Stimuli-responsive spherical brushes based on D-galactopyranose and 2-(dimethylamino)ethyl methacrylate

0423554 - ÚMCH 2014 RIV DE eng J - Journal Article
Arslan, H. - Pfaff, A. - Lu, Y. - Štěpánek, Petr - Müller, A. H. E.
Stimuli-responsive spherical brushes based on D-galactopyranose and 2-(dimethylamino)ethyl methacrylate.
Macromolecular Bioscience. Roč. 14, č. 1 (2014), s. 81-91. ISSN 1616-5187. E-ISSN 1616-5195
R&D Projects: GA ČR GA202/09/2078
Institutional support: RVO:61389013
Keywords : atom transfer radical polymerization (ATRP) * glycopolymers * LCST
Subject RIV: BO - Biophysics
Impact factor: 3.851, year: 2014

Stimuli-responsive spherical brushes composed of 6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-D-galactopyranose (MAIGal) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) are prepared via atom transfer radical polymerization (ATRP) using cross-linked polystyrene nanoparticles covered with a thin layer of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM) as ATRP initiator by the “grafting from” approach. The stimuli-responsive behavior of the deprotected spherical PMAGal-b-PDMAEMA block copolymer brushes is investigated by dynamic light scattering and cryogenic transmission electron microscopy. A brush with arms containing 160 MAGal and 170 DMAEMA monomer units shows a significant contraction of the hydrodynamic radius from 20 to 70 °C at pH = 8 with a cloud point at ≈40 °C, whereas no LCST is detected at pH = 6 and 7 due to the protonation of the DMAEMA units. Aggregates occur at low temperatures and pH 8 due to intermolecular interactions between the chains of different brushes, which disappear above LCST, when the PDMAEMA chains fold back to the core of the brushes, exposing the glycopolymer chains to the outside.
Permanent Link: http://hdl.handle.net/11104/0231646