Study On The Stabilization Of Non-aqueous Foam By Surface Modification Of Nanoparticles

Non-aqueous foam is widely used in petrochemical,food and cosmetics,etc.However,the formation of non-aqueous foam is difficult due to the low surface tension and dielectric constant of non-aqueous solvent,which affects the development of related industries.Nano-silica particles have the advantages of large specific surface area and good thermal stability,and have attracted more and more attention in the field of non-aqueous foams through surface modification.In this paper,by preparing nano-silica particles and modifying their surface wetness,the influence of nano-silica on the formation and stabilization of non-aqueous foam was studied,the mechanism of stabilizing the foaming was revealed,and the stabilization of nano-sio₂on non-aqueous foaming was realized.The following research work was carried out:1.Using L-arginine as basic catalyst,nano-sio₂particles were prepared as"seeds",and then"seed re-growth"was carried out by St（?）ber method with the aid of seed regeneration principle.By adjusting the reaction conditions of the seed regeneration stage,nano-silica particles with particle size between 10 nm and 180 nm were prepared.The microstructure and structure of nano-silica particles were analyzed by TEM,FT-IR and XRD.2.Surface modification of nano-silica particles 1H,1H,2H,2H-perfluorodecyl triethoxysilane（PFDTES）,3-（glycidyl oxypropyl）trimethoxysilane（GPTMS）and octanol were performed.The effects of reaction time,reaction temperature and dosage of modifier on surface wettability and hydroxyl group number of nano-silica particles were studied,and the wettability of nano-silica particles after modification was characterized.3.Study the effect of nano-silica particles modified by PFDTES on the formation and stabilization of non-aqueous foam.By adjusting the wetability,particle size and concentration of nano-silica particles in non-aqueous solvent,the stabilization of non-aqueous foam was realized.With the increase of solvent polarity,the optimal contact Angle of nano-silica increases.When the contact Angle of nano-silica particles is 60.3°,79.5°and 92.3°respectively,the particle size is 10 nm,and the concentration is 7 wt%,the foamability of nano-silica in strong polarity,medium polarity and non-polar solvents is the best,and the air holding rate of the foam formed is up to 80%.The stability is up to 65 days.4.Study the effects of solvent polarity,surface tension and viscosity on the formation and stabilization of non-aqueous foam.With the increase of solvent polarity,decreasing value of surface tension and viscosity,the foaming performance of nano-silica particles in non-aqueous solvent is gradually enhanced,the air holding rate of the foam is gradually increased,and the stability of the foam is gradually enhanced.When the foaming performance is the best,the foam formed has the highest gas holdup and the strongest stability.