Droplet Size Distribution in Water-Crude Oil Emulsions by Low-Field NMR

Morgan, Vinícius G.; Sad, Cristina M. S.; Constantino, André F.; Azeredo, Rodrigo Bagueira de Vasconcellos; Lacerda, Valdemar; Castro, Eustáquio Vinícius Ribeiro de; Barbosa, Lúcio L.

doi:10.21577/0103-5053.20190057

Cited by 11 publications

(9 citation statements)

References 29 publications

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“…One is related to the PUFA‐rich oil molecules within the OB's core and the other to the OB's interfacial surface. This pattern is in agreement with other reports (Liu et al, 2019; Morgan et al, 2019), dealing with oil‐in‐water emulsion. The T 1 and T 2 energy relaxation time of the OB's vesicle surface is not significantly affected by the water because the oil's energy relaxation time rate is much faster than water's energy relaxation time (Kleinberg et al, 1994).…”

Section: Resultssupporting

confidence: 94%

“…6c and Table 3 for LSE T 0 hours (2941–1287 ms, respectively) are postulated to represent TD of the proton populations based on the interaction of interfacial H 2 O of the aqueous phase and protons of the outer surface of the linseed OB's hydrophilic part of oleosin and polar head groups of phospholipids. TD of T 1 –T 2 of peak 2 of the same LSE T 0 hours sample (Table 3) is somewhat shorter (2732–1206 ms, respectively), postulated to be a larger OB vesicle size, as suggested in other reports (Liu et al, 2019; Morgan et al, 2019). Variation of OB size can be observed in the microscopic images and other supportive analyses shown in Fig.…”

Section: Resultssupporting

confidence: 73%

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Low‐Field Nuclear Magnetic Resonance Time Domain Characterization of Polyunsaturated Fatty Acid–Rich Linseed and Fish Oil Emulsions during Thermal Air Oxidation

Resende

Linder

Wiesman

2021

J Americ Oil Chem Soc

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Linseed contains high levels of polyunsaturated fatty acids (PUFA), such as α‐linolenic acid (> 50% ALA‐18:3), that are naturally protected against thermal oxidation by their encapsulation within linseed oil bodies (OB) by multiple components including antioxidant proteins and mucilage emulsifying agents. Linseed OB emulsions (LSE) can be produced by grinding linseed seeds, adding water, adjusting pH, and sonication. This is a process that can encapsulate externally added PUFA to minimize their thermal oxidation, as it does for the intrinsic ALA PUFA. Fish oil (FO) encapsulation into this LSE platform to form linseed fish oil emulsions (LSFE) offers the possibility of a nutritive delivery system of the biologically essential FO PUFA eicosapentaenoic acid and docosahexaenoic acid. In this study, 1H low‐field nuclear magnetic resonance (LF‐NMR) is used to characterize LSE's and LSFE's chemical and structural properties as well as their stability and changes under thermal oxidation (55 °C for 96 hours). 1H LF‐NMR data processing was developed to generate one‐dimensional (1D) T1 (spin–lattice), 1D T2 (spin–spin), and 2D (T1 vs. T2) relaxation time spectra that can characterize OB emulsions and monitor their time domain fingerprints (spectrum peaks) of chemical and structural changes during the oxidation process. The 1H LF‐NMR analysis were further supported and correlated with conventional peroxide value test, self‐diffusion, droplet size distribution, zeta potential estimation of surface stability, and gas chromatography–mass spectrometry analysis of fatty acid profile changes under thermal oxidation conditions. The 1D and 2D LF‐NMR relaxation spectra showed that the LSE and LSFE did not suffer intense oxidation process, due to PUFA assembly in OB oxidative protection. These results were further confirmed by the supportive analytical methodologies. The results of this study demonstrate the efficacy of 1H LF‐NMR methodology to monitor PUFA's rich oil and emulsion thermal oxidation.

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Section: Resultssupporting

confidence: 94%

Section: Resultssupporting

confidence: 73%

Low‐Field Nuclear Magnetic Resonance Time Domain Characterization of Polyunsaturated Fatty Acid–Rich Linseed and Fish Oil Emulsions during Thermal Air Oxidation

Resende

Linder

Wiesman

2021

J Americ Oil Chem Soc

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“…Similar to the measurement of T 2 , the diffusion coefficient D can also render information on the size of small structures, such as liquid-filled pores or emulsion droplets. If free movement of molecules is restricted, D decreases with pore or droplet size ( Broekmann, 2002 ; Morgan et al, 2019 ). Molecules reaching a barrier are “bouncing off” and back in the opposite direction, their signal wrongly attributed to molecules that travel slower.…”

Section: Resultsmentioning

confidence: 99%

Noninvasive characterization (EPR, μCT, NMR) of 3D PLA electrospun fiber sponges for controlled drug delivery

Zech

Mäder

Gündel

et al. 2020

International Journal of Pharmaceutics: X

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Highly porous 3D-scaffolds, made from cut, electrospun PLA fibers, are relatively new and promising systems for controlled drug-delivery applications. Because knowledge concerning fundamental processes of drug delivery from those scaffolds is limited, we noninvasively characterized drug-loading and drug-release mechanisms of these polymer-fiber sponges (PFS). We screened simplified PFS-implantation scenarios with EPR and μCT to quantify and 3D-visualize the absorption of model-biofluids and an oil, a possible drug-loading liquid. Saturation of PFS (6 × 8 mm, h x d) is governed by the high hydrophobicity of the material and air-entrapment. It required up to 45 weeks for phosphate-buffered saline and 11 weeks for a more physiological, surface-active protein-solution, indicating the slow fluid-uptake of PFS as an effective mechanism to substantially prolong the release of a drug incorporated within the scaffold. Medium-chain triglycerides, as a good wetting liquid, saturated PFS within seconds, suggesting PFS potential to serve as carrier-vessels for immobilizing hydrophobic drug-solutions to define a liquid's 3D-interface. Oil-retention under mechanical stress was therefore investigated. 1 H NMR permitted insights into PFS-oil interaction, confirming surface-relaxation and restricted diffusion; both did not influence drug release from oil-loaded PFS. Results facilitate better understanding of PFS and their potential use in drug delivery.

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“…TD-NMR is a technique that is non-destructible and non-invasive; provides fast measurements) [25][26][27][28][29][30] ; has the potential to be applied on line or in situ [28] ; and can provide a variety of information about physical, chemical and rheological properties of petroleum, distillates and fuel. [31][32][33][34][35][36] We have developed in previous work a methodology to determine the onset point using TD-NMR.…”

Section: Introductionmentioning

confidence: 99%

Time domain NMR: An alternative for study of the asphaltenes precipitated in petroleum

Morgan

Sad

Leite

et al. 2022

Magnetic Reson in Chemistry

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During the oil production and processing stages, the asphaltene precipitation is one of the great operation problems of oil industry. It can precipitate in the formation, tubing, or surface, causing operating problems, such as reduction in oil recovery by changing the reservoir permeability and wettability, clogging of the pipelines, and difficulty in separations process. The quantification of asphaltenes in petroleum by ASTM D6560 standard method is very laborious and use of a larger solvent volume than necessary. The present work proposes the use of time domain nuclear magnetic resonance (TD‐NMR) as new methodology to quantify the asphaltene precipitated in crude oil. Three (light, medium, and heavy) crude oils with asphaltenes content of 0.97, 1.88, and 7.00 wt% were mixed with n‐heptane in different R (ml of solvent/g of oil) values and analyzed by means of transverse relaxation time (T2). According NMR results, the R values enough for complete asphaltene precipitation for the oils A, B, and C were, respectively, equal to 16.50, 23.00, and 39.50 ml g−1. These outcomes represent a reduction of 58.75%, 42.50%, and 1.25% in the solvent volume per mass of oil for the oil A, B, and C, respectively, compared to the ASTM D6560 method, which imposes 40 ml g−1. Therefore, it has been shown that TD‐NMR can be applied to estimate the amount of asphaltene precipitated in petroleum and have potential to be applied in routine analysis with advantages of saving time and costs.

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Droplet Size Distribution in Water-Crude Oil Emulsions by Low-Field NMR

Cited by 11 publications

References 29 publications

Low‐Field Nuclear Magnetic Resonance Time Domain Characterization of Polyunsaturated Fatty Acid–Rich Linseed and Fish Oil Emulsions during Thermal Air Oxidation

Low‐Field Nuclear Magnetic Resonance Time Domain Characterization of Polyunsaturated Fatty Acid–Rich Linseed and Fish Oil Emulsions during Thermal Air Oxidation

Noninvasive characterization (EPR, μCT, NMR) of 3D PLA electrospun fiber sponges for controlled drug delivery

Time domain NMR: An alternative for study of the asphaltenes precipitated in petroleum

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