Polymer concentration profile near a liquid-solid interface: evanescent wave ellipsometry study

Kim, M.W.; Peiffer, Dennis G.; Chen, W.; Hsiung, Han-Hsing; Rasing, T.H.M.; Shen, Yong

doi:10.1021/ma00196a026

Cited by 21 publications

(10 citation statements)

References 10 publications

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“…Their results agreed best with the expected concentration profile of a semiflexible chain . Evanescent wave ellipsometry has also been used to study polymer depletion layers near surfaces, yielding a thickness of 7.0 nm for PS of molecular weight 100 000 dissolved in ethyl acetate …”

Section: Discussionsupporting

confidence: 59%

Effect of Solvent Quality on the Diffusion of Polystyrene Latex Spheres in Solutions of Poly(methyl methacrylate)

1996

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Dynamic light scattering has been used to study the diffusion of polystyrene (PS) latex spheres (≈0.2 μm radius) in poly(methyl methacrylate) (PMMA) solutions at 25 °C. The weight-average molecular weight of the PMMA was 350 000. The sign and magnitude of the deviations from the Stokes−Einstein (SE) equation varied dramatically with solvent quality. Positive deviations from SE behavior (ηD sphere/η0 D 0 > 1) were observed in good solvents for PMMA, such as dimethylformamide (DMF) and tetrahydrofuran (THF). We argue that these positive deviations are a result of a layer of solution locally surrounding the latex spheres that is rich in solvent and deficient in PMMA. This “depletion layer” is likely caused by a combination of entropic repulsion between the matrix PMMA and the latex spheres, and most importantly the immiscibility of PMMA and PS. A negative deviation (ηD sphere/η0 D 0 < 1) by almost of factor of 3 from the SE equation was observed in a dioxane−water mixed solvent, which is a ϑ-solvent for PMMA at 25 °C. PMMA adsorption onto the latex spheres is argued to occur under these unfavorable solvent conditions. At high matrix concentrations, entanglements of the adsorbed PMMA with free PMMA in solution likely occur. A very slow relaxation mode, in addition to the mode associated with sphere diffusion, was present in the CONTIN analyses of the PMMA/PS latex/dioxane−water system. It is possible that this mode is due to PMMA clusters, or less likely, bridged PS latex moieties.

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Section: Discussionsupporting

confidence: 59%

Effect of Solvent Quality on the Diffusion of Polystyrene Latex Spheres in Solutions of Poly(methyl methacrylate)

1996

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“…This rule applies at c=45.OO degrees and P greater than but near 45.00 degrees (first zone) . choose sign of Cof the other zones to assure approximately the same value of lIas (9) in the first zone.…”

Section: Eomentioning

confidence: 99%

Cylindrical waveguide evanescent field ellipsometry

Wang

1992

Opt. Eng.

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“…Using single reflection evanescent wave ellipsometry, Kim et al [10] studied polymer concentration profile near a liquid-solid interface, but they did not use waveguide. Waveguide sensors can employ more active area and are more sensitive than single reflection evanescent wave ellipsometry.…”

Section: Introductionmentioning

confidence: 99%

<title>Waveguide ellipsometry biosensors: concept and preliminary analysis</title>

Wang

1992

SPIE Proceedings

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The recent use of fiber optic wavaguidea for biochemical analyses is mainly based on light intensity changes. Waveguide ellipsometry sensors (WEFE) is proposed for biosensor applications. The WEFE is based on the principle of e].lipsometry. A laser beam propagates in the waveguide with two fundamental modes: transverse electric field, parallel to and perpendicular to the sensing surface. The evanescent waves interact with the adsorbed or conjugated layer of biomolecules, producing changes in the relative phase, Lt, and amplitude, 1t, upon interaction. The ellipsometric parameters change with biomolacule adsorption or conjugation on the sensing surface. From the ellipsometric parameter changes, the surface concentration and thus the solution concentration of the biomolecules can be estimated.Expected advantages of the WEFE are: (1) the WEFE measurement is independent of light intensity; (2) the WEFE measurement is independent of the waveguide coupler quality;(3) t is very sensitive to the thickness of the adsorbed layer, the WEFE is much more sensitive than sensors based on intensity; (4) optic fibers are commercialized, the WEFE will be easy to fabricate and use commercially. In this paper, a comparison of WEFE with other biosensors, the principle of WEFE including light propagation in waveguide and ellipsometry parameter analysis, the WEFE arrangement and instrumentation, and preliminary experimental results will be given.

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Polymer concentration profile near a liquid-solid interface: evanescent wave ellipsometry study

Cited by 21 publications

References 10 publications

Effect of Solvent Quality on the Diffusion of Polystyrene Latex Spheres in Solutions of Poly(methyl methacrylate)

Effect of Solvent Quality on the Diffusion of Polystyrene Latex Spheres in Solutions of Poly(methyl methacrylate)

Cylindrical waveguide evanescent field ellipsometry

<title>Waveguide ellipsometry biosensors: concept and preliminary analysis</title>

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