Mesoporous carbon materials thin films

For further details on the preparation of mesoporous siHcas and carbons, organic-inorganic hybrid materials (PMOs), and mesoporous thin films, the reader is referred to several reviews [179]. 

A variety of supports have been explored for supporting a thin film of IL [44, 45], such as flame-dried silica [43], mesoporous silica [46], diatomic earth [24], and other oxides. The biopolymer chitosan consisting mainly of 2-amino-2-deoxy-(l,4)-P-D-glucopyranose units is well suited because of its high polarity [47]. Also, carbon nanotubes are feasible supports when their surface is suitably modified for anchoring the thin film of IL, for example, by covalently binding one layer of the IL [48]. Polymers resins are modified by covalently bound ILs [39, 49-51] frequently without covering the material with additional IL. A summary on suitable support materials is presented in Chapter 3. 

Richman EK et al (2008) Ordered mesoporous silicon through magnesium reduction of polymer templated silica thin films. Nano Lett 8(9) 3075-3079 Shen L et al (2012) Magnesiothermically reduced diatomaceous earth as a porous silicon anode material for lithium ion batteries. J Power Sources 213 229-232 Shen X et al (2013) Si/mesoporous carbon composite as an anode material for lithium ion batteries. J Alloys Compounds 552 60-64... 

Experiments have shown that other types of gas sensors can also use mesoporous silicas as the sensing layer. For example, selective sensing of nitric oxide has been accomplished in the presence of carbon monoxide through the application of quartz crystal microbalance technology employing a cobalt phthalocyanine-modified sol-gel thin film (Palaniappan et al. 2006,2008). Electrochemical detection of nitrite has been accomplished using a metalloporphyrin-modified silicate material... 

FIGURE 12.15 Proposed self-assembly mechanism of mesoporous carbon-onion-like carbon nanocomposites ( brick and mortar ). The onion-like carbon as well as other carbon nanostructures such as CB is dispersed in the final OMC framework, whereas a mesoporous OLC framework bound by a thin carbon film from the resorcinol-formaldehyde carbon is obtained in excess of the nanoparticles (a). Calculated PSD curves (b) for OLC and CB/OMC nanocomposites. The mesopore diameters increased with increasing OLC and CB contents. (From Fulvio, P. F. et ah, Advanced Functional Materials, 21, 2208, 2011. With permission.)... 

FIGURE 15.11 Selection of carbon materials used for GDI. (a) Graphene (Adapted from Li, H. B. et al., Journal of Materials Chemistry, 19, 6773, 2009.) (b) multi-walled carbon nanotubes (Adapted from Zhang, D. et al.. Materials Chemistry and Physics, 97, 415, 2006.) (c) electrospun fibers (Adapted from Wang, M. et al.. New Journal of Chemistry, 34,1843,2010.) (d) activated carbon cloth (Adapted from Oh, H. J. et al.. Thin Solid Films, 515, 220,2006.) (e) carbon aerogel (Adapted from Li, J. etaL, Joumcd of Power Sources, 158,784,2(X)6.) and(f) ordered mesoporous carbon (Adapted from Peng, Z. et al.. Journal of Physical Chemistry C, 115,17068, 2011.). 

The synthesis of OMC involves the use of ordered mesoporous silica (OMS) template with a specific pore topology [7]. As illustrated in Figure 3.1, the appropriate carbon precursor (carbon sources such as sucrose, furfuryl alcohol, acetylene gas, pyrrole, and acrylonitrile) is fed into the pores of the template via the infiltration approach, followed by its carbonization to achieve the siUca-carbon composite and template removal in ethanol-water solution of HF or NaOH to obtain the mesoporous carbon replica. The structure of the as-obtained OMC strongly depends on the structure of the used template. Chang et al. [7] have reviewed the synthesis of OMC as support materials for fuel cell applications. The rod- and tube-type mesoporous carbon structures can be realized by filling carbon precursors in the template pores and coating carbon precursors as a thin film on the pore walls of the template, respectively. In order to get the well-defined structure of OMC, the template should have three-dimensional interconnected pore structure. On the other hand, the carbonization of the carbon precursors should be confined exclusively within the mesopores of the ordered mesoporous silica templates with sufficient carbon precursor filling therefore, before the pyrolysis process, the carbon soiu-ce should be converted to a cross-linked polymer induced by the use of the acid polymerization catalysts [5,7]. 

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