Synthesis And Wettability Evaluation Of Quaternary Ammonium Tetramer Surfactant

In this paper,three different type quaternary ammonium tetrameric surfactant were synthesized by using ethylenediamine epichlorohydrin as the initial reactant.After the first reaction,the products were reacted with N,N-dimethyl-dodecyl tertiary amine,N,N-dimethyl-tetradecyl tertiary amine,N,N-dimethyl-hexadecyl tertiary amine,respectively.Their basic physical and chemical properties and wettability were evaluated.The structure of the product was characterized by infrared and the experimental results showed that the structure of the product was consistent with the theoretical structure.The Krafft points of the three different quaternary ammonium salt tetrameric surfactants are all below zero.They have good compatibility with cationic surfactant CTAB and non-ionic surfactant APG.Their emulsifying capacity is higher than cationic surfactant CTAB.Using C12 QATS,C14 QATS,C16 QATS and CTAB processing quartz surface.When their concentration reaches critical micelle concentration,the contact angle is the largest.They are 73.4 °,81.5 °,88.1 ° and 82.5 °.Subsequently,the contact angle decreases with the increase of concentration.C16-QATS has the best ability to change the wettability of the quartz surface.The wetting mechanism of surfactant on solid surface was analyzed by SEM and AFM.Clean quartz surface is hydrophilic.Due to electrostatic attraction,cationic surfactant molecules adsorbed on the surface of quartz.The hydrophobic surfactant molecules toward the outside make the surface of quartz less hydrophilic.Wettability of quartz surface is close to neutral.The adsorption state of the surfactant on the surface of quartz is monolayer adsorption.Under the condition of low concentration,the adsorption state of surfactant on quartz surface is single-layer adsorption.With the increasing of the concentration of surfactant,the adsorption changes from single-layer adsorption to double-layer adsorption.