scholarly journals O/W Pickering Emulsions Stabilized with Cellulose Nanofibrils Produced through Different Mechanical Treatments

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1886
Author(s):  
Annachiara Pirozzi ◽  
Roberta Capuano ◽  
Roberto Avolio ◽  
Gennaro Gentile ◽  
Giovanna Ferrari ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Ball Milling ◽  
Cellulose Nanofibrils ◽  
Continuous Phase ◽  
Pickering Emulsions ◽  
Oil Droplets ◽  
Compact Structure ◽  
Tomato Pomace ◽  
3D Network ◽  
Emulsion Stabilization

This work aimed at studying the stabilization of O/W Pickering emulsions using nanosized cellulosic material, produced from raw cellulose or tomato pomace through different mechanical treatments, such as ball milling (BM) and high-pressure homogenization (HPH). The cellulose nanofibrils obtained via HPH, which exhibited longer fibers with higher flexibility than those obtained via ball milling, are characterized by lower interfacial tension values and higher viscosity, as well as better emulsion stabilization capability. Emulsion stability tests, carried out at 4 °C for 28 d or under centrifugation at different pH values (2.0, 7.0, and 12.0), revealed that HPH-treated cellulose limited the occurrence of coalescence phenomena and significantly slowed down gravitational separation in comparison with BM-treated cellulose. HPH-treated cellulose was responsible for the formation of a 3D network structure in the continuous phase, entrapping the oil droplets also due to the affinity with the cellulose nanofibrils, whereas BM-treated cellulose produced fibers with a more compact structure, which did adequately cover the oil droplets. HPH-treated tomato pomace gave similar results in terms of particle morphology and interfacial tension, and slightly lower emulsion stabilization capability than HPH-treated cellulose, suggesting that the used mechanical disruption process does not require cellulose isolation for its efficient defibrillation.

scholarly journals Surfactant-Free Cellulose Filaments Stabilized Oil in Water Emulsions

2021 ◽  
Author(s):  
Amir Varamesh ◽  
Ragesh Prathapan ◽  
Ali Telmadarreie ◽  
Jia Li ◽  
Keith Gourlay ◽  
...  
Keyword(s):  
Droplet Size ◽  
Fluorescent Protein ◽  
Fluorescent Microscopy ◽  
Cellulose Nanofibrils ◽  
Continuous Phase ◽  
Carbohydrate Binding ◽  
Pickering Emulsions ◽  
Cellulosic Material ◽  
Oil In Water ◽  
Wide Range

Abstract There has been significant interest over recent years in the production and application of sustainable and green materials. Among these, nanocellulose has incurred great interest because of its exceptional properties and wide range of potential applications, including in Pickering emulsions. However, the production cost of these cellulosic materials has limited their application. In this study, the capability of a new type of cheaper cellulosic material, cellulose filaments (CFs), in formulating stable oil in water Pickering emulsions was investigated and compared with three conventional nanocelluloses, namely cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs) and TEMPO-oxidized CNFs (TEMPO-CNFs). Results showed that CFs can provide stable surfactant-free emulsions over wide ranges of salt concentration (0 – 500 mM) and pH (2 – 10), as indicated by the near constant oil droplet size and dewatering index of the emulsions. This is due to the ability of CFs to strongly adsorb to the oil and water interface, as evidenced by visualizing labeled CFs with engineered carbohydrate-binding module (CBM2a) conjugated with green fluorescent protein (CBM2a-eGFP) under fluorescent microscopy. Compared to the emulsions stabilized by other types of nanocelluloses, the CFs-stabilized emulsion demonstrated a larger average droplet size and comparable (with CNFs) or better (than CNCs and TEMPO-CNFs) stability, which is partially attributed to the higher viscosity of continuous phase in the presence of CFs. The results of this study demonstrate the use of CFs as a novel and cheaper cellulosic material for stabilizing emulsions, which opens the door to a range of markets from the food industry to engineering applications.

Phase Inversion in Two-Phase Liquid Systems

1992 ◽  
Vol 57 (7) ◽  
pp. 1419-1423
Author(s):  
Jindřich Weiss
Keyword(s):  
Interfacial Tension ◽  
Phase Inversion ◽  
Continuous Phase ◽  
Considerable Effect ◽  
Weak Dependence ◽  
Dispersed Phase ◽  
Two Phase ◽  
Liquid Systems ◽  
Phase Liquid

New data on critical holdups of dispersed phase were measured at which the phase inversion took place. The systems studied differed in the ratio of phase viscosities and interfacial tension. A weak dependence was found of critical holdups on the impeller revolutions and on the material contactor; on the contrary, a considerable effect of viscosity was found out as far as the viscosity of continuous phase exceeded that of dispersed phase.

scholarly journals A Core Flood and Microfluidics Investigation of Nanocellulose as a Chemical Additive to Water Flooding for EOR

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1296 ◽  
Author(s):  
Reidun C. Aadland ◽  
Salem Akarri ◽  
Ellinor B. Heggset ◽  
Kristin Syverud ◽  
Ole Torsæter
Keyword(s):  
Contact Angle ◽  
Interfacial Tension ◽  
Oil Recovery ◽  
Cellulose Nanofibrils ◽  
Water Flooding ◽  
Low Salinity ◽  
The Core ◽  
Low Salinity Water ◽  
Salinity Water ◽  
Core Flood

Cellulose nanocrystals (CNCs) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (T-CNFs) were tested as enhanced oil recovery (EOR) agents through core floods and microfluidic experiments. Both particles were mixed with low salinity water (LSW). The core floods were grouped into three parts based on the research objectives. In Part 1, secondary core flood using CNCs was compared to regular water flooding at fixed conditions, by reusing the same core plug to maintain the same pore structure. CNCs produced 5.8% of original oil in place (OOIP) more oil than LSW. For Part 2, the effect of injection scheme, temperature, and rock wettability was investigated using CNCs. The same trend was observed for the secondary floods, with CNCs performing better than their parallel experiment using LSW. Furthermore, the particles seemed to perform better under mixed-wet conditions. Additional oil (2.9–15.7% of OOIP) was produced when CNCs were injected as a tertiary EOR agent, with more incremental oil produced at high temperature. In the final part, the effect of particle type was studied. T-CNFs produced significantly more oil compared to CNCs. However, the injection of T-CNF particles resulted in a steep increase in pressure, which never stabilized. Furthermore, a filter cake was observed at the core face after the experiment was completed. Microfluidic experiments showed that both T-CNF and CNC nanofluids led to a better sweep efficiency compared to low salinity water flooding. T-CNF particles showed the ability to enhance the oil recovery by breaking up events and reducing the trapping efficiency of the porous medium. A higher flow rate resulted in lower oil recovery factors and higher remaining oil connectivity. Contact angle and interfacial tension measurements were conducted to understand the oil recovery mechanisms. CNCs altered the interfacial tension the most, while T-CNFs had the largest effect on the contact angle. However, the changes were not significant enough for them to be considered primary EOR mechanisms.

scholarly journals Powder Metallurgy Processing and Mechanical Properties of Controlled Ti-24Nb-4Zr-8Sn Heterogeneous Microstructures

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1626
Author(s):  
Benoît Fer ◽  
David Tingaud ◽  
Azziz Hocini ◽  
Yulin Hao ◽  
Eric Leroy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Ball Milling ◽  
Processing Route ◽  
Fine Grain ◽  
Plasma Sintering ◽  
3D Network ◽  
Spark Plasma ◽  
Powder Particles ◽  
Heterogeneous Microstructures

This paper gives some insights into the fabrication process of a heterogeneous structured β-metastable type Ti-24Nb-4Zr-8Sn alloy, and the associated mechanical properties optimization of this biocompatible and low elastic modulus material. The powder metallurgy processing route includes both low energy mechanical ball milling (BM) of spherical and pre-alloyed powder particles and their densification by Spark Plasma Sintering (SPS). It results in a heterogeneous microstructure which is composed of a homogeneous 3D network of β coarse grain regions called “core” and α/β dual phase ultra-fine grain regions called “shell.” However, it is possible to significantly modify the microstructural features of the alloy—including α phase and shell volume fractions—by playing with the main fabrication parameters. A focus on the role of the ball milling time is first presented and discussed. Then, the mechanical behavior via shear tests performed on selected microstructures is described and discussed in relation to the microstructure and the probable underlying deformation mechanism(s).

Effect of Fluid Properties on Droplet Generation in a Microfluidic T-Junction

2014 ◽  
Author(s):  
Katerina Loizou ◽  
Voon-Loong Wong ◽  
Wim Thielemans ◽  
Buddhika Hewakandamby
Keyword(s):  
Interfacial Tension ◽  
Scaling Laws ◽  
Viscosity Ratio ◽  
Continuous Phase ◽  
Generation Mechanism ◽  
Droplet Generation ◽  
Dispersed Phase ◽  
Supporting Evidence ◽  
Fluid Properties ◽  
Break Up

Over the last decade, significant work has been performed in an attempt to quantify the effect of different parameters such as flowrate, geometrical and fluid characteristics on the droplet break up mechanism in microfluidic T-Junctions. This demand is dictated by the need of tight control of the size and dispersity of the droplets generated in such geometries. Even though several researchers have investigated the effect of viscosity ratio on both the droplet break up mechanism as well as on the regime transition, fluid properties have not been included in most scaling laws. It is therefore evident that the contribution of fluid properties has not been quantified thoroughly. In the present work, the effect of fluid properties on the volume of droplets generated in a microfluidic T-junction is investigated. The main aim of this work is to examine the influence of viscosity of both the dispersed and continuous phase as well as the effect of interfacial tension on the size of droplet generated along with the break up mechanism. Three different oils have been utilised as continuous phase in this work to enable investigation of the effect of viscosity of the continuous phase with experiments performed at constant Capillary numbers. Various glycerol weight percentages have been employed to vary the viscosity of the dispersed phase fluid (water). Lastly, the effect of interfacial tension has been explored using two of the oils at constant μcUc (viscous force term). High speed imaging has been utilised to visualise and measure the volume of the resulting droplets. The viscosity ratio (viscosity of dispersed phase over viscosity of continuous phase) between the two phases appears to affect the droplet generation mechanism, especially for the highest viscosity ratio employed (mineral oil-water system) where the system behaves in a noticeably different way. Influence of interfacial tension is also noticeable even though less evident. In terms of the effect of viscosity of dispersed phase on the droplet generation a small difference on the volume of the droplets generated in olive oil glycerol systems is also reported. In an attempt to enumerate the effect of fluid properties on the droplet generation mechanism in a microfluidic T-junction, this paper will present supporting evidence in detail on the above and a comparison of the findings with the existing theories.

scholarly journals Novel Fabrication of Zein-Soluble Soybean Polysaccharide Nanocomposites Induced by Multifrequency Ultrasound, and Their Roles on Microstructure, Rheological Properties and Stability of Pickering Emulsions

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 166
Author(s):  
Teng Song ◽  
Zhiyu Xiong ◽  
Tong Shi ◽  
Abdul Razak Monto ◽  
Li Yuan ◽  
...  
Keyword(s):  
Particle Size ◽  
Binding Capacity ◽  
Loss Modulus ◽  
Surface Hydrophobicity ◽  
Cd Spectroscopy ◽  
Composite Nanoparticles ◽  
Pickering Emulsions ◽  
Dual Frequency ◽  
Water Binding ◽  
3D Network

In this work, soluble soybean polysaccharides (SSPS) were employed together with multifrequency ultrasound to fabricate zein nanocomposites which were conducive to enhancing the stability of high internal phase emulsions (HIPEs). Compared with non-ultrasonic treated zein colloidal particle samples (132.23 ± 0.85 nm), the zein nanoparticles samples induced by dual-frequency ultrasound exhibited a smaller particle size (114.54 ± 0.23 nm). Furthermore, the particle size of the zein composite nanoparticles (256.5 ± 4.81) remarkably increased with SPSS coating, consequently leading to larger fluorescence intensity together with lower zeta-potential (−21.90 ± 0.46 mv) and surface hydrophobicity (4992.15 ± 37.28). Meanwhile, zein-SSPS composite nanoparticles induced by DFU showed remarkably enhanced thermal stability. Fourier transform infrared (FTIR) spectroscopy and Circular dichroism (CD) spectroscopy were also used to characterize zein-SSPS composite nanoparticles. The results confirmed that DFU combined with SSPS treatment significantly increased β-sheets (from 12.60% ± 0.25 b to 21.53% ± 0.37 c) and reduced α-helix content (34.83% ± 0.71 b to 23.86% ± 0.66 a) remarkably. Notably, HIPEs prepared from zein-SSPS nanocomposites induced by dual-frequency simultaneous ultrasound (DFU) at 40/60 kHz showed better storage stability. HIPEs stabilized by DFU induced zein-SSPS nanoparticles exhibited higher storage modulus (G′) and loss modulus (G″), leading to lower fluidity, together with better stability contributing to the water-binding capacity and three-dimensional (3D) network structure of the HIPEs emulsion. The findings of this study indicate that this method can be utilized and integrated to further extend the application of zein and SSPS and explore HIPEs.

scholarly journals Silica-Supported Styrene-Co-Divinylbenzene Pickering Emulsion Polymerization: Tuning Surface Charge and Hydrophobicity by pH and Co-Aid Adsorption

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1820
Author(s):  
Benoit Fouconnier ◽  
M. Ali Aboudzadeh ◽  
Francisco López-Serrano
Keyword(s):  
Emulsion Polymerization ◽  
Crosslinking Agent ◽  
Pickering Emulsion ◽  
Ammonium Persulfate ◽  
Continuous Phase ◽  
Pickering Emulsions ◽  
Hybrid Particles ◽  
Stabilizing Agents ◽  
Pickering Emulsion Polymerization ◽  
New Strategy

In this work, polymerizations of styrene (St) in the presence of divinylbenzene (DVB) as a crosslinking agent and sodium 4-vinylbenzenesulfonate (VBS) have been performed in Pickering emulsions, using silica nanoparticles (SNps) as stabilizing agents and ammonium persulfate as a hydrophilic initiator. In oil-in-water Pickering emulsions with alkaline continuous phase (pH = 9) at 1, 2, and 3 wt% DVB (relative to St), polydisperse spheroid copolymer submicronic nanoparticles were obtained. Comparatively, polymerizations performed in Pickering emulsions with acidic continuous phase (pH = 5) allowed preparing St-co-DVB microspheres with core–shell structures at 1 wt% DVB and St-co-DVB hybrid monoliths with bi-continuous morphologies at 2 and 3 wt% DVB. It is noteworthy that this work reports Pickering emulsion polymerization as a new strategy for preparing hybrid percolated scaffolds with bi-continuous porosity. The proposed mechanisms originated by pH, DVB, and VBS and the drastic impact caused on the final morphology obtained, either hybrid particles or monoliths, are discussed herein.

scholarly journals Integrated and Sustainable Preparation of Functional Nanocellulose via Formic Acid/Choline Chloride Solvents Pretreatment

2021 ◽  
Author(s):  
Meiyan Wu ◽  
Keyu Liao ◽  
Chao Liu ◽  
Guang Yu ◽  
Mehdi Rahmaninia ◽  
...  
Keyword(s):  
Formic Acid ◽  
Ball Milling ◽  
High Efficiency ◽  
Choline Chloride ◽  
Cellulose Nanofibrils ◽  
Deep Eutectic Solvents ◽  
Whole Process ◽  
Lower Viscosity ◽  
Oil In Water ◽  
Oil Water

Abstract Formic acid/choline chloride (F-DES), one of high-efficiency deep eutectic solvents (DES) for lignocellulose pretreatment, has great potential in the production of nanocellulose (NC). In this work, the integrated preparation of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) was developed using F-DES pretreatment and the followed ball milling. Then, the properties of the resultant NC products (F-NC) were comprehensively investigated. The NC samples obtained from direct ball milling and urea/choline chloride (U-DES) plus ball milling (i.e. B-NC, and U-NC, accordingly) were used for comparison. Characterization results showed that similar to U-DES, F-DES pretreatment could effectively enhance the fibrillation of cellulose and facilitate the followed ball milling for the production of NC, and the yields of NC (CNCs plus CNFs) were over 95%. Yet, compared with B-NC and U-NC, F-NC with surface ester groups had better ability to stabilize the oil/water interface for further preparation of oil-in-water Pickering emulsion. In addition, F-DES has lower viscosity than U-DES. The recovery rate of F-DES could reach 92% after three cycles, and the recycled F-DES without obvious increase of viscosity showed better reusability to make the whole process clean and sustainable.

scholarly journals Organic Solvent Nanofiltration of Water-in-Oil Pickering Emulsions—What Influences Permeability?

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 864
Author(s):  
Maresa Vivien Kempin ◽  
Anja Drews
Keyword(s):  
Organic Solvent ◽  
Membrane Filtration ◽  
Significant Loss ◽  
Parameter Study ◽  
Pickering Emulsions ◽  
Catalyst Recycling ◽  
Filtration Performance ◽  
Multiphase Reactions ◽  
3D Network ◽  
Organic Solvent Nanofiltration

Pickering emulsions (PEs) have received increasing interest for their application in catalytic multiphase reactions. Organic solvent nanofiltration of PEs was shown to be a promising procedure for efficient and effective catalyst recycling. In this work, a systematic parameter study to identify the main influencing parameters on PE filtration was conducted for a large variety of PE compositions for the first time. In addition to temperature, only the type of organic solvent significantly influenced the filtration performance, which could be mathematically modeled via a combination of the solution–diffusion and the resistance in the series model. Particle type and concentration, dispersed phase fraction and the presence of reaction (by-)products did not show any significant impact on the permeability. The stirrer speed only became important when emulsions stabilized by particles without the tendency to form 3D network structures were filtered in long-term filtration experiments. These results pave the way towards the application of PE membrane filtration for catalyst recovery in continuous liquid/liquid multiphase reactions and enable broad operation windows. As the mechanical separation of PEs was shown to be a very robust process, the emulsion composition can now be tuned to meet the needs of the reaction without any (significant) loss in filtration performance.

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