The effect of changing the molecular structure of the surfactant on the dissolution of lamellar phases

The Effect of Mixtures and Additives on Dissolving Surfactant Lamellar Phases

Understanding the dissolution process of surfactant solutions is important in formulating product design processes. The main goal of this study is to gain further insights into how additives and mixtures affect surfactant dissolution processes. To achieve this goal, dissipative particle dynamic simulations were used. Lamellar phases at 80% volume of surfactant were initially equilibrated with water. After reaching an equilibrium state, the dissolution simulations were carried out for different surfactant mixtures. To track the dissolution process, different metrics were used, including visual analysis, local concentration analysis, diffusion, and cluster size calculations. Results show that by having a mixture of surfactants, the diffusion of the micelles is not affected only by the size of the micelles as in pure surfactant systems, but there is also an effect due to the composition of the micelles. When oil is added to a surfactant system, the system acts like a longer chain surfactant system, but only when the chain of oil becomes sufficiently long.

Simulating the behavior of antioxidant to explore the mechanisms of oxidative stability in Pickering emulsion

This study explores effective strategies for bolstering emulsion oxidative stability via optimized interfacial distribution of varying hydrophobicity antioxidants (gallic acid, propyl gallate, octyl gallate) in zein nanoparticle (ZP) stabilized Pickering emulsions. Experimental and simulation methods revealed that antioxidant (AO) with higher hydrophobicity or loaded into ZP demonstrated stronger hydrogen bonding and van der Waals interactions with ZP. This increased interfacial loading of antioxidants resulted in improved oxidative stability in Pickering emulsions. The flow, distribution and orientation of AO, as revealed by dissipative dynamics simulations, highlighted the role of hydrophobic interactions during initial AO migration, influenced by varied alkyl chain lengths. Subsequent interface rearrangements arose from conservative force interactions between the AO's phenol hydroxyl ends and ZP. These findings inform effective interfacial engineering to optimize antioxidant efficiency, guiding practical applications in emulsion systems for improved oxidative stability.

Synthesis, surface activity, and corrosion inhibition capabilities of new non-ionic gemini surfactants

Several environmentally acceptable non-ionic gemini surfactants are synthesized in this work using natural sources, including polyethenoxy di-dodecanoate (GSC12), polyethenoxy di-hexadecanoate (GSC16), and polyethenoxy di-octadecenoate (GSC18). The produced surfactants are confirmed by spectrum studies using FT-IR, 1HNMR, and 13CNMR. It explored and examined how the length of the hydrocarbon chain affected essential properties like foaming and emulsifying abilities. Surface tension examinations are used to assess the surface activity of the examined gemini surfactants. The lower value of critical micelle concentrations (0.381 × 10-4M) is detected for GSC18. Their spontaneous character is shown by the negative values of the free energy of adsorption (ΔGads) and micellization (ΔGmic) which arranged in the order GSC18 > GSC16 > GSC12. Based on theoretical, weight loss, and electrochemical investigations, these novel surfactants were investigated for their possible use in inhibiting carbon steel from corroding in 1 M HCl. Measuring results show that GSC18 inhibits corrosion in carbon steel by 95.4%. The isotherm of adsorption evaluated for the investigated inhibitors and their behavior obeys Langmuir isotherm.