Microtexture

Randle, V. and Engler, O. (2000) Macrotexture, Microtexture and Orientation Mapping (Gordon Breach, New York). 

The pores of the silica template can be filled by carbon from a gas or a liquid phase. One may consider an insertion of pyrolytic carbon from the thermal decomposition of propylene or by an aqueous solution of sucrose, which after elimination of water requires a carbonization step at 900°C. The carbon infiltration is followed by the dissolution of silica by HF. The main attribute of template carbons is their well sized pores defined by the wall thickness of the silica matrix. Application of such highly ordered materials allows an exact screening of pores adapted for efficient charging of the electrical double layer. The electrochemical performance of capacitor electrodes prepared from the various template carbons have been determined and are tentatively correlated with their structural and microtextural characteristics. 

Toupin M., Brousse T., Belanger D. Influence of microtexture on the charge storage properties of chemically synthesized manganese dioxide, Chem Mater 2002 14 3946-52. 

Figure 1 presents the plot of the BET specific surface area vs the irreversible capacity measured for graphite samples milled in different atmospheres and sometimes post-treated by pyrolytic carbon deposition. The experimental values are quite scarce and, contrarily to several claims [7-9], there is not any linear dependence between these two parameters. It seems that the linearity would exist only for samples from the same family with comparable microtextures. 

Disordered carbons usually exhibit a multiscale organization (structure, microtexture, texture)4. Structurally, they are made of more or less distorted polyaromatic layers, nanometric in size. The spatial association or the layers, from the nanometric to the micrometric scales, gives rise to different microtextures (lamellar, porous, concentric, fibrous, etc.) forming the carbons skeleton4. The multiscale organization is the fingerprint of the kind of precursor and of the formation conditions (temperature, pressure, strains, time, etc.) met either in laboratory experiments or in Nature, and is directly related with numerous properties. 

Figure 2. HRTEM image analysis, a raw HKTEM image b corresponding skeletonized image c limits of a coherent domain, definition of the structural (L, La, Lc, d) and microtextural (a) parameters N is the number of layers stacked within a domain.

Carbon is unique among chemical elements since it exists in different forms and microtextures transforming it into a very attractive material that is widely used in a broad range of electrochemical applications. Carbon exists in various allotropic forms due to its valency, with the most well-known being carbon black, diamond, fullerenes, graphene and carbon nanotubes. This review is divided into four sections. In the first two sections the structure, electronic and electrochemical properties of carbon are presented along with their applications. The last two sections deal with the use of carbon in polymer electrolyte fuel cells (PEFCs) as catalyst support and oxygen reduction reaction (ORR) electrocatalyst. 

The evolution of spent fuel microstructure (e.g., increased porosity) and microtextures... 

J. P. Bard, Microtextures of Igneous and Metamorphic Rocks, Dordrecht, D. Reidel, 1986 A. Putnis, Introduction to Mineral Sciences, Cambridge, Cambridge University Press, 1992... 

Oberlin, A. et al. Electron microscopic study of kerogen microtexture, in Kerogen, (ed. Durand, B.) p. 191, Paris, Technip 1980... 

Padera R, Colton C. Time course of microtexture driven neovascularization. Biomaterials 1996, 17, 277-284. 

Cultures of primary cardiac myocytes (chick embryo) were formed on fibronectin patterned acrylic surfaces [198]. A microtextured PDMS chip with 20-urn-wide pegs was used to promote cell culture. After coating the PDMS chip with a thin layer of laminin, neonatal rat cardiac myocytes were cultured on it. The cultured cells are typically 50 p.m in length and 10-15 p.m in diameter. The PDMS chip was cast on a mold with parylene structures patterned on a Si wafer. Using the same mold, a poly(lactic/glycolic acid) (PLGA) chip could also be made for culture of rat cardiac fibroblasts [900]. 

Desai, T.A., Deutsch, J., Motlagh, D., Tan, W., Russell, B., Microtextured cell culture platforms Biomimetic substrates for the growth of cardiac myocytes and fibroblasts. Biomed. Microdevices 1999, 2(2), 123-129. 

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