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Foam is used in many fields with excellent performance. Moreover, disinfectants with ethanol as the main ingredient have increasingly been used in people's lives. However, the foam research of an ethanol-water mixed system is still in the initial stage. In this work, a perfluoroalkyl polyoxyethylene ether phosphate salt surfactant (FEP-Na) was synthesized through a new molecular design. The surfactant has good interfacial adsorption behavior in 50% ethanol-water mixing system, and the approximately spherical aggregates are observed in the volume phase of the solution. Moreover, FEP-Na showed good foaming property in 50% ethanol-water mixed solution. Interestingly, high concentration solutions with high surface activity have lower foam stability. And under the microscope, we see that the bubble burst is dominated by the phenomenon of coalescence. In this regard, we explain the mechanism of foam stability by electrostatic double layer theory and interfacial dilation rheology. It provides a new choice for the synthesis of foaming agent in the ethanol-water mixed system at a concentration of 50%.

A series of meglumine-based polysiloxane surfactants, (PSim-n) with different numbers of meglumine branches were prepared. The formed surfactants were characterized by FT-IR and NMR techniques. Physiochemical properties, such as surface activity, aggregation behavior, and wettability, were closely examined and used to differentiate the various samples. The findings demonstrate that PSim-n surfactants possess high surface activity and can wet-out a parafilm surface at all but extremely low concentrations. Furthermore, PSi6-4, the surfactant with the highest meglumine concentration, can form larger complex aggregates in aqueous solutions.

Novel polysiloxane amphiphiles obtained by introducing coal-based amphiphiles (butynediol ethoxylate) into polysiloxanes based on hydrosilylation reaction by two steps: first, synthesizing hydride terminated polysiloxane with different degree of polymerization (HTP); second, butynediol-ethoxylate was grafted on hydride terminated polysiloxane at terminals to get bola coal-based polysiloxane amphiphiles (EO-PSi-EO). In our work, EO-PSi-EO were compared together to investigate the impacts of different ratios of hydrophilic and hydrophobic groups on its properties. A conclusion was obtained from the work that EO-PSi-EO with various hydrophobic backbones have low surface tension, rich aggregate behavior, excellent wetting property and low foam.

A novel cationic fluorinated surfactant, (PFP-AI), was synthesized via amidation and quaterisation successively with perfluorinated acyl fluride (PFPF) as starting material. Their structure was analyzed by FT-IR, 1 H NMR and 19 F NMR. The TG indicated the PFP-AI possess thermal stability with initiation decomposition temperatures about 217 °C. The physicochemical properties of PFP-AI were studied systematically by equilibrium surface tension, dynamic surface tension, dynamic light scatting measurement (DLS) and transmission electron microscopy (TEM). The results revealed the PFP-AI exhibited high surface activity ( γ cmc = 16.4 mN/m) and could aggregate into vesicles at the concentration of 4.15 mmol/L. Furthermore, contact angle measurements demonstrated that PFP-AI exhibited efficient wettability on the hydrophobic surface.

A simple process to synthesize polyglycerol modified polysiloxane surfactants has been carried out applying a “grafting-to” approach. After formation of allyl polyglycerol ether (APGE) from diglycerol (DGY) and allyl glycidyl ether (AGE), polysiloxane modified by designed number of polyglycerol groups (PHMS-APGE) were obtained by connecting the APGE structure to different Si H functionalized polyhydromethyl siloxane (PHMS). The synthesized APGE-PHMS were characterized by IR and 1H NMR. Solubility measurements showed that the solubility of the as-prepared polymers increased in polar solvents with the increasing of the amount of hydrophilic APGE groups. Furthermore, the surface activity, surface adsorption, aggregation and spreading behaviors of APGE-PHMS were investigated utilizing surface tension measurements, dynamic light scattering (DLS), transmission electron microscopy (TEM) and contact angle measurements. The results showed that critical aggregation concentration (CAC) and the time needed to reach adsorption equilibrium on water surface decrease systematically with the increase in the number of APGE groups. These polymers in aqueous solutions could aggregate to form spherical assemblies. Moreover, the spreading behavior of these polymers on low energy surface was found to be influenced by the number of hydrophilic APGE groups.

Sodium perfluoropolyether carboxylate (PFPE-Na) was synthesized via hydrolyzing the corresponding hexafluoropropylene oxide oligomer (PFPF). The structure of PFPE-Na was characterized by FT-IR and 19F NMR. The micellization and aggregation properties of PFPE-Na surfactant in aqueous solution were studied systematically using equilibrium surface tension, electrical conductivity, dynamic surface tension, steady-state fluorescence, transmission electron microscopy (TEM) and contact angle methodologies. The results of equilibrium surface tension at 25 °C showed that the critical micelle concentration (CMC) and the surface tension at CMC (γCMC) of PFPE-Na aqueous solution are lower than sodium perfluorooctanoate [NaPFO, C7F15COONa], which revealing that as a kind of environment-friendly surfactant, PFPE-Na is a perfect substitute of NaPFO. Electrical conductivity measurements implied that the micellization of PFPE-Na in aqueous solution was an exothermic and entropy-driven process in the range of temperature investigated. Steady-state fluorescence and transmission electron microscopy (TEM) may indicate that PFPE-Na self-assemble in aqueous solution to form larger spherical aggregates with the increase of concentration. In addition, dynamic surface tension measurements of PFPE-Na solution showed an extremely efficient adsorption at concentrations above CMC while the determination of contact angle of PFPE-Na showed the wetting ability was general.

The spontaneous vesicle formation from a novel trisiloxane-tailed gemini surfactant were reported. The surface tension measurements revealed that aggregates are formed, and dynamic light scattering (DLS) measurements suggested the aggregates are vesicles. The size and morphology were observed by transmission electron microscopy (TEM). The vesicle formation was further confirmed by dye entrapment studies.