Synthesis, Characterization and Investigation of Different Properties of Three Novel Thiourea-Based Non-ionic Surfactants

摘要

Three novel thiourea-based non-ionic surfactants, 3-decanoyl-1,1-diphenylthiourea, 3-dodecanoyl-1,1-diphenylthiourea and 1,1-diphenyl-3-tetradecanoylthiourea were synthesized from carbonyl chlorides, potassium thiocyanate and amines in high yield. The synthesized compounds were characterized by different techniques like ~1H NMR, ~(13)C NMR, FTIR and UV-Visible spectrophotometry. These surfactants are soluble in nonpolar and polar organic solvents and resist solubility in water due to the presence of thiourea group. Electronic absorption spectroscopy was used to evaluate their critical micelle concentration (CMC) in different solvents. The CMC was found to decrease with increase in hydrophobic carbon chain length as expected. Moreover, the effect of pH on their spectral transition was investigated and the two peaks were found to merge in highly alkaline conditions.