Complex patterns in reactive microemulsions: self-organized nanostructures?

In a reverse microemulsion consisting of water, oil (octane), an anionic surfactant [aerosol OT (AOT)], and the reactants of the oscillating Belousov-Zhabotinsky (BZ) reaction, a variety of complex spatiotemporal patterns appear. These include traveling and standing waves, spirals that move either toward or away from their centers, spatiotemporal chaos, Turing patterns, segmented waves, and localized structures, both stationary and oscillatory. The system consists of nanometer-sized droplets of water containing the BZ reactants surrounded by a monolayer of AOT, swimming in a sea of oil, through which nonpolar BZ intermediates can diffuse rapidly. We present experimental and computational results on this fascinating system and comment on possible future directions for research.

[1]  P. Umbanhowar,et al.  Localized excitations in a vertically vibrated granular layer , 1996, Nature.

[2]  P Coullet,et al.  A new approach to data storage using localized structures. , 2004, Chaos.

[3]  Tomohiko Yamaguchi,et al.  Self-Organization of Hierarchy: Dissipative-Structure Assisted Self-Assembly of Metal Nanoparticles in Polymer Matrices , 2003 .

[4]  M. Baptista,et al.  Electrical Conductivity, Near-Infrared Absorption, and Thermal Lens Spectroscopic Studies of Percolation of Microemulsions , 1997 .

[5]  J. García-Ojalvo,et al.  Effects of noise in excitable systems , 2004 .

[6]  J. Sepulchre,et al.  Bistable reaction-diffusion systems can have robust zero-velocity fronts. , 2000, Chaos.

[7]  M. Cross,et al.  Pattern formation outside of equilibrium , 1993 .

[8]  J. Keener,et al.  Spiral waves in the Belousov-Zhabotinskii reaction , 1986 .

[9]  Vladimir K. Vanag,et al.  Inwardly Rotating Spiral Waves in a Reaction-Diffusion System , 2001, Science.

[10]  A. Zhabotinsky,et al.  Concentration Wave Propagation in Two-dimensional Liquid-phase Self-oscillating System , 1970, Nature.

[11]  R. J. Field,et al.  Oscillations and Traveling Waves in Chemical Systems , 1985 .

[12]  Dulos,et al.  Experimental evidence of a sustained standing Turing-type nonequilibrium chemical pattern. , 1990, Physical review letters.

[13]  R. J. Field,et al.  Stationary concentration patterns in the oregonator model of the Belousov-Zhabotinskii reaction , 1985 .

[14]  A. Mikhailov,et al.  Standing Wave Patterns in the CO Oxidation Reaction on a Pt(110) Surface: Experiments and Modeling † , 2000 .

[15]  Irving R Epstein,et al.  Packet waves in a reaction-diffusion system. , 2002, Physical review letters.

[16]  Vladimir K. Vanag,et al.  Pattern Formation in a Tunable Medium , 2001 .

[17]  Vladimir K. Vanag,et al.  Segmented spiral waves in a reaction-diffusion system , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[18]  Wavelength halving in a transition between standing waves and traveling waves. , 2005, Physical review letters.

[19]  Y. Nishiura,et al.  Dynamic transitions through scattors in dissipative systems. , 2003, Chaos.

[20]  A. Maitra,et al.  Solution behaviour of Aerosol OT in non-polar solvents , 1995 .

[21]  M. Almgren,et al.  Deactivation of excited species by diffusion-controlled quenching in clusters of reversed micelles , 1992 .

[22]  A. Turing.  The chemical basis of morphogenesis , 1952, Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences.

[23]  I. Epstein,et al.  Pattern formation in a tunable medium: the Belousov-Zhabotinsky reaction in an aerosol OT microemulsion. , 2001, Physical review letters.

[24]  Mikhailov,et al.  Bifurcation to traveling spots in reaction-diffusion systems. , 1994, Physical review letters.

[25]  Irving R Epstein,et al.  Dash waves in a reaction-diffusion system. , 2003, Physical review letters.

[26]  Irving R Epstein,et al.  Stationary and oscillatory localized patterns, and subcritical bifurcations. , 2004, Physical review letters.

[27]  I. Epstein,et al.  Modeling of Turing Structures in the Chlorite—Iodide—Malonic Acid—Starch Reaction System , 1991, Science.