Sat, 05 Jul 2008 05:28:28 BST CiteULike: di dchen chemical http://www.citeulike.org/user/dchen/tag/chemical CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2767685 <i>Phys. Rev. Lett. 100, 088301 (2008)</i><br /><br />The driving force in diffusion-driven pattern formation is the difference in the diffusional flux of the key species, which in the case of ionic systems builds up a local electric field at the concentration gradients. The arising additional migrational flux not only decreases but also enhances the instability of the base state, depending on the charge distribution among the components. The opposite charges on the slower diffusing autocatalyst and its reacting counterpart favor pattern formation and shift the onset of instability to a smaller difference in the diffusion coefficients. The same charges, in addition to having the opposite effect, may even lead to the complete stabilization of planar reaction fronts unstable in the neutral system. Diffusion-Driven Pattern Formation in Ionic Chemical Solutions Zsanett Virányi Ágota Tóth Dezső Horváth Phys. Rev. Lett. 100, 088301 (2008) 2008-05-07T23:25:52-00:00 Phys. Rev. Lett. 100, 088301 (2008) charge chemical diffusion theory http://www.citeulike.org/user/dchen/article/2750572 <i>Physical Review Letters, Vol. 54, No. 15. (15 April 1985), 1725.</i> Spatial Self-Organization of Surface Structure during an Oscillating Catalytic Reaction MP Cox G Ertl R Imbihl doi:10.1103/PhysRevLett.54.1725 Physical Review Letters, Vol. 54, No. 15. (15 April 1985), 1725. 2008-05-03T20:12:24-00:00 1985 Physical Review Letters 54 15 1725 American Physical Society 2007 chemical focus nobel http://www.citeulike.org/user/dchen/article/1337781 <i>Colloid & Polymer Science, Vol. 282, No. 1. (1 December 2003), pp. 7-13.</i><br /><br />We discuss a dispersion polymerization procedure for preparing monodisperse and micron-sized poly(methyl methacrylate) (PMMA) particles in hexanes with methacryloxypropyl-terminated polydimethylsiloxane stabilizers. We investigate the effects of the stabilizer molecular weight, stabilizer concentration, and monomer concentration on the particle size and polydispersity. We find that a minimum molecular weight of 10 000 g/mol is necessary to synthesize colloidally stable PMMA dispersions. The particle polydispersity is minimal (=5%) for stabilizer to monomer weight ratios of 0.02 to 0.1, while PMMA particles prepared under conditions outside this range are polydisperse. The particle diameter can be varied from 0.4 to 1.5 µm by appropriate choices of stabilizer and monomer concentrations. Stable PMMA suspensions can be prepared at up to 26.3% solids. The dispersions are stable in most liquid aliphatics, and are monodisperse enough to form ordered domains at high concentration. This single-stage synthesis, requiring only commercially available materials, may be of interest to those seeking a simple way to prepare highly monodisperse non-aqueous dispersions in the micron size range. Preparation of monodisperse PMMA microspheres in nonpolar solvents by dispersion polymerization with a macromonomeric stabilizer Sascham Klein Vinothann Manoharan Davidj Pine Fredf Lange doi:10.1007/s00396-003-0915-0 Colloid & Polymer Science, Vol. 282, No. 1. (1 December 2003), pp. 7-13. 2007-05-27T21:14:34-00:00 2003 Colloid & Polymer Science 282 1 7 13 chemical colloids pine