Carbon core size

Figure 11. Pore/core size distribution curves for silica gel Si-100 1 - carbon tetrachloride, 2 - acetone, 3 - n-butanol, 4 (points) - pore size distribution derived from nitrogen adsorption data.

Protection against airborne radioactive particles is a problem in the nuclear industry. Microfilament yams may be densely woven to produce fabrics with maximum pore size of 20-30 pm for use in the nuclear industry compared with the 75-300 pm pore size of typical cotton and polyester cotton fabrics. Incorporation of filaments with a carbon core greatly reduces the atttaction of radioactive particulates by static electricity on to the fabric during wear, as does the inclusion of an absorbing activated carbon layer as used in nuclear, biological and chemical (NBC) suits in military use (see Section 10.3.3.4). 

To improve visualization of the changes in local pore size, SiC was converted into CDC nnder parallel activation. The reaction was stopped after 2.5 h, resulting in a final carbide conversion of 25%. The resulting nanoporous carbon core shell structure covering the remaining carbide was then activated for an additional 2.5 h without reactive extraction. Figure 13.7 compares the pore size... 

HMC is a very interesting porous carbon material with unique hierarchical macro/mesoporous spherical morphology. HMCs with various core sizes and/or shell thicknesses can be fabricated through the independent control of the core sizes and/or shell thicknesses of the SCMS silica templates [28,62,63], while the micro- and mesoporosity of the HMCs can be controlled to some extent by the source type and amount of carbon precursor incorporated into the SCMS silica template. HMC with different core shapes (non-spherical) have been synthesised through nanocasting techniques [61,64], A key factor for the s)mthesis of HMCs with diverse shapes and sizes lies in the fabrication of SCMS silica replica templates. 

Diesel soot particles are almost entirely of respirable size, and consist of an elemental carbon core formed of aggregated primary particles and a variable amount of adsorbed organic sulfur, and metal compounds condensed onto the... 

Barium carbonate of finely controlled particle size reacts in the soHd state when heated with iron oxide to form barium ferrites. Magnetically aligned barium ferrite [11138-11-7] powder can be pressed and sintered into a hard-core permanent magnet which is used in many types of small motors. Alternatively, ground up magnetic powder can be compounded into plastic strips which are used in a variety of appHances as part of the closure mechanism. 

Similar results were found by Bacsa el al. [26] for cathode core material. Raman scattering spectra were reported by these authors for material shown in these figures, and these results are discussed below. Their HRTEM images showed that heating core material in air induces a clear reduction in the relative abundance of the carbon nanoparticles. The Raman spectrum of these nanoparticles would be expected to resemble an intermediate between a strongly disordered carbon black synthesized at 850°C (Fig. 2d) and that of carbon black graphitized in an inert atmosphere at 2820°C (Fig. 2c). As discussed above in section 2, the small particle size, as well as structural disorder in the small particles (dia. —200 A), activates the D-band Raman scattering near 1350 cm . ... 

For solid wastes to be suitable as a full or partial replacement for components in other applications, it should be free of objectionable material such as wood, garbage, and metal that can be introduced at the foundry. It should be free of foreign material and thick coatings of burnt carbon, binders, and mold additives that could inhibit product manufacture, such as cement hydration. It may be necessary to crush the solid waste to reduce the size of oversized core butts or unclasped molds. Magnetic separation is a good solution to producing a suitable coarse or fine aggregate product. 

---