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Membrane Materials Design Trends
Published in Andreas Sapalidis, Membrane Desalination, 2020
Shadia R. Tewfik, Mohamed H. Sorour, Abdelghani M.G. Abulnour, Hayam F. Shaalan, Heba A. Hani, Marwa M.H. El-Sayed, Yomna O. Abdelrahman, Eman S. Sayed, Aya N. Mohamed, Amany A. Al-Mansoup, Nourhan A. Shawky
Synthesis of PANI by chemical oxidation way involves the use of acid in the presence of ammonium persulfate as the oxidizing agent in the aqueous medium Chemical synthesis requires three reactants: aniline, an acidic medium (aqueous or organic) and an oxidant. The more common acids are essentially hydrochloric acid (HCl) and sulfuric acid (H2SO4). Ammonium persulfate ((NH4)2S2O8), potassium dichromate (K2Cr2O7), cerium sulfate (Ce(SO4)2), sodium vanadate (NaVO3), potassium ferricyanide (K3(Fe(CN)6)), potassium iodate (KIO3), hydrogen peroxide (H2O2) are recommended as oxidants (Malinauskas, 2001)
Polymer Technologies
Published in Ghenadii Korotcenkov, Handbook of Humidity Measurement, 2020
Chemical polymerization (oxidative coupling) is followed by the oxidation of monomers to a cation radical and their coupling to form dications. The repetition of this process generates a polymer, and all classes of conjugated polymers can be synthesized using this technique. Chemical polymerization is conducted with relatively strong chemical oxidants. The reaction is controlled by the concentration and oxidizing power of the oxidant. Chemical polymerization occurs in the bulk of the solution, and the resulting polymers precipitate as insoluble solids. The polymer formed by chemical synthesis is generally a black powder. Among all of the above-listed techniques, chemical polymerization is the most used for preparing large amounts of conductive polymers, such as polypyrrole, polythiophene, polyfuran, polyisothionapthalene, polyindole, polyaniline, polycarbazole, poly p-phenylene vinylene (PPV), and polypyrene (Gurunathan et al. 1999). Synthesis of polymers by oxidative coupling polymerization is a very easy and simple method (Malinauskas 2001). The procedure involves simple mixing of monomer and oxidant in aqueous or organic protonic acid solution. Commonly used oxidants are ammonium peroxydisulfate (APS), ferric chloride, hydrogen peroxide, permanganate or bichromate anions, cerium sulfate, etc. A comprehensive picture of the fundamentals of chemical polymerization may be obtained from some review reports (Waltman and Bargon 1986; Okamoto and Nakano 1994; Toshima and Hara 1995; Feast et al. 1996; Smith 1998; Corrigan et al. 2016; Ren et al. 2016; Pan et al. 2018).
Combustion Performance of Model Propellant with Boron and Boron-Containing Compounds
Published in WeiQiang Pang, Luigi T. De Luca, XueZhong Fan, Oleg G. Glotov, FengQi Zhao, Boron-Based Fuel-Rich Propellant, 2019
WeiQiang Pang, Luigi T. De Luca, XueZhong Fan, Oleg G. Glotov, FengQi Zhao
The reagents used: Cerium sulfate, 0.20–0.25 N solution in 1 M sulfuric acid.Mohr's salt (ferrous ammonium sulfate), 0.20–025 N solution in 1 M sulfuric acid.Phenylanthranylic acid or ferroin (0.1% aqueous solution as indicator).
Aqueous stability relations in the hydrometallurgical processing of cerium bastnasite
Published in Mineral Processing and Extractive Metallurgy, 2022
Isehaq Al-Nafai, K. Osseo-Asare
Referring to , it has a broad stability window that is slightly affected by the addition of sulphuric acid, which makes it a good corrosion inhibitor. Furthermore, is widely used in other applications such as insulators and polishing materials. can be produced by treatment of cerium sulphate with concentrated alkaline solutions (Brigante and Schulz 2012). As noted in Figure 6 diagrams, the conversion of to can be achieved by alkaline treatment as shown by Equation 17.