Optimization of Walnut Oil Nanoemulsions Prepared Using Ultrasonic Emulsification: A Response Surface Method

Response surface methodology-central composite rotatable design (RSM-CCRD) was applied to determine effects of ultrasonic time (UT, 5–15 minutes), walnut oil (WO, 4–10% w/w) content, and concentration ratio of Span 80 to Tween 80 (K ₀, 0.55–0.80), on the some physicochemical characteristics of WO/water nanoemulsion including average particle size, Span and loss of antioxidant activity (LAA). Analysis of variance (ANOVA) showed that second-order polynomial models with high R ² (0.944–0.983) were well adjusted to predict response variables. The linear effect of UT was found to be most significant in all response surface models. The optimal conditions were: UT of 5.0 minutes, WO content of 7.35% w/w, and K ₀ of 0.8. Under these conditions, the average particle size, Span, and LAA were 356.08 nm, 0.548%, and 10.96. The adequacy of the models was confirmed by production this nanoemulsion under optimum values given by the model.     

Walnut Oil Nanoemulsion: Optimization of the Emulsion Capacity,Cloudiness, Density,and Surface Tension

Response surface methodology (RSM) in conjunction with central composite rotatable design (CCRD) was employed to find out the influence of preparation properties of walnut oil/water nanoemulsion namely ultrasonic time (5–15 minutes), walnut oil content (4–10% w/w) and concentration ratio of Span 80 to Tween 80 (K ₀, 0.55–0.80) on response variables including emulsion capacity, cloudiness, density and surface tension. The calculated regression models with high value of coefficient of determination (0.910–0.973) and insignificant lack of fit test indicated satisfactory agreement of empirical models with experimental observations. The results revealed linear term of walnut oil concentration was the most significant (p < 0.05) parameter on the all responses. The overall optimum region to achieve the ideal characteristics was ultrasonic time of 11.74 minutes, walnut oil content of 4.00% (w/w) and K ₀ of 0.80.     

Demulsification Efficiency of Some New Demulsifiers Based on 1,3,5-Triethanolhexahydro-1,3,5-triazine

This study mainly concentrates on the synthesis of three novel demulsifiers and the investigation of their demulsification efficiency. The demulsifiers were derived from 1,3,5-triethanolhexahydro-1,3,5-triazine, which was prepared by the reaction of monoethanol amine with formaldehyde. The 1,3,5-triethanolhexahydro-1,3,5-triazine was ethoxylated by introducing 20 units of ethylene oxide and then esterified at different molar ratios with oleic acid (1, 2, and 3) to give three demulsifiers, namely, E₂₀TO, E₂₀TO₂, and E₂₀TO₃. The chemical structures of the prepared demulsifiers were confirmed by ¹H NMR and FTIR spectrum. The demulsification efficiency of these demulsifiers was tested on the natural water-in-oil (w/o) emulsions (50% water content). From the obtained results, it has been found that the investigated demulsifiers have a great potential to break the w/o emulsions. The trioleat ester (E₂₀TO₃) exhibited the maximum demulsification efficiency (96%) after 120 minutes at 55°C.     

Antioxidant Activity Degradation,Formulation Optimization,Characterization, and Stability of Equisetum Arvense Extract Nanoemulsion

Equisetum arvense supercritical CO₂ extracts (EAE) contained an initial antioxidant activity of 10.3 mM TEAC that suffered a sharp first order kinetics decay characterized by half-life time (t_1/2) of 1.05 ± 0.03 and 0.86 ± 0.03 weeks at 25 and 4°C, respectively. The aim of the present work was to develop a nanoemulsion formulation for providing EAE protection against deleterious environmental factors and extending its shelf-life functionality. The nanoemulsion area was identified by constructing pseudoternary phase diagrams and response surface methodology was used to optimize the preparation conditions. The best formulation achieved an EAE encapsulation efficiency of 97.5 ± 0.5% and antioxidant activity half-life time (t_1/2) was extended to 12.32 ± 0.40 and 14.56 ± 0.60 weeks at 25 and 4°C, respectively.      

Dielectric Analysis on the Microscopic Characteristics of the Cloudy Silwet L-77 Solution

Dielectric relaxation spectra of the cloudy Silwet L-77 solutions were investigated from 40 Hz to 110 MHz. A striking Maxwell-Wagner relaxation was observed at about 10⁶ Hz, which was assigned to the interfacial polarization between the micelle particle (L₁) and the continuous water (W). Based on the concentration and the temperature dependence of the dielectric increment and the low-frequency conductivity (σ _l ), the critical data and the corresponding micellar structures of the Silwet L-77 solutions under cloudy state were clarified. Furthermore, the viscosity evolution in the W-L₁ region was confirmed according to an anomalous lower temperature dependence of σ _l .