@article {2473,
	title = {Poly(oligo(ethylene glycol)acrylamide) Brushes by Surface Initiated Polymerization: Effect of Macromonomer Chain Length on Brush Growth and Protein Adsorption from Blood Plasma},
	journal = {Langmuir},
	volume = {25},
	number = {6},
	year = {2009},
	note = {ISI Document Delivery No.: 418JRTimes Cited: 12Cited Reference Count: 45Kizhakkedathu, Jayachandran N. Janzen, Johan Le, Yevgeniya Kainthan, Rajesh K. Brooks, Donald E.},
	month = {Mar},
	pages = {3794-3801},
	type = {Article},
	abstract = {Three hydrolytically stable polyethyleneglycol (PEG)-based N-substituted acrylamide macromonomers, methoxypolyethyleneglycol (350) acrylamide (MPEG(350)Am) methoxypolyethyleneglycol (750) acrylamide(MPEG(750)Am) and methoxypolyethyleneglycol (2000)acrylamide (MPEG(2000)Am) with increasing PEG chain length were synthesized. Surface-initiated aqueous atom transfer radical polymerization (ATRP) using CuCl/1,1,4,7,10,10-hexamethyl triethylene tetramine (HMTETA) catalyst was utilized to generate dense polymer brushes from these monomers via an ester linker group on the surface of model polystyrene (PS) particles. The molecular weight, hydrodynamic thickness, and graft densities of the grafted polymer layers were controlled by changing the reaction parameters of monomer concentration, addition of Cu(II)Cl-2, and sodium chloride. The graft densities of surface-grafted brushes decreased with increasing PEG macromonomer chain length, 350 > 750 >> 2000, under similar experimental conditions. The molecular weight of grafts increased with increase in monomer concentration, and only selected conditions produced narrow distributed polymer chains. The molecular weight of grafted polymer chains differs significantly to those formed in solution. The hydrodynamic thicknesses of the grafted polymer layers were fitted to the Daoud and Cotton model (DCM) for brush height on spherical surfaces. The results show that the size of the pendent groups on the polymer chains has a profound effect on the hydrodynamic thickness of the brush for a given degree of polymerization. The new PEG-based surfaces show good protection against nonspecific protein adsorption from blood plasma compared to the bare surface. Protein adsorption decreased with increasing surface density of grafted polymer chains. Poly(MPEG(750)Am) brushes were more effective in preventing protein adsorption than poly(MPEG(350)Am) even at low graft densities, presumably due to the increase in PEG content in the grafted layer.},
	keywords = {AQUEOUS ATRP, COPOLYMER BRUSHES, density, METHYL-METHACRYLATE, MODEL, N-DIMETHYLACRYLAMIDE), OLIGO(ETHYLENE GLYCOL) METHACRYLATE, PHOSPHORYLCHOLINE, POLY(N, POLYMERS, TRANSFER RADICAL POLYMERIZATION},
	isbn = {0743-7463},
	url = {<Go to ISI>://000264145000068},
	author = {Kizhakkedathu, J. N. and Janzen, J. and Le, Y. and Kainthan, R. K. and Brooks, D. E.}
}
@article {909,
	title = {Synthesis and characterization of well-defined hydrophilic block copolymer brushes by aqueous ATRP},
	journal = {Polymer},
	volume = {45},
	number = {22},
	year = {2004},
	note = {ISI Document Delivery No.: 862NOTimes Cited: 27Cited Reference Count: 79},
	month = {Oct},
	pages = {7471-7489},
	type = {Article},
	abstract = {Homopolymer brushes of poly(N,N-dimethylacrylamide) (PDMA), poly(methoxyethylacrylamide) (PMEA) and poly(N-isopropylacrylamide)(PNIPAM) grown on atom transfer radical polymerization (ATRP) initiator functionalized latex particles were used as macroinitiators for the synthesis of PDMA-b-PNIPAM/PMEA, PMEA-b-PDMA/PNIPAM and PNIPAM-b-PDMA block copolymer brushes by surface initiated aqueous ATRP. The grafted homopolymer and block copolymer brushes were analyzed for molecular weight, molecular weight distribution, chain grafting density, composition and hydrodynamic thickness (HT) using gel permeation chromatography-multi-angle laser light scattering, H-1 NMR, particle size analysis and atomic force microscopy (AFM) techniques. The measured graft molecular weight increased following the second ATRP reaction in all cases, indicating the second block had been added. Chain growth depended on the nature of the monomer used for block copolymerization and its concentration. Unimodal distribution of polymer chains in GPC with non-overlap of molar mass-elution volume curves implied an efficient block copolymerization. This was supported by the increase in HT measured by particle size analysis, equilibrium thickness observed by AFM and the composition of the block copolymer layer by H-1 NMR analysis, both in situ and on cleaved chains in solution. 1H NMR analysis of the grafted latex and cleaved polymers from the surface demonstrated that accurate determination of the copolymer composition by this method is possible without detaching polymer chains from surface. Block copolymer brushes obey the same power law dependence of HT on molecular weight as homopolymer brushes in good solvent conditions. The NIPAM-containing block copolymer brushes were sensitive to changes in the environment as shown by a decrease in HT with increase in the temperature of the medium. (C) 2004 Elsevier Ltd. All rights reserved.},
	keywords = {AMBIENT-TEMPERATURE, aqueous atom transfer radical polymerization, ATOMIC-FORCE MICROSCOPY, BRUSHES, CONTROLLED GROWTH, hydrophilic diblock copolymers, LIGHT-SCATTERING, METHYL-METHACRYLATE, N-DIMETHYLACRYLAMIDE), POLY(N, POLYELECTROLYTE BRUSHES, POLYMER BRUSHES, SELF-ASSEMBLED MONOLAYERS, SIZE-EXCLUSION CHROMATOGRAPHY, TRANSFER RADICAL POLYMERIZATION},
	isbn = {0032-3861},
	url = {<Go to ISI>://000224497900011},
	author = {Kizhakkedathu, J. N. and Kumar, K. R. and Goodman, D. and Brooks, D. E.}
}
@article {910,
	title = {Synthesis of well-defined environmentally responsive polymer brushes by aqueous ATRP},
	journal = {Macromolecules},
	volume = {37},
	number = {3},
	year = {2004},
	note = {ISI Document Delivery No.: 771TWTimes Cited: 102Cited Reference Count: 56},
	month = {Feb},
	pages = {734-743},
	type = {Article},
	abstract = {Functionalized anionic polystyrene latex particles with ATRP initiators were synthesized by surfactant-free shell-growth emulsion polymerization of styrene and 2-(2{\textquoteright}-chloropropionato)ethyl acrylate (HEA-Cl). N-Isopropylacrylamide (NIPAM) was polymerized from these particles by surface-initiated aqueous ATRP using PMDETA/CuCl and HMTETA/CuCl catalysts to synthesize poly(N-isopropylacrylamide) (PNIPAM) brushes. The grafted latexes were characterized for molecular weight of the PNIPAM chains, grafting density, and hydrodynamic thickness of the grafted polymer layer. Molecular weights of the grafted PNIPAM chains depended on the monomer concentration, concentration of copper(II) complex, and the presence of external initiator in the reaction medium. M-n of the grafted chains increases with increase in the monomer concentration and decreases with addition of copper(II) complex and external initiator. The HMTETA/CuCl catalyst produces higher molecular weight chains than PMDETA/CuCl. Molecular weights from similar to50 000 to 800 000 with low polydispersities, between 1.25 and 1.4, were achieved. The grafting density of PNIPAM on the surface increases with increasing monomer concentration and decreases with addition of copper(II) catalyst and external initiator. Block copolymerization of N,N-dimethylacrylamide from PNIPAM-grafted latex demonstrated that the chains are terminated with a chlorine atom, and the grafting reactions are taking place by the ATRP mechanism. The hydrodynamic thickness (HT) of the grafted PNIPAM layer scales as DP0.66 (where DP = degree of polymerization) at constant grafting density (chains/nm(2)). The HT values for PNIPAM brushes are sensitive to temperature and salt concentration. Since the transition from extended coil to collapsed structure occurs over a range of temperature and salt concentration, it follows a second-order transition, as predicted by theory. The thickness of the collapsed brush is sensitive to the type of stimulus used to induce the phase transition.},
	keywords = {GLOBULE TYPE TRANSITIONS, INTERFACES, N-DIMETHYLACRYLAMIDE) BRUSHES, PARTICLES, POLY(N, POLY(N-ISOPROPYLACRYLAMIDE), PROTEIN, SILICA, SURFACE-INITIATED POLYMERIZATIONS, TEMPERATURE, TRANSFER RADICAL POLYMERIZATION},
	isbn = {0024-9297},
	url = {<Go to ISI>://000188803000010},
	author = {Kizhakkedathu, J. N. and Norris-Jones, R. and Brooks, D. E.}
}
