Oil-sorbent to hydrosorbent switching in Poly-9-octadecenylacrylate and Poly-9-octadecenylacrylate/Au nanocomposites

Abstract

In this paper we have synthesized Poly-9-octadecenylacrylate (PODA) and Poly-9-octadecenylacrylate/Au (PODA/Au) nanocomposites and characterized the polymer by Fourier Transformed Infrared spectrometer, Scanning Electron Microscopy, Thermogravimetric Analysis and X-ray Diffraction study. It is observed that the swelling properties of PODA and that of PODA/Au nanocomposites are completely different. PODA is found to have high swelling ratio with most of organic solvents like chloroform, tetrahydrofuran, benzene, toluene, pyridine and oils like kerosene and gasoline. PODA/Au nanocomposites, on the other hand, are sorbent to water, salt solutions and alcohol/water mixtures. Alternating current impedance measurements show that there is a sharp decrease in impedance values on addition of Au nanoparticles to PODA. The AC conductivity values at 35°C for PODA is found to be 7.60×10−9Scm−1, while that of [PODA/Au] in the ratios 1:0.0117M, 1:0.0233M and 1:0.0397M increases to 9.86×10−7, 1.14×10−5 and 1.19×10−4Scm−1 respectively. Ionic transport number measurement shows that while PODA does not have any ionic contribution, PODA/Au nanocomposites have up to 40% ionic conduction. A possible mechanism to explain this switching from oil-sorbent to hydrosorbent in PODA and PODA/Au nanocomposites is also discussed.