Introduction of polyoxyethylene
The introduction of polyoxyethylene groups into ionic surfactant molecules helps to reduce the charge density of the molecules and thus weakens the strong electrostatic interactions between the ionic head groups. At the same time, due to the weak hydrophilicity and weak lipophilicity of the polyoxyethylene chain, it not only increases the polarity of the surfactant, but also increases the length of the hydrophobic group. The hydrophilicity and site-blocking effect of the polyoxyethylene chain attenuates the interaction between the positive and negative ionic surfactants, thus having a significant inhibitory effect on precipitation or coagulation.
Choice of Polar Groups – Alkyl Sulfonates
Salt instead of alkyl sulfate For single-component systems, the water solubility of alkyl sulfonates is obviously lower than that of alkyl sulfates, so it is customarily believed that when mixed with cationic surfactants such as alkyl quaternary ammonium salts, the water solubility of alkyl sulfonate-alkyl quaternary ammonium salt mixed systems is lower than that of alkyl sulfate-alkyl quaternary ammonium salt mixed systems. Therefore, when compounding with cationic surfactants, people generally do not use alkyl sulfonates. However, on the contrary, the water solubility of the sodium alkyl sulfate-alkyl quaternary ammonium salt hybrid system is much higher than that of the sodium alkyl sulfate-alkyl quaternary ammonium salt hybrid system.
In addition, from the point of view of sodium alkylsulfonate, the addition of the cationic surfactant alkyl triethyl quaternary ammonium salt increases the solubility of sodium alkylsulfonate and lowers its Krafft point. The Krafft point of the one-component system of sodium alkylsulfonate was higher. In other words, the addition of the cationic surfactant increased the solubility of the anionic surfactant.
Addition of amphoteric surfactant
Amphoteric surfactants are not as surface active as anionic and cationic surfactants. Adding it to the positive and negative ionic surfactant compounding system is conducive to improving the solubility performance of the compounding system.
Adding non-ionic surfactants
Adding non-ionic surfactants with larger solubility, the solubility of positive and negative ionic surfactants in water increases significantly. That is, the solubilizing effect of nonionic surfactant improves the solubility performance of positive and negative ion surfactants. And the nonionic surfactant has its own excellent washing performance, not ionized in aqueous solution, exists in a molecular state, and other types of surfactants have good compatibility, so it can be well mixed. Therefore, the addition of nonionic surfactant in the positive and negative ionic surfactant compounding system is not only conducive to the increase of solubility of the compounding system, but also can play a double role in enhancing the washing effect.
Anionic surfactant-based, adding a small amount of cationic surfactant, and sometimes the appropriate amount of nonionic surfactant auxiliary, it is possible to get a better performance, reasonable price, high efficiency compounding formula products.
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