Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Structural changes of viscoelastic solutions of zwitterionic and anionic surfactant mixtures under the influence of simple salt

Różańska Sylwia, Warmbier Ewelina, Wagner Patrycja, Różański Jacek

Chemical and Process Engineering : New Frontiers

2023

Vol. 44, nr 2

art. no. e10

The paper presents the effects of sodium chloride on the rheological properties of aqueous solutions of cocamidopropyl betaine (CAPB) and sodium dodecylbenzene sulfonate (SDBS) mixtures. Studies were carried out in the CAPB/SDBS molar ratio range of 0.95 to 3.5, at sodium chloride concentrations varying from 0.03 M to 0.75 M. Continuous and oscillatory flow measurements showed that the impact of sodium chloride concentration on shear viscosity and relaxation time was closely linked to the CAPB/SDBS molar ratio. The maximum shear viscosity and the longest Maxwell relaxation time were obtained at the CAPB/SDBS molar ratio of 2. Based on CryoTEM images, it was determined that the shear viscosity and relaxation time peaks identified at a certain concentration of sodium chloride could be attributed to the transition of the entangled wormlike micellar network into branched wormlike micelles. Changes in the micellar microstructure accompanying modifications of the CAPB/SDBS molar ratio and sodium chloride concentration were accounted for on the basis of the packing parameter.

Pressure drops during the flow of solutions of cocamidopropyl betaine and cocamide DEA mixtures with the addition of ethylene glycol

Różańska Sylwia, Różański Jacek, Wagner Patrycja, Warmbier Ewelina

Polish Journal of Chemical Technology

2022

Vol. 24, nr 4

67--71

The paper presents the results of experimental studies on pressure drops during the flow of cocamidopropyl betaine (CAPB) and DEA cocamide solutions with the addition of ethylene glycol. The degree of drag reduction during the flow of the CAPB/DEA aqueous solution and with the 10% addition of ethylene glycol was similar. A significant reduction in pressure drops was also observed at the 20% concentration of ethylene glycol. However, the increase in the concentration of ethylene glycol resulted in the reduction of flow resistance at higher temperatures. The resistance of the micellar microstructure of CAPB/DEA solutions to mechanical degradation depends strongly on the pH level. Significant changes in flow properties were observed when the initial pH was alkaline. The solution with initial pH close to neutral was stable over time, though reduced resistance to degradation with time was also observed.