Described herein is the synthesis of a dipyrrolylquinoxaline (DPQ) monomeric species containing methacrylamide functionality, and its subsequent copolymerisation with methyl methacrylate (MMA). The resulting copolymers were drop casted onto glass substrates, and the resulting thin films displayed distinct colorimetric change upon exposure to hydrofluoric acid (HF) vapour. Furthermore, glass substrates coated with the DPQ-MMA copolymer could be used as dip sticks to test for trace acid in solution, turning from yellow to red upon immersion in an aqueous solution of HF. Analysis by UV-vis spectroscopic titration allowed the association constant (K a) for interaction with fluoride (as the tetrabutylammonium salt) to be calculated as 6.1610 5M 1 in CH 2Cl 2. Polymer coatings of this type could find applications in the colorimetric detection of HF vapour, a common hazard associated with industrial processes, such as aluminium smelting.
Bibliographical noteFunding Information:
This work was supported by the NIH (grant GM 58907 to J.L.S.) and the Robert A. Welch Foundation (grants no. F-1018 and F-1621 to J.L.S. and C.W.B, respectively).
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