In order to give fibers an antibacterial function and to increase their deodorant function, some trials on supporting minute particles of different metals, such as Ag, Cu and Mn, have been performed. Desorption of gas can be accelerated by raising the temperature on activated carbon fibers.ДЄnother advantage of activated carbon fibers is the ability to prepare woven clothes and non-woven mats, which has been developed as a large application in small purification systems for city water and also as a deodorant in refrigerators, for example. 5-15, the adsorption and desorption behaviors of toluene are compared on these two carbons. Therefore, the adsorption rate as well as the amount of adsorption of gases into activated carbon fibers are much higher than those into granular activated carbons. In granular activated carbons, gas molecules always have to reach micropores by passing through macropores and mesopores, whereas in activated carbon fibers most micropores are exposed directly to gas. It is known that micropores are responsible for gas adsorption.

Granular activated carbons have different sizes of pores, macropores, mesopores and micropores, whereas activated carbon fibers have mostly micropores on their surfaces. 5-7a), and the differences between activated carbon fibers and granular activated carbons are listed in Table 5-2. 5-7b, by comparing it with that of granular activated carbon ( Fig. Their pore structure is schematically shown in Fig. The principal merit to prepare in fibrous morphology is its pore structure and a large physical surface area. These alloyed carbons showed higher adsorption capacities for water and ethanol because of the presence of nitrogen atoms on the pore wall.ДЄctivated carbon fibers have a number of advantages over granular activated carbons. XPS analyses showed that the nitrogen exists either as pyridinic or quaternary nitrogen. The CVD experiments at 7вЊ gave activated carbon fibres alloyed with nitrogen and with their original micropore structures almost unchanged. They carried out pyridine CVD over pitch-based activated carbon fibres, HTT 700 to 1000вЊ. introduced nitrogen into the pores of activated carbon fibres. Д¬hemical modification of micropore walls may give porous carbons some novel properties and functions. carbonized waste resins containing calcium ions and confirmed the formation of uniform micropores as seen in Fig. , Copyright (1999) with permission from Elsevier Science).ДЇrom a practical point of view, this method is very promising, because waste ion-exchange resins can be converted to MSC by this method. Pore volume distribution curves of MSCs prepared from the ion-exchange resins with a different metal cation. The metal sulphides and/or the metals formed in the decomposition of the sulphonate groups with di- or tri-valent metal cations behave as pillars standing between the carbon layers, the presence of such pillars preventing collapse of micropores during carbonizations.ДЇig. put forward the following explanation for such behavior. This suggests that micropore sizes are controllable by changing the cation.

The average pore diameter of the former resins varied 0.38 to 0.45 nm, depending on the multivalent cation. Carbons prepared from resins with di- or tri-valent cations (Ca, Fe, Ni, Cu and Zn) have larger micropore volumes than those with uni-valent cations (H, Na and K).

Although the starting resin materials were very similar, the pore size distribution curves differed considerably. The metal and its loading (mol kg в€’1 of resin) are denoted by the symbol of the element followed by a number. Figure 1 shows accumulated pore volume distributions of the resultant carbons with metal additions at different loadings. The resins were ion-exchanged with several types of cations and carbonized at 500 to 900вЊ. The ion-exchange resin was a spherical polystyrene-based resin with sulphonic acid groups as ion exchangeable sites. proposed the use of an ion-exchange resin as the precursor. There are two main methods to prepare MSC one is synthesis by pyrolysis of a suitable carbon precursor(s) and the other is the modification of existing porosity of a suitable porous carbon.

Porus history