Chemical locomotives based on polymer supported catalytic nanoparticles

Abstract

In this letter, we report the development of a polymer-based chemical locomotive. Pd nanoparticle coated polymer resin beads were used for catalytic decomposition of H₂O₂ in aqueous medium. The oxygen bubbles generated in this way stuck to the beads after their formation. When there were sufficient numbers of bubbles formed or when the bubbles were large, vertical movement of the bead with constant velocity could be observed. The velocity could be as much as 0.59 cm s^-1 at the highest H₂O₂ concentration used. Further, the vertical velocity could systematically be controlled by changing the viscosity of the medium (by addition of glycerol). We observed that the velocity was inversely proportional to the viscosity of the medium. Appropriate theoretical analysis has also been reported. Once the vertical velocity was zero, horizontal motion and rotational motion could be observed. Further, a collection of such beads was used to propel large macroscopic objects providing linear and rotational motions.