ToF-SIMS Study of Polymer Nanocomposites
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ToF-SIMS Study of Polymer Nanocomposites. Vladimir S. Zaitsev, Young-Soo Seo1, Kwanwoo Shin1, Wenhua Zhang1, Steven A. Schwarz, Jonathan Sokolov1, and Miriam H. Rafailovich1. Department of Physics, Queens College of CUNY, Flushing, NY 11367, USA 1 Department of Materials Science and Engineering, SUNY, Stony Brook, NY 11794, USA ABSTRACT Films of deuterated polystyrene (dPS) and poly(methyl methacrylate) (PMMA) blends, as well as dPS and PMMA and poly(ethylene-co-propylene) (PEP) blends have been spin-cast from toluene solution and annealed at temperatures above their glass transition temperatures for up to 72 hours. Surface topography of the cast and annealed films was measured by atomic force microscopy (AFM). Dynamic secondary ion mass spectrometry (SIMS) was used to study microphase segregation of the polymer films. A series of two-dimensional (2D) images of the films were acquired during sample sputtering. A reconstruction of the sample three-dimensional (3D) structure from 2D data was performed. Spatial distributions of H, D, C, O, and higher mass fragments revealed microphases with dimensions on the order of a few microns. We describe the method that corrects height distortion to 3D SIMS images. After sputtering, AFM is used to produce a topographic image of the area analyzed by SIMS. The surface height variation array from SIMS data was compared with that observed by AFM. A limitation of the correction method is discussed. INTRODUCTION Nanocomposite materials are attracting more and more commercial interest due to demand for lighter and stronger materials. Though such materials may appear to be homogeneous at the macroscopic level, their components are segregated into microscopic domains. Secondary ion mass spectrometry has been used routinely as a powerful method for element distribution examination of conducting and semi-conducting surfaces at high spatial resolution and with a high sensitivity. Acquisition of two- and three-dimensional spatially resolved images of element distributions in such samples, as well as different methods of 2D to 3D image transformation, were reported recently [15]. Also it was shown that in order to provide an accurate reconstruction of threedimensional information obtained by SIMS, it is necessary to take into account the topography of the original surface and the relative sputter rates of the different structures within the volume [6]. 2D SIMS imaging of thin organic films and polymer distributions on conducting or metal-coated substrates is well known [7,8]. However, an application of imaging SIMS for nonconducting materials such as biological and geological samples is still rare. 3D structure reconstruction of polymer blends and particularly polymer nanocomposites from SIMS data should be an even more complicated task due to surface charging and topography. The use of AFM topographic images before and after sample sputtering for KK6.2.1
the correction of 3D SIMS image for height and sputtering rate variation is time consuming and requires a precise alignment and scaling of
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