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Karthikeyan N, Schiller UD. Formation of bijels stabilized by magnetic ellipsoidal particles in external magnetic fields. SOFT MATTER 2024. [PMID: 39387401 DOI: 10.1039/d4sm00751d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2024]
Abstract
Bicontinuous interfacially-jammed emulsion gels (bijels) are increasingly used as emulsion templates for the fabrication of functional porous materials including membranes, electrodes, and biomaterials. Control over the domain size and structure is highly desirable in these applications. For bijels stabilized by spherical particles, particle size and volume fraction are the main parameters that determine the emulsion structure. Here, we investigate the use of ellipsoidal magnetic particles and study the effect of external magnetic fields on the formation of bijels. Using hybrid Lattice Boltzmann-molecular dynamics simulations, we analyze the effect of the magnetic field on emulsion dynamics and the structural properties of the resulting bijel. We find that the formation of bijels remains robust in the presence of magnetic fields, and that the domain size and tortuosity become anisotropic when ellipsoidal particles are used. We show that the magnetic fields lead to orientational ordering of the particles which in turn leads to alignment of the interfaces. The orientational order facilitates enhanced packing of particles in the interface which leads to different jamming times in the directions parallel and perpendicular to the field. Our results highlight the potential of magnetic particles for fabrication and processing of emulsion systems with tunable properties.
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Affiliation(s)
- Nikhil Karthikeyan
- Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA
| | - Ulf D Schiller
- Department of Computer and Information Sciences, University of Delaware, Newark, DE 19716, USA.
- Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA
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2
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Livitz D, Dhatt-Gauthier K, Bishop KJM. Magneto-capillary particle dynamics at curved interfaces: inference and criticism of dynamical models. SOFT MATTER 2023; 19:9017-9026. [PMID: 37970890 DOI: 10.1039/d3sm01256e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Time-varying fields drive the motion of magnetic particles adsorbed on liquid drops due to interfacial constraints that couple magnetic torques to capillary forces. Such magneto-capillary particle dynamics and the associated fluid flows are potentially useful for propelling drop motion, mixing drop contents, and enhancing mass transfer between phases. The design of such functions benefits from the development and validation of predictive models. Here, we apply methods of Bayesian data analysis to identify and validate a dynamical model that accurately predicts the field-driven motion of a magnetic particle adsorbed at the interface of a spherical droplet. Building on previous work, we consider candidate models that describe particle tilting at the interface, field-dependent contributions to the magnetic moment, gravitational forces, and their combinations. The analysis of each candidate is informed by particle tracking data for a magnetic Janus sphere moving in a precessing field at different frequencies and angles. We infer the uncertain parameters of each model, criticize their ability to describe and predict experimental data, and select the most probable candidate, which accounts for gravitational forces and the tilting of the Janus sphere at the interface. We show how this favored model can predict complex particle trajectories with micron-level accuracy across the range of driving fields considered. We discuss how knowledge of this "best" model can be used to design experiments that inform accurate parameter estimates or achieve desired particle trajectories.
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Affiliation(s)
- Dimitri Livitz
- Department of Chemical Engineering, 500 W 120 St, New York, NY, USA.
| | | | - Kyle J M Bishop
- Department of Chemical Engineering, 500 W 120 St, New York, NY, USA.
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3
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Dhatt-Gauthier K, Livitz D, Wu Y, Bishop KJM. Accelerating the Design of Self-Guided Microrobots in Time-Varying Magnetic Fields. JACS AU 2023; 3:611-627. [PMID: 37006772 PMCID: PMC10052236 DOI: 10.1021/jacsau.2c00499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 06/19/2023]
Abstract
Mobile robots combine sensory information with mechanical actuation to move autonomously through structured environments and perform specific tasks. The miniaturization of such robots to the size of living cells is actively pursued for applications in biomedicine, materials science, and environmental sustainability. Existing microrobots based on field-driven particles rely on knowledge of the particle position and the target destination to control particle motion through fluid environments. Often, however, these external control strategies are challenged by limited information and global actuation where a common field directs multiple robots with unknown positions. In this Perspective, we discuss how time-varying magnetic fields can be used to encode the self-guided behaviors of magnetic particles conditioned on local environmental cues. Programming these behaviors is framed as a design problem: we seek to identify the design variables (e.g., particle shape, magnetization, elasticity, stimuli-response) that achieve the desired performance in a given environment. We discuss strategies for accelerating the design process using automated experiments, computational models, statistical inference, and machine learning approaches. Based on the current understanding of field-driven particle dynamics and existing capabilities for particle fabrication and actuation, we argue that self-guided microrobots with potentially transformative capabilities are close at hand.
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Affiliation(s)
- Kiran Dhatt-Gauthier
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Dimitri Livitz
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Yiyang Wu
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Kyle J. M. Bishop
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
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4
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Suwa M, Tsukahara S, Watarai H. Applications of magnetic and electromagnetic forces in micro-analytical systems. LAB ON A CHIP 2023; 23:1097-1127. [PMID: 36636900 DOI: 10.1039/d2lc00702a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Novel applications of magnetic fields in analytical chemistry have become a remarkable trend in the last two decades. Various magnetic forces have been employed for the migration, orientation, manipulation, and trapping of microparticles, and new analytical platforms for separating and detecting molecules have been proposed. Magnetic materials such as functional magnetic nanoparticles, magnetic nanocomposites, and specially designed magnetic solids and liquids have also been developed for analytical purposes. Numerous attractive applications of magnetic and electromagnetic forces on magnetic and non-magnetic materials have been studied, but fundamental studies to understand the working principles of magnetic forces have been challenging. These studies will form a new field of magneto-analytical science, which should be developed as an interdisciplinary field. In this review, essential pioneering works and recent attractive developments are presented.
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Affiliation(s)
- M Suwa
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - S Tsukahara
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - H Watarai
- R3 Institute for Newly-Emerging Science Design, Osaka University, Toyonaka, Osaka 560-8531, Japan.
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5
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Active Colloids on Fluid Interfaces. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2022.101629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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6
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Gas generation due to photocatalysis as a method to reduce the resistance force in the process of motors motion at the air-liquid interface. J Colloid Interface Sci 2022; 627:774-782. [PMID: 35901558 DOI: 10.1016/j.jcis.2022.07.073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 11/20/2022]
Abstract
HYPOTHESIS The problem of the development of miniature motors able to move on the air-liquid interface at low Reynolds numbers is a crucial challenge due to dominating role of viscous force. To solve this problem the chemical generation of gas can be used. Generated gas pushes liquid out from the surfer surface, so the resistance force is reduced. EXPERIMENTS Surfer composed of TiO2 nanoparticles and ferromagnetic cobalt microparticles moves at the interface of an aqueous solution of hydrogen peroxide under the action of magnetic force. After irradiation with UV or visible light, the gas cavern is formed at the surfer surface due to photo-catalytic decomposition of hydrogen peroxide. As a result, the area of surfer contact with liquid is reduced. FINDINGS The resistance force acting on the surfer is reduced due to the liquid pushing out from the surfer surface. This effect is strengthened with the increase in the intensity of gas generation. The resistance force is increased when increasing the liquid viscosity or using a surfactant. The proposed method allows control of the velocity of the motors in a rather wide range by changing the gradient of the magnetic field and parameters of light.
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8
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Guzmán E, Martínez-Pedrero F, Calero C, Maestro A, Ortega F, Rubio RG. A broad perspective to particle-laden fluid interfaces systems: from chemically homogeneous particles to active colloids. Adv Colloid Interface Sci 2022; 302:102620. [PMID: 35259565 DOI: 10.1016/j.cis.2022.102620] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 01/12/2023]
Abstract
Particles adsorbed to fluid interfaces are ubiquitous in industry, nature or life. The wide range of properties arising from the assembly of particles at fluid interface has stimulated an intense research activity on shed light to the most fundamental physico-chemical aspects of these systems. These include the mechanisms driving the equilibration of the interfacial layers, trapping energy, specific inter-particle interactions and the response of the particle-laden interface to mechanical perturbations and flows. The understanding of the physico-chemistry of particle-laden interfaces becomes essential for taking advantage of the particle capacity to stabilize interfaces for the preparation of different dispersed systems (emulsions, foams or colloidosomes) and the fabrication of new reconfigurable interface-dominated devices. This review presents a detailed overview of the physico-chemical aspects that determine the behavior of particles trapped at fluid interfaces. This has been combined with some examples of real and potential applications of these systems in technological and industrial fields. It is expected that this information can provide a general perspective of the topic that can be exploited for researchers and technologist non-specialized in the study of particle-laden interfaces, or for experienced researcher seeking new questions to solve.
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Affiliation(s)
- Eduardo Guzmán
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain; Unidad de Materia Condensada, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII 1, 28040 Madrid, Spain.
| | - Fernando Martínez-Pedrero
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
| | - Carles Calero
- Departament de Física de la Matèria Condensada, Facultat de Física, Universitat de Barcelona, Avenida Diagonal 647, 08028 Barcelona, Spain; Institut de Nanociència i Nanotecnologia, IN2UB, Universitat de Barcelona, Avenida, Diagonal 647, 08028 Barcelona, Spain
| | - Armando Maestro
- Centro de Fı́sica de Materiales (CSIC, UPV/EHU)-Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain; IKERBASQUE-Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain
| | - Francisco Ortega
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain; Unidad de Materia Condensada, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII 1, 28040 Madrid, Spain
| | - Ramón G Rubio
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain; Unidad de Materia Condensada, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII 1, 28040 Madrid, Spain.
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9
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Enhanced cargo loading of electrically powered metallo-dielectric pollen bearing multiple dielectrophoretic traps. J Colloid Interface Sci 2021; 588:611-618. [PMID: 33303245 DOI: 10.1016/j.jcis.2020.10.147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 12/18/2022]
Abstract
The use of active particles for cargo transport offers unique potential for applications ranging from targeted drug delivery to lab-on-a-particle systems. Previously, deployment of metallo-dielectric Janus spherical particles (JPs) as mobile microelectrodes for transport and dielectrophoretic manipulation of cargo has been shown to be singularly controlled via an applied electric field. Herein, we extended this to a metallo-dielectric pollen featuring multiple dielectrophoretic traps associated with its many spikes, and characterized its loading capacities for various cargo sizes and frequencies. When compared to spherical JPs, the active pollen exhibited a significantly enhanced cargo loading capacity due to its multiple dielectrophoretic traps. These findings open new opportunities for application of bio-hybrid particles with diverse and irregular shapes, such as pollen, as efficient cargo carriers, local electroporation and targeted drug delivery.
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10
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Dou Y, Tzelios PM, Livitz D, Bishop KJM. Programmable topotaxis of magnetic rollers in time-varying fields. SOFT MATTER 2021; 17:1538-1547. [PMID: 33331388 DOI: 10.1039/d0sm01443e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We describe how spatially uniform, time-periodic magnetic fields can be designed to power and direct the migration of ferromagnetic spheres up (or down) local gradients in the topography of a solid substrate. Our results are based on a dynamical model that considers the time-varying magnetic torques on the particle and its motion through the fluid at low Reynolds number. We use both analytical theory and numerical simulation to design magnetic fields that maximize the migration velocity up (or down) an inclined plane. We show how "topotaxis" of spherical particles relies on differences in the hydrodynamic resistance to rotation about axes parallel and perpendicular to the plane. Importantly, the designed fields can drive multiple independent particles to move simultaneously in different directions as determined by gradients in their respective environments. Experiments on ferromagnetic spheres provide evidence for topotactic motions up inclined substrates. The ability to program the autonomous navigation of driven particles within anisotropic environments is relevant to the design of colloidal robots.
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Affiliation(s)
- Yong Dou
- Department of Chemical Engineering, Columbia University, New York, NY, USA.
| | - Peter M Tzelios
- Department of Chemical Engineering, Columbia University, New York, NY, USA.
| | - Dimitri Livitz
- Department of Chemical Engineering, Columbia University, New York, NY, USA.
| | - Kyle J M Bishop
- Department of Chemical Engineering, Columbia University, New York, NY, USA.
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11
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Xie Q, Harting J. Controllable Capillary Assembly of Magnetic Ellipsoidal Janus Particles into Tunable Rings, Chains and Hexagonal Lattices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006390. [PMID: 33448100 PMCID: PMC11468573 DOI: 10.1002/adma.202006390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Colloidal assembly at fluid interfaces has a great potential for the bottom-up fabrication of novel structured materials. However, challenges remain in realizing controllable and tunable assembly of particles into diverse structures. Herein, the capillary assembly of magnetic ellipsoidal Janus particles at a fluid-fluid interface is reported. Depending on their tilt angle, that is, the angle the particle main axis forms with the fluid interface, these particles deform the interface and generate capillary dipoles or hexapoles. Driven by capillary interactions, multiple particles thus assemble into chain-, hexagonal-lattice-, and ring-like structures, which can be actively controlled by applying an external magnetic field. A field-strength phase diagram is predicted in which various structures are present as stable states. Owing to the diversity, controllability, and tunability of assembled structures, magnetic ellipsoidal Janus particles at fluid interfaces could therefore serve as versatile building blocks for novel materials.
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Affiliation(s)
- Qingguang Xie
- Department of Applied PhysicsEindhoven University of TechnologyP.O. Box 5135600MBEindhovenThe Netherlands
| | - Jens Harting
- Helmholtz Institute Erlangen‐Nürnberg for Renewable Energy (IEK‐11)Forschungszentrum JülichFürther Str. 24890429NürnbergGermany
- Department of Chemical and Biological Engineering and Department of PhysicsFriedrich‐Alexander‐Universität Erlangen‐NürnbergFürther Str. 24890429NürnbergGermany
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12
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Martínez-Pedrero F. Static and dynamic behavior of magnetic particles at fluid interfaces. Adv Colloid Interface Sci 2020; 284:102233. [PMID: 32961419 DOI: 10.1016/j.cis.2020.102233] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 10/23/2022]
Abstract
This perspective work reviews the current status of research on magnetic particles at fluid interfaces. The article gives both a unified overview of recent experimental advances and theoretical studies centered on very different phenomena that share a common characteristic: they involve adsorbed magnetic particles that range in size from a few nanometers to several millimeters. Because of their capability of being remotely piloted through controllable external fields, magnetic particles have proven essential as building blocks in the design of new techniques, smart materials and micromachines, with new tunable properties and prospective applications in engineering and biotechnology. Once adsorbed at a fluid-fluid interfase, in a process that can be facilitated via the application of magnetic field gradients, these particles often result sorely confined to two dimensions (2D). In this configuration, inter-particle forces directed along the perpendicular to the interface are typically very small compared to the surface forces. Hence, the confinement and symmetry breaking introduced by the presence of the surface play an important role on the response of the system to the application of an external field. In monolayers of particles where the magnetic is predominant interaction, the states reached are strongly determined by the mode and orientation of the applied field, which promote different patterns and processes. Furthermore, they can reproduce some of the dynamic assemblies displayed in bulk or form new ones, that take advantage of the interfacial phenomena or of the symmetry breaking introduce by the confining boundary. Magnetic colloids are also widely used for unraveling the guiding principles of 2D dynamic self-assembly, in designs devised for producing interface transport, as tiny probes for assessing interfacial rheological properties, neglecting the bulk and inertia contributions, as well as actuated stabilizing agents in foams and emulsions.
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13
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Abstract
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Previous micromotor-based
biosensing studies used to functionalize
the surface of the micromotor with specific molecular probes for binding
of target analyte, thus limiting the use of the micromotor for the
specific target. In contrast, here, we introduce a novel approach
of using a nonfunctionalized micromotor as a generic cargo carrier
being able to perform label-free and dynamic loading, transport, and
release of functionalized beads. Hence, such an approach enables one
to use the same micromotor system for sensing of varying targets via different commercially
available functionalized beads, demonstrating the use of micromotors
as a practical and versatile means for biosensing. We have also introduced
a simplified microfluidic design that can be used for immunosensing
or DNA binding tests without necessity for complicated fluid handling
(buffer exchange, washing, etc.) steps. We expect this approach to
open up new realizations of simplified and generic biosensing platforms.
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Affiliation(s)
- Sinwook Park
- Faculty of Mechanical Engineering, Micro- and Nanofluidics Laboratory, Technion−Israel Institute of Technology, Technion City 3200000, Israel
| | - Gilad Yossifon
- Faculty of Mechanical Engineering, Micro- and Nanofluidics Laboratory, Technion−Israel Institute of Technology, Technion City 3200000, Israel
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14
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Fei W, Tzelios PM, Bishop KJM. Magneto-Capillary Particle Dynamics at Curved Interfaces: Time-Varying Fields and Drop Mixing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36. [PMID: 31859516 DOI: 10.1021/acs.langmuir.9b03119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Spatially uniform magnetic fields induce nonzero forces on magnetic particles adsorbed at curved liquid interfaces thereby driving their motion. Such motions, prohibited in bulk fluids, arise due to interfacial constraints that couple magnetic torques to capillary forces at curved interfaces. Here, we show that time-varying (spatially uniform) magnetic fields can be used to drive a variety of steady particle motions on water drops in decane. Upon application of a precessing field, magnetic Janus particles with amphiphilic surface chemistry move either along circular orbits at the drop poles or along zigzag paths at the drop equator. The different magneto-capillary motions depend on the frequency and precession angle of the field as well as the initial position of the particle on the drop surface. Our experimental observations are reproduced and explained by a mathematical model that accounts for the relevant magnetic, capillary, and hydrodynamic forces and torques that contribute to particle motion. In addition to ferromagnetic Janus particles, we show that similar dynamics can be achieved using superparamagnetic carbonyl iron particles, which are manufactured on industrial scales and respond to even weaker magnetic fields. We demonstrate how the field-driven motion of such particles at the drop interface can induce fluid flows that effectively mix the drop interior. These results suggest that magneto-capillary particle motions could be used to enhance mass transfer within emulsions stabilized by magnetic particles.
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Affiliation(s)
- Wenjie Fei
- Department of Chemical Engineering, Columbia University, New York, United States
| | - Peter M Tzelios
- Department of Chemical Engineering, Columbia University, New York, United States
| | - Kyle J M Bishop
- Department of Chemical Engineering, Columbia University, New York, United States
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15
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Long TW, Córdova-Figueroa UM, Kretzschmar I. Measuring, Modeling, and Predicting the Magnetic Assembly Rate of 2D-Staggered Janus Particle Chains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:8121-8130. [PMID: 31117723 DOI: 10.1021/acs.langmuir.9b00163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The assembly of magnetic Janus particles in a quasi-two-dimensional environment with a dipole moment shifted from the center and oriented perpendicular to the Janus cap height is studied with optical microscopy and found to adhere to a general model accounting for the particle dipole strength, the particle Brownian dynamics, the initial concentration, and, most importantly, the magnetic dipole shift. The particle aggregates are treated as diffusing spherocylinders with length and width dependent on the magnetic dipole shift. Aggregation occurs irreversibly once particle aggregates enter within a distance at which Brownian and dipole forces are equal, defined as the capture distance. The capture distance model is expressed as a general Smoluchowski coagulation rate kernel for chains of an arbitrary length, dipole strength, and dipole shift, allowing for aggregation rate predictions for related systems.
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Affiliation(s)
- Thomas W Long
- Department of Chemical Engineering , City College of the City University of New York (CUNY) , New York , New York 10031 , United States
| | - Ubaldo M Córdova-Figueroa
- Department of Chemical Engineering , University of Puerto Rico-Mayagüez (UPRM) , Mayaguez , Puerto Rico 00681 , United States
| | - Ilona Kretzschmar
- Department of Chemical Engineering , City College of the City University of New York (CUNY) , New York , New York 10031 , United States
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16
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Kirillova A, Marschelke C, Synytska A. Hybrid Janus Particles: Challenges and Opportunities for the Design of Active Functional Interfaces and Surfaces. ACS APPLIED MATERIALS & INTERFACES 2019; 11:9643-9671. [PMID: 30715834 DOI: 10.1021/acsami.8b17709] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Janus particles are a unique class of multifunctional patchy particles combining two dissimilar chemical or physical functionalities at their opposite sides. The asymmetry characteristic for Janus particles allows them to self-assemble into sophisticated structures and materials not attainable by their homogeneous counterparts. Significant breakthroughs have recently been made in the synthesis of Janus particles and the understanding of their assembly. Nevertheless, the advancement of their applications is still a challenging field. In this Review, we highlight recent developments in the use of Janus particles as building blocks for functional materials. We provide a brief introduction into the synthetic strategies for the fabrication of JPs and their properties and assembly, outlining the existing challenges. The focus of this Review is placed on the applications of Janus particles for active interfaces and surfaces. Active functional interfaces are created owing to the stabilization efficiency of Janus particles combined with their capability for interface structuring and functionalizing. Moreover, Janus particles can be employed as building blocks to fabricate active functional surfaces with controlled chemical and topographical heterogeneity. Ultimately, we will provide implications for the rational design of multifunctional materials based on Janus particles.
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Affiliation(s)
- Alina Kirillova
- Department of Mechanical Engineering and Materials Science, Edmund T. Pratt Jr. School of Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Claudia Marschelke
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6 , 01069 Dresden , Germany
- Fakultät Mathematik und Naturwissenschaften , Technische Universität Dresden , 01062 Dresden , Germany
| | - Alla Synytska
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6 , 01069 Dresden , Germany
- Fakultät Mathematik und Naturwissenschaften , Technische Universität Dresden , 01062 Dresden , Germany
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Abstract
We formulate the dynamics of overdamped Brownian active particles (swimmers) moving on any Riemannian 2-manifold. To characterize such dynamics at short times, an analytical expression for the variance of swimmers diffusing on any Riemmanian 2-manifold is derived. To show the generality of the present work, we apply the latter dynamics to swimmers moving on the surface of a spheroid and a torus, and offer analytical expressions for both their long-time variances and steady angular marginal probability density functions. Finally, Brownian dynamics simulations are used to validate our theoretical findings.
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Affiliation(s)
- Leonardo Apaza
- Faculty of Pure and Natural Sciences, Universidad Mayor de San Andres, La Paz, Bolivia
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