Mesoporous Platinum Films from Lyotropic Liquid Crystalline Phases

Abstract

symmetries in the finite-difference grid. For example, the fault-parallel components of the velocity as well as the normal and an shear stresses are antisymmetric, whereas the fault-perpendicular component of the velocity and the uyx and a , stresses are symmetric across a vertical fault in the xz plane. By careful examination of the numerical implementation, it can be shown that, if the numerical values of the velocity and stress have the aforementioned symmetries about the fault plane at the Nth time step, then they do at upgraded (N + 1)th time step as well. Details of the numerical application of the boundary conditions are described in (76). 10. J. Virieux and R. Madariaga, Bull. Seismol. Soc. Am. 72, 345 (1 98'2). 11. Slip-weakening friction laws similar to Eq. 2 have been extensively studied by rock mechanicists in Japan; see, foiexample, M. Ohnaka, Y. Kuwahara, and K. Yamamoto [Tectonophysics 144, 109 (1987)], M. Ohnaka [Proc. Natl. Acad. Sci. U.S.A. 93, 3795 (1996)], and M. Matsu'ura, H. Kataoka, and B. Shibazaki [Tectonophysics. 21 1, 135 (1 992)J. 12. Actually, the only physical requirement is that friction dissipates energy, such that T integrated over the fault will be less than zero. To our knowledge, the consequences of this less strict requirement have not been reported in the literature. 13. The study of slip weakening and the conditions for spontaneous rupture were introduced in seismology by Y. Ida [J. Geophys. Res. 77, 3796 (1972)], although the conditions had been used in dynamic fracture mechanics [B. Kostrov, L. V. Nikitin, L. M. Flintman, Mech. Solids 4, 112 (1969)l. The friction law used in our simulation is described by A. Palmer and J. Rice [Proc. R. Soc. London Ser. A Recent studies have shown that certain tute for Chemical Biology, The Scripps ~esearch Instielectrochemical etches of single-crystal ptute,

Lyotropic liquid crystal directed synthesis of nanostructured materials

“…In particular, they showed that the reduction of platinum salts in this system led to Pt whose nanostructure was a cast of LLC phase architecture. Such granular nanostructured metals could be directly used in catalysis, but they were of limited relevance for the electrochemical or sensor devices in which the metal was required as a thin film [58].…”

Breaking the mould: Casting on the nanometre scale

“…Casting such structures -which have aspect ratios One way to make templates on the nanometrescale exploits the amphiphilic nature of soaps: lyotropic liquid crystals self-assemble depending on solvent concentration and temperature into an astonishing array of soft nanostructures. Sol-gel or electrodeposition in only the aqueous compartments of the structure are used to cast templates, resulting in nanomaterials that are impossible to produce in any other way 8,9 (Fig. 2b).…”

3D design of self-assembled nanoporous colloids

“…A cationic assembly can exchange its counteranion, for example, chloride, with a mineralizable inorganic anion, protonated silicate. Synthesis of mesoporous thin films [7,14,18,[21][22][23]29], spheres [17,30,31], curved shaped solids [16,18], tubes [24,32], rods and fibers [18,33], membranes [34], and monoliths [35] has been reported recently. While chemistry of this process is rather well understood, the mechanism of formation of nanoporous silica shapes is not well elaborated.…”