scholarly journals The Impact of Micelle Formation on Surfactant Adsorption–Desorption

ACS Omega ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 2248-2254 ◽  
Author(s):  
Dirk J. Groenendijk ◽  
Johannes N. M. van Wunnik
Keyword(s):  
Micelle Formation ◽  
Surfactant Adsorption ◽  
Adsorption Desorption ◽  
The Impact

Synthesis of Ethylenediaminetetraacetic Acid Disodium Salt Functionalized Magnetite/Chitosan Nanospheres for the Highly Efficient Removal of Methylene Blue

2021 ◽  
Vol 21 (3) ◽  
pp. 1694-1702
Author(s):  
Mengke Zheng ◽  
Zhenguo Wu ◽  
Yang Wang ◽  
Nannan Chen ◽  
Zhaogang Teng ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Ethylenediaminetetraacetic Acid ◽  
Disodium Salt ◽  
Pseudo Second Order ◽  
Sorption Parameters ◽  
Adsorption Kinetics And Isotherm ◽  
Adsorption Desorption ◽  
The Impact ◽  
Desorption Cycle ◽  
Ethylenediaminetetraacetic Acid Disodium Salt

In this paper, novel Ethylenediaminetetraacetic acid disodium salt (EDTA) functionalized magnetite/ chitosan nanospheres (Fe3O4/CS-EDTA) are synthesized by combining solvothermal method and chemical modification, and they are further applied as a kind of adsorbent to eliminate dye of methylene blue (MB) from wastewater. The properties as well as structure exhibited by the fabricated adsorbent are characterized through FTIR, XRD, TG and TEM, together with VSM. The impact exerted by sorption parameters (time of contact, initial dye concentration, temperature, etc.) on the adsorptions were evaluated in batch system. These results demonstrated that our magnetic materials held the adsorption capacity for MB of 256 mg g−1 (pH = 11), and the kinetic model of pseudo-second-order and the Langmuir model could make an effective simulation regarding the adsorption kinetics and isotherm, respectively. Besides, the external magnetic field can assist in easily separating dye adsorbed Fe3O4/CS-EDTA from solution for regeneration. The removal efficiency of recycled adsorbents remained above 92% in the 5th adsorption/desorption cycle. These superioritiesmake Fe3O4/CS-EDTA a high-efficientmultifunctional adsorbent for removing dyes from wastewater.

scholarly journals Surfactant adsorption kinetics in microfluidics

2016 ◽  
Vol 113 (41) ◽  
pp. 11465-11470 ◽  
Author(s):  
Birte Riechers ◽  
Florine Maes ◽  
Elias Akoury ◽  
Benoît Semin ◽  
Philipp Gruner ◽  
...  
Keyword(s):  
Nonionic Surfactants ◽  
Adsorption Process ◽  
Surfactant Adsorption ◽  
Kinetic Measurement ◽  
Small Droplet ◽  
Kinetics Of Adsorption ◽  
Droplet Flow ◽  
Surfactant Interactions ◽  
Adsorption Desorption ◽  
Kinetics Of

Emulsions are metastable dispersions. Their lifetimes are directly related to the dynamics of surfactants. We design a microfluidic method to measure the kinetics of adsorption of surfactants to the droplet interface, a key process involved in foaming, emulsification, and droplet coarsening. The method is based on the pH decay in the droplet as a direct measurement of the adsorption of a carboxylic acid surfactant to the interface. From the kinetic measurement of the bulk equilibration of the pH, we fully determine the adsorption process of the surfactant. The small droplet size and the convection during the droplet flow ensure that the transport of surfactant through the bulk is not limiting the kinetics of adsorption. To validate our measurements, we show that the adsorption process determines the timescale required to stabilize droplets against coalescence, and we show that the interface should be covered at more than 90% to prevent coalescence. We therefore quantitatively link the process of adsorption/desorption, the stabilization of emulsions, and the kinetics of solute partitioning—here through ion exchange—unraveling the timescales governing these processes. Our method can be further generalized to other surfactants, including nonionic surfactants, by making use of fluorophore–surfactant interactions.

MODELING THE IMPACT OF FERRIHYDRITE ON ADSORPTION-DESORPTION OF SOIL PHOSPHORUS

Soil Science ◽  
2004 ◽  
Vol 169 (4) ◽  
pp. 271-281 ◽  
Author(s):  
G. V. Wilson ◽  
F. E. Rhoton ◽  
H. M. Selim
Keyword(s):  
Soil Phosphorus ◽  
Adsorption Desorption ◽  
The Impact

Impact of DOM in Reclaimed Water on Nitrogen/Phosphate Adsorption in Sediments

2013 ◽  
Vol 395-396 ◽  
pp. 678-685 ◽  
Author(s):  
Chun Fa Zhou ◽  
Zi Gong Ning ◽  
Wei Zhao ◽  
Yun Kai Li ◽  
Ming Chao Liang ◽  
...  
Keyword(s):  
Confidence Level ◽  
Reclaimed Water ◽  
Phosphate Adsorption ◽  
Urban Rivers ◽  
Adsorption Coefficient ◽  
Adsorption Dynamic ◽  
Rivers And Lakes ◽  
Adsorption Of Nitrogen ◽  
Adsorption Desorption ◽  
The Impact

The nitrogen and phosphate were regarded as the target pollutants in this paper to study the balance of adsorption / desorption to nitrogen and phosphate, the adsorption dynamic characteristics under the action of four kinds of urban rivers and lakes sediments in Beijing as well as the impact of DOM in reclaimed water to absorb nitrogen and phosphate. Results show that: the processes of sorption of nitrogen and phosphate in the four sediments could be described by the Linear and Freundlich models, while the adsorption-desorption goes with hysteresis effect. The adsorption of nitrogen and phosphate were inhibited by DOM in reclaimed water, with an adsorption coefficient Kddecreasing by 0.04% -56.88%, reaching a significant level (confidence level α = 0.05);And DOM increased the nonlinear parameter 1/n, up to 2.20 times at most, resulting in a lower adsorption stable.

scholarly journals Impact of Soil Aeration on the Environmental Fate of Pre-Emergent Herbicide Metolachlor

2021 ◽  
Vol 11 (18) ◽  
pp. 8567
Author(s):  
Ramdas Kanissery ◽  
Wenwen Liu ◽  
Ruby Tiwari ◽  
Gerald Sims
Keyword(s):  
Weed Management ◽  
Environmental Fate ◽  
Field Application ◽  
Anaerobic Conditions ◽  
Soil Microcosms ◽  
Soil Redox ◽  
Herbicide Metolachlor ◽  
Adsorption Desorption ◽  
The Impact ◽  
Kinetics Of

The impact of the aeration status of soils on the environmental fate of the soil-applied pre-emergent herbicide metolachlor is of significance to sustainable agriculture practices and has not been investigated thoroughly by existing research works. To address this knowledge gap, we examined the adsorption, desorption, degradation, and mineralization of radioactively labeled [14C] metolachlor in Catlin, Flanagan, and Drummer soils under aerobic and anaerobic conditions. Based on our findings, anaerobic conditions in the soil significantly reduced the adsorption of 14C-metolachlor while also promoting its desorption, thereby potentially releasing a greater amount of herbicide from the soil after a field application. The first-order degradation and mineralization kinetics of 14C-metolachlor were distinctively enhanced by anaerobic conditions in all the soils tested. Furthermore, the degradation and mineralization rates of 14C-metolachlor in non-sterilized versus sterilized soil microcosms clearly indicated microbial activity in the degradation of metolachlor in soil. The results from this study suggest that soil redox conditions could impact the bioavailability and environmental fate of herbicide metolachlor and should be taken into consideration as part of sustainable weed management programs.

scholarly journals Performance Analysis of a Solar Cooling System with Equal and Unequal Adsorption/Desorption Operating Time

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6749
Author(s):  
Farkad A. Lattieff ◽  
Mohammed A. Atiya ◽  
Jasim M. Mahdi ◽  
Hasan Sh. Majdi ◽  
Pouyan Talebizadehsardari ◽  
...  
Keyword(s):  
Cooling System ◽  
Operating Time ◽  
Operating Conditions ◽  
Solar Cooling ◽  
Overall Heat Transfer Coefficient ◽  
Experimental Findings ◽  
Solar Cooling System ◽  
Adsorption Desorption ◽  
The Impact ◽  
Adsorption Systems

In solar-thermal adsorption/desorption processes, it is not always possible to preserve equal operating times for the adsorption/desorption modes due to the fluctuating supply nature of the source which largely affects the system’s operating conditions. This paper seeks to examine the impact of adopting unequal adsorption/desorption times on the entire cooling performance of solar adsorption systems. A cooling system with silica gel–water as adsorbent-adsorbate pair has been built and tested under the climatic condition of Iraq. A mathematical model has been established to predict the system performance, and the results are successfully validated via the experimental findings. The results show that, the system can be operational at the unequal adsorption/desorption times. The performance of the system with equal time is almost twice that of the unequal one. The roles of adsorption velocity, adsorption capacity, overall heat transfer coefficient, and the performance of the cooling system are also evaluated.

scholarly journals The Effects of Food on Cannabidiol Bioaccessibility

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3573
Author(s):  
Khadijeh Mozaffari ◽  
Stephanie Willette ◽  
Ben F. Lucker ◽  
Sarah E. Kovar ◽  
Francisco Omar Holguin ◽  
...  
Keyword(s):  
Bile Salts ◽  
Micelle Formation ◽  
Food Matrix ◽  
Fed State ◽  
Lipase Enzyme ◽  
Three Phase ◽  
The Impact ◽  
Substrate Concentrations ◽  
Fatty Acid Absorption

Cannabidiol (CBD) is a hydrophobic non-psychoactive compound with therapeutic characteristics. Animal and human studies have shown its poor oral bioavailability in vivo, and the impact of consuming lipid-soluble CBD with and without food on gut bioaccessibility has not been explored. The purpose of this research was to study the bioaccessibility of CBD after a three-phase upper digestion experiment with and without food, and to test lipase activity with different substrate concentrations. Our results showed that lipase enzyme activity and fatty acid absorption increased in the presence of bile salts, which may also contribute to an increase in CBD bioaccessibility. The food matrix used was a mixture of olive oil and baby food. Overall, the fed-state digestion revealed significantly higher micellarization efficiency for CBD (14.15 ± 0.6% for 10 mg and 22.67 ± 2.1% for 100 mg CBD ingested) than the fasted state digestion of CBD (0.65 ± 0.7% for 10 mg and 0.14 ± 0.1% for 100 mg CBD ingested). The increase in bioaccessibility of CBD with food could be explained by the fact that micelle formation from hydrolyzed lipids aid in bioaccessibility of hydrophobic molecules. In conclusion, the bioaccessibility of CBD depends on the food matrix and the presence of lipase and bile salts.

Surfactant-induced retardation of the thermocapillary migration of a droplet

1997 ◽  
Vol 340 ◽  
pp. 35-59 ◽  
Author(s):  
JINNAN CHEN ◽  
KATHLEEN J. STEBE
Keyword(s):  
Surface Tension ◽  
Surfactant Concentration ◽  
Surface Concentration ◽  
Terminal Velocity ◽  
Control Surface ◽  
Surfactant Adsorption ◽  
Thermocapillary Migration ◽  
Marangoni Stress ◽  
Surface Convection ◽  
The Impact

A neutrally buoyant droplet in a fluid possessing a temperature gradient migrates under the action of thermocapillarity. The drop pole in the high-temperature region has a reduced surface tension. The surface pulls away from this low-tension region, establishing a Marangoni stress which propels the droplet into the warmer fluid. Thermocapillary migration is retarded by the adsorption of surfactant: surfactant is swept to the trailing pole by surface convection, establishing a surfactant-induced Marangoni stress resisting the flow (Barton & Subramanian 1990).The impact of surfactant adsorption on drop thermocapillary motion is studied for two nonlinear adsorption frameworks in the sorption-controlled limit. The Langmuir adsorption framework accounts for the maximum surface concentration Γ′∞ that can be attained for monolayer adsorption; the Frumkin adsorption framework accounts for Γ′∞ and for non-ideal surfactant interactions. The compositional dependence of the surface tension alters both the thermocapillary stress which drives the flow and the surfactant-induced Marangoni stress which retards it. The competition between these stresses determines the terminal velocity U′, which is given by Young's velocity U′0 in the absence of surfactant adsorption. In the regime where adsorption–desorption and surface convection are of the same order, U′ initially decreases with surfactant concentration for the Langmuir model. A minimum is then attained, and U′ subsequently increases slightly with bulk concentration, but remains significantly less than U′0. For cohesive interactions in the Frumkin model, U′ decreases monotonically with surfactant concentration, asymptoting to a value less than the Langmuir velocity. For repulsive interactions, U′ is non-monotonic, initially decreasing with concentration, subsequently increasing for elevated concentrations. The implications of these results for using surfactants to control surface mobilities in thermocapillary migration are discussed.

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