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Titolo:
Capillary wave properties of a spread film of a polybutadiene-poly(ethylene oxide) block copolymer: 2. Cyclohexane-water interface
Autore:
Milling, AJ; Hutchings, LR; Richards, RW;
Indirizzi:
Univ Durham, Interdisciplinary Res Ctr Polymer Sci & Technol, Durham DH1 3LE, England Univ Durham Durham England DH1 3LE ci & Technol, Durham DH1 3LE, England
Titolo Testata:
LANGMUIR
fascicolo: 17, volume: 17, anno: 2001,
pagine: 5305 - 5313
SICI:
0743-7463(20010821)17:17<5305:CWPOAS>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
SURFACE LIGHT-SCATTERING; AMPHIPHILIC GRAFT COPOLYMER; AIR-WATER; NEUTRON REFLECTOMETRY; POLY(ETHYLENE OXIDE); COUPLED OSCILLATORS; LIQUID SURFACES; VISCOELASTICITY; FLUCTUATIONS; ORGANIZATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
32
Recensione:
Indirizzi per estratti:
Indirizzo: Richards, RW Univ Durham, Interdisciplinary Res Ctr Polymer Sci & Technol,Durham DH1 3LE, England Univ Durham Durham England DH1 3LE Durham DH1 3LE, England
Citazione:
A.J. Milling et al., "Capillary wave properties of a spread film of a polybutadiene-poly(ethylene oxide) block copolymer: 2. Cyclohexane-water interface", LANGMUIR, 17(17), 2001, pp. 5305-5313

Abstract

A diblock copolymer of polybutadiene and poly(ethylene oxide) has been spread at the interface between cyclohexane and water, and the properties of the capillary waves were determined by light scattering. As the concentration of block copolymer at the interface increases, the capillary wave frequency and damping decrease at a rapid rate initially but tend to asymptotic values at interfacial concentrations of 2 mg m(-2) and greater. Analysis of the correlation functions of the scattered light for the interfacial viscoelastic moduli (interfacial tension, dilational modulus, and dilational viscosity) required the incorporation of the dilational terms to obtain a fit tothe data that displays uncorrelated residuals. Interfacial tensions obtained by light scattering were in reasonable agreement with those obtained from interfacial pressure isotherms and exhibited the same dependence on the interfacial concentration of the copolymer. The dilational moduli from the light scattering data were in rather poor agreement with the values from isotherm data, and this is attributed to the low sensitivity of the light scattering data to the dilational modulus because of the reduced coupling at liquid-liquid interfaces. The dilational viscosity however had the same characteristics that have been observed for graft copolymers at the air-water interface, and a Kramers-Kronig type relation has been invoked to explain theobservations in a qualitative manner. The frequency dependence at fixed copolymer concentration of the interfacial tension and dilational modulus displays no characteristic behavior, but the dilational viscosity shows an extremely regular dependence on the capillary wave frequency. The behavior canbe explained in a qualitative way by. invoking relations used for surfactant solutions where a barrier to surface adsorption is postulated.

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Documento generato il 24/10/20 alle ore 10:51:48