Composition Profiling in a Binary Polymer Blend Thin Film Using Polarized Neutron Reflectivity

Published

April 1, 2000

Author(s)

H Grull, A Schreyer, Norman F. Berk, Charles Majkrzak, Charles C. Han

Abstract

The concentration profile in an ultra-thin film (film thickness d=440 ) of a high molecular mass poly(isoprene)/deuterated poly(butadiene) blend is measured in the bulk system=s miscible region with a new polarized neutron reflectivity method. By using a buried ferromagnetic layer inside the wafer and a polarized neutron beam, it is possible to obtain the phase angle of the complex neutron specular reflection intensity. A model independent and unambiguous profile of the film potential can be obtained by fitting the reflection amplitude. The scattering length density profile thus obtained reveals poly(isoprene) segregating symmetrically to the polymer/air and polymer/Si interfaces. The adsorption profile at both interfaces can be approximately described using an exponential- or tanh-function with a decay constant smaller than the bulk correlation length.

Citation

Europhysics Letters

Volume

50

Issue

No. 1

Pub Type

Journals

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Keywords

neutron reflectivity, polymer blend, solid-fluid interface, thermodynamics of surfaces and interface, thin film, wetting adsorption

Citation

Grull, H. , Schreyer, A. , Berk, N. , Majkrzak, C. and Han, C. (2000), Composition Profiling in a Binary Polymer Blend Thin Film Using Polarized Neutron Reflectivity, Europhysics Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851608 (Accessed March 14, 2025)