Star Poly(N-isopropylacrylamide) Tethered to Polyhedral Oligomeric Silsesquioxane (POSS) Nanoparticles by a Combination of ATRP and Click Chemistry. (7th June 2012)

• Record Type: Journal Article
• Authors: Kuo, Shiao-Wei; Hong, Jing-Long; Huang, Yu-Chan; Chen, Jem-Kun; Fan, Shih-Kang; Ko, Fu-Hsiang; Chu, Chih-Wei; Chang, Feng-Chih
• Other Names: Prado Luis Antonio Sanchez de Almeida Academic Editor.
• Is Part Of: Journal of nanomaterials. Volume 2012(2012)
• Publication Date: 2012-06-07
• Subjects: Nanostructured materials -- Periodicals; Nanotechnology -- Periodicals; Nanomatériaux; Nanostructured materials; Nanotechnology; Nanostructures; Nanotechnology; Periodicals; Fulltext; Internet Resources; Periodicals; 620.115
• DOI: 10.1155/2012/749732
• Languages: English
• ISSNs: 1687-4110

Abstract

Abstract : New star poly( N -isopropylacrylamide)- b -polyhedral oligomeric silsesquioxane (PNIPAm- b -POSS) copolymers were synthesized from octa-azido functionalized POSS (N3 -POSS) and alkyne-PNIPAm, which was prepared using an alkyne-functionalized atom transfer radical polymerization (ATRP) initiator (propargyl 2-bromo-2-methylpropionamide), via click chemistry. These star PNIPAm- b -POSS copolymers undergo a sharp coil-globule transition in water at above 32°C changing from a hydrophilic state below this temperature to a hydrophobic state above it, which is similar to linear PNIPAm homopolymers. More interestingly, we found that these star polymers exhibited strong blue photoluminescence in water above a lower critical solution temperature (LCST). This photoluminescence was likely due to the constrained geometric freedom and relatively rigid structure caused by intramolecular hydrogen bonding within the star PNIPAm polymers, which exhibit an intrinsic fluorescent behavior.