TiO2 doped polydimethylsiloxane (PDMS) and Luffa cylindrica based photocatalytic nanosponge to absorb and desorb oil in diatom solar panels

Abstract

Our previous report(s) demonstrated that piezoelectric disc fabricated diatom solar panels worked as micro resonating devices. Such devices have potential to harvest oils from living diatom cultures. However, it is observed that the collection and separation of oil from culture media using these devices are found to be difficult due to the presence of both living and dead diatom cells, which simultaneously get collected during this process. In this study we made a highly biocompatible nanosponge using TiO₂ nanoparticle doped polydimethylsiloxane (PDMS) and Luffa cylindrica. Such hybrid nanosponge selectively absorbs and desorbs oil on exposure to ultraviolet light. The fabricated PDMS-Luffa-TiO₂ nanosponge was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and atomic force microscopy to show the surface characteristics and affinity of nanoparticles to the membranous structure of PDMS-Luffa. A maximum 38% oil absorption was found in PDMS-Luffa-TiO₂ nanosponge which was almost double that of sponges made up of PDMS (19%), PDMS-Luffa (18%) and PDMS-TiO₂ coated (24%). Thus PDMS-Luffa-TiO₂ nanosponge serves as a selective and recyclable oil absorption membranous structure. Furthermore, this hybrid nanosponge exhibited excellent recyclability by repeated absorption–desorption processes on exposure to UV light.