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Kim J, Lee J. Liquid-Suspended and Liquid-Bridged Liquid Metal Microdroplets. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2108069. [PMID: 35150080 DOI: 10.1002/smll.202108069] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/19/2022] [Indexed: 06/14/2023]
Abstract
Liquid metals (LMs) and alloys are attracting increasing attention owing to their combined advantages of high conductivity and fluidity, and have shown promising results in various emerging applications. Patterning technologies using LMs are being actively researched; among them, direct ink writing is considered a potentially viable approach for efficient LM additive manufacturing. However, true LM additive manufacturing with arbitrary printing geometries remains challenging because of the intrinsically low rheological strength of LMs. Herein, colloidal suspensions of LM droplets amenable to additive manufacturing (or "3D printing") are realized using formulations containing minute amounts of liquid capillary bridges. The resulting LM suspensions exhibit exceptionally high rheological strength with yield stress values well above 103 Pa, attributed to inter-droplet capillary attraction mediated by the liquid bridges adsorbed on the oxide skin of the LM droplets. Such liquid-bridged LM suspensions, as extrudable ink-type filaments, are based on uncurable continuous-phase liquid media, have a long pot-life and outstanding shear-thinning properties, and shape retention, demonstrating excellent rheological processability suitable for 3D printing. These findings will enable the emergence of a variety of new advanced applications that necessitate LM patterning into highly complicated multidimensional structures.
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Affiliation(s)
- Jieun Kim
- Department of Chemical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Korea
| | - Joohyung Lee
- Department of Chemical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Korea
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2
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Kim J, Jeong J, Hyun Y, Chung SK, Lee J. Electrostatic Stabilization of Nano Liquid Metals in Doped Nonpolar Liquids. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2104143. [PMID: 34623028 DOI: 10.1002/smll.202104143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/08/2021] [Indexed: 06/13/2023]
Abstract
Liquid metals and alloys are attracting renewed attention owing to their potential for application in various advanced technologies. Eutectic gallium-indium (EGaIn) has been focused on in particular because of its integrated advantages of high conductivity, low melting point, and low toxicity. In this study, the colloidal behavior of nano-dispersed EGaIn in nonpolar oils is investigated. Although the nonpolar oil continuous phase is commonly considered to be free of electric charges, electrostatic repulsion appears to be crucial in the colloidal stabilization of the nano-dispersed EGaIn phases, the modulation of which is possible by doping the oil phases with different types of oil-soluble surfactants. The qualitative correlation between the observed colloidal stabilities and the "zero field" particle mobilities inferred from the field-dependent electrophoretic mobilities indicates that the electric charging of EGaIn particles in surfactant-doped nonpolar oils is a static phenomenon that is maintained in equilibrium, rather than a solely field-induced process. A systematic investigation of the charging properties of these unique biphasic particles, consisting of the liquid Ga-In bulk and the solid Ga2 O3 surface that formed spontaneously, reveals the complicated system-dependent nature of the charging mechanisms mediated by ionic and nonionic surfactants in nonpolar media.
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Affiliation(s)
- Jieun Kim
- Department of Chemical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Korea
| | - Jinwon Jeong
- Department of Mechanical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Korea
| | - Youngbin Hyun
- Department of Mechanical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Korea
| | - Sang Kug Chung
- Department of Mechanical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Korea
| | - Joohyung Lee
- Department of Chemical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Korea
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3
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Stock S, Jakob F, Röhl S, Gräff K, Kühnhammer M, Hondow N, Micklethwaite S, Kraume M, von Klitzing R. Exploring water in oil emulsions simultaneously stabilized by solid hydrophobic silica nanospheres and hydrophilic soft PNIPAM microgel. SOFT MATTER 2021; 17:8258-8268. [PMID: 34550151 DOI: 10.1039/d1sm00942g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A general drawback of microgels is that they do not stabilize water-in-oil (w/o) emulsions of non-polar oils. Simultaneous stabilization with solid hydrophobic nanoparticles and soft hydrophilic microgels overcomes this problem. For a fundamental understanding of this synergistic effect the use of well defined particle systems is crucial. Therefore, the present study investigates the stabilization of water droplets in a highly non-polar oil phase using temperature responsive, soft and hydrophilic PNIPAM microgel particles (MGs) and solid and hydrophobic silica nanospheres (SNs) simultaneously. The SNs are about 20 times smaller than the MGs. In a multiscale approach the resulting emulsions are studied from the nanoscale particle properties over microscale droplet sizes to macroscopic observations. The synergy of the particles allows the stabilization of water-in-oil (w/o) emulsions, which was not possible with MGs alone, and offers a larger internal interface than the stabilization with SNs alone. Furthermore, the incorporation of hydrophilic MGs into a hydrophobic particle layer accelerates the emulsions sedimentation speed. Nevertheless, the droplets are still sufficiently protected against coalescence even in the sediment and can be redispersed by gentle shaking. Based on droplet size measurements and cryo-SEM studies we elaborate a model, which explains the found phenomena.
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Affiliation(s)
- Sebastian Stock
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Franziska Jakob
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Susanne Röhl
- Chair of Chemical and Process Engineering, Technische Universität Berlin, Berlin, Germany
| | - Kevin Gräff
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Matthias Kühnhammer
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Nicole Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds, UK
| | | | - Matthias Kraume
- Chair of Chemical and Process Engineering, Technische Universität Berlin, Berlin, Germany
| | - Regine von Klitzing
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
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Taboada-López MV, Bartczak D, Cuello-Núñez S, Goenaga-Infante H, Bermejo-Barrera P, Moreda-Piñeiro A. AF4-UV-ICP-MS for detection and quantification of silver nanoparticles in seafood after enzymatic hydrolysis. Talanta 2021; 232:122504. [PMID: 34074453 DOI: 10.1016/j.talanta.2021.122504] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 12/15/2022]
Abstract
A method based on asymmetric flow field-flow fractionation (AF4) coupled to ultraviolet-visible (UV-vis) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS) has been developed for silver nanoparticles (Ag NPs) detection and quantification in bivalve molluscs. Samples were pre-treated using a conventional enzymatic (pancreatin and lipase) hydrolysis procedure (37 °C, 12 h). AF4 was performed using a regenerated cellulose (RC) membrane (10 kDa, 350 μm spacer) and aqueous 5 mM Tris-HCl pH = 7.4 as carrier. AF4 separation was achieved with a program that included a focusing step with tip and focus flows of 0.20 and 3.0 mL min-1, respectively, and an injection time of 4.0 min. Elution of different size fractions was performed using a cross flow of 3.0 mL min-1 for 15 min, followed by linear cross flow decrease for 7.5 min, and a washing step for 9.4 min with no cross flow. Several bivalve molluscs (clams, oysters and variegated scallops) were analysed for total Ag content (ICP-MS after microwave assisted acid digestion), and for Ag NPs by the method presented here. Results show that Ag NPs are detected at the same elution time than proteins (UV monitoring at 280 and 405 nm), which suggests a certain interaction occurred between Ag NPs with proteins in the enzymatic extracts. AF4-UV-ICP-MS fractograms also suggest different Ag NPs size distributions for selected samples. Membrane recoveries, determined by peak area comparison of fractograms with and without application of cross flow, were within the 49-121% range. Confirmation of the presence Ag NPs in the investigated enzymatic extracts was demonstrated by SEM after an oxidative pre-treatment based on hydrogen peroxide and microwave irradiation.
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Affiliation(s)
- María Vanesa Taboada-López
- Trace Element, Spectroscopy and Speciation Group (GETEE), Strategic Grouping in Materials (AEMAT), Department of Analytical Chemistry, Nutrition and Bromatology. Faculty of Chemistry. Universidade de Santiago de Compostela. Avenida Das Ciencias, S/n. 15782, Santiago de Compostela. Spain
| | - Dorota Bartczak
- LGC Limited. Queen's Road, TW11 0LY, Teddington, United Kingdom
| | | | | | - Pilar Bermejo-Barrera
- Trace Element, Spectroscopy and Speciation Group (GETEE), Strategic Grouping in Materials (AEMAT), Department of Analytical Chemistry, Nutrition and Bromatology. Faculty of Chemistry. Universidade de Santiago de Compostela. Avenida Das Ciencias, S/n. 15782, Santiago de Compostela. Spain
| | - Antonio Moreda-Piñeiro
- Trace Element, Spectroscopy and Speciation Group (GETEE), Strategic Grouping in Materials (AEMAT), Department of Analytical Chemistry, Nutrition and Bromatology. Faculty of Chemistry. Universidade de Santiago de Compostela. Avenida Das Ciencias, S/n. 15782, Santiago de Compostela. Spain.
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5
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Stock S, Schlander A, Kempin M, Geisler R, Stehl D, Spanheimer K, Hondow N, Micklethwaite S, Weber A, Schomäcker R, Drews A, Gallei M, von Klitzing R. The quantitative impact of fluid vs. solid interfaces on the catalytic performance of pickering emulsions. Phys Chem Chem Phys 2021; 23:2355-2367. [PMID: 33449989 DOI: 10.1039/d0cp06030e] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Pickering emulsions (PEs), i.e. particle stabilized emulsions, are used as reaction environments in biphasic catalysis for the hydroformylation of 1-dodecene into tridecanal using the catalyst rhodium (Rh)-sulfoxantphos (SX). The present study connects the knowledge about particle-catalyst interactions and PE structure with the reaction results. It quantifies the efficiency of the catalytic performance of the catalyst localized in the voids between the particles (liquid-liquid interface) and the catalyst adsorbed on the particle surface (liquid-solid interface) using a new numerical approach. First, it is ensured that the overall packing density and geometry at the droplet interface and the size of the water droplets of the resulting w/o PEs are predictable. Second, it is shown that approximately all particles assemble at the droplet surface after emulsion preparation and neither the packing parameter nor the droplet size change with the particle surface charge or size when the total particle cross section is kept constant. Third, studies on the influence of the catalyst on the emulsion structure reveal that irrespective of the particle charge the surface active and negatively charged catalyst Rh-SX reduces the PE droplet size significantly and decreases the particle packing parameter from s = 0.91 (hexagonal packing in 2D) to s = 0.69 (shattered structure). In this latter case, large voids of the free w/o interface form and become covered with the catalyst. With a deep knowledge about the PE structure the reaction efficiencies of the liquid-liquid vs. the solid-liquid interface are quantified. By excluding any other influence factors, it is shown that the activity of the catalyst is the same at the fluid and solid interface and the performance of the reaction is explained by the geometry of the system. After the reaction, the catalyst retention via membrane filtration is shown to be successfully achieved without damaging the emulsions. This enables the continuous recovery of the catalyst, i.e. the most expensive compound in PE-based catalytic reactions, being a crucial criterion for industrial applications.
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Affiliation(s)
- Sebastian Stock
- Department of Physics, Soft Matter at Interfaces, Technische Universität Darmstadt, Darmstadt, Germany.
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6
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Smith GN, van Meurs S, Armes SP. The extent of counterion dissociation at the interface of cationic diblock copolymer nanoparticles in non-polar solvents. J Colloid Interface Sci 2020; 577:523-529. [PMID: 32534191 DOI: 10.1016/j.jcis.2020.04.102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 11/16/2022]
Abstract
HYPOTHESIS Diblock copolymer nanoparticles prepared in non-polar solvents that are sterically stabilized but possess ionic functionality from the inclusion of cationic comonomers in the stabilizer shell are known to exhibit complex electrokinetic behavior (Chem. Sci. 9 (2018) 922-934). For example, core-shell nanoparticles with cationic comonomers located solely within the shell layer have lower magnitude electrophoretic mobilities than nanoparticles containing the same cationic comonomers located within the core, whereas nanoparticles prepared using a minor fraction of steric stabilizer chains containing cationic comonomer repeat units have comparable electrophoretic mobilities to nanoparticles prepared with this cationic comonomer solely located within the core. We hypothesize that these observations can be explained in terms of the strength of the Coulombic interaction between counterions and the nanoparticle interface. EXPERIMENTS The highly-fluorinated anionic counterion associated with these cationic nanoparticles is studied by 19F nuclear magnetic resonance (NMR) spectroscopy in n-dodecane. This revealed only one type of 19F environment for a soluble macromolecular cation (the oil-soluble steric stabilizer chains used to prepare the nanoparticles), whereas two distinct environments were observed for the sterically-stabilized cationic nanoparticles. Both 19F diffusion NMR and 19F-13C heteronuclear single quantum correlation (HSQC) measurements support the existence of two environments for this counterion. FINDINGS The existence of two distinct 19F environments for the highly-fluorinated anion associated with the sterically-stabilized nanoparticles demonstrates the presence of spectroscopically distinguishable populations of ion pairs and of fully dissociated free anions. 19F NMR spectra recorded for sterically-stabilized nanoparticles with a fully ionic shell (all stabilizer chains containing the cationic comonomer) and those with a partly ionic shell (10% of stabilizer chains containing the cationic comonomer) reveal a higher proportion of dissociated anions in the partly ionic case. This suggests a stronger Coulombic interaction between counterions and the cationic interface when the shell is fully ionic, which accounts for the observed reduction in the magnitude of the electrophoretic mobility.
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Affiliation(s)
- Gregory N Smith
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, United Kingdom; Niels Bohr Institute, University of Copenhagen, H. C. Ørsted Institute, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
| | - Sandra van Meurs
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, United Kingdom
| | - Steven P Armes
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, United Kingdom
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7
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Smith GN. Electrolytic conductivity of ionic polymers in a nonpolar solvent. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2020; 43:52. [PMID: 32743710 DOI: 10.1140/epje/i2020-11976-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
The electrolytic conductivity of two electrolytes as solutions in the nonpolar solvent, n -dodecane, as a function of concentration has been studied. One was a small molecule electrolyte (tetraalkyl cation and a highly fluorinated tetraphenylborate anion), and the other was a macromolecular electrolyte (cation-containing poly(alkyl methacrylate) chain with the same anion). Two series of the macromolecular cation were prepared: one with entirely cation-containing molecules and the other with a small proportion (10%) cation-containing and the rest nonionic. The conductivity data were qualitatively similar for all systems, which formed both single ions and triple ions. The data from the two series of macromolecular electrolytes were particularly informative to understand some recent and counterintuitive electrokinetic data for particles that were stabilized by these polymers. Reducing the proportion of cationic chains in the stabilizer of the particles was found to increase their electrophoretic mobility. In the conductivity data in this study, reducing the proportion of cationic chains in solution was found to increase the magnitude of the single-ion equilibrium constant and suppress the formation of triple ions. These data should support the development of models to understand these electrokinetic results.
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Affiliation(s)
- Gregory N Smith
- Department of Chemistry, University of Sheffield, Brook Hill, S3 7HF, Sheffield, South Yorkshire, UK.
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8
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Robben B, Strubbe F, Beunis F, Callens M, Johansson T, Beales G, Fleming R, Neyts K. Polarity-Dependent Adsorption of Inverse Micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6521-6530. [PMID: 32441944 DOI: 10.1021/acs.langmuir.0c00943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The adsorption of charged inverse micelles at the electrode-liquid interface has an important effect on field screening and on the voltage drop over diffuse double layers. Recently, we analyzed the behavior of inverse micelles in a nonpolar liquid close to this electrode-liquid interface. For the fluorocarbon/surfactant system under study, we are in the limit of slow adsorption and negligible desorption of inverse micelles on the electrodes. Upon applying a voltage step, this results in a measurable Stern layer buildup in the time range of hours clearly distinguishable from the diffuse double layer buildup, which happens in less than 1 s. This Stern layer buildup manifests itself by a shift in the voltage drop from the diffuse double layer to the Stern layer until the voltage drop over the Stern layers reaches the applied voltage, leaving a zero bulk field without the diffuse double layer. New measurements of the transients of Stern layer buildup show that the buildup of charges in the Stern layer is more complex. We explain the observed transient behavior by introducing an asymmetry in the adsorption rate of charged inverse micelles. We provide an equivalent electrical network, an analytical solution to explain the behavior in more detail, and simulations within the diffuse double layer limit for a range of adsorption rates.
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Affiliation(s)
- Bavo Robben
- Electronics and Information Systems Department and Center for Nano and Biophotonics, Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Belgium
| | - Filip Strubbe
- Electronics and Information Systems Department and Center for Nano and Biophotonics, Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Belgium
| | - Filip Beunis
- Electronics and Information Systems Department and Center for Nano and Biophotonics, Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Belgium
| | - Michiel Callens
- CLEARink Displays, 3011 North First Street, San Jose, California 95134, United States
| | - Thomas Johansson
- CLEARink Displays, 123 Cambie Street, Suite 600, Vancouver, BC V6B 1B8, Canada
| | - Graham Beales
- CLEARink Displays, 123 Cambie Street, Suite 600, Vancouver, BC V6B 1B8, Canada
| | - Robert Fleming
- CLEARink Displays, 3011 North First Street, San Jose, California 95134, United States
| | - Kristiaan Neyts
- Electronics and Information Systems Department and Center for Nano and Biophotonics, Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Belgium
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9
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Masukawa MK, Hayakawa M, Takinoue M. Surfactant concentration modulates the motion and placement of microparticles in an inhomogeneous electric field. RSC Adv 2020; 10:8895-8904. [PMID: 35496525 PMCID: PMC9050010 DOI: 10.1039/d0ra00703j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 02/17/2020] [Indexed: 12/15/2022] Open
Abstract
This study examined the effects of surfactants on the motion and positioning of microparticles in an inhomogeneous electric field. The microparticles were suspended in oil with a surfactant and the electric field was generated using sawtooth-patterned electrodes. The microparticles were trapped, oscillating, or attached to the electrodes. The proportion of microparticles in each state was defined by the concentration of surfactant and the voltage applied to the electrodes. Based on the trajectory of the microparticles in the electric field, we developed a new physical model in which the surfactant adsorbed on the microparticles allowed the microparticles to be charged by contact with the electrodes, with either positive or negative charges, while the non-adsorbed surfactant micellizing in the oil contributed to charge relaxation. A simulation based on this model showed that the charging and charge relaxation, as modulated by the surfactant concentration, can explain the trajectories and proportion of the trapped, oscillating, and attached microparticles. These results will be useful for the development of novel self-assembly and transport technologies and colloids sensitive to electricity.
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Affiliation(s)
- Marcos K Masukawa
- Department of Computer Science, Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama Kanagawa 226-8502 Japan
| | - Masayuki Hayakawa
- Department of Computational Intelligence and Systems Science, School of Computing, Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama Kanagawa 226-8502 Japan .,RIKEN Center for Biosystems Dynamics Research Kobe Hyogo 650-0047 Japan
| | - Masahiro Takinoue
- Department of Computer Science, Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama Kanagawa 226-8502 Japan.,Department of Computational Intelligence and Systems Science, School of Computing, Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama Kanagawa 226-8502 Japan
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10
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Ponto BS, Berg JC. Nanoparticle charging with mixed reverse micelles in apolar media. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Bulavchenko AI, Shaparenko NO, Kompan’kov NB, Popovetskiy PS, Demidova MG, Arymbaeva AT. The formation of free ions and electrophoretic mobility of Ag and Au nanoparticles in n-hexadecane–chloroform mixtures at low concentrations of AOT. Phys Chem Chem Phys 2020; 22:14671-14681. [DOI: 10.1039/d0cp02153a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The electrophoretic mobility of Ag and Au nanoparticles in n-hexadecane–chloroform mixtures was studied as a function of the chloroform content (from 0 to 100 vol%).
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Affiliation(s)
| | - Nikita O. Shaparenko
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Nikolay B. Kompan’kov
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Pavel S. Popovetskiy
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Marina G. Demidova
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Aida T. Arymbaeva
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
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12
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Lim S, Park H, Yang J, Kwak C, Lee J. Stable colloidal dispersion of octylated Ti3C2-MXenes in a nonpolar solvent. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.123648] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Botin D, Wenzl J, Niu R, Palberg T. Colloidal electro-phoresis in the presence of symmetric and asymmetric electro-osmotic flow. SOFT MATTER 2018; 14:8191-8204. [PMID: 30259053 DOI: 10.1039/c8sm00934a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We characterize the electro-phoretic motion of charged sphere suspensions in the presence of substantial electro-osmotic flow using a recently introduced small angle super-heterodyne dynamic light scattering instrument (ISASH-LDV). Operation in integral mode gives access to the particle velocity distribution over the complete cell cross-section. Obtained Doppler spectra are evaluated for electro-phoretic mobility, wall electro-osmotic mobility and particle diffusion coefficient. Simultaneous measurements of differing electro-osmotic mobilities leading to asymmetric solvent flow are demonstrated in a custom made electro-kinetic cell fitting standard microscopy slides as exchangeable sidewalls. The scope and range of our approach are discussed demonstrating the possibility of an internal calibration standard and using the simultaneously measured electro-kinetic mobilities in the interpretation of a microfluidic pumping experiment involving an inhomogeneous electric field and a complex solvent flow pattern.
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Affiliation(s)
- Denis Botin
- Institute of Physics, Johannes Gutenberg University, D-55099 Mainz, Germany.
| | - Jennifer Wenzl
- Institute of Physics, Johannes Gutenberg University, D-55099 Mainz, Germany.
| | - Ran Niu
- Institute of Physics, Johannes Gutenberg University, D-55099 Mainz, Germany.
| | - Thomas Palberg
- Institute of Physics, Johannes Gutenberg University, D-55099 Mainz, Germany.
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14
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Lee J. Charge carriers created by interaction of a nonionic surfactant with water in a nonpolar medium. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2018.06.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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15
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Smith GN. Proton transfer in nonpolar solvents: an approach to generate electrolytes in aprotic media. Phys Chem Chem Phys 2018; 20:18919-18923. [PMID: 29974921 DOI: 10.1039/c8cp02349b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Stabilizing charged species in nonpolar solvents is challenging due to their low dielectric constant. As a contrast to formally ionic electrolytes, two series of acidic "potential" electrolytes have been developed in this study. These can be ionized by combining them stoichiometrically with a small molecule base in a typical nonpolar solvent, n-dodecane. The electrolytic conductivity of solutions of bis(2-ethylhexyl)phosphoric acid as mixtures with linear and branched dioctylamines and trioctylamines was measured, and the solutions were found to become increasingly conductive as the concentration increased, demonstrating that proton transfer occurred between the two species. Linear octylamines were found to be most effective at deprotonation. An acid-tipped poly(lauryl methacrylate) polymer (PLMA48-COOH) was also studied to give a polymer soluble in n-dodecane with a single ionizable group located precisely at the end of the polymer chain. Trioctylamine could successfully deprotonate this acid group. Even in an aprotic solvent, the transfer of protons between acidic and basic moieties is a useful method for controlling the properties of dissolved molecules.
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Affiliation(s)
- Gregory N Smith
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
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16
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Abstract
Highly hydrophobic, water-insoluble nonionic surfactants are often considered irrelevant to the ionization of interfaces at which they adsorb, despite observations that suggest otherwise. In the present study, we provide unambiguous evidence for the participation of a water-insoluble surfactant in interfacial ionization by conducting electrophoresis experiments for surfactant-stabilized nonpolar oil droplets in aqueous continuous phase. It was found that the surfactant with amine headgroup positively charged the surface of oil suspended in aqueous continuous phase (oil/water interface), which is consistent with its basic nature. In nonpolar oil continuous phase, the same surfactant positively charged the surface of solid silica (solid/oil interface) which is often considered acidic. The latter observation is exactly opposite to what the traditional acid-base mechanism of surface charging would predict, most clearly suggesting the possibility for another charging mechanism.
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Affiliation(s)
- Joohyung Lee
- Department of Chemical Engineering , Myongji University , Yongin , Gyeonggi 17058 , Korea
| | - Zhang-Lin Zhou
- Hewlett-Packard Company , 16399 W Bernardo Drive , San Diego , California 92127 , United States
| | - Sven Holger Behrens
- School of Chemical & Biomolecular Engineering , Georgia Institute of Technology , 311 Ferst Drive NW , Atlanta , Georgia 30332 , United States
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17
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Schreuer C, Vandewiele S, Strubbe F, Neyts K, Beunis F. Electric field induced charging of colloidal particles in a nonpolar liquid. J Colloid Interface Sci 2018; 515:248-254. [DOI: 10.1016/j.jcis.2018.01.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 10/18/2022]
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18
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Strubbe F, Neyts K. Charge transport by inverse micelles in non-polar media. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:453003. [PMID: 28895874 DOI: 10.1088/1361-648x/aa8bf6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Charged inverse micelles play an important role in the electrical charging and the electrodynamics of nonpolar colloidal dispersions relevant for applications such as electronic ink displays and liquid toner printing. This review examines the properties and the behavior of charged inverse micelles in microscale devices in the absence of colloidal particles. It is discussed how charge in nonpolar liquids is stabilized in inverse micelles and how conductivity depends on the inverse micelle size, water content and ionic impurities. Frequently used nonpolar surfactant systems are investigated with emphasis on aerosol-OT (AOT) and poly-isobutylene succinimide (PIBS) in dodecane. Charge generation in the bulk by disproportionation is studied from measurements of conductivity as a function of surfactant concentration and from generation currents in quasi steady-state. When a potential difference is applied, the steady-state situation can show electric field screening or complete charge separation. Different regimes of charge transport are identified when a voltage step is applied. It is shown how the transient and steady-state currents depend on the rate of bulk generation, on insulating layers and on the sticking or non-sticking behavior of charged inverse micelles at interfaces. For the cases of AOT and PIBS in dodecane, the magnitude of the generation rate and the type of interaction at the interface are very different.
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Affiliation(s)
- Filip Strubbe
- Electronics and Information Systems Department and Center for Nano and Biophotonics, Ghent University, Technologiepark Zwijnaarde 15, 9052 Zwijnaarde, Belgium
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19
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Prasad M, Strubbe F, Beunis F, Neyts K. Electrokinetics and behavior near the interface of colloidal particles in non-polar dispersions. SOFT MATTER 2017; 13:5604-5612. [PMID: 28737178 DOI: 10.1039/c7sm00559h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The electrokinetics and charging of nonpolar colloidal dispersions subjected to a voltage are investigated by electric current and optical measurements. From electric current measurements in response to an alternating triangular voltage with a peak value of a few hundred volts, we find that polystyrene toner particles are compacted near the electrodes and their charge increases by more than a factor of 20. The important increase of charge is interpreted by a mechanism in which counter charges, which are originally at the particle surface, are desorbed. Optical measurements performed under a dc voltage of the order of a few hundred volts demonstrate that the charge of the particles can again decrease or even be inverted. These phenomena are attributed to the movement of counter charged species from the interface layers onto the surface of the particles. The findings of this study are relevant for electrophoretic displays and liquid toner printing.
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Affiliation(s)
- Manoj Prasad
- Electronics and Information Systems, Ghent University, Technologiepark Zwijnaarde 15, 9052 Gent, Belgium.
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20
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Sethi V, Mishra J, Bhattacharyya A, Sen D, Ganguli AK. Hydrotrope induced structural modifications in CTAB/butanol/water/isooctane reverse micellar systems. Phys Chem Chem Phys 2017; 19:22033-22048. [DOI: 10.1039/c7cp03191b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
SAXS and NMR studies to gain insight of structural alterations in reverse micellar nanotemplates in presence of hydrotropes.
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Affiliation(s)
- Vaishali Sethi
- Department of Chemistry
- Indian Institute of Technology
- New Delhi-110016
- India
| | - Jayanti Mishra
- Department of Chemistry
- Indian Institute of Technology
- New Delhi-110016
- India
| | - Arpan Bhattacharyya
- Surface Physics and Material Science Division
- Saha Institute of Nuclear Physics
- Kolkata-700064
- India
| | - Debasis Sen
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai-400085
- India
| | - Ashok K. Ganguli
- Department of Chemistry
- Indian Institute of Technology
- New Delhi-110016
- India
- Institute of Nano Science & Technology
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21
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Prasad M, Strubbe F, Beunis F, Neyts K. Different Types of Charged-Inverse Micelles in Nonpolar Media. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:5796-5801. [PMID: 27231768 DOI: 10.1021/acs.langmuir.6b00468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Over the last few years, the electrodynamics of charged inverse micelles (CIMs) in nonpolar liquids and the generation mechanism and properties of newly generated CIMs have been studied extensively for the model system of polyisobutylene succinimide in dodecane. However, the newly generated CIMs, which accumulate at the electrodes when a continuous voltage is applied, behave differently compared to the regular CIMs present in equilibrium in the absence of a field. In this work, we use transient current measurements to investigate the behavior of the newly generated CIMs when the field is reduced to zero or reversed. We demonstrate that the newly generated CIMs do not participate in the diffuse double layer near the electrode formed by the regular CIMs but form an interface layer at the electrode surface. A fraction of the newly generated negative CIMs can be released from this interface layer when the field there becomes zero. The findings of this study provide a better understanding of fundamental processes in nonpolar liquids and are relevant for applications such as electronic ink displays and liquid toner printing.
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Affiliation(s)
- Manoj Prasad
- Electronics and Information Systems and Center for Nano and Biophotonics (NB-Photonics), Ghent University , Technologiepark Zwijnaarde 15, 9052 Gent, Belgium
| | - Filip Strubbe
- Electronics and Information Systems and Center for Nano and Biophotonics (NB-Photonics), Ghent University , Technologiepark Zwijnaarde 15, 9052 Gent, Belgium
| | - Filip Beunis
- Electronics and Information Systems and Center for Nano and Biophotonics (NB-Photonics), Ghent University , Technologiepark Zwijnaarde 15, 9052 Gent, Belgium
| | - Kristiaan Neyts
- Electronics and Information Systems and Center for Nano and Biophotonics (NB-Photonics), Ghent University , Technologiepark Zwijnaarde 15, 9052 Gent, Belgium
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Lee J, Zhou ZL, Behrens SH. Charging Mechanism for Polymer Particles in Nonpolar Surfactant Solutions: Influence of Polymer Type and Surface Functionality. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4827-4836. [PMID: 27135950 DOI: 10.1021/acs.langmuir.6b00583] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surface charging phenomena in nonpolar dispersions are exploited in a wide range of industrial applications, but their mechanistic understanding lags far behind. We investigate the surface charging of a variety of polymer particles with different surface functionality in alkane solutions of a custom-synthesized and purified polyisobutylene succinimide (PIBS) polyamine surfactant and a related commercial surfactant mixture commonly used to control particle charge. We find that the observed electrophoretic particle mobility cannot be explained exclusively by donor-acceptor interactions between surface functional groups and surfactant polar moieties. Our results instead suggest an interplay of multiple charging pathways, which likely include the competitive adsorption of ions generated among inverse micelles in the solution bulk. We discuss possible factors affecting the competitive adsorption of micellar ions, such as the chemical nature of the particle bulk material and the size asymmetry between inverse micelles of opposite charge.
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Affiliation(s)
- Joohyung Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
| | - Zhang-Lin Zhou
- HP Incorporated, 16399 West Bernardo Drive, San Diego, California 92127, United States
| | - Sven Holger Behrens
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
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23
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Lee J, Yezer BA, Prieve DC, Behrens SH. Janus Particles in a Nonpolar Solvent. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3095-3099. [PMID: 26974187 DOI: 10.1021/acs.langmuir.5b04255] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Amphiphilic Janus particles are currently receiving great attention as "solid surfactants". Previous studies have introduced such particles with a variety of shapes and functions, but there has so far been a strong emphasis on water-dispersible particles that mimic the molecular surfactants soluble in polar solvents. Here we present an example of lipophilic Janus particles which are selectively dispersible in very nonpolar solvents such as alkanes. Interfacial tension measurements between the alkane dispersions and pure water indicate that these particles do have interfacial activity, and like typical hydrophobic, nonionic surfactants, they do not partition to the aqueous bulk. We also show that the oil-borne particles, by retaining locally polar domains where charges can reside, generate electric conductivity in nonpolar liquids-another feature familiar from molecular surfactants and one commonly exploited to mitigate explosion hazards due to flow electrification during petroleum pumping and in the formulation of electronic inks.
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Affiliation(s)
- Joohyung Lee
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Benjamin A Yezer
- Center for Complex Fluids Engineering and Department of Chemical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Dennis C Prieve
- Center for Complex Fluids Engineering and Department of Chemical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Sven Holger Behrens
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
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