Swelling-induced emission enhancement in substituted acetylene polymer film with large fractional free volume: Fluorescence response to organic solvent stimuli

The fluorescence property of poly[1-phenyl-2-(p-trimethylsilyl) phenylacetylacetylene] (PTMSDPA) and its high gas and vapor permeability that serve as the basis for a unique and practical application of PTMSDPA film to the optical detection of various organic solvent chemicals, was reported. The Swelling-Induced Emission Enhancement (SIEE) was observed when the PTMSDPA film was contacted to poor solvent such as hydrocarbons of n-hexane, n-decane, and paraffin oil. The SIEE phenomenon is very useful for optical detection of various VOC's in a fluorescence-enhancing mode unlike the TNT detection in a fluorescence turn-off mode. The control of pore size and FFV in fluorescent conjugated polymer film may be achieved by a delicate molecular design, which can make it possible to recognize the molecular sizes of analytes. The sensor application of PTMSDPA derivative films may extend to optical detection of either gaseous, small-sized molecules or large-sized supramolecules or virus molecular clusters by controlling the pore size in film.