American Chemical Society, Journal of Physical Chemistry C, 23(116), p. 12844-12853, 2012
DOI: 10.1021/jp300754b
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Upon conjugation of thermoresponsive polymers to nanomaterials such as gold nanoparticles (Aunps), whether and to what extent the properties of the polymer-coated Aunps differ from that of the free polymer depends on the interaction between polymer and the nanoparticle scaffold. Here, we studied the interaction between positively charged Aunps and negatively charged poly(N-isopropylacrylamide) (PNIPAAM) copolymers with different sizes of the charged block (poly(3-sulfopropyl methacrylate potassium), PSPMA), as well as the resulting temperature-dependent optical behavior of the polymer nanoconstructs using UV–vis spectroscopy, quartz crystal microbalance with dissipation monitoring (QCM-D), dynamic light scattering (DLS), as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). We demonstrate that by controlling the charge density matching between Aunp and copolymer we can induce gel formation with random inclusion of Aunps, form single monolayer-covered thermoresponsive Au nanostructures, or use the Au nanostructures as branching units to induce gel formation below LCST.