Fate of Emulsifier in Invert Emulsion Drilling Fluids: Hydrolysis and Adsorption on Solids

Emulsifier concentration in SBM is an important factor of drilling fluid stability. Proper concentration of amidoamine emulsifier is imperative for controlling low fluid loss and maintaining emulsion stability. This study investigates the physical and chemical interactions between emulsifier and other additives and describes the processes by which emulsifier is depleted from the drilling fluid. Three main pathways of emulsifier consumption are identified: emulsifier adsorption on solids found in drilling fluids and low gravity solids (LGS), chemical degradation, and to stabilize the invert emulsion. Design of experiments model and analytical procedure based on 1H NMR (nuclear magnetic resonance) spectroscopy was used to quantify the required emulsifier concentration in Non-Aqueous Fluid system (NAF). Additionally, model systems were used to estimate the excess of emulsifier, evaluate the emulsifier losses due to alkaline hydrolysis at elevated temperature, and measure adsorption of emulsifier on barite and various LGS types. Calculations for emulsifier depletion based on model systems were correlated to performance of formulated drilling fluids for verification. Typical emulsifier requirement in high performance NAF is 8-12 pounds per barrel (ppb). Majority of the emulsifier is adsorbed on weighting agents (barite) and rheology modifiers (clays), which are used to formulate NAF, that contribute to their effective dispersion in the solution and control fluid rheology. The adsorption process is found to be sensitive to the emulsifier concentration, solids mineralogy, wetting agent and temperature. Analytical Langmuir-Freundlich isotherm was used to describe adsorption data and estimate the adsorption capacity of the system. The emulsifier degradation pathway is another important factor of emulsifier consumption; however, emulsifier degradation at 250°F is not significant. While NAF are generally run ‘rich’ to mitigate depletion and maintain fluid stability, adsorption onto minerals will become an issue especially at high LGS concentration. These results will be greatly beneficial in the further development of NAF drilling fluid formulations and will assist field engineers in understanding the effect excess emulsifier will have on the drilling fluid and enable them to more effectively control the fluid properties under variations in emulsifier and LGS concentration during drilling.

Premix Membrane Emulsification: Preparation and Stability of Medium-Chain Triglyceride Emulsions with Droplet Sizes below 100 nm

Premix membrane emulsification is a promising method for the production of colloidal oil-in-water emulsions as drug carrier systems for intravenous administration. The present study investigated the possibility of preparing medium-chain triglyceride emulsions with a mean particle size below 100 nm and a narrow particle size distribution using sucrose laurate as an emulsifier. To manufacture the emulsions, a coarse pre-emulsion was repeatedly extruded through alumina membranes (Anodisc™) of 200 nm, 100 nm and 20 nm nominal pore size. When Anodisc™ membranes with 20 nm pore size were employed, nanoemulsions with z-average diameters of about 50 nm to 90 nm and polydispersity indices smaller than 0.08 could be obtained. Particle growth due to Ostwald ripening was observed over 18 weeks of storage. The Ostwald ripening rate linearly depended on the emulsifier concentration and the concentration of free emulsifier, indicating that micelles in the aqueous phase accelerated the Ostwald ripening process. Long-term stability of the nanoemulsions could be achieved by using a minimised emulsifier concentration or by osmotic stabilisation with soybean oil added in a mass ratio of 1:1 to the lipid phase.

Formulation and optimization of astaxanthin nanoemulsions with marine phospholipids derived from large yellow croaker (Larimichthys crocea) roe

The aim of this work was to investigate the emulsifying capacity of marine phospholipids derived from large yellow croaker roe (LYCRPLs). Initially, conditions for preparing astaxanthin (1% w/w) nanoemulsions with LYCRPLs were optimized based on single-factor experiments, including homogenization pressure, homogenization cycle, emulsifier concentration and corn oil concentration via the response surface methodology. The optimal homogenization pressure was 60 MPa, the optimal number of homogenization cycles was nine, the optimal emulsifier concentration was 4.7%, and the optimal oil concentration was 20%. Under these conditions, the stability, particle size and polydispersity index of nanoemulsions were 0.018 ± 0.0016, 247 ± 4.5 nm and 0.215±0.019, respectively. The droplets of nanoemulsions were characterized by transmission electron microscopy, which revealed that all the droplets were more or less spherical and nonaggregated. In addition, the storage experiments indicated that the nanoemulsions were stable at different temperatures. Therefore, LYCRPLs could be explored as carriers for the delivery of insoluble bioactive compounds in the food industry.

Pengaruh Perbedaan Konsentrasi Emulgator terhadap Karakterisasi Fisik Sediaan Krim Ekstrak Rosella (Hibiscus sabdariffa)

The formulation and physical characterization test of rosella extract cream preparations have been carried out using various types of non-ionic emulsifier concentration ratios (combination of tween 80 and span 80). Comparison of the concentrations of tween 80 and span 80 used in this study were 2%, 3%, and 4%. The aim of this study included organoleptic test, homogeneity test, pH test, viscosity test, dispersion test, and emulsion type test. The result obtained from the physical characterization test were the organoleptic tests for the three formulas showed the same organoleptic results, namely red color, characteristic smell of rosella, and semisolid consistency. Homogeinity test shows that the formula is homogenous. The pH test showed that F1 4,29; F2 4,6; F3 5. Viscosity test showed that F1 432,4 mPas; F2 434,3 mPas; 435,3 mPas. The dispersion test was carried out without using a load of 50 g, 100 g, and 200 g. the results shown form the spreadability test of three formulas were were F1 5 cm; 5,5 cm; and 6 cm; F2 6 cm; 6,35 cm; 7,25; and 7,5 cm. F3 6,25 cm; 7,5 cm; 7,75 cm; 8 cm. The emulsion type indicated by the three formulas is oil in water. Based on these results, it can be seen that the emulsifier concentration has an effect on PH, viscosity, and spreadibility. The higher the concentration of emulsifier used, the higher pH value, viscosity, and spreadibility.

Stability of the PEG Fatty Acid Glycerides Based O/W Emulsions

In the present work, oil-in-water (O/W) emulsion systems were prepared by using the PEG-7 lauric acid glycerides as the emulsifiers and the liquid paraffin as the oil phase. The influence of processing parameters such as emulsification temperature, stirring speed, emulsifier concentration, oil-water volume ratio and polymer addition on the stability of the emulsion systems was investigated. In order to determine the optimal conditions for the preparation of the emulsion systems based on PEG-7 lauric acid glycerides, a laser drop size analyser and a rotational rheometer were used. As the stability of the O/W emulsion systems increased, the average droplet size of the O/W emulsions measured by the laser droplet size analyser became smaller and the viscosity, storage modulus and loss modulus of the O/W emulsions measured by the rotational rheometer became larger. The following optimal conditions were determined in this study: emulsification temperature 80°C, stirring speed 500 r/min, emulsifier concentration 5 wt%, oil-water volume ratio 1:1 and added amount of xanthan gum 0.2 wt%. The droplet morphology of the O/W emulsion prepared under the optimal conditions, which was characterised by a super high magnification microscope, is small. Furthermore, the long-term stability of the emulsion system prepared under the optimal conditions was investigated over a period of time (4 weeks). The O/W emulsion proves to be well stable even after 4 weeks, with a water separation rate of 0%.

C9 Fraction inverse emulsion oligomerization conditions and characteristics of petroleum resins correlation

It has been studied the production of petroleum resins by low-temperature inverse emulsion oligomerization of C9 fraction of diesel fuel pyrolysis liquid by-products. It is established that the determining factors of the C9 fraction of the inverse emulsion oligomerization are the following: reaction time, emulsifier concentration and phase ratio. Yield and physicochemical characteristics of oligomers сorrelations were established. Multiple linear regression of oligomer yield depends on the main significant parameters of the fraction C9 inverse emulsion oligomerization is proposed.

Effect of Salt on the Stability of Vegetable Oil-in-Water Emulsions Stabilized by Soybean Protein and Microgel

The preparation of vegetable oil-water emulsions stabilized by soybean protein and microgel is described. The soybean protein was obtained from n-hexane-defatted soybean powder using a Soxhlet extractor. Using equal volumes of oil and water, vegetable oil-water emulsions were formed either by handshaking the mixture or homogenizing the mixture using a Lab homogenizer. The emulsion was characterized using a drop test and microscopy observation. The drop test shows that the preferred emulsion is vegetable oil-in-water (o/w). The effect of salt and emulsifier concentration on the stability and emulsion drop size was investigated. Emulsions stabilized by soybean protein without addition of salt breakdown after 3 days of preparation because of decomposition of the protein. For emulsions stabilized by microgel in the absence of salt, phase separation occurred within 1 hour. At a fixed salt concentration, it was found that increasing the emulsifier concentration has a significant effect on the stability and drop size of the emulsions stabilized by both protein and microgel. For emulsions stabilized by soybean protein, the stability of emulsions increased with increasing salt concentration without any significant influence on the drop size. The results obtained from the surface tension measurement revealed that different mechanisms of stabilization exist in emulsions stabilized by the protein and microgel.

COMPARISION OF CURCUMIN NANOEMULSION DROPS SIZE BETWEEN HOMINIZATION AND ULTRASONICATION SUPPORTING

In this paper, curcumin nano-emulsions were successfully prepared by combining hominization and ultra-sonication methods which have been mentioned. The optimal conditions for the hominization method have been established as follows: 3% emulsifier concentration, 20,000 rpm of capacity in 60 minutes, the average size of nano drops was 78 nm. Meanwhile, the optimal conditions of the ultrasonic method are also constructed as follows: 2% emulsifier concentration, 450 w/g of ultrasonic power, 20 kHz frequency, the average size of the droplet was 58 nm. Nano-emulsion system has been stable after 4 months of cold storage.