Benchmarking the Self‐Assembly of Surfactin Biosurfactant at the Liquid–Air Interface to those of Synthetic Surfactants

Abstract

The adsorption of surfactin, a lipopeptide biosurfactant, at the liquid–air interface has been investigated in this work. The maximum adsorption density and the nature and the extent of lateral interaction between the adsorbed surfactin molecules at the interface were estimated from surface tension data using the Frumkin model. The quantitative information obtained using the Frumkin model was also compared to those obtained using the Gibbs equation and the Langmuir–Szyszkowski model. Error analysis showed a better agreement between the experimental and the calculated values using the Frumkin model relative to the other two models. The adsorption of surfactin at the liquid–air interface was also compared to those of synthetic anionic, sodium dodecylbenzenesulphonate (SDBS), and nonionic, octaethylene glycol monotetradecyl ether (C14E8), surfactants. It has been estimated that the area occupied by a surfactin molecule at the interface is about 3- and 2.5-fold higher than those occupied by SDBS and C14E8 molecules, respectively. The interaction between the adsorbed molecules of the anionic biosurfactant (surfactin) was estimated to be attractive, unlike the mild repulsive interaction between the adsorbed SDBS molecules.

Evaluation of the saponin green extraction from Ziziphus spina-christi leaves using hydrothermal, microwave and Bain-Marie water bath heating methods

“…Biosurfactants are biologically produced using numerous microorganisms or isolated from different plants and their derivatives. Biosurfactants have two main functional groups in their structure namely, hydrophobic and hydrophilic parts [3][4][5][6][7]. As compared to synthesized and commercial surfactants, biosurfactants have several advantages including being environmental friendly, higher surface tension reduction, biodegradability and selectivity in room temperature and normal pH, as well as lower toxicity [3,[5][6][7].…”

“…Biosurfactants have two main functional groups in their structure namely, hydrophobic and hydrophilic parts [3][4][5][6][7]. As compared to synthesized and commercial surfactants, biosurfactants have several advantages including being environmental friendly, higher surface tension reduction, biodegradability and selectivity in room temperature and normal pH, as well as lower toxicity [3,[5][6][7]. Due to their excellent emulsification, foamability, water binding capacity and wetting properties, biosurfactants have been widely used in different industries and products such as cosmetics, food, medicine, pharmaceuticals, and oil and gas production processes [8].…”

Production of Saponin Biosurfactant from Glycyrrhiza glabra as an Agent for Upgrading Heavy Crude Oil

“…Like other surfactants [1][2][3], biosurfactants consist of both hydrophobic and hydrophilic functional groups. Biosurfactants have many advantages over commonly used commercial surfactants such as surface tension reduction, higher biodegradability, lower toxicity, preferable environmental compatibility, high selectivity and specific activity at extreme salinity, temperatures and pH [1,[4][5][6]. Rhamnolipids and surfactin are the main group of microbial biosurfactants [7].…”

“…The diverse physicochemical and biological properties of saponins have been successfully exploited as emulsifiers and sweeteners in the food industry, the pharmaceutical industry, agricultural and cosmetics and in rare cases the oil industry [11]. For instance, saponin extracted from Saponaria officinalis, the native European soapwort wild flower, is used by commercial oil industries for enhanced oil recovery and oil spill clean-up [5,21]. It seems that saponin could be a suitable and inexpensive emulsifier for reduction of the viscosity of heavy crude oil.…”

Enhanced oil recovery from high‐salinity reservoirs by cationic gemini surfactants

“…BA‐14 solutions of 500 mg/L, 1000 mg/L, 2000 mg/L, and 3000 mg/L were prepared with a concentration of 60 g/L NaCl. At the same time, the adsorption of 1000 mg/L trimethyl tetradecyl ammonium chloride and sodium lauryl sulfate solutions were tested for comparison . Reservoir sand in the amount of 6.0 g was placed in a 250 mL conical flask, 150 mL of sample solution was added, and then the flask was balanced on a shaking table for 24 h.…”