Butynediol-ethoxylate based trisiloxane: Structural characterization and physico-chemical properties in water

A trisiloxane surfactant was synthesized with grafting butynediol ethoxylate onto hydrophobic heptamethyltrisiloxane. The structural analysis of this surfactant was done by 1H, 13C and 29Si NMR. The surface activity, adsorption kinetics, aggregation behaviors in aqueous solutions, and dynamic spreading performances of this siloxane amphiphile were investigated by surface tension, transmission electron microscopy (TEM), dynamic light scattering (DLS) and contact angle techniques at 298 K. The surface tension of this trisiloxane surfactant measured at critical aggregate concentration (CAC) was observed to be significantly lower than that of acetylenic diol based surfactants. Adsorption model for this amphiphile is diffusion-controlled model. Aggregates of this nonionic surfactant formed in aqueous solutions could be assigned as spherical assemblies as suggested by analysis using TEM and DLS. The spreading performances on low-energy Teflon film and paraffin film interface was studied by the contact angle measurement with sessile drop method and proved that it has a potential as spreading agents in industry.