Generative force of self-oscillating gel

J Phys Chem B. 2014 Mar 6;118(9):2576-81. doi: 10.1021/jp412806y. Epub 2014 Feb 21.

Abstract

We succeeded in measuring the generative force of a self-oscillating polymer gel in an aqueous solution comprising the three substrates of the Belousov-Zhabotinsky (BZ) reaction (malonic acid, sodium bromate, and nitric acid) under constant temperature. In this study, we developed an apparatus with a microforce sensor for measuring the generative force of small-sized gels (1 mm(3)). The self-oscillating polymer gel directly converts the chemical energy of the BZ reaction into mechanical work. It was determined that the generative force of the self-oscillating gel was 972 Pa, and the period of self-oscillation was 480 s at 18 °C. We demonstrated that the generative force of the gel was about a hundredth the generative force of a muscle in the body. We analyzed the time dependence of the color change in the self-oscillating polymer gel. The color of the gel changed periodically owing to the cyclic change in the redox state of the Ru moiety, induced by the BZ reaction. The peaks of the waveforms of the generative force and color change were almost identical. This result showed that the generative force was synchronized with the periodical change in the oxidation number of the Ru catalytic moiety in the gel. To understand a theoretical basis for the generative force of a self-oscillating gel, we considered a general theory that is based on the volume phase transition of gel and the two-parameter Oregonator model of the BZ reaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylamides / chemistry
  • Acrylic Resins / chemistry
  • Alkanesulfonates / chemistry
  • Bromates / chemistry
  • Catalysis
  • Gels / chemistry*
  • Malonates / chemistry
  • Nitric Acid / chemistry
  • Organometallic Compounds / chemistry
  • Sodium Compounds / chemistry

Substances

  • Acrylamides
  • Acrylic Resins
  • Alkanesulfonates
  • Bromates
  • Gels
  • Malonates
  • Organometallic Compounds
  • Sodium Compounds
  • tris(2,2'-bipyridyl)ruthenium(II)
  • poly-N-isopropylacrylamide
  • Nitric Acid
  • 2-acrylamido-2-methylpropanesulfonate
  • malonic acid
  • sodium bromate