Effect of diutan microbial polysaccharide on the stability and rheological properties of O/W nanoemulsions formed with a blend of Span20-Tween20

2018 ◽  
Vol 39 (11) ◽  
pp. 1644-1654 ◽  
Author(s):  
Long Xu ◽  
Zhe Qiu ◽  
Houjian Gong ◽  
Chenguang Liu ◽  
Yajun Li ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Microbial Polysaccharide ◽  
The Stability

scholarly journals Effect of Photoinitiator on Precursory Stability and Curing Depth of Thiol-Ene Clickable Gelatin

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1877
Author(s):  
Kai-Hung Yang ◽  
Gabriella Lindberg ◽  
Bram Soliman ◽  
Khoon Lim ◽  
Tim Woodfield ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Visible Light ◽  
Rheological Properties ◽  
Swelling Ratio ◽  
Sodium Persulfate ◽  
Photo Polymerization ◽  
Gelation Kinetics ◽  
The Stability ◽  
Over Time

Recent advances highlight the potential of photopolymerizable allylated gelatin (GelAGE) as a versatile hydrogel with highly tailorable properties. It is, however, unknown how different photoinitiating system affects the stability, gelation kinetics and curing depth of GelAGE. In this study, sol fraction, mass swelling ratio, mechanical properties, rheological properties, and curing depth were evaluated as a function of time with three photo-initiating systems: Irgacure 2959 (Ig2959; 320–500 nm), lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP; 320–500 nm), and ruthenium/sodium persulfate (Ru/SPS; 400–500 nm). Results demonstrated that GelAGE precursory solutions mixed with either Ig2959 or LAP remained stable over time while the Ru/SPS system enabled the onset of controllable redox polymerization without irradiation during pre-incubation. Photo-polymerization using the Ru/SPS system was significantly faster (<5 s) compared to both Ig2959 (70 s) and LAP (50 s). Plus, The Ru/SPS system was capable of polymerizing a thick construct (8.88 ± 0.94 mm), while Ig2959 (1.62 ± 0.49 mm) initiated hydrogels displayed poor penetration depth with LAP (7.38 ± 2.13 mm) in between. These results thus support the use of the visible light based Ru/SPS photo-initiator for constructs requiring rapid gelation and a good curing depth while Ig2959 or LAP can be applied for photo-polymerization of GelAGE materials requiring long-term incubation prior to application if UV is not a concern.

scholarly journals Assessment of Fennel Oil Microfluidized Nanoemulsions Stabilization by Advanced Performance Xanthan Gum

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 693
Author(s):  
Rubén Llinares ◽  
Pablo Ramírez ◽  
José Antonio Carmona ◽  
Luis Alfonso Trujillo-Cayado ◽  
José Muñoz
Keyword(s):  
Essential Oil ◽  
Rheological Properties ◽  
Xanthan Gum ◽  
Mechanical Energy ◽  
Physical Stability ◽  
Processing Condition ◽  
Oil In Water ◽  
Mechanical Spectra ◽  
The Stability ◽  
Fennel Oil

In this work, nanoemulsion-based delivery system was developed by encapsulation of fennel essential oil. A response surface methodology was used to study the influence of the processing conditions in order to obtain monomodal nanoemulsions of fennel essential oil using the microchannel homogenization technique. Results showed that it was possible to obtain nanoemulsions with very narrow monomodal distributions that were homogeneous over the whole observation period (three months) when the appropriate mechanical energy was supplied by microfluidization at 14 MPa and 12 passes. Once the optimal processing condition was established, nanoemulsions were formulated with advanced performance xanthan gum, which was used as both viscosity modifier and emulsion stabilizer. As a result, more desirable results with enhanced physical stability and rheological properties were obtained. From the study of mechanical spectra as a function of aging time, the stability of the nanoemulsions weak gels was confirmed. The mechanical spectra as a function of hydrocolloid concentration revealed that the rheological properties are marked by the biopolymer network and could be modulated depending on the amount of added gum. Therefore, this research supports the role of advanced performance xanthan gum as a stabilizer of microfluidized fennel oil-in-water nanoemulsions. In addition, the results of this research could be useful to design and formulate functional oil-in-water nanoemulsions with potential application in the food industry for the delivery of nutraceuticals and antimicrobials.

Nanoemulsion with Controlled Rheology under Different Temperature for Effective Removal of Oil-based Drilling Fluid in Offshore Drilling

2021 ◽  
Author(s):  
Renzhou Meng ◽  
Chengwen Wang ◽  
Xiliang Dong ◽  
Chao Xiong
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Rheological Properties ◽  
Drilling Fluid ◽  
Offshore Drilling ◽  
Emulsion Droplets ◽  
Effective Removal ◽  
Engineering Requirement ◽  
Important Means ◽  
The Stability

Abstract Oil-based drilling fluid (OBDF) is an important means for offshore drilling, but it would affect the cementing quality. Nanoemulsions shows potential for OBDF removal, but how to prepare nanoemulsion meeting the engineering requirement is lack of good understanding. Moreover, nanoemulsions usually behave badly under low/high temperature, which would restrict the application. Revealing removal mechanisms of nanoemulsion and improving nanoemulsion stability at different temperature are of great significance. The nanoemulsion could rapidly spread on the wellbore surfaces, cause the adhering OBDF to curl into little droplets, and solubilize the removed OBDF. The removal efficiency can reach more than 98%. Low temperature and higher concentration of dispersed phase both increased the viscosity of nanoemulsions stabilized by surfactants. PEGs can induce the bridging of emulsion droplets at low temperature, leading to significant increase of nanoemulsions viscoelasticity at low temperature (around 5°C). To control the rheological properties of nanoemulsions, a hydrophobic association polymer, HAAP, was proposed. Nanoemulsions containing HAAP does not gel at low temperature (&lt; 15°C). And the viscoelasticity of nanoemulsions increased slightly when the temperature is higher than 70°C because of the thermoassociating behavior of polymer, which can ensure the stability of the nanoemulsions at high temperature. This paper is helpful to establish a generic route for preparing nanoemulsions with controlled rheological properties under different temperature, which is benefit for their applications in offshore.

scholarly journals Soft channel formation and symmetry breaking in exotic active emulsions

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
L. N. Carenza ◽  
G. Gonnella ◽  
A. Lamura ◽  
D. Marenduzzo ◽  
G. Negro ◽  
...  
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Self Assembly ◽  
Contractile Activity ◽  
Active Material ◽  
Fluid Flows ◽  
Shear Rates ◽  
Two Phases ◽  
The Stability ◽  
Isotropic Fluid

Abstract We use computer simulations to study the morphology and rheological properties of a bidimensional emulsion resulting from a mixture of a passive isotropic fluid and an active contractile polar gel, in the presence of a surfactant that favours the emulsification of the two phases. By varying the intensity of the contractile activity and of an externally imposed shear flow, we find three possible morphologies. For low shear rates, a simple lamellar state is obtained. For intermediate activity and shear rate, an asymmetric state emerges, which is characterized by shear and concentration banding at the polar/isotropic interface. A further increment in the active forcing leads to the self-assembly of a soft channel where an isotropic fluid flows between two layers of active material. We characterize the stability of this state by performing a dynamical test varying the intensity of the active forcing and shear rate. Finally, we address the rheological properties of the system by measuring the effective shear viscosity, finding that this increases as active forcing is increased—so that the fluid thickens with activity.

A simple and effective strategy to enhance the stability and solid–liquid interfacial interaction of an emulsion by the interfacial dilational rheological properties

Soft Matter ◽  
2020 ◽  
Vol 16 (24) ◽  
pp. 5650-5658
Author(s):  
Jinmei Lei ◽  
Yuxia Gao ◽  
Xu Hou ◽  
Zhizhi Sheng ◽  
Chenhui Zhang ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Emulsion Stability ◽  
Interfacial Interaction ◽  
Effective Strategy ◽  
The Stability ◽  
Solid Liquid

Schematic showing the influence of dilational rheological properties on the emulsion stability and solid–liquid interfacial interaction.

scholarly journals Evaluating the potential of surface-modified silica nanoparticles using internal olefin sulfonate for enhanced oil recovery

2019 ◽  
Vol 17 (3) ◽  
pp. 722-733 ◽  
Author(s):  
Afaque Ahmed ◽  
Ismail Mohd Saaid ◽  
Abdelazim Abbas Ahmed ◽  
Rashidah M. Pilus ◽  
Mirza Khurram Baig
Keyword(s):  
Silica Nanoparticles ◽  
Rheological Properties ◽  
Oil Recovery ◽  
Displacement Efficiency ◽  
Shear Rates ◽  
Oil Water ◽  
Core Flood ◽  
The Stability ◽  
Modified Silica Nanoparticles ◽  
Surface Modified

AbstractRecently, nanoparticles have proven to enhance oil recovery on the core-flood scale in challenging high-pressure high-temperature reservoirs. Nanomaterials generally appear to improve oil production through wettability alteration and reduction in interfacial tension between oil and water phases. Besides, they are environmentally friendly and cost-effective enhanced oil recovery techniques. Studying the rheological properties of nanoparticles is critical for field applications. The instability of nanoparticle dispersion due to aggregation is considered as an unfavorable phenomenon in nanofluid flooding while conducting an EOR process. In this study, wettability behavior and rheological properties of surface-treated silica nanoparticles using internal olefins sulfonates (IOS20–24 and IOS19–23), anionic surfactants were investigated. Surface modification effect on the stability of the colloidal solution in porous media and oil recovery was inspected. The rheology of pure and surface-treated silica nanoparticles was investigated using a HPHT rheometer. Morphology and particle size distributions of pure and coated silica nanoparticles were studied using a field emission scanning electron microscope. A series of core-flood runs was conducted to evaluate the oil recovery factor. The coated silica nanoparticles were found to alter rheological properties and exhibited a shear-thinning behavior as the stability of the coated silica nanoparticles could be improved considerably. At low shear rates, the viscosity slightly increases, and the opposite happens at higher shear rates. Furthermore, the surface-modified silica nanoparticles were found to alter the wettability of the aqueous phase into strongly water-wet by changing the contact angle from 80° to 3° measured against glass slides representing sandstone rocks. Oil–water IFT results showed that the surface treatment by surfactant lowered the oil–water IFT by 30%. Also, the viscosity of brine increased from 0.001 to 0.008 Pa s by introducing SiO2 nanoparticles to the aqueous phase for better displacement efficiency during chemical-assisted EOR. The core-flood experiments revealed that the ultimate oil recovery is increased by approximately 13% with a surfactant-coated silica nanofluid flood after the conventional waterflooding that proves the potential of smart nanofluids for enhancing oil recovery. The experimental results imply that the use of surfactant-coated nanoparticles in tertiary oil recovery could facilitate the displacement efficiency, alter the wettability toward more water-wet and avoid viscous fingering for stable flood front and additional oil recovery.

Comparison of Several Common Types of Grease Performance Based AR 2000ex Remoter

2014 ◽  
Vol 620 ◽  
pp. 254-262
Author(s):  
Chun Xia He ◽  
Su Zheng Wu ◽  
Hang Song Yang ◽  
Jian Xiu Liu
Keyword(s):  
Rheological Properties ◽  
Work Situation ◽  
Flow Curves ◽  
Lithium Grease ◽  
Impact Performance ◽  
Shear Sensitivity ◽  
Continuous Shear ◽  
The Stability ◽  
The Impact ◽  
Grease Composition

Different substrates grease composition due to differences in their varying degrees of change in viscosity after shearing studied the rheological properties of three different substrates grease. Used AR2000ex rheometer, investigated the effects of different sessions on the rheological properties of the grease. It was found that the stability of lithium grease from the grease either stops working, or their work situation by cutting lubrication properties, are superior to calcium-based grease and urea-based grease. Urea-based grease on the shear sensitivity is smaller relatively than lithium and the recovery of viscosity after being subjected to continuous shear weak, easily lost during use based the grease flow curves with Herschel-Bulkley model, and the impact performance of the grease thixotropic grease is yield stress.

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