X-ray spectromicroscopy of immiscible polymer blends: polystyrene-poly(methyl methacrylate)

C. Morin, H. Ikeura-Sekiguchi, T. Tyliszczak, R. Cornelius, J.L. Brash, A.P. Hitchcock

BIMR, McMaster University, Hamilton, ON, Canada L8S 4M1

A. Scholl, F. Nolting

Advanced Light Source, Berkeley Lab, Berkeley, CA 94720

G. Appel, A. D. Winesett, K. Kaznacheyev and H. Ade

Dept. of Physics, North Carolina State University, Releigh, NC 27695

(Received 10 Dec 2000; accepted 20 Mar 2001)

Abstract

       Spun-cast and annealed thin films of polystyrene (PS) and poly(methyl methacrylate) (PMMA) blends have been studied using Scanning Transmission X-Ray Microscopy (STXM) and X-ray Photoemission Electron Microscopy (X-PEEM) to probe the bulk and surface composition, respectively. Results from X-PEEM and STXM are compared to atomic force microscopy (AFM) results for as-prepared and annealed films of several different compositions. Both low molecular and high molecular weight blends were studied with nominal compositions ranging from 66/33 weight%/weight% up to 10/90 weight%/weight% PS/PMMA. The relative chemical sensitivities of these three techniques are compared. Samples far from and closer to thermodynamic equilibrium have been studied. All samples are observed to have a PS signal from PMMA surface areas, even though neither polymer should be able to wet the other at thermodynamic equilibrium. Possible explanations for this observation are discussed.

@ 2001Elsevier Science B.V. All rights reserved.