A non-gassing electroosmotic pump with sandwich of poly(2-ethyl aniline)-Prussian blue nanocomposite and PVDF membrane

Abstract

Low voltage, non-gassing electroosmotic pump (EOP) was assembled with poly(2-ethyl aniline) (EPANI)-Prussian blue nanocomposite electrode and commercially available hydrophilic PVDF membranes. The nanocomposite material combines excellent oxidation/reduction capacity of EPANI with exceptional stability by shuttling of proton between Prussian blue nanoparticles and EPANI redox matrix. The flow rate was highly dependent on the electrode composition but it was linear with applied voltage. The flow rate at 5 V for different nanocomposite, EPANI, EPANI-A, EPANI-B, and EPANI-C were 127.29, 187.41, 148.51, and 95.47 µL/min cm² , respectively, which increases substantially with increase in the Prussian blue content. The obtained best electro osmotic flux was 43 µL/min/V/cm² for EPANI-A. It was higher than most of the EOP assembled using polyquinone and polyanthraquinone redox polymers. The assembled EOP remained exceptionally stable until the electrode charge capacity was fully utilized. The best EOP produces a maximum stall pressure of 1.2 kPa at 2 V. These characteristics make it suitable for a variety of microfluidic/device applications.

Keywords: Electro-osmotic pump; Microfluidics; PVDF membrane; Poly(2-ethyl aniline); Polyaniline; Prussian blue.