Laboratoire Charles Coulomb UMR 5221 CNRS/UM2 (L2C)


Accueil > La Recherche > Axes & Equipes > Matière Molle & Verres > Equipe : Matière Molle > Theme : Soft composites

Structure of non-NIPAM core-shell microgels

par Christophe BLANC - publié le

Structure of non-NIPAM core-shell microgels

People involved : M. Cors (PhD), A. Banc (MdC), A.C. Genix (MdC), T. Hellweg (PR, Bielefeld), J. Oberdisse (DR)

Our research activities in the field of polymer microgels are currently funded by a joint ANR-DFG grant, obtained together with T. Hellweg (University of Bielefeld, Germany), and financing mainly a common PhD student.
Microgels are microsized, crosslinked hydrogels in aqueous suspension. The project aims at the synthesis of non-N-isopropylacrylamide based smart microgels with core-shell architecture and at establishing structure property relationships for this kind of particles. The particles are synthesized from N-isopropylmethacrylamide (NIPMAM) and N-n-propylacrylamide (NNPAM), which leads to unexpected new properties due to the large difference of the volume phase transition temperature of the two monomers. In preliminary work such particles were found to exhibit a large linear domain in the swelling curve. This effect still remains to be fully exploited and understood which is the major objective of the present project. It can be presumed that changes of the crosslinker content of the shell will produce different swelling curves and thus different intermediate morphologies during swelling. We study these systems using small angle scattering techniques (mainly with neutrons) to understand the structural changes related to the swelling of these systems on a local scale. Moreover, the domain of linear swelling will be studied by means of AFM techniques to study the force which can be produced by these particles. Therefore, deposition of microgels on silicon wafers are currently studied, including their swelling behavior with respect to the one in aqueous suspension. An AFM image of a dry layer of microgel particles is shown below.