Poly(N-isopropylacrylamide) microgel particles were prepared via a ''classical'' surfactant-free precipitation polymerization and a continuous monomer feeding approach. It is anticipated that this yields microgel particles with different internal structures, namely a dense core with a fluffy shell for the classical approach and a more even crosslink distribution in the case of the continuous monomer feeding approach. A thorough structural investigation of the resulting microgels with dynamic light scattering, atomic force microscopy and small angle neutron scattering was conducted and related to neutron spin echo spectroscopy data. In this way a link between structural and dynamic features of the internal polymer network was made.Germany.

The tunable properties of stimuli-responsive polymer coatings at solid surfaces inspire their application in different electronic devices, as functional tissue in regenerative medicine or even for drug release. Especially promising is the exploitation of thermo-responsive poly-Nisopropylacrylamide (PNIPAM) microgels as cell-surface adhesion control systems. In this context we present a morphological and internal structure investigation of thermo-responsive PNIPAM microgels adsorbed on a silicon-surface. By means of Grazing Incidence Small-Angle Neutron Scattering and Atomic Force Microscopy the swelling behaviour of adsorbed PNIPAM microgel particles and the influence of the N,N'-methylenebisacrylamide (cross-linker) content in the microgel network on the layer formation were investigated. The influence of the surface confinement on the responsivity of the polymer system is discussed.

No abstract