Autonomous Motion of Catalytic Nanoparticles

Open Access
Author:
Paxton, Walter
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
June 27, 2006
Committee Members:
  • Ayusman Sen, Committee Chair
  • Thomas E Mallouk, Committee Member
  • Alan James Benesi, Committee Member
  • Seong H Kim, Committee Member
Keywords:
  • colloids
  • autonomous
  • micropumps
  • nanomotors
  • electrophoresis
  • catalysis
  • energy transduction
Abstract:
In this thesis, I explore and discuss a system that uses the platinum catalyzed decomposition of hydrogen peroxide to induce interfacial effects that result in the autonomous motion of micro-/nanosized particles. Chapter 2 describes the behavior of platinum-gold (PtAu) striped nanorods in hydrogen peroxide and its dependence on a number of factors. Chapter 3 explores several different mechanisms that may contribute to the motion of the PtAu nanorods, and discusses an interfacial tension mechanism for motion in depth. In Chapter 4, I discuss the electrochemical decomposition of hydrogen peroxide involving both Pt and Au and how this bimetallic catalytic process can induce electrokinetic effects to drive the motion of PtAu nanorods in H2O2 solutions. In Chapter 5, I describe a switchable catalytic micropump composed of a Pt/Au interdigitated array electrode in contact with H2O2 solution, expanding on the concept of catalytically induced electrokinetics discussed in Chapter 4. This work has important implications when considering the development of functional nano- and micromachines powered by catalytic reactions, particularly those that utilize oxidation reduction processes to induce electrokinetic effects.