Activated carbon fabrics

Effect of Oxidative Treatment on the Capacitance of Activated Carbon Fabrics... 

The use of activated carbon fabric as the adsorbent in an H2 PSA process has also been reported.56 The advantage of the fabric is that it does not require additional supports like metal mesh, paper, and aluminum foil, and the bulk density of the adsorbent material in the PSA adsorber is increased. 

Hu, C. C., and C. C. Wang. 2004. Effects of electrolytes and electrochemical pretreatments on the capacitive characteristics of activated carbon fabrics for supercapacitors. Journal of Power Sources 125 299-308. 

Zhang, Q., J. Rong, D. Ma, and B. Wei. 2011. The governing self-discharge processes in activated carbon fabric-based supercapacitors with different organic electrolytes. Energy Environmental Science 4 2152-2159. 

Effect of the Average Pore Size on the Adsorption Capacity and Off-Gassing Characteristics of Activated Carbon Fabrics for Decontamination of Surfaces... 

Table 1 presents a comparison of the CEES and HD adsorption capacities of fom different activated carbon fabrics that were examined. 

Figure I. Activated Carbon Fabric Adsorption Capacity for HD and CEES V5. Volume Average Pore Diameter...

As compared to non-adsorbent fabrics that could also be used to remove hazardous liquids contaminants from solid surfaces, the adsorptive properties of the activated carbon fabrics mitigates off-gassing from used wipes. When the used wipes are repackaged in a sealable hermetic envelope, the adsorptive properties provide a redimdant means of agent isolation. The used wipes can thus be safely handled imtil they are destroyed, for example, by incineration, or decontaminated by standard means, such as immersion in bleach solution. 

Off-gassing tests were performed with CEES and with Agent HD to establish the effect of agent loading on swatches of activated carbon fabrics on the rate and extent of agent evaporation into an air stream flowing over a swatch. 

Off-gassing tests were performed with 1.75 in (4.5 cm) diameter discs of the following Calgon Zorflex activated carbon fabrics 50K knitted fabric, 100 micro woven fabric, and 100 meso woven fabric. The volume average pore size and specific surface area of each of these fabrics are as follows ... 

The amount of CEES off-gassed in one hour, as a percentage of the initial amount of CEES added to a sorbent, is presented in Figure 5, for the various sorbents and initial CEES loads examined. The amount of CEES off-gassed from the three activated carbon fabrics examined, at initial loads of 10 wt-% and 20 wt-%, are presented in Figure 6. For these fabries, at an initial CEES loading of 3.24 wt-%, the amoimt of CEES off-gassed was not measurable. 

In general, the amount of CEES off-gassed increased with the initial CEES loading on the sorbent, and, at any of the concentrations examined, there was significantly more off-gassing from the M 100 powder than from aity of the activated carbon fabrics tested. 

Figure 6. Off-Gassing of CEES from Selected Activated Carbon Fabrics at High (lOwt-% and 20 wt-%) CEES Loadings...

The level of off-gassing observed from the M 100 powder is at least an order of magnitude higher than that observed from the activated carbon fabrics, over 2% evaporation at a 3.24 wt-% initial load, and over 10% at a 10 wt-% initial load. Because of the high levels of off-gassing obtained at a 10 wt-% initial load, this powder was not tested at a 20 wt-% initial load. This higher level of off-gassing occitrs because the M 100 powder has a much lower specific surface area than the activated carbon fabrics. 

Figure 7. HD Off-Gassing from Zorflex 5 OK Activated Carbon Fabric...

The adsorption capacity of activated carbon fabrics for CEES and HD dissolved in HFE-7100 increases with the specific surface area and as a function of the the volume average pore diameter, over the range of 0.2 nm to 2.9 nm. There is an excellent correlation between the HD adsorption values and the CEES adsorption values. Fabrics with a high mesopore concentration will exhibit significantly more liquid phase capacity for CEES and HD than microporous fabrics. Negligible off-gassing of CEES or HD is observed from activated carbon fabrics at low contaminant loadings when the contaminant is contained within the pores of the fabric. 

For CEES loadings greater than the pore capacity for CEES, the level of CEES off-gassing from an activated carbon fabric, the level of CEES offgassing from the fabrics varies as a function of the CEES load per unit surface area of the fabric, for both microporous and mesoporous fabrics. At comparable CEES loadings, there is significantly less CEES off-gassing from activated carbon fabrics than from the M 100 powder used in the M 295 decontamination kit. This is a result of the much lower specific surface area of this powder. 

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