To obtain more stable W/O emulsion for liquid surfactant membrane technique, a series of glutamic acid dialkyl esters and dialkyl type quaternary ammonium salts as new surfactants in place of Span 80 and polyamine were synthesized. The adsorption equilibria between aqueous solution and organic solution containing the synthesized surfactants were elucidated and the stability of liquid surfactant membrane made of these surfactants was examined in a stirred tank. A series of synthesized surfactants having two long alkyl chains in hydrophobic site gave more stable emulsion at a lower concentration compared with Span 80 and polyamine. Among them, glutamic acid dioleyl ester formed the most stable emulsion.
The effects of additives on the filling process of high-aspect-ratio Through Silicon Via (TSV) have been studied by the kinetic Monte Carlo (KMC) simulation. We included accelerators, suppressors, and levelers in the solution. The synergistic effect of suppressors and levelers is taken into account. We used three kinds of waveforms of the applied current: the pulse current, the pulse reverse current, and the 2-step current (the combination of the pulse current and the pulse reverse current). We confirmed that the dependence of the filling pattern on the leveler concentration corresponds to the experimental results. It is found that the initial distribution of additives plays an important role in the filling. The dependence of filling efficiency on waveforms is also studied. We succeeded in the void-free filling of 12 aspect ratio via(10μm×120μm) by using 2-step current.
It is important to economically recover oxometallic ions such as Mo(VI), V(V), and Au(III) from industrial wastewater because these ions are essential for advanced technology. In our previous article, we found that cedar bark can effectively adsorb oxometallic anions. In this article, we prepared filter paper that contained metal-adsorptive cedar bark for easy handling and for the prevention of secondary contamination of treated water. It was found that filter paper with cedar bark adsorbs oxometallic and tetrachloroauric anions. Cation-exchanging adsorption ability for the filter paper with cedar bark, except for Fe adsorption, became significantly lower than that of cedar-bark powders. However, for anion-exchanging adsorption, such as Mo(IV), V(V), and Au(III), the extent of decrease in the adsorption corresponded to the mass fraction of the cedar bark in the filter paper, indicating the preferred adsorption of metal having the anion-exchanging mechanism. In addition, the adsorption of Au ions on the filter paper containing cedar bark was accompanied by their reduction to zero-state Au, resulting in the formation of gold metal microparticles on the adsorbent surface.
Extraction and stripping of copper with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester dissolved in n-heptane were carried out at 303 K in both a stirred transfer cell and a membrane extractor using a hollow fiber, along with a study of the interfacial adsorption equilibria of extractant and copper complex between aqueous and organic solutions. These results obtained by use of both the stirred transfer cell and the membrane extractor were explained by a diffusion model with interfacial reaction.
Fibroblast growth factor-21 (FGF-21) is a metabolic regulator with beneficial effects on glucolipid metabolism. Since FGF-21 has lipid-lowering, anti-inflammatory and anti-oxidant properties, it may play a protective role against atherosclerosis. However, blood FGF-21 levels in coronary artery disease (CAD) or peripheral artery disease (PAD) have not been elucidated.
A kinetic study concerning the stripping of copper chelate complex in toluene with hydrochloric acid was carried out at 303 K, using a stirred transfer cell and pure copper complex prepared from copper and synthesized N-8-quinolyl-p-dodecylbenzenesulfonamide. It was found that the mechanism of copper stripping could not be explained as simply a reverse process of the copper extraction by this extractant from acetate buffer media, due to the reaction between the extractant and hydrochloric acid and the low solubility of the ion pair complex formed by this reaction. Moreover, it was confirmed that the stripping rate was determined by the first step of the interfacial reaction between the copper complex and the acid, and by mass transfer of the copper complex.
