A series of thermosensitive copoly(oligoethylene oxide) acrylates with narrow polydispersities were prepared by the copolymerization of oligo(ethylene oxide) acrylate and di(ethylene oxide) ethyl ether acrylate using reversible addition−fragmentation chain transfer polymerization (RAFT). These copolymers exhibit tunable LCST behavior over the range of 15−90 °C dependent on their monomer compositions. Subsequently, these copolymers were grafted onto gold nanoparticle (GNP) surfaces yielding thermosensitive gold nanoparticles. The thermoresponsive properties of these hybrid GNPs/poly(OEG-A-co-DEG-A) nanoparticles were evaluated in solution using dynamic light scattering and UV−vis spectroscopy. In addition, the susceptibility of these GNPs to protein fouling was assessed by a Bradford’s assay and found to be significantly reduced by the copolymer stabilizing layer. We also demonstrate, in a unique one-pot assembly process, the synthesis of a hybrid nanoparticle that shows dual temperature responsiveness. These hybrid nanoparticles open new applications in biotechnology and medicine.

A series of water‐soluble thermoresponsive hyperbranched copoly(oligoethylene glycol)s were synthesized by copolymerization of di(ethylene glycol) methacrylate (DEG‐MA) and oligo(ethylene glycol) methacrylate (OEG‐MA, Mw = 475 g/mol), with ethylene glycol dimethacrylate (EGD‐MA) used as the crosslinker, via reversible addition fragmentation chain transfer polymerization. Polymers were characterized by size exclusion chromatography and nuclear magnetic resonance analyses. According to the monomer composition, that is, the ratio of OEG‐MA: DEG‐MA: EGD‐MA, the lower critical solution temperature (LCST) could be tuned from 25 °C to 90 °C. The thermoresponsive properties of these hyperbranched copolymers were studied carefully and compared with their linear analogs. It was found that molecular architecture influences thermoresponsive behavior, with a decrease of around 5–10 °C in the LCST of the hyperbranched polymers compared with the LCST of linear chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2783–2792, 2010

A series of amphiphilic triblock copolymers, poly [oligo(ethylene glycol) methacrylate] x -block-poly(e-caprolactone)-block-poly[oligo(ethylene glycol) methacrylate] x , POEGMA Co (x), were synthesized. Formation of hydrophobic domains as cores of the micelles was studied by fluorescence spectroscopy. The critical micelle concentrations in aqueous solution were found to be in the range of circa 10 À6 M. A novel methodology by modulated temperature differential scanning calorimetry was developed to determine critical micelle temperature. A significant concentration dependence of cmt was found. Dynamic light scattering measurements showed a bidispersed size distribution.The micelles showed reversible dispersion/aggregation in response to temperature cycles with lower critical solution temperature between 75 and 85 C. The interplay of the two hydrophobic and one thermoresponsive macromolecular chains offers the chance to more complex morphologies. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: [4909][4910][4911][4912][4913][4914][4915][4916][4917][4918][4919][4920][4921] 2010