China
Africa
Explore chapters and articles related to this topic
Surfactant Solutions: Adsorption and Aggregation Properties
Published in E. D. Goddard, K. P. Ananthapadmanabhan, Interactions of Surfactants with Polymers and Proteins, 2018
The process of micellization itself is dependent on temperature in a complex way. For example, cooling of a micellar solution of SDS below 12°C results in the precipitation of the surfactant. Here, the concentration of the surfactant in solution is equal to the CMC. This temperature, referred to as the Krafft temperature or Krafft, point is the temperature at which the solubility of the surfactant equals the CMC and above this temperature the total solubility of the surfactant increases markedly because of the formation of micelles, but below it only surfactant monomers exist and therefore, the total solubility is drastically limited. A typical phase diagram for an anionic surfactant is given in Figure 15.
Synthesis, colloidal-chemical and petroleum collecting properties of new counterion coupled gemini surfactants based on hexadecylbis(2-hydroxypropyl)amine and dicarboxylic acids
Published in Journal of Dispersion Science and Technology, 2020
Ziyafaddin H. Asadov, Saida M. Huseynova, Gulnara A. Ahmadova, Ravan A. Rahimov, Seyran U. Sharbatov, Fedor I. Zubkov, Rana A. Jafarova
Cocogem surfactants obtained by chemical reaction between primary alkyl amines and dicarboxylic acids usually do not dissolve in water.[10,15] Noori et al.[16] obtained cocogem surfactants as a result of the interaction between tertiary amines and adipoyl chloride. According to their research, increasing the length of the chain in these surfactants decreases the water solubility properties even further and increases the Krafft temperature. As a result of their researches, Wang et al.[19] found that when the temperature of the water is above 50 °C, it significantly increases the surfactants’ solubility. In comparison to previous surfactants, the surfactants obtained in this research which are based on hydroxylamine are easy and economical to synthesize. Furthermore, these surfactants have high water-solubility. The reaction scheme for the synthesis of the surfactants is given below in Scheme 1:
Two new cationic Gemini surfactants: synthesis, surface activity, and applicability as a corrosion inhibitor
Published in Journal of Dispersion Science and Technology, 2023
Krafft temperature (Kt), the critical micelle temperature, is regarded as the minimum temperature at which ionic surfactants form aggregates.[17] When the temperature of the solvent is below the Kt, there are no micelles formed. The value of Kt for the prepared surfactant is below 0 °C, which manifests the surfactant possesses good water solubility. In addition, the solubility of 1 wt% surfactants in water at different temperatures is shown in the ESI.†
Performance and potential of bacterial biodegradation of polycyclic aromatic hydrocarbons from micellar solutions
Published in Environmental Technology Reviews, 2021
When the surfactant concentration exceeds a CMC at a temperature higher than its Krafft temperature, then surfactant molecules in an aqueous solution will aggregate to form micelles of colloidal-size, at which PAH molecules are entrapped inside the hydrophobic cores of the micelles, resulting in an improved apparent aqueous solubility of PAHs [108,109]. The structure of the surfactant, its HLB value, and its dose will have an effect on the distribution of PAH molecules in the system by emulsification or micellar solubilization.