Humidity Sensing Performance of Nanoscale Copper Oxide and Non-Stoichiometric Copper Sulfide Entrenched in Engineering Thermoplastic Matrix

摘要

We herein report of the feasibility of facile polymer-inorganic solid state reaction route for simultaneous in-situ generation of semiconducting copper sulfide nanostructures in polymer network wherein an engineering thermoplastic viz. polyphenylene sulphide (PPS) acts as chalcogen source as well as stabilizing matrix for the resultant nanoscale products. Typical solid state reaction was accomplished by simply heating the physical admixture of the two reactants i.e., copper carbonate and PPS by varying molar ratios viz; 1:1, 1:5, 1:10, 1:15, 1:20 at the crystalline melting temperature (285℃) of PPS. The synthesized nano particles were characterized using various physicochemical characterization techniques like X-ray diffractometry, field emission scanning electron microscopy, transmission electron microscopy, uv-visible spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. The prima facie observations suggests formation of nanocrystalline Cu_(1.96)S as a sub-phase along with nanoscale copper oxide phases in the thermoplastic matrix. The TEM analysis reveals nanoscale polydispersity (15 nm-100 nm) and prevalence of mainly spherical morphological features in all the cases with occasional indications of decagon and cubical morphological features depending upon the reaction molar ratio. The humidity sensing properties of these nanocomposites were studied. The sensors exhibited linear behavior. Maximum humidity sensing was obtained for the nanocomposite corresponding to 1:5 molar ratio reaction.