Alkaline hydroxide activation activating agents

This trend observed for chemically activated carbon fibers is very different from that obtained for the ACF prepared by physical activation of the same raw carbon fiber with C02 and steam, where the maximum scattering appears at the external zone of the fiber (see Figure 4.19). In the case of NaOH and KOH activation, the results indicate that the activating agents penetrate the fiber, which is a new interesting observation, which points out that alkaline hydroxides penetrate much better than C02 and steam. The different evolution of porosity obtained for the chemically activated carbon fibers compared to the physically activated carbon fibers could be explained considering the important differences between the mechanisms of both the activation methods. 

All oxidizing agents decompose it readily HaO and arsenic trioxid being formed by the less active oxidants, and HaO and arsenic acid by the more active. Solid potassium hydroxid decomposes the gas partially, and becomes coated with a dark deposit, which seems to be elementary arsenic. Solution of the alkaline, hydroxids absorb and decompose it H is given off and an alkaline-... 

During the last 15 years our group has been researching carbon activation by alkaline hydroxides, analyzing its different aspects. Thus, we have compared both NaOH and KOH with other chemical agents [23], we have analyzed several variables of this activation process [21,23,42,43,70-72,77,88,98], we have studied the reactions taking place [99-101], we have worked on their porosity characterization [12,13,70,102-106], and, finally, we have studied these ACs in several applications [71,107-114]. From all these studies, which cover most of the aspects of carbon activation by alkaline hydroxides, we have been able to identify additional advantages to those mentioned earlier (1) the precursor ash content has no... 

A material blended from alkali hydroxides and such alkaline salts as borates, carbonates, phosphates, or sihcates. The cleaning action may be enhanced by the addition of surface-active agents and special solvents. 

Cained alkaline by the addition of sodium hydroxide solution [220, 221]. Ferricyanide is probably the active oxidising agent in homogeneous solution and it is regenerated electrochemically. 

Cationization of starch by dry reaction with 2,3-epoxypropyltrimethylammonium chloride is a commercially significant process. The key to a dry reaction is an intimate, homogenous mixture of the reagent and the catalyst. One process38,39 describes an activator consisting of spray dried, precipitated silica with a surface area of 190m2/g (BET) that contains an alkaline agent such as calcium oxide or calcium hydroxide and/or silicates. Different ratios of silica to alkali and 1-3% catalyst (based... 

---