Development of poly(p-phenylene vinylene) for actuator and controlled drug delivery applications

Abstract

This study evaluated and characterized the use of poly (p-phenylene vinylene) (PPV) as the electroactive polymer and in the controlled drug delivery application. Polydimethylsiloxane(PDMS) gel and PPV/PDMS blends were prepared and investigated as an electroactive polymer. The storage modulus, G’, of PDMS gel increases linearly with crosslink density but nonlinearly with electric field. The gel with the crosslink ratio of 0.01 possesses the highest G’ sensitivity of 41% at 2 kV/mm. For PPV/PDMS blends, the storage modulus, G’, of each blends in higher than that of the purely crosslinked PDMS, due to PPV particles acting as a filler in the matrix. On application of an electric field of 2 kV/mm, the storage modulus response, G’, increases between 7-50%, depending on PPV volume fraction. The stress generated in caused by the induced polarized PPV particles leading to interparticle interactions. Salicylic acid-loaded polyacrylamide hydrogels, SA-loaded PAAM, and salicylic acid-doped poly (phenylene vinylene) /polyacrylamide hydrogels, SA-doped PPV/PAAM were prepared and investigated as the controlled drug delivery device. The apparent diffusion coefficient, Dapp of SA-doped PPV/PAAM is higher than that of the SA-loaded PAAM, and increases with increasing electric field strength due to the combined mechanisms: the expansion of PPV chains inside the hydrogel; the reduction reaction under a negative potential driving the anionic SA through the PAAM matrix; and the electroporation of the matrix pore. Thus, the presences of the conductive polymer and applied electric field can be combined to control the drug releaser rate at an optimal desired level.