polymers Article Controlling Growth of Poly (Triethylene Glycol Acrylate-Co-Spiropyran Acrylate) Copolymer Liquid Films on a Hydrophilic Surface by Light and Temperature Aziz Ben-Miled 1 , Afshin Nabiyan 2 , Katrin Wondraczek 3, Felix H. Schacher 2,4 and Lothar Wondraczek 1,* 1 Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, D-07743 Jena, Germany;
[email protected] 2 Institute of Organic Chemistry and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, D-07743 Jena, Germany;
[email protected] (A.N.);
[email protected] (F.H.S.) 3 Leibniz Institute of Photonic Technology (Leibniz IPHT), D-07745 Jena, Germany;
[email protected] 4 Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, D-07743 Jena, Germany * Correspondence:
[email protected]; Tel.: +49-3641-9-48500 Abstract: A quartz crystal microbalance with dissipation monitoring (QCM-D) was employed for in situ investigations of the effect of temperature and light on the conformational changes of a poly (triethylene glycol acrylate-co-spiropyran acrylate) (P (TEGA-co-SPA)) copolymer containing 12–14% of spiropyran at the silica–water interface. By monitoring shifts in resonance frequency and in acoustic dissipation as a function of temperature and illumination conditions, we investigated the evolution of viscoelastic properties of the P (TEGA-co-SPA)-rich wetting layer growing on the sensor, Citation: Ben-Miled, A.; Nabiyan, A.; from which we deduced the characteristic coil-to-globule transition temperature, corresponding to Wondraczek, K.; Schacher, F.H.; the lower critical solution temperature (LCST) of the PTEGA part.