Poly(aniline-co-m-aminobenzoic acid): A Novel Ester Vapor Sensor and its Thin Film Deposition on Silane Functionalized SAM Glass Surface

In recent years, a great deal of attention has been paid on coating the surface of glass and related inorganic substrate with a layer of polymers having special properties to prepare various functional materials. On a smooth surface of glass, the adhesion of a conductive polymer is generally poor. The increase of the surface adhesion was achieved through a chemical pre-treatment. One of the method is to generate a self-assembly monolayer or patterned SAM monolayer to increase the surface adhesion property of glass surface towards polymer solutions 1,2. Self-assembled monolayers (SAMs) are monomolecular layers which are spontaneously formed upon immersing a solid substrate into a solution containing functional molecules. SAMs can be prepared using different types of molecules and different substrates. Aminosilanes such as (3-Aminopropyl)-triethoxysilane (APTES) are attractive for such applications 3. Particularly, aminosilanes have the advantage of catalytic activity by the amine group that facilitates formation of siloxane bonds with surface silanols. In present study, a 3-step procedure for the introduction of APTES on glass pieces is described. After chemisorptions of APTES, poly (aniline-co-m-aminobenzoic acid) synthesised by inverse emulsion polymersation route was coated on to the functionalised glass surface in the form of a solution prepared in DMSO. The modified glass was characterized mainly by IR spectroscopy and contact angle measurement. The coated glass was used for ester sensing.