Water reorientation dynamics in colloidal water–oil emulsions

Author(s):  
Eliane P. van Dam ◽  
Roland Gouzy ◽  
Eddie Pelan ◽  
Krassimir P. Velikov ◽  
Huib J. Bakker

Polarization resolved pump–probe infrared spectroscopy of colloidal oil-in-water emulsions demonstrates that the total surface area of oil droplets is independent of the average droplet size, indicating that the oil droplets are strongly corrugated.

2020 ◽  
Vol 44 (32) ◽  
pp. 13534-13541
Author(s):  
Xin Gao ◽  
Qiang Ma ◽  
Zhengwei Jin ◽  
Pei Nian ◽  
Zheng Wang

A switchable superlyophobic ZIF-8 membrane can selectively remove oil droplets in oil-in-water emulsions via superoleophobicity and water droplets in water-in-oil emulsions via superhydrophobicity.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1048
Author(s):  
Junjing Wang ◽  
Morane Jousse ◽  
Jitesh Jayakumar ◽  
Alejandro Fernández-Arteaga ◽  
Silvia de Lamo-Castellví ◽  
...  

There is a pressing need to extend the knowledge on the properties of insect protein fractions to boost their use in the food industry. In this study several techno-functional properties of a black soldier fly (Hermetia illucens) protein concentrate (BSFPC) obtained by solubilization and precipitation at pH 4.0–4.3 were investigated and compared with whey protein isolate (WPI), a conventional dairy protein used to stabilize food emulsions. The extraction method applied resulted in a BSFPC with a protein content of 62.44% (Kp factor 5.36) that exhibited comparable or higher values of emulsifying activity and foamability than WPI for the same concentrations, hence, showing the potential for emulsion and foam stabilization. As for the emulsifying properties, the BSFPC (1% and 2%) showed the capacity to stabilize sunflower and lemon oil-in-water emulsions (20%, 30%, and 40% oil fraction) produced by dynamic membranes of tunable pore size (DMTS). It was proved that BSFPC stabilizes sunflower oil-in-water emulsions similarly to WPI, but with a slightly wider droplet size distribution. As for time stability of the sunflower oil emulsions at 25 °C, it was seen that droplet size distribution was maintained for 1% WPI and 2% BSFPC, while for 1% BSFPC there was a slight increase. For lemon oil emulsions, BSFPC showed better emulsifying performance than WPI, which required to be prepared with a pH 7 buffer for lemon oil fractions of 40%, to balance the decrease in the pH caused by the lemon oil water soluble components. The stability of the emulsions was improved when maintained under refrigeration (4 °C) for both BSFPC and WPI. The results of this work point out the feasibility of using BSFPC to stabilize O/W emulsions using a low energy system.


2021 ◽  
pp. 1-27
Author(s):  
Reza Taheri ◽  
P. Buyung Kosasih ◽  
Hongtao Zhu

Abstract Vegetable oil-in-water (VO/W) emulsions are common cold rolling lubricants. However, maintaining the required dispersion for polar oil droplets for consistent lubrication and proper surface self-cleaning after rolling remains a practical challenge. In this study, titanium silicate TiO2-SiO2 nanoparticle (NP) stabilised soybean oil emulsions are produced and NPs function as dispersant, lubrication enhancer, and detergent agent to clean up oil residue are explored. Cold rolling of SS316 reveals a threshold of NPs wt %, at which stably dispersed oil droplets improve tribology and lower the rolling parameters relative to that without or at high wt % of NPs. Cleaner as-rolled strips are also obtained with NPs. Favourable results are attributed to formation of NP-coating layers on oil droplets which enhances dispersion, optimises plate-out while keeping adequate wetting, and provides a 3-body abrasive rolling as opposed to 2-body adhesion without NPs. A model of sliding-rolling lubrication in cold rolling is also discussed.


2008 ◽  
Vol 22 (5) ◽  
pp. 3450-3458 ◽  
Author(s):  
Augusto M. Araujo ◽  
Leila M. Santos ◽  
Montserrat Fortuny ◽  
Rosana L. F. V. Melo ◽  
Raquel C. C. Coutinho ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Vaida Juškaitė ◽  
Kristina Ramanauskienė ◽  
Vitalis Briedis

The objective of this study was to formulate optimal formulations of microemulsions (MEs) and evaluate their feasibility for delivery of resveratrol into human skinex vivo.Oil-in-water MEs were formulated using surfactant (S) PEG-8 caprylic/capric glycerides and cosurfactant (CoS) polyglyceryl-6-isostearate. Ethyl oleate was used as an oily phase. MEs were formulated using 5 : 1, 6 : 1, and 7 : 1 surfactant and cosurfactant (S : CoS) weight ratios. Pseudoternary phase diagrams were constructed and optimal compositions of MEs were obtained using Design Expert software. Mean droplet size for optimized ME formulations was determined to be 68.54 ± 1.18 nm, 66.08 ± 0.16 nm, and 66.66 ± 0.56 nm for systems with S : CoS weight ratios 5 : 1, 6 : 1, and 7 : 1, respectively. Resveratrol loading resulted in mean droplet size increase. The distribution of droplet size between fractions changed during storage of formulated MEs. Results demonstrated the increase of number of droplets and relative surface area when S : CoS weight ratios were 6 : 1 and 7 : 1 and the decrease when S : CoS weight ratio was 5 : 1. The highest penetration of resveratrol into the skinex vivowas determined from ME with S : CoS weight ratio 5 : 1. It was demonstrated that all MEs were similar in their ability to deliver resveratrol into the skinex vivo.


1983 ◽  
Vol 92 (1) ◽  
pp. 269-272 ◽  
Author(s):  
F.V DiStefano ◽  
O.M Shaffer ◽  
M.S El-Aasser ◽  
J.W Vanderhoff

2020 ◽  
Vol 5 (2) ◽  
pp. 165-174
Author(s):  
Aeshah Salem

Background: Possessions of components, described by their shape and size (S&S), are certainly attractive and has formed the foundation of the developing field of nanoscience. Methods: Here, we study the S&S reliant on electronic construction and possession of nanocrystals by semiconductors and metals to explain this feature. We formerly considered the chemical dynamics of mineral nanocrystals that are arranged according to the S&S not only for the big surface area, but also as a consequence of the considerably diverse electronic construction of the nanocrystals. Results: The S&S of models, approved by using the Fractional Fourier Transform Infrared Spectroscopy (FFTIR), indicate the construction of CdSe and ZnSe nanoparticles. Conclusion: In order to study the historical behavior of the nanomaterial in terms of S&S and estimate further results, the FFTIR was used to solve this project.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 358
Author(s):  
Phui Yee Tan ◽  
Beng Ti Tey ◽  
Eng Seng Chan ◽  
Oi Ming Lai ◽  
Hon Weng Chang ◽  
...  

Calcium carbonate (CaCO3) has been utilized as a pH-responsive component in various products. In this present work, palm tocotrienols-rich fraction (TRF) was successfully entrapped in a self-assembled oil-in-water (O/W) emulsion system by using CaCO3 as the stabilizer. The emulsion droplet size, viscosity and tocotrienols entrapment efficiency (EE) were strongly affected by varying the processing (homogenization speed and time) and formulation (CaCO3 and TRF concentrations) parameters. Our findings indicated that the combination of 5000 rpm homogenization speed, 15 min homogenization time, 0.75% CaCO3 concentration and 2% TRF concentration resulted in a high EE of tocotrienols (92.59–99.16%) and small droplet size (18.83 ± 1.36 µm). The resulting emulsion system readily released the entrapped tocotrienols across the pH range tested (pH 1–9); with relatively the highest release observed at pH 3. The current study presents a potential pH-sensitive emulsion system for the entrapment and delivery of palm tocotrienols.


2021 ◽  
Vol 9 (1) ◽  
pp. 97
Author(s):  
Merv Fingas

The visual appearance of oil spills at sea is often used as an indicator of spilled oil properties, state and slick thickness. These appearances and the oil properties that are associated with them are reviewed in this paper. The appearance of oil spills is an estimator of thickness of thin oil slicks, thinner than a rainbow sheen (<3 µm). Rainbow sheens have a strong physical explanation. Thicker oil slicks (e.g., >3 µm) are not correlated with a given oil appearance. At one time, the appearance of surface discharges from ships was thought to be correlated with discharge rate and vessel speed; however, this approach is now known to be incorrect. Oil on the sea can sometimes form water-in-oil emulsions, dependent on the properties of the oil, and these are often reddish in color. These can be detected visually, providing useful information on the state of the oil. Oil-in-water emulsions can be seen as a coffee-colored cloud below the water surface. Other information gleaned from the oil appearance includes coverage and distribution on the surface.


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