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Titolo:
Organisation and interactions in aqueous dispersions of polystyrene-polyethylene oxide block copolymer micelles
Autore:
Brown, GJ; Richards, RW; Heenan, RK;
Indirizzi:
Univ Durham, IRC Polymer Sci & Technol, Dept Chem, Durham DH1 3LE, EnglandUniv Durham Durham England DH1 3LE l, Dept Chem, Durham DH1 3LE, England Rutherford Appleton Lab, ISIS Sci Div, Didcot OX11 0QX, Oxon, England Rutherford Appleton Lab Didcot Oxon England OX11 0QX 1 0QX, Oxon, England
Titolo Testata:
POLYMER
fascicolo: 18, volume: 42, anno: 2001,
pagine: 7663 - 7673
SICI:
0032-3861(200108)42:18<7663:OAIIAD>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
DIBLOCK COPOLYMER; CONCENTRATION-DEPENDENCE; POLY(ETHYLENE OXIDE); SELECTIVE SOLVENTS; ORDERED STRUCTURE; POLYMER-SOLUTIONS; LIGHT-SCATTERING; INTERFACE; SEGREGATION; DYNAMICS;
Keywords:
Yukawa potential; polystyrene; polyethylene;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
41
Recensione:
Indirizzi per estratti:
Indirizzo: Richards, RW Univ Durham, IRC Polymer Sci & Technol, Dept Chem, Durham DH13LE, England Univ Durham Durham England DH1 3LE Durham DH1 3LE, England
Citazione:
G.J. Brown et al., "Organisation and interactions in aqueous dispersions of polystyrene-polyethylene oxide block copolymer micelles", POLYMER, 42(18), 2001, pp. 7663-7673

Abstract

Diblock copolymers of polystyrene (PS) and polyethylene oxide (PEO) with atotal molecular weight of circa 7500 g mol(-1) and a PS weight fraction ofcirca 0.15 have been synthesised in all possible variants of hydrogenous and deuterated forms. The copolymers have been dispersed at concentration above the critical micelle concentration (cmc) in aqueous dispersion mediums of varying contents of Light and heavy water to contrast match selected components of the micelles. Small angle neutron scattering has been used to determine the size of the micelles, the radius of the PS core and the thickness of the PEO corona using data for dispersions with concentrations less than or equal to 1x10(-2) g ml(-1). At higher concentrations, a structure factor peak becomes increasingly evident as the concentration increases to 6.5x 10(-2) g ml(-1). The total scattering could not be fitted using the structure factor for an assembly of hard spheres; a structure factor originallydeveloped for coulombically stabilised micelles was used and excellent fits to the data obtained. The structure factor is described in terms of a Yukawa potential between the micelles and the values of the repulsion potentials have been used to calculate the repulsive force between the micelles andcompared to the predictions for two brush-lice polymer layers approaching each other. There is partial agreement with the model, the disagreement being identical to that observed when the results from force balance experiments are compared with the model. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/09/20 alle ore 09:39:33