Preferential adsorption of cations and anions of mixed electrolytes on aqueous surfaces

1985 ◽  
Vol 89 (7) ◽  
pp. 1140-1147 ◽  
Author(s):  
Shoichi Ikeda ◽  
Hideshi Okuda
2019 ◽  
Vol 123 (27) ◽  
pp. 16711-16720 ◽  
Author(s):  
Max F. Döpke ◽  
Johannes Lützenkirchen ◽  
Othonas A. Moultos ◽  
Bertrand Siboulet ◽  
Jean-François Dufrêche ◽  
...  

1995 ◽  
Vol 60 (10) ◽  
pp. 1641-1652 ◽  
Author(s):  
Henri C. Benoît ◽  
Claude Strazielle

It has been shown that in light scattering experiments with polymers replacement of a solvent by a solvent mixture causes problems due to preferential adsorption of one of the solvents. The present paper extends this theory to be applicable to any angle of observation and any concentration by using the random phase approximation theory proposed by de Gennes. The corresponding formulas provide expressions for molecular weight, gyration radius, and the second virial coefficient, which enables measurements of these quantities provided enough information on molecular and thermodynamic quantities is available.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 208
Author(s):  
Ramona B. J. Ihlenburg ◽  
Anne-Catherine Lehnen ◽  
Joachim Koetz ◽  
Andreas Taubert

New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further.


2017 ◽  
Vol 1 (7) ◽  
Author(s):  
Wenjie Wang ◽  
Honghu Zhang ◽  
Surya Mallapragada ◽  
Alex Travesset ◽  
David Vaknin

2021 ◽  
Author(s):  
Yaping Zhang ◽  
Daofei Lv ◽  
Jiayu Chen ◽  
Zewei Liu ◽  
Chongxiong Duan ◽  
...  

The separation of ethylene/ethane mixture using energy-efficient technologies is important but challenging. Here, we prepared a Zr-based metal-organic framework (MOF-545) possessing high Brunauer-Emmett-Teller (BET) surface area of 2265.4 m2/g, and...


2021 ◽  
Author(s):  
M. Hegemann ◽  
P. P. Bawol ◽  
A. Köllisch-Mirbach ◽  
H. Baltruschat

AbstractIn order to advance the development of metal-air batteries and solve possible problems, it is necessary to gain a fundamental understanding of the underlying reaction mechanisms. In this study we investigate the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER, from species formed during ORR) in Na+ containing dimethyl sulfoxide (DMSO) on poly and single crystalline Pt and Au electrodes. Using a rotating ring disk electrode (RRDE) generator collector setup and additional differential electrochemical mass spectrometry (DEMS), we investigate the ORR mechanism and product distribution. We found that the formation of adsorbed Na2O2, which inhibits further oxygen reduction, is kinetically favored on Pt overadsorption on Au. Peroxide formation occurs to a smaller extent on the single crystal electrodes of Pt than on the polycrystalline surface. Utilizing two different approaches, we were able to calculate the heterogeneous rate constants of the O2/O2− redox couple on Pt and Au and found a higher rate for Pt electrodes compared to Au. We will show that on both electrodes the first electron transfer (formation of superoxide) is the rate-determining step in the reaction mechanism. Small amounts of added Li+ in the electrolyte reduce the reversibility of the O2/O2− redox couples due to faster and more efficient blocking of the electrode by peroxide. Another effect is the positive potential shift of the peroxide formation on both electrodes. The reaction rate of the peroxide formation on the Au electrode increases when increasing the Li+ content in the electrolyte, whereas it remains unaffected on the Pt electrode. However, we can show that the mixed electrolytes promote the activity of peroxide oxidation on the Pt electrode compared to a pure Li+ electrolyte. Overall, we found that the addition of Li+ leads to a Li+-dominated mechanism (ORR onset and product distribution) as soon as the Li+ concentration exceeds the oxygen concentration. Graphical abstract


2014 ◽  
Vol 47 (12) ◽  
pp. 4048-4055 ◽  
Author(s):  
Jose Alonzo ◽  
Juan Pablo Hinestrosa ◽  
Jimmy W. Mays ◽  
S. Michael Kilbey

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