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Chemicals from Paraffin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Sulfonation is a chemical reaction in which the sulfonic acid functional group (SO3H) is introduced into a molecule (Michael and Weiner, 1936). For example, sulfonation with sulfur trioxide and sulfuric acid converts benzene into benzene sulfonic acid:
Adsorption of anionic dye by anionic surfactant modified chitosan beads: Influence of hydrophobic tail and ionic head-group
Published in Journal of Dispersion Science and Technology, 2018
Cuiying Lin, Shuo Wang, Haoqi Sun, Rong Jiang
The adsorption of dyes onto CS beads has been studied in a large number of literatures, and many results demonstrated that the adsorption behaviors depend mainly on electrostatic interaction and physical adsorption.[17,18] To further improve adsorption capacity of chitosan beads, it would be better to consider some other interaction between CS beads and dyes. In previous investigations, conventional surfactants were used to modify chitosan, and it was found that hydrophobic interaction may play an important role in the adsorption.[192021] It is well known, that the surfactant has hydrophilic head-group and hydrophobic tail chain, so ionic interaction and hydrophobic interaction might both be involved in the adsorption process. In order to better understand the effect of the hydrophobic interaction, anionic surfactant was the choice to be investigated for the removal of anionic dyes from aqueous solution. Although the negatively charged “head” of anionic surfactants is apparently disadvantageous to the adsorption of anionic dyes for the electrostatic repulsions, ionic head-group is involved in the micelle formation and micelle characteristics such as micelle size. In order to investigate the role of ionic head-group, different anionic head-group surfactants like sodium dodecyl sulfate (SDS), sodium dodecyl sulfonate (SDOS), and dodecyl benzenesulfonic acid sodium salt (SDBS) were used to modify the CS beads in this study.
Investigation of the correlation between molecular structures with high-temperature and salt resistance for acrylamides polymer in drilling fluid
Published in Journal of Dispersion Science and Technology, 2023
Yuanzhi Qu, Wenchao Zhang, Han Ren, YueHui Yuan, Xinyu Zhou, Gang Yang, Xianfa Zhang
In contrast to the development and the failure mechanism of the previous anti-temperature and anti-salt polymeric filtration reducers,[33–35] this article presents a comparative analysis of the relationship between six polymers containing different functional groups and their anti-temperature and anti-salt performance in water-based drilling fluids from the perspective of molecular structure, and the conclusions are obtained as follows.For the prepared acrylamide-based copolymers, the pyrrole ring groups, quaternary amine groups, long-chain sulfonate groups, and benzenesulfonic acid are effective in improving the stability of the polymer at high temperatures in aqueous solutions. In contrast, a single sulfonic acid group is less effective in improving stability.The sulfonic acid groups, carboxylic acid groups, and other hydration groups can better maintain the colloidal stability of drilling fluids at high temperatures. Thus the clay possesses a small particle size and excellent dispersion, which is conducive to forming a dense mud cake of drilling fluids and reducing the filtration.Under HTHS conditions, the quaternary ammonium groups and pyrrole rings can enhance polymers’ adsorption on the clay surface due to charge attraction. However, they are harmful to clay dispersion and drilling fluid stabilization.In comparing the six functional groups, the benzenesulfonic acid group is the most optimal in improving the high-temperature and salt resistance of acrylamide copolymer in drilling fluid. The benzenesulfonic acid group can improve the high temperature stability of the polymer in aqueous solutions and the polymer adsorption on the clay surface, form a thicker hydration film on the clay surface, effectively resist the destructive effect of HTHS on the clay, and improve the performance of drilling fluid under HTHS conditions.
Effect of Nb doping on the structural, optical, and photocatalytic properties of SrTiO3 nanopowder synthesized by sol-gel auto combustion technique
Published in Journal of Asian Ceramic Societies, 2022
Pornnipa Nunocha, Malinee Kaewpanha, Theerachai Bongkarn, Apiluck Eiad-Ua, Tawat Suriwong
Thereby, the Ecb of the STNO samples are 0.01 V (vs.NHE) for x = 0, −0.07 V (vs.NHE) for x = 0.01, −0.14 V (vs.NHE) for x = 0.03, and −0.21 V (vs.NHE) for x = 0.05. The mechanism of photocatalytic decolorization of MB dye on STNO photocatalyst under UV irradiation is shown in Figure 10. The process of photocatalysis reaction can be partitioned into three steps. First, the photocatalysis of STNO is energized by UV light with photo-energy higher than the Eg of the photocatalysis to create photoinduced electrons (e−) and gaps (h+). The electron is produced when electrons from the valence band (VB) move to the conduction band (CB), during which process gaps within the valence band are produced (Eq. 11). Next, the e− and h+ respond with O2 and H2O (or OH−) to produce highly receptive hydroxyl radicals (OH•) and superoxide radicals (). The H2O or that are adsorbed on the surface of the photocatalysis are oxidized by the h+ to create (Eq.12). The O2 accompanying the adsorption on the surface by the photocatalysis reacts with e− to generate the (Eq.13). In a further step, reacts with H2O to produce hydroperoxyl radical () (Eq.14). Finally, these hydroxyl radicals, superoxide radicals, and hydroperoxyl radicals decompose the MB dye into CO2, H2O and degraded products of MB, which could be 2-amino-5-(NN-methylformamide) benzene sulfonic acid, 2-amino-5-(methylamino)-hydroxybenzene sulfonic acid, and benzenesulfonic acid [55] (Eq.15). This entire process can be summarized in the following equations: