Surface characterization of polymeric materials by x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry: Biomedical materials and forensic applications

Biomedical materials research and forensic science are two fields in which the ability to characterize polymeric surfaces is important. The use to state of the art spectroscopic techniques such as X-ray Photoelectron Spectroscopy and Secondary Ion Mass Spectrometry have allowed for the assessment of surface chemistry, morphology and the detection of environmental changes in a variety of polymeric materials.; The use of modification procedures such as radiation induced grafting and reactive ion beam etching yielded materials with unique surface chemistry, different from the starting materials. Additionally, novel synthesis methods were used to produce materials with high surface segregation of fluorine. The ability to correlate the surface characteristics of these materials to their interactions with biological environments provides a basis for judging the suitability of these materials for biomedical materials applications. The evaluation of both hydrophilic surfaces, radiation induced grafting and reactive ion beam etching, and hydrophobic surfaces, novel polymers, illustrates multiple approaches to the problem of biocompatibility.; Xerographic toner and writing ink are several polymeric materials routinely encountered in forensic situations. The ability to characterize toner material by X-ray Photoelectron Spectroscopy for both manufacturer identification and to evaluate environmental changes as a result of age provide valuable information which would not otherwise be available. The ability of Secondary Ion Mass Spectrometry to identify unique components of various writing inks allowed for the determination of the sequence of written strokes in the context of a line crossing problem. Additionally, the changes occurring to writing inks with time was detected by this technique and will allow for the discrimination of writings of the same ink formulation prepared at different times, and the possible determination of the relative date of preparation of multiple writings.