China
Africa
Explore chapters and articles related to this topic
Comparison of Healing Effect of DMSP in Green Sea Algae and Mesenchymal Stem Cells on Various Inflammatory Disorders
Published in Se-Kwon Kim, Marine Biochemistry, 2023
3-Dimethyl-2-carboxyethyl sulfonium (dimethylsulfoniopropionate [DMSP]) (C5H10O2S, M.W. 134.04) is a tertiary sulfoniopropionate (sulfobetaine) zwitterion. The compound is synthesized by equimolar amounts of dimethylsulfide and propionate (halide) by refluxing under moderate temperature for about half a day. The compound is very soluble in water and methyl alcohol but insoluble in etylether. The products were identified by Nuclear magnetic resonance (NMR), Infrared absorption spectrometry (IR), elemental and mass analysis or x-ray or thermal-degradation. The element analysis of DMSP exhibited 99% purity. The compound has, in particular, the highest substrate specificity for the enzyme, dimethylthetine- and betaine-homocysteine methltransferase [E.C.2.1.1.3. and 2.1.1.5.], and the most active structure among closely related compounds for the attraction of feeding behaviors in fish (Nakajima, 1996).
Membrane Materials for Vanadium Redox Flow Battery
Published in Sam Zhang, Materials for Energy, 2020
A few other modification methods are listed below. Ma et al. (2013) prepared the Nafion-g-DMAEMA composite membranes by radiation-induced graft copolymerization of the N, N-dimethylaminoethylmethacrylate (DMAEMA). The Nafion-g-PSSA was synthesized via the oxygen plasma induced grafting with poly(styrenesulfonic acid) (PSSA) (Yang et al. 2017). The Nafion-g-PSBMA was produced by grafting the zwitterionic sulfobetaine methacrylate (SBMA) onto Nafion via surface-initiated atom transfer radical polymerization (SI-ATRP) technique (Dai et al. 2018). Zhang and co-workers fabricated the Nafion/GO hybrid membranes by spin-coating the cross-linked GO layer onto the Nafion (Zhang et al. 2019). The membranes with angstrom-scaled channels could efficiently repel the vanadium ion permeability. In addition, surfactant treatment is also an effective technique to enhance the Nafion membrane. Teng and co-workers compared three kinds of surfactants for treating Nafion membranes for the VRFBs, i.e., tetramethylammonium bromide (cationic), sodium dodecyl sulfate (anionic), and Triton X-100 (non-ionic) (Teng et al. 2014). The micellar pore structure can be changed by the surfactants and further influence the transport of redox couples through the membrane. The Triton X-100-modified Nafion membranes exhibited the best performance among them.
Daily Applications of Systems with Wormlike Micelles
Published in Raoul Zana, Eric W. Kaler, Giant Micelles, 2007
Shmaryahu Ezrahi, Eran Tuval, Abraham Aserin, Nissim Garti
Considering this demand for high foaming, it is clear that a shower gel, which is intended to clean the entire body, must foam intensively, delivering a large amount of foam per dose.48 Foam boosters (or stabilizers), usually varying in amount from 2 to 5 wt%, are added to improve lather quality. These boosters, usually fatty acid mono and dialkanolamides, strengthen the surfactant film enveloping each bubble so that the quality and longevity of the foam is improved.48 Yet, as was formerly alluded, alkanolamides contain free diethano-lamine which is thought to be linked to the formation of nitrosamines in the presence of nitrosating agents. Amineoxides suffer from the same problem. Besides monitoring nitrosamines content and inhibiting their formation when using N-containing foam boosters, this problem can also be solved by using substituents such as fatty acid polyglycol ester sulfates,50 organo sulfobetaine zwitterion, siloxane based surfactant compounds,51 polymers, protein-fatty acid condensates, and proteins.35
Studies on interfacial interactions between petroleum sulfonate and sulfobetaine molecules by rheological measurements
Published in Journal of Dispersion Science and Technology, 2021
Zhao-yang Guo, Xu-long Cao, Lan-lei Guo, Zhi-yi Zhao, Bao-dong Ma, Lei Zhang, Lu Zhang, Sui Zhao
In this paper, the zwitterionic surfactant alkyl sulfobetaine (ASB) was synthesized by our laboratory with purity more than 95% and checked by 1 H NMR spectroscopy. Scheme 1 shows the structural formula of ASB. The anionic surfactant of petroleum sulfonate (KPS) used in this paper was obtained from Kelamayi oilfield of China. Kerosene was further purified by glass chromatography column filled with the silica gel layer until the stable interfacial tension between kerosene and water reaches about 40 mN/m. Ultrapure water with 18.2 MΩ•cm resistivity was used in the preparation of the simulate water, which was employed to prepare surfactants solution for the experiments. The compositions of the formation brine with a TDS of 10260 mg/L were reported early.[7]