Adsorption and Aggregation behaviors of tetrasiloxane-tailed gemini surfactants with (EO)m spacers.

Adsorption and aggregation behaviors of novel tetrasiloxane-tailed gemini surfactants N,N'-ditetrasiloxane-N,N'-digluconamide oligo ethylene glycol diglycidyl (Si-m-Si, where m is the number of ethylene glycol of 1, 2, and 3) were investigasted using surface tension, bromophenol blue encapsulation, dynamic light scattering (DLS), and transmission electron microscope (TEM) methods. The static surface tension of the aqueous Si-m-Si solutions measured at the critical aggregate concentration (CAC) was observed to be lower than that of traditional hydrocarbon gemini surfactants. This suggests that these newly synthesized gemini surfactants are capable of forming a closely packed monolayer film at the air/aqueous solution interface.

Adsorption and aggregation behavior of tetrasiloxane-tailed surfactants containing oligo(ethylene oxide) methyl ether and a sugar moiety.

Three novel amphiphilic dicephalic (double-headed) surfactants containing oligo(ethylene-oxide)methyl-ether and a sugar moiety TGA-m (m = 1, 2, and 3) that incorporate a tetrasiloxane at the terminus of a hydrocarbon chain were designed and synthesized. Their surface activity and aggregation behavior in aqueous solution were systematically investigated by surface tension, dynamic light scattering (DLS), and transmission electron microscopy (TEM) techniques at 298 K. The surface tension measurements provided the critical aggregation concentration (CAC) and the surface tension at the CAC (γ(cac)).

Carbohydrate-modified siloxane surfactants and their adsorption and aggregation behavior in aqueous solution.

Four carbohydrate-modified siloxane surfactants, Si(n)N-GA and Si(n)N-LA (n = 3, 4), were designed and synthesized. Their surface activities, adsorption, and aggregation behavior in aqueous solution were investigated by surface tension measurements, dynamic light scattering (DLS) and transmission electron microscopy (TEM). Due to the bulky siloxane moiety at the end of hydrophobic chains, the surfactant solutions displayed low critical aggregation concentration (cac) and low surface tension.

Effect of temperature on dynamic rheological behavior of discontinuous cubic liquid crystal.

The dynamic rheological properties of discontinuous cubic liquid crystal, formed by nonionic surfactant C(12-14)E(12), were investigated in the discrete and continuous patterns of raising temperature. In the discrete pattern, the discontinuous cubic phase appears in two types of viscoelastic behaviors under the melting points of cubic phase: elastic gel and viscoelastic liquid. When the discontinuous cubic phase begins to melt, it has the weak polymer-like viscoelasticity.