Oil dispersion, a crucial process in oil transport, involves the detachment of oil droplets from slicks and their introduction into the water column, influencing subsequent oil migration and transformation. This study examines oil dispersion, considering characteristics, stability, and mechanisms, while evaluating the impact of dispersants and salinity. Results show the significant role of surfactant type in dispersants on oil dispersion characteristics, with anionic surfactants exhibiting higher sensitivity to salinity changes compared to nonionic surfactants. The dispersion efficiency varies with salinity, with anionic surfactants performing better in low salinity (<20‰) and nonionic surfactants showing superior performance at 30-35‰ salinities. Rheological analysis illustrates the breakup and coalescence of oil droplets within the shear rates of breaking waves. An increase in interfacial film rigidity impedes the coalescence of oil droplets, contributing to the dynamic stability of the oil-water hybrid system. The use of GM-2, a nonionic dispersant, results in the formation of a solid-like interface, characterized by increased elastic modulus, notably at 20‰ salinity. However, stable droplet size distribution (DSD) at 35‰ salinity for 60 h suggests droplets can remain dispersed in seawater. The enhancement of stability of oil dispersion is interpreted as the result of two mechanisms: stabilizing DSD and developing the strength of viscoelastic interfacial film. These findings offer insights into oil dispersion dynamics, highlighting the importance of surfactant selection and salinity in governing dispersion behavior, and elucidating mechanisms underlying dispersion stability.
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http://dx.doi.org/10.1016/j.jenvman.2024.120888 | DOI Listing |
Nat Commun
December 2024
Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education (HUST), School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
Large-amount encapsulation and subsequent expressing are common characteristics for many biomedical applications, such as cosmetic creams and medical ointments. Emulsion gels can accomplish that, but often undergo exclusive, complex, multiple synthesis steps, showing extremely laborious and non-universal. The method here is simple via precisely interfacial engineering in homogenizing a nanoparticle aqueous dispersion and a polymer oil solution, gaining interfacial 45° three-phase-contact-angle for the nanoparticle that can bridge across oil emulsions' interfaces and ultimately form interconnected macroscopic networks.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, People's Republic of China. Electronic address:
A straightforward and effective approach was introduced for creating a multifunctional cellulose fabric in this paper. The epoxy groups in epoxidized soybean oil participated in ring-opening reactions with hydroxyl groups present in cellulose fibers and amino groups found in polyhexamethylene guanidine hydrochloride, respectively, under alkaline conditions. Polyhexamethylene guanidine hydrochloride could introduce cationic groups, while epoxidized soybean oil could contribute hydrophobic alkane chains.
View Article and Find Full Text PDFFood Chem
December 2024
Food and Soft Materials Research Group, Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, Canada. Electronic address:
This study investigated the oleogelation of cellulose bead dispersions in a sunflower oil oleogel made with solvent-transferred whey protein isolate. The microstructure and rheology of the mixed gels depended on the ratio of hydrated cellulose beads to proteins (9:1, 8:2, 7:3, and 1:1). Two gel stabilization mechanisms were identified.
View Article and Find Full Text PDFMar Pollut Bull
December 2024
Universidade Federal de Pernambuco, Departamento de Química Fundamental, Av. Jornalista Aníbal Fernandes, s/n, Cidade Universitária, 50740-560 Recife, PE, Brazil. Electronic address:
In August 2019, Brazil experienced its largest large oil spill, which impacted extensive areas and significantly affected the northeastern region, particularly Pernambuco. Polycyclic aromatic hydrocarbons (PAHs), major oil components, are critical for assessing fish contamination risks. This study presents two sample pretreatment methods for fish samples - ultrasound-enhanced air-assisted liquid-liquid microextraction (UE-AA-LLME) for low molar mass PAHs, and matrix solid-phase dispersion for high molar mass PAHs - followed by a Gas-Chromatography coupled to Mass Spectrometry (GC-MS) detection.
View Article and Find Full Text PDFGels
December 2024
College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
In the oil dispersion of chitosan, the formation of a capillary bridge was triggered by adding a small amount of water to obtain an oleogel. With this method, the types of liquid oil and the ratio of oil/chitosan/water were explored to achieve an optimal oleogel. MCT performed best, followed by soybean oil, which was chosen for its edibility and cost.
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