Studies of surface and interface segregation in polymer blends by secondary ion mass spectrometry

Abstract

Dynamic secondary ion mass spectrometry (SIMS) has recently been employed to obtain high resolution depth profiles in polymer blend thin films and is now regarded as a key probe of surface and interfacial segregation in these systems. Segregation phenomena strongly impact blend properties such as adhesion, friction and weatherability. The strengths and limitations of the SIMS polymer profiling technique are described and contrasted with the complementary techniques of forward recoil elastic scattering (FRES) and neutron reflectivity (NR). The procedures developed for sample preparation and data acquisition are discussed. Experimental results for the effect of incident O2 + energy and angle on depth resolution and sputtering rate in polystyrene (PS) are presented. Ongoing SIMS studies of model blend systems are described: Segregation from dPS (deuterated)/PS blends to vacuum and Si interfaces is examined as a function of the molecular weight of the blend components and preparation of the Si substrate, reve...