Smart structures for sensing environmental pollution

We present a novel composite sensing agent consisting of calix[4]resorcinarene (C[4]RA) and the conducting polyorthomethoxyaniline (POMA) and propose different sensing mechanisms that can take advantage of its nanoporosity and unique complexation reactions. The two main purposes of combining the materials are, to improve the deposition of the materials as Langmuir-Blodgett (LB) films and to create a nanoporous material that improves on the absorbtion / desorbtion behaviour of the films giving higher gas diffusion coefficients. LB films offer the highest control of film properties in comparison to alternative deposition methods and the inclusion of flexible calixarene in the polymer structure offers enhanced response and recovery times in comparison to straight chain molecules than steric acid. Further effects such as conductivity increases of the material of up to two orders of magnitude upon exposure to saturated vapours are also described. The results of the present studies are encouraging and promise potential for extended studies with alternative composites utilising different electroactive conjugated polymers and varying crown size calixarenes, but using the same deposition method.