimuli-sensitive emulsions, the stability of which can be made pH-sensitive. However, the stability is not governed by electrostatic interactions and it is even possible to prepare stable emulsions with oppositely charged droplets.
