Highly and Fully Water Dilutable Sustainable Microemulsions with Dibasic Esters as Oil Phase

Abstract

In this study, we show a strategy of formulating highly and fully water dilutable sustainable microemulsions with dibasic esters as oil pseudophase. First, dimethyl or diethyl DBEs with different numbers of carbon atoms between the ester functions (succinate C2, glutarate C3, and adipate C4) or DBE blends and a surfactant–cosurfactant melt consisting of sodium dodecylsulfate and 1-pentanol with a constant weight ratio of 1:2 are used. We investigated the extent of the realms of existence of homogeneous single phases and represent them with pseudoternary phase diagrams. It was possible to formulate fully water dilutable oil-rich single-phase solutions with all dimethyl dibasic esters but not with the diethyl ones. By mixing the most hydrophilic dibasic ester with the most hydrophobic one with a mass ratio of 3:2, a fully water dilutable oil-rich single phase could also be obtained. The presence of water-in-oil, bicontinuous, and oil-in-water microemulsions was checked with conductivity and dynamic light scattering measurements. A percolative behavior was observed for all systems. Second, to formulate green and sustainable microemulsions, we replaced successively sodium dodeylsulfate by sodium oleate and 1-pentanol by ethanol or 1,5-pentanediol. With sodium oleate, highly water dilutable microemulsions were obtained. Homogeneous and translucid samples in the very diluted area turned bluish after several days. Longtime pH measurements of systems containing sodium oleate showed no degradation of the dibasic esters at low water content and a rapid hydrolysis at high water content with 1-pentanol as cosurfactant. Always in presence of sodium oleate, the substitution of 1-pentanol by ethanol or 1,5-pentanediol drives the system to microemulsions showing an instability of the ester at any water concentrations. Thermal gravimetric analysis measurements at 32 °C for 24 h confirmed a rapid evaporation of ethanol and water and negligible evaporation of 1,5-pentanediol.

Molecular Dynamics Simulation Insight into Interfacial Stability and Fluidity Properties of Microemulsions

“…The microemulsions assembled from monochain surfactants need the usage of cosurfactants indispensably. Medium length alkyl alcohols with four or five carbon atoms are generally considered to be suitable as cosurfactants, which promote the formation of microemulsions accompanied by synergistic effects. , However, the massive usage of cosurfactants with high cost generally limits their industrial applications.…”

Oil-in-water microemulsion containing ferrocene: A new fire suppressant

“…By definition, oil-in-water (O/W) "macroemulsions" are heterogeneous, opaque, and thermodynamically unstable systems in which oil droplets will coalesce, eventually leading to phase separation. In contrast, oil-in-water "microemulsions" have nano-sized oil droplets and are macroscopically homogeneous and thermodynamically stable systems; they also have some distinguishing physicochemical properties: optical transparency, isotropy, and low viscosity [18]. The present work focuses on the fire-suppression capability of ferrocene-containing microemulsions.…”

Benign Fabrication of Fully Stereocomplex Polylactide with High Molecular Weights via a Thermally Induced Technique

“…DBE is known as a low-risk green solvent that is derived from biomass which is biodegradable. 17,18 DBE solution provides an environment beneficial to the formation of stereocomplex crystals. On the basis of previous studies, the thermally induced technique is reported to be an easy scalable method, which separates the mixture solution into two phases (polymer-rich/polymer-lean phase) either by exposing the solution to an immiscible solvent or by cooling the solution below its solubility temperature.…”

“…In this paper, we reported the preparation of complete high molecular-weight (HMW) SCPLA using the thermally induced technology with dibasic ester (DBE) as medium. DBE is known as a low-risk green solvent that is derived from biomass which is biodegradable. , DBE solution provides an environment beneficial to the formation of stereocomplex crystals. On the basis of previous studies, the thermally induced technique is reported to be an easy scalable method, which separates the mixture solution into two phases (polymer-rich/polymer-lean phase) either by exposing the solution to an immiscible solvent or by cooling the solution below its solubility temperature. − This whole system reduced the temperature of preparation of SCPLA, which effectively inhibited the PLA degradation and reduced the energy consumption.…”