NONDESTRUCTIVE EVALUATION OF POLYMERIC PAINTS AND COATINGS USING 2-PHOTON LASER-SCANNING CONFOCAL MICROSCOPY

A 120 mu m thick tri-layer polymer paint on an aluminium substrate was imaged in three-dimensions using multichannel two-photon confocal las er scanning microscopy. Each layer is doped with a different fluoropho re so that the fluorescence emission from the layers can be separated into different channels. Use of i.r. excitation light allows deeper pe netration in the polymer layers. The image reveals fine details within each layer, as well as information about the interfaces between layer s. The substrate features are also visible with excellent resolution i n negative contrast. This technique provides a nondestructive method t o probe thick multilayer polymer materials. (C) 1997 Elsevier Science Ltd.