Electrical conductivity and humidity sensing studies on synthetic organic–inorganic Poly-o-toluidine–titanium(IV)phosphate cation exchange nanocomposite

Electrically conductive Poly-o-toluidine–titanium(IV)phosphate (POT–TiP) cation exchange nanocomposite was synthesized by sol–gel mixing of organic polymer (Poly-o-toluidine) into inorganic precipitate of titanium(IV)phosphate (TiP). The material was characterized by using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The humidity sensing response of the nanocomposite was examined. It was found that the conductivity varied according to low humidity to high humidity. The composite showed good humidity response, ion-exchange capacity and electrical conductivity. Poly-o-toludine–TiP nanocomposite was also used to study electrical conductivity under isothermal conditions in the temperature range 50–130 °C. The composite was found stable under ambient conditions below 90 °C in terms of DC electrical conductivity retention. These studies suggest that the cation exchange nanocomposite could be a good sensing material for humidity.

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► Synthesis of POT–TiP cation exchange nanocomposite by sol–gel method.
► TEM prove that the prepared cation exchanger POT–TiP is a nanocomposite material.
► The composite showed excellent ion-exchange capacity and electrical conductivity.
► Cation exchange nanocomposite shows better sensing for humidity.
► This is the first attempt to study such type of cation exchange composite for humidity sensing applications.