1992 C-R-BURCH-PRIZE - TOF SIMS IN POLYMER SURFACE STUDIES

This review describes advances made in the study of polymer surfaces at Sheffield University between 1988 and 1993. Over this period, we have taken advantage of the increased surface sensitivity, extended mass range, and imaging capability of Time-of-Flight Secondary Ion Mass Spectrometry (TOF SIMS) to investigate the surfaces of 'as-received', degraded, and modified polymers, as well as organic surface coatings prepared by plasma polymerization. This review is divided into six sections: 1. Secondary ion mass spectrometry in polymer surface studies. 2. The surface structure of polymer blends. 3. The surface photo-oxidation of polystyrene (PS) and photostabilised PS. 4. Monitoring the effects of plasma surface treatment by TOF SIMS. 5. An investigation of plasma polymer structure. 6. Conclusions and the future outlook for TOF SIMS. The first section gives a brief overview of the developments in SIMS technology and experimental methodology that now allow its routine use in polymer surface studies. The following four sections describe some selected data from the different projects in which we have been involved. In each, a short introduction to the topic is followed by a statement of the (original) objectives of our study. A summary of established results is presented along with some newer (unpublished) data. The intention is not simply to draw attention to what we have already done, but to give an idea of where our studies are progressing. The work described is ongoing, indeed, in all the examples selected for this review, more potential areas of investigation have been opened than closed. In the final section, the different themes of the preceding sections are brought together, and some weaknesses in the present use and understanding of SIMS, in polymer surface studies, are identified. Experiments designed to address these problems are described. In this section we also speculate on how recent advances in instrumentation could result in new applications.