Charcoal Cloth Research Articles

An investigation of surface area and porosity in solids by small-angle neutron scattering (SANS)

An investigation of surface area and porosity in solids by small-angle neutron scattering (SANS)

163. Comparison of the adsorptive performance of CDE charcoal cloth and granular charcoal

163. Comparison of the adsorptive performance of CDE charcoal cloth and granular charcoal

Adsorptive properties of microporous carbons: primary and secondary micropore filling

A study has been made of the mechanisms of micropore filling with particular reference to the adsorptive properties of two samples of activated charcoal cloth, having predominantly narrow slit-shaped pores, and a coke-based carbon, having a wider distribution of micropores. Nitrogen adsorption data at 77 K have been analysed by use of the αs -method and the Dubinin-Radushkevich equation. Integral heats of adsorption for a range of organic adsorptives have been derived from heat of immersion data in conjunction with physisorption data. The findings support the view that there are two distinctive mechanisms of micropore filling: (a) a primary process, which takes place at very low p/p° and involves enhanced adsorbent-adsorbate interactions and (b) a secondary process, which leads to a more gradual approach to the plateau of a Type I isotherm and is the result of co-operative effects associated with the filling of wider micropores (the supermicropores of Dubinin).

Purification of amphoteric polystyrene latex colloids

A series of polystyrene-based zwitterionic (amphoteric) latex colloids were prepared with integral acid (carboxyl) and base (amine) surface groups, resulting in a range of isoelectric points (iep). Following a series of different cleaning procedures, the resulting dispersions were evaluated by techniques including conductometric/potentiometric titrations and microelectrophoresis. The cleaning was by one or more of the following procedures—dialysis, ion exchange, ultrafiltration, centrifugation-decantation, and activated charcoal cloth equilibration. The monodisperse latices cleaned by these methods showed little variation in iep or in the magnitude of the electrophoretic mobility at any pH relative to the iep. In contrast, the surface charge, as measured by both conductometric and potentiometric titrations, varied greatly with cleaning procedure. With dialysis, ion exchange, and/or activated charcoal cloth equilibration, the observed capacitance at the pze was greater than is theoretically possible, indicating that these techniques may not successfully clean a surface simultaneously charged with acid and base sites. The overall results of some seven different cleaning procedures for four different amphoteric latex materials are presented.

The adsorption of organic and inorganic phosphates onto a new activated carbon adsorbent

A study was made of the adsorption characteristics of triethyl phosphate (TEP), dimethyl phosphate (DMP), and orthophosphate (OP), from aqueous solution onto activated charcoal cloth (ACC). The isotherms obtained were of a Langmuir type and, at neutral pH, and 293°K, the equilibrium adsorption capacities were 2430, 107, and 44.6 μmol g −1 from TEP, DMP, and OP solutions, respectively. DMP and OP adsorption was found to be strongly pH dependent. It is suggested that this dependence arises because of a combination of their p K values and the charge on the charcoal cloth surface in aqueous media. The latter was established by measurement of the electrophoretic mobility as a function of pH. No pH effect was evident in the TEP adsorption. Prior to reaching equilibrium it was shown that adsorption was proportional to ( time) 1 2 indicating a dependence on intrafibril (particle) diffusion.

116. The adsorption of low boiling point gases by activated charcoal cloth

116. The adsorption of low boiling point gases by activated charcoal cloth

Physical adsorption and heat of immersion studies of microporous carbons

Physisorption and heat of immersion measurements have been made with two microporous carbons—a sample of charcoal cloth (BET area, 1250 m 2 g −1; pore volume, 0.59 cm 3 g −1 having predominantly narrow micropores and a sample of Amoco carbon (BET area, 3700 m 2 g −1; pore volume, 1.9 cm 3 g −1), having a wider distribution of micropores extending into the supermicropore range (pore width, ca. 1–2 nm). The adsorption isotherms of nitrogen and toluene are of Type 1 and reveal that the external surface of both samples is very small. The heat of immersion measurements were carried out with the aid of a Tian-Calvet microcalorimeter and with the following liquids: n-hexane, cyclohexane, neo-hexane, toluene, mesitylene and isodurene. A sample of non-porous graphitized carbon black (Vulcan 3G: BET area, 71.1 m 2 g −1) was studied. Immersion calorimetry shows that in spite of the larger adsorptive capacity of the Amoco carbon, the sample of charcoal cloth has a higher adsorption affinity. The differences in the corresponding heats of immersion and in the adsorptive properties indicate that many of the pores in charcoal cloth are slit-shaped, whereas those in the Amoco carbon appear to be more cylindrical in shape.

Performance of the porton down charcoal cloth diffusive sampler

The Porton Down diffusive sampler has been calibrated for eight organic vapours and the results were compared with theoretical calculations of the rate of diffusive uptake. Diffusive uptake by the sampler is affected by ambient air velocity below about 0.1 m s–1, a value exceeded in most personal sampling situations, and also by the capacity of the charcoal cloth adsorbent. A procedure is described which estimates the time of onset of saturation under given conditions of vapour concentration and ambient humidity and the results are compared with laboratory calibrations of the samplers. Field trials confirmed that under appropriate conditions the Porton sampler gives valid results.

A system with some unique features for maintaining desired body temperature in anesthetized and/or immobilized animals

We describe the design and unique features of a system for precisely regulating body temperature of anesthetized and/or immobilized small mammals during prolonged neurophysiological experiments. The system uses a flexible, insulated, charcoal cloth conducting blanket which can be intimately wrapped around the animal's body. The temperature of the blanket is continuously regulated by an electronic system which compares the animal's actual temperature with the desired temperature. The system can react to differences of 0.1 to 0.001 degrees C and introduces no recording artifacts. With modification the system may have clinical application.

The mechanical properties of activated charcoal cloth

It is shown that whilst the carbon yields of cellulosic chars are increased byprior treatment with inorganic salts, the concomitant increases in char breaking strengthare variable. Data are given to show how both strength and flexibility are influenced bypretreatment, method of preparation and subsequent activation. In some cases activation causes marked changes in strength whilst in others little or no change occurs.