Silica-activated carbon fibers

FIGURE 8.10 The procedure of manufacturing carbon fibers and silica-activated carbon fibers. 

Figure 9.2 Fiber and foam structures, (a) Knitted silica fibers catalyst. (Reprinted from [7].) (b) Woven active carbon fiber catalyst. (Reprinted from [8].) (c) Aluminum foam. (Reprinted from [9].)...

We have an excellent activated carbon of fiber morphology, so called activated carbon fiber ACF[3]. This ACF has considerably uniform slit-shaped micropores without mesopores, showing characteristic adsorption properties. The pore size distribution of ACF is very narrow compared with that of traditional granular activated carbon. Then, ACF has an aspect similar to the regular mesoporous silica in particular in carbon science. Consequently, we can understand more an unresolved problem such as adsorption of supercritical gas using ACF as an microporous adsorbent. 

Hydrated silica—coated activated carbon fiber... 

Our previous papers [15,16] and the current work show that die imprinting of mesophase pitch particles with colloidal silica is an efficient technique to prepare mesoporous carbons with uniform spherical pores as well as carbons with bimodal pore size distributions. These carbons exhibit negligible amount of micropores, which can be further eliminated during graphitization process. If micropores are need, they can be created by controlled oxidation analogous to that used in the preparation of activated carbon fibers. The possibility of tailoring the size of uniform spherical mesopores is of great importance for catalysis, adsorption and other advanced applications such as die manufacture of hi -quaiity electrochemical double-layer capacitors, fuel cells and lidiium batteries. 

A representative case of physical activation is activation with silica, reported by Im et al. [138], The activation agent was embedded into the fibers and then removed by physically removing the agents. The process of activation by silica is presented in Fig 8.11. The silica-activated carbons nanofibers are shown in Fig. 8.12. The pores generated by physical activation are clearly observed. 

The high-throughput purification in a discovery environment and the removal of transition metals using adsorption on or crystallization in the presence of activated carbon, glass-bead sponges, polymeric fibers, or silica-bound scavengers and the preparative isolation of radiolabeled compounds are out of the scope of this contribution. 

Air (CDDs) Drawing of approximately 325 m3 of air through quartz fiber filter/polyurethane foam Soxhlet extraction with benzene, volume reduction clean-up using silica, alumina, activated carbon volume reduction addition of [13C12]2,3,7,8-TCDD. HRGC/HRMS MID (EPA TO-9) 1-5 pg/m3 68-140 from ultra pure, filtered air EPA1988g... 

In the supported systems the catalyst can be coated on the walls of the reactor, supported on a solid substrate or deposited around the case of the light source. Many are the supported materials used in literature, such as glass beads, and tubes [69], silica-based materials [70], hollow beads, membranes [71], optical fibers, zeolites, activated carbon, organic fibers [72], and so on. 

In most other processes, the presence of moisture in filler either requires a process correction in the amount of the active ingredient or the moisture must be removed. In the case of hygroscopic fillers (which are very important to industry), the surface of the filler must be treated to lower moisture uptake. Montmorillonite, glass beads and fibers, silica, titanium dioxide, aramid fiber, mbber particles, and carbon fiber were studied to improve their moisture absorption and impart the hydrophobic properties. "... 

While air and atmospheric analyses have been the subjects of many research articles, chromatographic determinations of pesticides in these types of sample are scant. Various methods for sampling pesticides in air have been reported, which use silica gel, Tenax, Chromosorb, XAD-2, polyurethane foam plug, glass fiber filters, and activated carbon or carbon fiber filters as sampling... 

Carbon fiber has been found to be an effective thermistor [192-194], such as a cement paste reinforced with chopped carbon fiber (about 5 mm long) with silica fume (15 wt% cement). Its electrical resistivity decreased reversibly with increasing temperature (1-45°C), with activation energy of electrical conduction (electron hopping) of 0.4 eV. This value is comparable to semiconductors (typical thermistor materials) and is higher than that of carbon fiber polymer matrix composites. The current-voltage characteristics of carbon fiber reinforced silica fume cement paste were linear up to 8 V at 20°C. 

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