The cloud-point phenomenon in the solutions containing a mixture of nonionic and amphoteric surfactants

摘要

Crystal violet was recovered from aq.2-5 mg/l.solns.by cloud-p.extn.with oxyethylenated(n =9)methyl dodeca-noate as nonionic and cocamidopropyl betaine as zwitte-rionic surfactant.The dye was recovered(2500 rpm)in 92.1%.from the system contg.dodecanoate 2.5,betaine 0.5%,and NaCl 1 mol/l;heating time 6 hrs,The formation of the dye-contg.surfactant phase was incomplete.The water phase contained surfactant-rich agglomerates.NaCl reduced the time of formation and the size of the sepg.agglomerates.In solns.contg.the two surfactants,betaine concn.(should not exceed 0.5%)controlled the cloud p.In aq.01-5% betaine solns.,no cloud p.occurred over 0-100deg C.