Preparation And Properties Of Anionic Silicone Surfactants

Silicone surfactants have drawn much attention due to the special surface properties.However,few anionic silicone surfactants were reported for lack of synthetic or purification methods.In the present work,many kinds of organic synthetic methods,such as thioester oxydation reaction,thiol-ene click reaction,P-R reaction and grignard reagent reaction were introduced to gain serial anionic silicone surfactants which contained different hydrophobic or hydrophilic part.Surface properties and aggregation behaviors of gained sulfonated and carboxylated salts were systemically investigated via surface tension,conductivity,TEM,DLS,contact angle,and fluorescence steady quenching tests.It could be seen that the surfactant property is influenced by the hydrophobic segment of surfactants structure.By studying these data,it can provide reference for the application of anionic silicon surfactant in practical production.This dissertation is divided into six parts as follows:The first part,the types,synthesized methods,application fields and study progress of silicone surfactants are summarized.The second part,a series of sulfonate silicone surfactants with different hydrophobic groups are designed and synthesized.The results of 1H NMR,FT-IR,and ESI-MS indicate that these anionic silicone surfactants are objective products.The third part,the surface activity and aggregation behavior of MeSi4K,MeSi3K,EtSi3K,PhSi3K,MeSi2K were systematically investigated by surface tension,electrical conductivity and TEM.The results indicated that the aqueous behavior of the surfactants was distinctly influenced by the hydrophobic groups.The ?CAC results of these five sulfonate silicone surfactants following the order:MeSi4K<MeSi3K<MeSi2K<EtSi3K<PhSi3K.The contact angle testing result indicated that MeSi4K performed excellent super spreading property that the contact angle of MeSi4K solution could be reduced to 0°within 30 seconds.The fourth part,the impact of counterions on the sulfonate silicone surfactants,MeSi4K,MeSi4Na,MeSi4Li was investigated by surface tension,DLS,and TEM tests The results showed that the counterions affect the surface activity and the aggregation behavior obviously.The CAC values and the Amin following the order:MeSi4K<MeSi4Na<MeSi4Li.The K+with smaller hydrated ion radius than Na+,and Li+permite a better surface activity of MeSi4K.This sulfonate surfactant in aqueous solution could form spherical vesicles spontaneously,and the size of the vesicles ranging from 200 nm to 400 nm could be adjusted by changing the counterionsThe fifth part,a series of carbonate silicone surfactants with different hydrophobic groups are designed and synthesized.The results of 1H NMR and ESI-MS indicate that these anionic silicone surfactants are objective products.The sixth part,the impact of hydrophobic groups and silicone skeleton on the surface activity and aggregation behavior of Si3O-COONa,Si2O-COONa,Si3C-COONa,Si2C-COONa was investigated by surface tension,electrical conductivity,and fluorescence steady quenching method.All the carbonate surfactants have excellent surface activities reducing the surface tension of water to 20.0 mN/m,that we attribute to the silicone hydrophobic structure.The hydrolysis resistance of carbosilane based carboxylate surfactant was better than that of siloxane-based carboxyl ate surfactant.The differences of hydrolysis processes for the surfactants were confirmed by mass spectrum and dynamic stability analysis.Meanwhile,the aggregation number(Nagg)of Si-C-Si surfactant(48.0)was determined by the fluorescence quenching method for first time.