1
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Hill A, Tanaka M, Aptowicz KB, Mishra CK, Yodh AG, Ma X. Depletion-driven antiferromagnetic, paramagnetic, and ferromagnetic behavior in quasi-two-dimensional buckled colloidal solids. J Chem Phys 2023; 158:2890481. [PMID: 37184019 DOI: 10.1063/5.0146155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/10/2023] [Indexed: 05/16/2023] Open
Abstract
We investigate quasi-two-dimensional buckled colloidal monolayers on a triangular lattice with tunable depletion interactions. Without depletion attraction, the experimental system provides a colloidal analog of the well-known geometrically frustrated Ising antiferromagnet [Y. Han et al., Nature 456, 898-903 (2008)]. In this contribution, we show that the added depletion attraction can influence both the magnitude and sign of an Ising spin coupling constant. As a result, the nearest-neighbor Ising "spin" interactions can be made to vary from antiferromagnetic to para- and ferromagnetic. Using a simple theory, we compute an effective Ising nearest-neighbor coupling constant, and we show how competition between entropic effects permits for the modification of the coupling constant. We then experimentally demonstrate depletion-induced modification of the coupling constant, including its sign, and other behaviors. Depletion interactions are induced by rod-like surfactant micelles that change length with temperature and thus offer means for tuning the depletion attraction in situ. Buckled colloidal suspensions exhibit a crossover from an Ising antiferromagnetic to paramagnetic phase as a function of increasing depletion attraction. Additional dynamical experiments reveal structural arrest in various regimes of the coupling-constant, driven by different mechanisms. In total, this work introduces novel colloidal matter with "magnetic" features and complex dynamics rarely observed in traditional spin systems.
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Affiliation(s)
- Analisa Hill
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Michio Tanaka
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Kevin B Aptowicz
- Department of Physics and Engineering, West Chester University, West Chester, Pennsylvania 19383, USA
| | - Chandan K Mishra
- Discipline of Physics, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382055, India
| | - A G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Xiaoguang Ma
- Center for Complex Flows and Soft Matter Research, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
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2
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Liu P, Ning L, Zong Y, Ye F, Yang M, Chen K. Lattice Induced Short-Range Attraction between Like-Charged Colloidal Particles. PHYSICAL REVIEW LETTERS 2022; 129:018002. [PMID: 35841542 DOI: 10.1103/physrevlett.129.018002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 04/13/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
We perform experiments and computer simulations to study the effective interactions between like-charged colloidal tracers moving in a two-dimensional fluctuating background of colloidal crystal. By a counting method that properly accounts for the configurational degeneracy of tracer pairs, we extract the relative probability of finding a tracer pair in neighboring triangular cells formed by background particles. We find that this probability at the nearest neighbor cell is remarkably greater than those at cells with larger separations, implying an effective attraction between the tracers. This effective attraction weakens sharply as the background lattice constant increases. Furthermore, we clarify that the lattice-mediated effective attraction originates from the minimization of free energy increase from deformation of the crystalline background due to the presence of diffusing tracers.
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Affiliation(s)
- Peng Liu
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Luhui Ning
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Yiwu Zong
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Fangfu Ye
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Mingcheng Yang
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Ke Chen
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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3
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Singh JP, Pattanayak S, Mishra S, Chakrabarti J. Effective single component description of steady state structures of passive particles in an active bath. J Chem Phys 2022; 156:214112. [DOI: 10.1063/5.0088259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We model a binary mixture of passive and active Brownian particles in two dimensions using the effective interaction between passive particles in the active bath. The activity of active particles and the size ratio of two types of particles are the two control parameters in the system. The effective interaction is calculated from the average force on two particles generated by the active particles. The effective interaction can be attractive or repulsive, depending on the system parameters. The passive particles form four distinct structural orders for different system parameters, viz., homogeneous structures, disordered cluster, ordered cluster, and crystalline structure. The change in structure is dictated by the change in nature of the effective interaction. We further confirm the four structures using a full microscopic simulation of active and passive mixture. Our study is useful to understand the different collective behavior in non-equilibrium systems.
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Affiliation(s)
- Jay Prakash Singh
- Department of Physics, Indian Institute of Technology (BHU), Varanasi 221005, India
| | - Sudipta Pattanayak
- Laboratoire de Physique Théorique et Modélisation, CNRS UMR 8089, CY Cergy Paris Université, 95302 Cergy-Pontoise, France
| | - Shradha Mishra
- Department of Physics, Indian Institute of Technology (BHU), Varanasi 221005, India
| | - Jaydeb Chakrabarti
- S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata 700106, India
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4
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Yu JJ, Chen LF, Li GY, Li YR, Huang Y, Bake M, Tian Z. Rotational viscosity of nematic lyotropic chromonic liquid crystals. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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5
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Ma X, Mishra CK, Habdas P, Yodh AG. Structural and short-time vibrational properties of colloidal glasses and supercooled liquids in the vicinity of the re-entrant glass transition. J Chem Phys 2021; 155:074902. [PMID: 34418931 DOI: 10.1063/5.0059084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We investigate the short-time vibrational properties and structure of two-dimensional, bidisperse, colloidal glasses and supercooled liquids in the vicinity of the re-entrant glass transition, as a function of interparticle depletion attraction strength. The long-time spatiotemporal dynamics of the samples are measured to be non-monotonic, confirming that the suspensions evolve from repulsive glass to supercooled liquid to attractive glass with increasing depletion attraction. Here, we search for vibrational signatures of the re-entrant behavior in the short-time spatiotemporal dynamics, i.e., dynamics associated with particle motion inside its nearest-neighbor cage. Interestingly, we observe that the anharmonicity of these in-cage vibrations varies non-monotonically with increasing attraction strength, consistent with the non-monotonic long-time structural relaxation dynamics of the re-entrant glass. We also extract effective spring constants between neighboring particles; we find that spring stiffness involving small particles also varies non-monotonically with increasing attraction strength, while stiffness between large particles increases monotonically. Last, from study of depletion-dependent local structure and vibration participation fractions, we gain microscopic insight into the particle-size-dependent contributions to short-time vibrational modes in the glass and supercooled liquid states.
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Affiliation(s)
- Xiaoguang Ma
- Center for Complex Flows and Soft Matter Research, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Chandan K Mishra
- Discipline of Physics, Indian Institute of Technology (IIT) Gandhinagar Palaj, Gandhinagar, Gujarat 382355, India
| | - P Habdas
- Department of Physics, Saint Joseph's University, Philadelphia, Pennsylvania 19131, USA
| | - A G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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6
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Yang Q, Zhu H, Liu P, Liu R, Shi Q, Chen K, Zheng N, Ye F, Yang M. Topologically Protected Transport of Cargo in a Chiral Active Fluid Aided by Odd-Viscosity-Enhanced Depletion Interactions. PHYSICAL REVIEW LETTERS 2021; 126:198001. [PMID: 34047594 DOI: 10.1103/physrevlett.126.198001] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/22/2021] [Indexed: 06/12/2023]
Abstract
The discovery of topological edge states that unidirectionally propagate along the boundary of system without backscattering has enabled the development of new design principles for material or information transport. Here, we show that the topological edge flow supported by the chiral active fluid composed of spinners can even robustly transport an immersed intruder with the aid of the spinner-mediated depletion interaction between the intruder and boundary. Importantly, the effective interaction significantly depends on the dissipationless odd viscosity of the chiral active fluid, which originates from the spinning-induced breaking of time-reversal and parity symmetries, rendering the transport controllable. Our findings propose a novel avenue for robust cargo transport and could open a range of new possibilities throughout biological and microfluidic systems.
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Affiliation(s)
- Qing Yang
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongwei Zhu
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
- Inner Mongolia Dynamic and Mechanical Institute, Hohhot 010010, China
| | - Peng Liu
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Rui Liu
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Qingfan Shi
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Ke Chen
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Ning Zheng
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Fangfu Ye
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- Oujiang Laboratory, Wenzhou, Zhejiang 325000, China
| | - Mingcheng Yang
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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7
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Helden L, Knippenberg T, Tian L, Archambault A, Ginot F, Bechinger C. Critical Casimir interactions of colloids in micellar critical solutions. SOFT MATTER 2021; 17:2737-2741. [PMID: 33533371 DOI: 10.1039/d0sm02021d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We study the temperature-dependence of critical Casimir interactions in a critical micellar solution of the nonionic surfactant C12E5 dissolved in water. Experimentally, this is achieved with total internal reflection microscopy (TIRM) which measures the interaction between a single particle and a flat wall. For comparison, we also studied the pair interactions of a two dimensional layer of colloidal particles in the identical micellar system which yields good agreement with the TIRM results. Although, at the surfactant concentration considered here, the fluid forms a dynamical network of wormlike micelles whose structure is considerably more complex than that of simple critical molecular fluids, the temperature-dependence of the measured interactions is - for surface-to-surface distances above 160 nm - in excellent quantitative agreement with theory. Below 160 nm, deviations arise which we attribute to the adsorption of micelles to the interacting surfaces.
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Affiliation(s)
- Laurent Helden
- 2. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550, Germany.
| | - Timo Knippenberg
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany
| | - Li Tian
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany
| | - Aubin Archambault
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany
| | - Felix Ginot
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany
| | - Clemens Bechinger
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany
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8
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Feng F, Lei T, Zhao N. Tunable depletion force in active and crowded environments. Phys Rev E 2021; 103:022604. [PMID: 33736064 DOI: 10.1103/physreve.103.022604] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/12/2021] [Indexed: 12/26/2022]
Abstract
We adopt two-dimensional Langevin dynamics simulations to study the effective interactions between two passive colloids in a bath crowded with active particles. We mainly pay attention to the significant effects of active particle size, crowding-activity coupling, and chirality. First, a transition of depletion force from repulsion to attraction is revealed by varying particle size. Moreover, larger active crowders with sufficient activity can generate strong attractive force, which is in contrast to the cage effect in passive media. It is interesting that the attraction induced by large active crowders follows a linear scaling with the persistence length of active particles. Second, the effective force also experiences a transition from repulsion to attraction as volume fraction increases, as a consequence of the competition between the two contrastive factors of activity and crowding. As bath volume fraction is relatively small, activity generates a dominant repulsion force, while as the bath becomes concentrated, crowding-induced attraction becomes overwhelming. Lastly, in a chiral bath, we observe a very surprising oscillation phenomenon of active depletion force, showing an evident quasiperiodic variation with increasing chirality. Aggregation of active particles in the vicinity of the colloids is carefully examined, which serves as a reasonable picture for our observations. Our findings provide an inspiring strategy for the tunable active depletion force by crowding, activity, and chirality.
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Affiliation(s)
- Fane Feng
- Department of Physical Chemistry, College of Chemistry, Sichuan University, Chengdu 610065, China
| | - Ting Lei
- Department of Physical Chemistry, College of Chemistry, Sichuan University, Chengdu 610065, China
| | - Nanrong Zhao
- Department of Physical Chemistry, College of Chemistry, Sichuan University, Chengdu 610065, China
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9
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Liu P, Ye S, Ye F, Chen K, Yang M. Constraint Dependence of Active Depletion Forces on Passive Particles. PHYSICAL REVIEW LETTERS 2020; 124:158001. [PMID: 32357018 DOI: 10.1103/physrevlett.124.158001] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/22/2020] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
Using simulations and experiments, we demonstrate that the effective interaction between passive particles in an active bath substantially depends on an external constraint suffered by the passive particles. Particularly, the effective interaction between two free passive particles, which is directly measured in simulation, is qualitatively different from the one between two fixed particles. Moreover, we find that the friction experienced by the passive particles-a kinematic constraint-similarly influences the effective interaction. These remarkable features are in significant contrast to the equilibrium cases, and mainly arise from the accumulation of the active particles near the concave gap formed by the passive spheres. This constraint dependence not only deepens our understanding of the "active depletion force," but also provides an additional tool to tune the effective interactions in an active bath.
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Affiliation(s)
- Peng Liu
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Simin Ye
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fangfu Ye
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Ke Chen
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Mingcheng Yang
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
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10
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Ma X, Liu J, Zhang Y, Habdas P, Yodh AG. Excess entropy and long-time diffusion in colloidal fluids with short-range interparticle attraction. J Chem Phys 2019; 150:144907. [PMID: 30981231 DOI: 10.1063/1.5091564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Liquid structure and dynamics are experimentally investigated in colloidal suspensions with short-range depletion attraction. The colloidal fluid samples consist of hard-sphere colloidal particles suspended along with rodlike depletants based on surfactant micelles. The spheres have a range of surface chemistries, diameters, and packing fractions, and the rodlike micelle length depends on the temperature. Thus, the combination of hard-spheres and depletants generates a sample wherein short-range interparticle attraction can be temperature-tuned in situ. Video optical microscopy and particle tracking techniques are employed to measure particle trajectories from which structural and dynamical quantities are derived, including the particle pair correlation function [g(r)], mean square displacement, long-time diffusion coefficient, and the sample two-body excess entropy (S2). The samples with stronger short-range attractions exhibit more order, as characterized by g(r) and S2. The stronger short-range attractions are also observed to lead to slower long-time diffusion and more heterogeneous dynamics at intermediate time scales. Finally, the excess entropy scaling law prediction, i.e., the exponential relationship between two-body excess entropy and long-time diffusivity, is observed across the full range of samples.
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Affiliation(s)
- Xiaoguang Ma
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jiachen Liu
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yikang Zhang
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Piotr Habdas
- Department of Physics, Saint Joseph's University, Philadelphia, Pennsylvania 19131, USA
| | - A G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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11
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Leite LR, Lucena D, Potiguar FQ, Ferreira WP. Depletion forces on circular and elliptical obstacles induced by active matter. Phys Rev E 2016; 94:062602. [PMID: 28085454 DOI: 10.1103/physreve.94.062602] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Indexed: 06/06/2023]
Abstract
Depletion forces exerted by self-propelled particles on circular and elliptical passive objects are studied using numerical simulations. We show that a bath of active particles can induce repulsive and attractive forces which are sensitive to the shape and orientation of the passive objects (either horizontal or vertical ellipses). The resultant force on the passive objects due to the active particles is studied as a function of the shape and orientation of the passive objects, magnitude of the angular noise, and distance between the passive objects. By increasing the distance between obstacles the magnitude of the repulsive depletion force increases, as long as such a distance is less than one active particle diameter. For longer distances, the magnitude of the force always decreases with increasing distance. We also found that attractive forces may arise for vertical ellipses at high enough area fraction.
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Affiliation(s)
- L R Leite
- Universidade da Integração Internacional da Lusofonia Afro-Brasileira, Campus dos Palmares, 62785-000 Acarape, Ceará, Brazil
- Universidade Federal do Ceará, Departamento de Física Caixa Postal 6030, 60455-760 Fortaleza, Ceará, Brazil
| | - D Lucena
- Universidade Federal do Ceará, Departamento de Física Caixa Postal 6030, 60455-760 Fortaleza, Ceará, Brazil
| | - F Q Potiguar
- Universidade Federal do Pará, Faculdade de Física, ICEN, Av. Augusto Correia, 1, Guamá, 66075-110, Belém, Pará, Brazil
| | - W P Ferreira
- Universidade Federal do Ceará, Departamento de Física Caixa Postal 6030, 60455-760 Fortaleza, Ceará, Brazil
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12
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Elbaradei A, Brown SL, Miller JB, May S, Hobbie EK. Interaction of polymer-coated silicon nanocrystals with lipid bilayers and surfactant interfaces. Phys Rev E 2016; 94:042804. [PMID: 27841530 DOI: 10.1103/physreve.94.042804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 06/06/2023]
Abstract
We use photoluminescence (PL) microscopy to measure the interaction between polyethylene-glycol-coated (PEGylated) silicon nanocrystals (SiNCs) and two model surfaces: lipid bilayers and surfactant interfaces. By characterizing the photostability, transport, and size-dependent emission of the PEGylated nanocrystal clusters, we demonstrate the retention of red PL suitable for detection and tracking with minimal blueshift after a year in an aqueous environment. The predominant interaction measured for both interfaces is short-range repulsion, consistent with the ideal behavior anticipated for PEGylated phospholipid coatings. However, we also observe unanticipated attractive behavior in a small number of scenarios for both interfaces. We attribute this anomaly to defective PEG coverage on a subset of the clusters, suggesting a possible strategy for enhancing cellular uptake by controlling the homogeneity of the PEG corona. In both scenarios, the shape of the apparent potential is modeled through the free or bound diffusion of the clusters near the confining interface.
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Affiliation(s)
- Ahmed Elbaradei
- North Dakota State University, Fargo, North Dakota 58108, USA
| | - Samuel L Brown
- North Dakota State University, Fargo, North Dakota 58108, USA
| | - Joseph B Miller
- North Dakota State University, Fargo, North Dakota 58108, USA
| | - Sylvio May
- North Dakota State University, Fargo, North Dakota 58108, USA
| | - Erik K Hobbie
- North Dakota State University, Fargo, North Dakota 58108, USA
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13
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Gratale MD, Ma X, Davidson ZS, Still T, Habdas P, Yodh AG. Vibrational properties of quasi-two-dimensional colloidal glasses with varying interparticle attraction. Phys Rev E 2016; 94:042606. [PMID: 27841543 DOI: 10.1103/physreve.94.042606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Indexed: 06/06/2023]
Abstract
We measure the vibrational modes and particle dynamics of quasi-two-dimensional colloidal glasses as a function of interparticle interaction strength. The interparticle attractions are controlled via a temperature-tunable depletion interaction. Specifically, the interparticle attraction energy is increased gradually from a very small value (nearly hard-sphere) to moderate strength (∼4k_{B}T), and the variation of colloidal particle dynamics and vibrations are concurrently probed. The particle dynamics slow monotonically with increasing attraction strength, and the particle motions saturate for strengths greater than ∼2k_{B}T, i.e., as the system evolves from a nearly repulsive glass to an attractive glass. The shape of the phonon density of states is revealed to change with increasing attraction strength, and the number of low-frequency modes exhibits a crossover for glasses with weak compared to strong interparticle attraction at a threshold of ∼2k_{B}T. This variation in the properties of the low-frequency vibrational modes suggests a new means for distinguishing between repulsive and attractive glass states.
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Affiliation(s)
- Matthew D Gratale
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Xiaoguang Ma
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Complex Assemblies of Soft Matter, CNRS-Solvay-UPenn UMI 3254, Bristol, Pennsylvania 19007-3624, USA
| | - Zoey S Davidson
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Tim Still
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Piotr Habdas
- Department of Physics, Saint Joseph's University, Philadelphia, Pennsylvania 19131, USA
| | - A G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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