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Chushkin Y, Gulotta A, Roosen-Runge F, Pal A, Stradner A, Schurtenberger P. Probing Cage Relaxation in Concentrated Protein Solutions by X-Ray Photon Correlation Spectroscopy. PHYSICAL REVIEW LETTERS 2022; 129:238001. [PMID: 36563210 DOI: 10.1103/physrevlett.129.238001] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 10/21/2022] [Indexed: 06/17/2023]
Abstract
Diffusion of proteins on length scales of their size is crucial for understanding the machinery of living cells. X-ray photon correlation spectroscopy (XPCS) is currently the only way to access long-time collective diffusion on these length scales, but radiation damage so far limits the use in biological systems. We apply a new approach to use XPCS to measure cage relaxation in crowded α-crystallin solutions. This allows us to correct for radiation effects, obtain missing information on long time diffusion, and support the fundamental analogy between protein and colloid dynamical arrest.
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Affiliation(s)
- Yuriy Chushkin
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
| | - Alessandro Gulotta
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
| | - Felix Roosen-Runge
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
- Department of Biomedical Science and Biofilms Research Center for Biointerfaces (BRCB), Faculty of Health and Society, Malmö University, Sweden
| | - Antara Pal
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
| | - Anna Stradner
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
- Lund Institute of advanced Neutron and X-ray Science LINXS, Lund University, Lund, Sweden
| | - Peter Schurtenberger
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
- Lund Institute of advanced Neutron and X-ray Science LINXS, Lund University, Lund, Sweden
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2
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Molecular dynamics in amorphous double active ionic liquid developed by chemical structural modification of ibuprofen. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Li Q, Peng X, Chen D, McKenna GB. Softness mapping of the concentration dependence of the dynamics in model soft colloidal systems. J Colloid Interface Sci 2021; 605:398-409. [PMID: 34332413 DOI: 10.1016/j.jcis.2021.07.089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/06/2021] [Accepted: 07/16/2021] [Indexed: 11/28/2022]
Abstract
The dynamics of a series of soft colloids comprised of polystyrene cores with poly(N-isopropylacrylamide) (PNIPAM) coronas was investigated by diffusing wave spectroscopy (DWS). The modulus of the coronas was varied by changing the cross-link density and we were able to interpret the results within a hard-soft mapping framework. The soft, swellable particle properties were modeled using an extended Flory-Rehner theory and a Hertzian pair potential. Following volume fraction jumps, softness effects on the concentration dependence of dynamics were determined, with a 'soft colloids make strong glass-forming liquid'-type of behavior observed close to the nominal glass transition volume fraction, φg. Such behavior from the current systems cannot be fully explained by the osmotic deswelling model alone. However, inspired by the soft-hard mapping from Schmiedeberg et al, [Europhys. Lett. 2011, 96(3), 36010] we estimated effective hard-sphere diameters and achieved a successful mapping of the α-relaxation times to a master curve below φg. Above φg, the curves no longer collapse but show strong deviations from a Vogel-Fulcher type of divergence onto soft jamming plateaux. Our results provide evidence that osmotic deswelling itself cannot fully explain the observed dynamics. Softness also plays an important role in the dynamics of soft, concentrated colloids.
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Affiliation(s)
- Qi Li
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Xiaoguang Peng
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Dongjie Chen
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Gregory B McKenna
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States.
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4
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Donofrio CJ, Weeks ER. Neglecting polydispersity degrades propensity measurements in supercooled liquids. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2021; 44:65. [PMID: 33970360 DOI: 10.1140/epje/s10189-021-00049-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
We conduct molecular dynamics simulations of a bidisperse Kob-Andersen (KA) glass former, modified to add in additional polydispersity. The original KA system is known to exhibit dynamical heterogeneity. Prior work defined propensity, the mean motion of a particle averaged over simulations reconstructing the initial positions of all particles but with randomized velocities. The existence of propensity shows that structure and dynamics are connected. In this paper, we study systems which mimic problems that would be encountered in measuring propensity in a colloidal glass former, where particles are polydisperse (they have slight size variations). We mimic polydispersity by altering the bidisperse KA system into a quartet consisting of particles both slightly larger and slightly smaller than the parent particles in the original bidisperse system. We then introduce errors into the reconstruction of the initial positions that mimic mistakes one might make in a colloidal experiment. The mistakes degrade the propensity measurement, in some cases nearly completely; one no longer has an iso-configurational ensemble in any useful sense. Our results show that a polydisperse sample is suitable for propensity measurements provided one avoids reconstruction mistakes.
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Affiliation(s)
| | - Eric R Weeks
- Department of Physics, Emory University, Atlanta, GA, 30322, USA.
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5
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Wang Z, Faraone A, Yin P, Porcar L, Liu Y, Do C, Hong K, Chen WR. Dynamic Equivalence between Soft Star Polymers and Hard Spheres. ACS Macro Lett 2019; 8:1467-1473. [PMID: 35651190 DOI: 10.1021/acsmacrolett.9b00617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Understanding the dynamics of soft colloids, such as star polymers, dendrimers, and microgels, is of scientific and practical importance. It is known that the excluded volume effect plays a key role in colloidal dynamics. Here, we propose a condition of compressibility equivalence that provides a simple method to experimentally evaluate the excluded volume of soft colloids from a thermodynamic view. We apply this condition to survey the dynamics of a series of star polymer dispersions. It is found that, as the concentration increases, the slowing of the long-time self-diffusivity of the star polymer, normalized by the short-time self-diffusivity, can be mapped onto the hard-sphere behavior. This phenomenon reveals the dynamic equivalence between soft colloids and hard spheres, despite the apparent complexity of the interparticle interaction of the soft colloids. The methods for measuring the osmotic compressibility and the self-diffusivities of soft colloidal dispersions are also presented.
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Affiliation(s)
- Zhe Wang
- Department of Engineering Physics and Key Laboratory of Particle and Radiation Imaging (Tsinghua University) of Ministry of Education, Tsinghua University, Beijing 100084, China.,Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Antonio Faraone
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100, United States
| | - Panchao Yin
- South China Advanced Institute for Soft Matter Science and Technology, South China University of Technology, Guangzhou 510640, China
| | - Lionel Porcar
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble CEDEX 9, France
| | - Yun Liu
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100, United States
| | - Changwoo Do
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Kunlun Hong
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Wei-Ren Chen
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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6
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Du CR, Nosenko V, Thomas HM, Lin YF, Morfill GE, Ivlev AV. Slow Dynamics in a Quasi-Two-Dimensional Binary Complex Plasma. PHYSICAL REVIEW LETTERS 2019; 123:185002. [PMID: 31763898 DOI: 10.1103/physrevlett.123.185002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/24/2019] [Indexed: 06/10/2023]
Abstract
Slow dynamics in an amorphous quasi-two-dimensional complex plasma, comprised of microparticles of two different sizes, was studied experimentally. The motion of individual particles was observed using video microscopy, and the self-part of the intermediate scattering function as well as the mean-squared particle displacement was calculated. The long-time structural relaxation reveals the characteristic behavior near the glass transition. Our results suggest that binary complex plasmas can be an excellent model system to study slow dynamics in classical supercooled fluids.
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Affiliation(s)
- Cheng-Ran Du
- College of Science, Donghua University, 201620 Shanghai, People's Republic of China
| | - Vladimir Nosenko
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt, 82234 Weßling, Germany
| | - Hubertus M Thomas
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt, 82234 Weßling, Germany
| | - Yi-Fei Lin
- College of Science, Donghua University, 201620 Shanghai, People's Republic of China
| | - Gregor E Morfill
- BMSTU Centre for Plasma Science and Technology, 105005 Moscow, Russia
| | - Alexei V Ivlev
- Max Plank Institute for Extraterrestrial Physics, 85748 Garching, Germany
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7
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Safna Hussan KP, Thayyil MS, Deshpande SK, Jinitha TV, Manoj K, Ngai KL. Molecular dynamics, physical and thermal stability of neat amorphous amlodipine besylate and in binary mixture. Eur J Pharm Sci 2018; 119:268-278. [PMID: 29702233 DOI: 10.1016/j.ejps.2018.04.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/18/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022]
Abstract
In this paper, a stable amorphous solid dispersion of an antihypertensive drug, amlodipine besylate (AMB) was prepared by entrapping it in a polymer matrix, polyvinyl pyrrollidone, in different weight ratios (AMB/PVP 05:95, 10:90, 20:80, 30:70). The glass forming ability of all binary dispersions were studied by means of differential scanning calorimetry and found good correlation between experimental Tg and Fox Flory's prediction. By considering the daily dosage limit of 5 mg, a weight ratio of 05:95 was further considered for the study. The structures of neat and binary of AMB were characterized by density functional theory, Fourier transform infrared spectroscopy, Fourier transform Raman spectroscopy and UV-visible spectroscopy. Further, detailed molecular dynamics of both pure and binary were investigated using broadband dielectric spectroscopy to judge the physical stability of the amorphous dispersions. Translation-rotation coupling of AMB possibly explains the dual conductivity and dipolar nature of the secondary relaxation in neat AMB. Thus, the binary dispersion of AMB with commercially acceptable weight ratio with strong glass forming behaviour and better shelf life was prepared and characterized for practical applications.
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Affiliation(s)
- K P Safna Hussan
- Department of Physics, University of Calicut, Malappuram, 673635, Kerala, India.
| | | | - S K Deshpande
- UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC, Mumbai, 40085, India
| | - T V Jinitha
- Department of Chemistry, University of Calicut, Malappuram, 673635, Kerala, India
| | - K Manoj
- College of Pharmaceutical Sciences, Govt. Medical College, Kozhikode, 673008, Kerala, India
| | - K L Ngai
- CNR-IPCF, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
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8
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Wang J, Wu C. Reexamination of the Origin of Slow Relaxation in Semidilute Polymer Solutions—Reptation Related or Not? Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00298] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jianqi Wang
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
- Heifei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Anhui, China
| | - Chi Wu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
- Heifei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Anhui, China
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9
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Mallamace F, Corsaro C, Mallamace D, Chen SH. The fragile-to-strong dynamical crossover and the system viscoelasticity in attractive glass forming colloids. Colloid Polym Sci 2015. [DOI: 10.1007/s00396-015-3713-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Vogel N, Retsch M, Fustin CA, del Campo A, Jonas U. Advances in Colloidal Assembly: The Design of Structure and Hierarchy in Two and Three Dimensions. Chem Rev 2015; 115:6265-311. [DOI: 10.1021/cr400081d] [Citation(s) in RCA: 531] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Nicolas Vogel
- Institute
of Particle Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Cauerstrasse
4, 91058 Erlangen, Germany
- Cluster
of Excellence - Engineering of Advanced Materials, University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Markus Retsch
- Physical
Chemistry 1 - Polymer Systems, University of Bayreuth, Universitätsstraße
30, 95447 Bayreuth, Germany
| | - Charles-André Fustin
- Institute
of Condensed Matter and Nanosciences (IMCN), Bio- and Soft Matter
Division (BSMA), Université catholique de Louvain, Place Louis
Pasteur 1, B-1348 Louvain-la-Neuve, Belgium
| | - Aranzazu del Campo
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Ulrich Jonas
- Macromolecular
Chemistry, Cμ - The Research Center for Micro- and Nanochemistry
and Engineering, University of Siegen, Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
- Bio-Organic Materials Chemistry Laboratory (BOMCLab), Institute of Electronic Structure & Laser (IESL), Foundation for Research and Technology - Hellas (FORTH), Nikolaou Plastira 100, Vassilika Vouton, P.O. Box 1527, 71110 Heraklion, Crete, Greece
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11
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Su W, Zhao K, Wei J, Ngai T. Dielectric relaxations of poly(N-isopropylacrylamide) microgels near the volume phase transition temperature: impact of cross-linking density distribution on the volume phase transition. SOFT MATTER 2014; 10:8711-8723. [PMID: 25263641 DOI: 10.1039/c4sm01516a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Dielectric relaxation behaviors of three types of thermally sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels with different cross-linking density distributions were investigated in a frequency range from 40 Hz to 110 MHz at temperatures from 15 °C to 55 °C. After eliminating the electrode polarization at low frequency, two remarkable relaxations were observed, one in the kHz frequency range and the other in the MHz range. The low-frequency relaxation is attributed to the counterion polarization in the whole measuring temperature range, while the relaxation at high-frequency is probably dominated by different polarization mechanisms depending on below or above the volume phase transition temperature (VPTT): it is considered as micro-Brownian motion of side groups of PNIPAM when T < VPTT and interfacial polarization when T > VPTT. The temperature dependence of the dielectric parameters for both the relaxations presents an abrupt change around 32.5 °C, indicating the occurrence of phase transition. Based on the analysis and discussion about the micro-Brownian motion of the side groups, a possible microstructure for the microgels before and after the collapse of PNIPAM was suggested. A dielectric model to describe the collapsing microgel suspension was proposed, from which the electrical and structural parameters of the suspension were calculated. The information on the internal structure and hydration dynamic behavior of microgels was obtained by using the thermodynamic parameters which were calculated based on the Eyring equation. Our results reveal that the spatial distribution of the cross-linking density distribution has almost no effect on the volume phase transition temperature, but markedly affects the swelling capacity of PNIPAM microgels at low temperatures.
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Affiliation(s)
- Wenjuan Su
- College of Chemistry, Beijing Normal University, Beijing 100875, China
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12
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Abstract
It has recently been shown that suspensions of long and thin charged fibrous viruses (fd) form a glass at low ionic strengths. The corresponding thick electric double layers give rise to long-ranged repulsive electrostatic interactions, which lead to caging and structural arrest at concentrations far above the isotropic-nematic coexistence region. Structural arrest and freezing of the orientational texture are found to occur at the same concentration. In addition, various types of orientational textures are equilibrated below the glass transition concentration, ranging from a chiral-nematic texture with a large pitch (of about 100 μm), an X-pattern, and a tightly packed domain texture, consisting of helical domains with a relatively small pitch (of about 10 μm) and twisted boundaries. The dynamics of both particles as well as the texture are discussed, below and above the glass transition. Dynamic light scattering correlation functions exhibit two dynamical modes, where the slow mode is attributed to the elasticity of helical domains. On approach of the glass-transition concentration, the slow mode increases in amplitude, while as the amplitudes of the fast and slow mode become equal at the glass transition. Finally, interesting features of the "transient" behaviors of charged fd-rod glass are shown as the initial caging due to structural arrest, the propagation of flow originating from stress release, and the transition to the final metastable glass state. In addition to the intensity correlation function, power spectra are presented as a function of the waiting time, at the zero-frequency limit that may access to the thermal anomalities in a charged system.
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Affiliation(s)
- Kyongok Kang
- Forschungszentrum Jülich, Institute of Complex Systems (ICS-3), D-52425 Jülich, Germany.
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13
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Mallamace F, Corsaro C, Stanley HE, Mallamace D, Chen SH. The dynamical crossover in attractive colloidal systems. J Chem Phys 2013; 139:214502. [DOI: 10.1063/1.4833595] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Kang K, Dhont JKG. Glass transition in suspensions of charged rods: structural arrest and texture dynamics. PHYSICAL REVIEW LETTERS 2013; 110:015901. [PMID: 23383809 DOI: 10.1103/physrevlett.110.015901] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Indexed: 05/20/2023]
Abstract
We report on the observation of a glass transition in suspensions of very long and thin, highly charged colloidal rods (fd-virus particles). Structural particle arrest is found to occur at a low ionic strength due to caging of the charged rods in the potential setup by their neighbors through long-ranged electrostatic interactions. The relaxation time of density fluctuations as probed by dynamic light scattering is found to diverge within a small concentration range. The rod concentration where structural particle arrest occurs is well within the full chiral-nematic state, far beyond the two-phase isotropic-nematic coexistence region. The morphology of the suspensions thus consists of nematic domains with various orientations. We quantify the dynamics of the resulting texture with image-time correlation spectroscopy. Interestingly, the decay times of image correlation functions are found to diverge in a discontinuous fashion at the same concentration of charged rods where structural particle arrest is observed. At the glass-transition concentration, we thus find both structural arrest and freezing of the texture dynamics.
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Affiliation(s)
- K Kang
- Forschungszentrum Jülich, Institute of Complex Systems, ICS-3, D-52425 Jülich, Germany
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15
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Wiemann M, Schneider R, Bartsch E. Synthesis of PEG-Stabilized Fluoro-Acrylate Particles and Study of their Glass Transition in Aqueous Dispersion. ACTA ACUST UNITED AC 2012. [DOI: 10.1524/zpch.2012.0263] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Synthesis of colloidal particles which are sterically stabilized in water and at the same time isorefractive in aqueous dispersion has been achieved by copolymerizing a fluoracrylate monomer with a PEG-macromonomer. Colloidal stability against salt addition and freeze-thawing cycles is demonstrated, indicating that the particles consist of a core of fluoroacrylate and a stabilizing surface layer of grafted PEG. To test the performance as a model system for studies of colloidal vitrification in aqueous media, the dynamics of a binary mixture of these particles with a size ratio of 0.8 and a number ratio of 1.3 (small : large particles) were studied in an isorefractive mixture of water and DMSO (≈ 11 mol % DMSO). The characteristic features of a system close to the glass transition were observed in the density density autocorrelation function f(q, τ) as measured by DLS. However, the glass transition occurred at an unexpectedly low volume fraction of 0.262. This discrepancy correlates with an unusually large difference between TEM and DLS radii and is explained by the presence of a rather extended hairy PEG surface layer.
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Affiliation(s)
- Malte Wiemann
- Department of Physical Chemistry, Freiburg, Deutschland
| | - René Schneider
- Department of Macromolecular Chemistry, Freiburg, Deutschland
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16
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Hunter GL, Weeks ER. The physics of the colloidal glass transition. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2012; 75:066501. [PMID: 22790649 DOI: 10.1088/0034-4885/75/6/066501] [Citation(s) in RCA: 334] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
As one increases the concentration of a colloidal suspension, the system exhibits a dramatic increase in viscosity. Beyond a certain concentration, the system is said to be a colloidal glass; structurally, the system resembles a liquid, yet motions within the suspension are slow enough that it can be considered essentially frozen. For several decades, colloids have served as a valuable model system for understanding the glass transition in molecular systems. The spatial and temporal scales involved allow these systems to be studied by a wide variety of experimental techniques. The focus of this review is the current state of understanding of the colloidal glass transition, with an emphasis on experimental observations. A brief introduction is given to important experimental techniques used to study the glass transition in colloids. We describe features of colloidal systems near and in glassy states, including increases in viscosity and relaxation times, dynamical heterogeneity and ageing, among others. We also compare and contrast the glass transition in colloids to that in molecular liquids. Other glassy systems are briefly discussed, as well as recently developed synthesis techniques that will keep these systems rich with interesting physics for years to come.
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Affiliation(s)
- Gary L Hunter
- Department of Physics, Emory University, Math and Science Center 400 Dowman Dr., N201 Atlanta, GA 30322, USA
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17
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Erk KA, Douglas JF. Stretched Exponential Stress Relaxation in a Thermally Reversible, Physically Associating Block Copolymer Solution. ACTA ACUST UNITED AC 2012. [DOI: 10.1557/opl.2012.335] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTThe shear stress relaxation of a thermally reversible, physically associating solution formed from a triblock copolymer in solvent selective for the mid-block was found to be well described over a broad temperature range by a stretched exponential function with a temperature independent ‘stretching exponent’, β ≈ 1/3. This same exponent value has been suggested to have particular significance in describing structural relaxation in a wide range of disordered viscoelastic materials ranging from associating polymer materials (‘gels’) to glass-forming liquids. We quantify the temperature dependence of the high frequency, or short time, shear modulus as function of temperature and find that this property also follows a variation often observed in gels and glass-forming materials.
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18
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Abstract
Colloidal dispersions have been studied for decades as a result of their utility in numerous applications and as models for molecular and atomic condensed phases. More recently, a number of groups have exploited in such studies submicrometer-sized hydrogel particles (microgels) that have environmentally tunable sizes. The experimental convenience of tuning the dispersion's colloidal volume fraction while maintaining a constant number density of particles provides a clear advantage over more tedious studies that employ traditional hard-sphere particles. However, as studies delved deeper into the fundamental physics of colloidal dispersions comprising microgel particles, it became abundantly clear that a microgel's utility as a tunable hard sphere was limited and that the impact of softness was more profound than previously appreciated. Herein we review the brief history of microgel-based colloidal dispersions and discuss their transition from tunable hard spheres to a class of soft matter that has revealed a landscape of physics and chemistry notable for its extraordinary richness and diversity.
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Affiliation(s)
- L Andrew Lyon
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, 30332, USA.
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19
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Hoffmann I, Heunemann P, Prévost S, Schweins R, Wagner NJ, Gradzielski M. Self-aggregation of mixtures of oppositely charged polyelectrolytes and surfactants studied by rheology, dynamic light scattering and small-angle neutron scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4386-4396. [PMID: 21428323 DOI: 10.1021/la104588b] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this study, the phase behavior, structure and properties of systems composed of the cationic, cellulose-based polycation JR 400 and the anionic surfactants sodium dodecylbenzenesulfonate (SDBS) or sodium dodecylethoxysulfate (SDES), mainly in the semidilute regime, were examined. This system shows the interesting feature of a very large viscosity increase by nearly 4 orders of magnitude as compared to the pure polymer solution already at very low concentrations of 1 wt%. By using rheology, dynamic light scattering (DLS), and small-angle neutron scattering (SANS), we are able to deduce systematic correlations between the molecular composition of the systems (characterized by the charge ratio Z=[+(polymer)]/[−(surfactant)]), their structural organization and the resulting macroscopic flow behavior. Mixtures in the semidilute regime with an excess of polycation charge form highly viscous network structures containing rodlike aggregates composed of surfactant and polyelectrolyte that are interconnected by the long JR 400 chains. Viscosity and storage modulus follow scaling laws as a function of surfactant concentration (η~c(s)(4); G(0)~c(s)(1.5)) and the very pronounced viscosity increase mainly arises from the strongly enhanced structural relaxation time of the systems. In contrast, mixtures with excess surfactant charges form solutions with viscosities even below those of the pure polymer solution. The combination of SANS, DLS, and rheology shows that the structural, dynamical, and rheological properties of these oppositely charged polyelectrolyte/surfactant systems can be controlled in a systematic fashion by appropriately choosing the systems composition.
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Affiliation(s)
- Ingo Hoffmann
- Stranski Laboratorium für Physikalische und Theoretische Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany.
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20
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Kiryanova EV. Temperature-concentration oscillations as a result of nanoheterophase structure of concentrated aqueous solutions of salts. CRYSTAL RESEARCH AND TECHNOLOGY 2010. [DOI: 10.1002/crat.201000168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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21
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Lietor-Santos JJ, Gasser U, Vavrin R, Hu ZB, Fernandez-Nieves A. Structural changes of poly(N-isopropylacrylamide)-based microgels induced by hydrostatic pressure and temperature studied by small angle neutron scattering. J Chem Phys 2010; 133:034901. [DOI: 10.1063/1.3447386] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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22
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Abstract
Glass formation in colloidal suspensions has many of the hallmarks of glass formation in molecular materials. For hard-sphere colloids, which interact only as a result of excluded volume, phase behaviour is controlled by volume fraction, phi; an increase in phi drives the system towards its glassy state, analogously to a decrease in temperature, T, in molecular systems. When phi increases above phi* approximately 0.53, the viscosity starts to increase significantly, and the system eventually moves out of equilibrium at the glass transition, phi(g) approximately 0.58, where particle crowding greatly restricts structural relaxation. The large particle size makes it possible to study both structure and dynamics with light scattering and imaging; colloidal suspensions have therefore provided considerable insight into the glass transition. However, hard-sphere colloidal suspensions do not exhibit the same diversity of behaviour as molecular glasses. This is highlighted by the wide variation in behaviour observed for the viscosity or structural relaxation time, tau(alpha), when the glassy state is approached in supercooled molecular liquids. This variation is characterized by the unifying concept of fragility, which has spurred the search for a 'universal' description of dynamic arrest in glass-forming liquids. For 'fragile' liquids, tau(alpha) is highly sensitive to changes in T, whereas non-fragile, or 'strong', liquids show a much lower T sensitivity. In contrast, hard-sphere colloidal suspensions are restricted to fragile behaviour, as determined by their phi dependence, ultimately limiting their utility in the study of the glass transition. Here we show that deformable colloidal particles, when studied through their concentration dependence at fixed temperature, do exhibit the same variation in fragility as that observed in the T dependence of molecular liquids at fixed volume. Their fragility is dictated by elastic properties on the scale of individual colloidal particles. Furthermore, we find an equivalent effect in molecular systems, where elasticity directly reflects fragility. Colloidal suspensions may thus provide new insight into glass formation in molecular systems.
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Ngai KL, Rendell RW. A coupling model analysis of dynamics of concentrated colloidal suspensions. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13642819808204989] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- K. L. Ngai
- a Naval Research Laboratory , Washington , DC , 20375-5320 , USA
| | - R. W. Rendell
- a Naval Research Laboratory , Washington , DC , 20375-5320 , USA
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24
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Motion of microgels in electric fields. Adv Colloid Interface Sci 2009; 147-148:178-85. [PMID: 18790469 DOI: 10.1016/j.cis.2008.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 06/30/2008] [Accepted: 07/08/2008] [Indexed: 11/23/2022]
Abstract
We review existing experimental results on the motion of microgels in the presence of electric fields and find that there can be striking differences depending on whether the polymer network comprising the microgel is neutral or charged: While for neutral microgels, the electrophoretic mobility, micro, typically decreases as the particle swells, in the case of ionic microgels, micro typically increases with particle swelling. We explain this difference in behavior by recurring to electro-osmotic fluid flows inside the particles, which are relevant in the presence of electric fields when the polymer network is ionized; these flows render the particles permeable to the solvent qualitatively changing the way to think about their electrophoretic behavior. We show that this interpretation is consistent with calculations of the drag force experienced by a permeable object as it moves inside a liquid and with recent theoretical models for the electrophoresis of soft particles. The analysis emphasizes that the electrophoresis of neutral microgels can be qualitatively treated as that of charged hard spheres, irrespective on whether the particles are swollen or de-swollen. By contrast, ionic microgels behave like free-draining polyelectrolytes in the presence of electric fields.
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25
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Vlassopoulos D, Fytas G. From Polymers to Colloids: Engineering the Dynamic Properties of Hairy Particles. HIGH SOLID DISPERSIONS 2009. [DOI: 10.1007/12_2009_31] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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26
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Monti F, Fu SY, Iliopoulos I, Cloitre M. Doubly responsive polymer-microgel composites: rheology and structure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11474-11482. [PMID: 18781781 DOI: 10.1021/la8018056] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mixtures of alkali swellable microgels and linear PNIPAm chains exhibit doubly responsive properties both with pH and temperature. Below the lower critical solution temperature (LCST), the linear chains of PNIPAm are soluble and increase the osmotic pressure outside the microgels, which causes them to deswell. Above the LCST, the PNIPAm chains become insoluble and form spherical colloidal particles confined between the microgels that subsequently reswell. The swelling and deswelling of the microgels change the rheological properties of the composites, providing a unique way to tune the elasticity of the composites with temperature. The structure of the composites above the LCST is studied using multiple light scattering and fluorescence confocal microscopy. The phase separation of PNIPAm above the LCST is strongly affected by the confinement of the PNIPAm chains between the microgels.
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Affiliation(s)
- Fabrice Monti
- Matière Molle et Chimie, UMR ESPCI-CNRS 7167, ESPCI - ParisTech, 10 rue Vauquelin, 75231 Paris, France
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27
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Capaccioli S, Thayyil MS, Ngai KL. Critical Issues of Current Research on the Dynamics Leading to Glass Transition. J Phys Chem B 2008; 112:16035-49. [DOI: 10.1021/jp8057433] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- S. Capaccioli
- Dipartimento di Fisica, Università di Pisa and CNR-INFM, polylab, Largo Bruno Pontecorvo, 3, I-56127 Pisa, Italy
| | - M. Shahin Thayyil
- Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo, 3, I-56127 Pisa, Italy, and Department of Physics, University of Calicut, Kerala, India
| | - K. L. Ngai
- Naval Research Laboratory, Washington, DC 20375-5320
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Lynch I, Miller I, Gallagher WM, Dawson KA. Novel method to prepare morphologically rich polymeric surfaces for biomedical applications via phase separation and arrest of microgel particles. J Phys Chem B 2007; 110:14581-9. [PMID: 16869558 DOI: 10.1021/jp061166a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We outline here a simple method to prepare polymeric surfaces of controlled surface topography on the micrometer scale, via assembly and arrest of microgel particles, for use in a range of biological applications to modify cell adhesion and spreading. In previous work by other groups, it has transpired that topography on the nanoscale is unlikely to be useful for this purpose, as roughness on this scale is often covered or coated by serum derived proteins during the early stages of cell adhesion and cells can easily bridge nanoscale roughness. Therefore, in our work, we have focused on roughness or topographic variations on the micrometer length scale. The basic idea is to modify the interactions between particles, thereby causing the microgel particles to phase separate into particle-dense and particle-dilute domains and to arrest these domains on the surface. The result is the creation of surfaces with controlled topography. By changing the particle size, it is possible to alter the size of the pores formed and their distribution in the film. Preliminary results show that the system can readily be arrested into a homologous series of such structures (formed from microgel particles of the same size and same chemical structure) with biological implications. At the extremes of this series, large phenotypic differences are observed between cells, ranging (at one end) from localization of the cells in the pores to (at the other end) cells that avoid such localization, and remain extended, growing along the ridges between the pores. This constitutes a sort of cell localization transition on a surface with identical chemical components, where only the morphology has been adjusted.
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Affiliation(s)
- Iseult Lynch
- Irish Centre for Colloid Science & Biomaterials, Department of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
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29
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Greenall MJ, Cates ME. Crossover behavior and multistep relaxation in a schematic model of the cut-off glass transition. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:051503. [PMID: 17677069 DOI: 10.1103/physreve.75.051503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Indexed: 05/16/2023]
Abstract
We study a schematic mode-coupling model in which the ideal glass transition is cut off by a decay of the quadratic coupling constant in the memory function. (Such a decay, on a time scale tau I , has been suggested as the likely consequence of activated processes.) If this decay is complete, so that only a linear coupling remains at late times, then the alpha relaxation shows a temporal crossover from a relaxation typical of the unmodified schematic model to a final strongly slower-than-exponential relaxation. This crossover, which differs somewhat in form from previous schematic models of the cutoff glass transition, resembles light-scattering experiments on colloidal systems, and can exhibit a "slower-than- alpha " relaxation feature hinted at there. We also consider what happens when a similar but incomplete decay occurs, so that a significant level of quadratic coupling remains for t>>tau I . In this case the correlator acquires a third, weaker relaxation mode at intermediate times. This empirically resembles the beta process seen in many molecular glass formers. It disappears when the initial as well as the final quadratic coupling lies on the liquid side of the glass transition, but remains present even when the final coupling is only just inside the liquid (so that the alpha relaxation time is finite, but too long to measure). Our results are suggestive of how, in a cutoff glass, the underlying "ideal" glass transition predicted by mode-coupling theory can remain detectable through qualitative features in dynamics.
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Affiliation(s)
- M J Greenall
- SUPA, School of Physics, University of Edinburgh, JCMB King's Buildings, Edinburgh, UK
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30
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Affiliation(s)
- E. Bartsch
- a Institut für Physikalische, Chemie Universität Mainz , Jakob-Welder-Weg , 15 D-55099 , Mainz , Germany
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31
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Schosseler F, Kaloun S, Skouri M, Munch JP. Diagram of the aging dynamics in laponite suspensions at low ionic strength. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:021401. [PMID: 16605333 DOI: 10.1103/physreve.73.021401] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Indexed: 05/08/2023]
Abstract
We measure the dynamic structure factor (DSF) of probe particles embedded in an aging laponite suspension quenched by cessation of shear and the associated relaxation time tau as a function of wave vector q and aging time t(w). The different q dependences measured in the successive exponential and full aging regimes, respectively, tau approximately q(-2) and tau approximately q(-1.25), yield a weak positive q dependence for the aging time t(wc) corresponding to the crossover between the two regimes. This implies that the full aging behavior is first seen when investigating large length scales in the aging suspension. We propose a qualitative diagram of the aging dynamics and discuss the features of the DSF of the probes and of the matrix in the two aging regimes. Consistently with the idea that the full aging regime is first observed when probing large length scales, t(wc) is markedly shorter when the motion of the probes is tracked instead of the collective fluctuations of concentration in the matrix. The exponential aging regime is most probably related to the liquid-glass transition induced by the cessation of shear rather than to the aging of a glass.
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Affiliation(s)
- F Schosseler
- Institut Charles Sadron, UPR 22, 6 rue Boussingault, 67083 Strasbourg Cedex, France
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33
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Abstract
The last decade of research in the physical sciences has seen a dramatic increase in the study of nanoscale materials. Today, "nanoscience" has emerged as a multidisciplinary effort, wherein obtaining a fundamental understanding of the optical, electrical, magnetic, and mechanical properties of nanostructures promises to deliver the next generation of functional materials for a wide range of applications. While this range of efforts is extremely broad, much of the work has focused on "hard" materials, such as Buckyballs, carbon nanotubes, metals, semiconductors, and organic or inorganic dielectrics. Meanwhile, the soft materials of current interest typically include conducting or emissive polymers for "plastic electronics" applications. Despite the continued interest in these established areas of nanoscience, new classes of soft nanomaterials are being developed from more traditional polymeric constructs. Specifically, nanostructured hydrogels are emerging as a promising group of materials for multiple biotechnology applications as the need for advanced materials in the post-genomic era grows. This review will present some of the recent advances in the marriage between water-swellable networks and nanoscience.
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Affiliation(s)
- Satish Nayak
- Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, 30332-0400, USA
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34
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Grandjean J, Mourchid A. Entropic attraction and fluid-glass transition in micellar solutions of associative diblock copolymers. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:041503. [PMID: 16383381 DOI: 10.1103/physreve.72.041503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Indexed: 05/05/2023]
Abstract
We report quantitative determination of the strength of attraction between spherical micelles of associative diblock copolymers. We offer detailed characterization of the dilute micellar solutions by neutron and dynamic light scattering techniques and by viscometry, and we interpret the data with the aid of the adhesive hard-sphere model. This model permits estimate of the stickiness parameter for varying fraction of stickers on the micelles. At this range of attraction the solutions exhibit, in the crowded regime, rheological and dynamics behavior representative of both repulsive caging and attractive bonding glassy dynamics.
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Affiliation(s)
- Julien Grandjean
- Complex Fluids Laboratory, Unité Mixte de Recherche, CNRS-Rhodia (UMR 166), Cranbury, New Jersey 08512, USA
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35
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Mason TG, Lin MY. Density profiles of temperature-sensitive microgel particles. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:040801. [PMID: 15903650 DOI: 10.1103/physreve.71.040801] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2004] [Indexed: 05/02/2023]
Abstract
We have performed small angle neutron scattering measurements (SANS) on dilute aqueous dispersions of polymer microgel particles as a function of temperature, T . The microgel particles are spherical crosslinked assemblies of a loose gel network of a poly-N-isopropylacrylamide (NIPAM) polymer. When the temperature is raised beyond a critical temperature, T(lc) approximately 32 degrees C , the polymer becomes more strongly attracted to itself than the solvent, and the microgel particles contract. The measured form factor, F (q) , for dilute suspensions of uniform microgel particles exhibits many peaks that are characteristic of solid polymer nanospheres. The position and amplitude of the peaks as a function of wave number, q , provide insight into the density profile of poly-NIPAM within the microgels. These peaks can be described well over a wide range of temperature by a model of the polymer density within the particles that is constant up to an inner radius, R1 , and decreases linearly to zero at an outer radius, R2 .
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Affiliation(s)
- T G Mason
- Department of Chemistry and Biochemistry, University of California, Los Angeles 90095, USA
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36
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Loppinet B, Fytas G, Vlassopoulos D, Likos CN, Meier G, Liu GJ. Dynamics of Dense Suspensions of Star-Like Micelles with Responsive Fixed Cores. MACROMOL CHEM PHYS 2005. [DOI: 10.1002/macp.200400165] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Cornelius V, Snowden M, Silver J, Fern G. A study of the binding of the biologically important hematin molecule to a novel imidazole containing poly(N-isopropylacrylamide) microgel. REACT FUNCT POLYM 2004. [DOI: 10.1016/j.reactfunctpolym.2003.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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38
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Chen WR, Mallamace F, Glinka CJ, Fratini E, Chen SH. Neutron- and light-scattering studies of the liquid-to-glass and glass-to-glass transitions in dense copolymer micellar solutions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 68:041402. [PMID: 14682940 DOI: 10.1103/physreve.68.041402] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2003] [Indexed: 05/24/2023]
Abstract
Recent mode coupling theory (MCT) calculations show that if a short-range attractive interaction is added to the pure hard sphere system, one may observe a new type of glass originating from the clustering effect (the attractive glass) as a result of the attractive interaction. This is in addition to the known glass-forming mechanism due to the cage effect in the hard sphere system (the repulsive glass). The calculations also indicate that if the range of attraction is sufficiently short compared to the diameter of the particle, within a certain interval of volume fractions where the two glass-forming mechanisms nearly balance each other, varying the external control parameter, the effective temperature, makes the glass-to-liquid-to-glass reentrance and the glass-to-glass transitions possible. Here we present experimental evidence of both transitions, obtained from small-angle neutron-scattering and photon correlation measurements taken from dense L64 copolymer micellar solutions in heavy water. Varying the temperature in certain predicted volume fraction range triggers a sharp transition between these two different types of glass. In particular, according to MCT, there is an end point (called A3 singularity) of this glass-to-glass transition line, beyond which the long-time dynamics of the two glasses become identical. Our findings confirm this theoretical prediction. Surprisingly, although the Debye-Waller factors, the long-time limit of the coherent intermediate scattering functions, of these two glasses obtained from photon correlation measurements indeed become identical at the predicted volume fraction, they exhibit distinctly different intermediate time relaxation. Furthermore, our experimental results obtained from volume fractions beyond the end point are characterized by the same features as the repulsive glass obtained before the end point. A complete phase diagram giving the boundaries of the structural arrest transitions for L64 micellar system is given.
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Affiliation(s)
- Wei-Ren Chen
- Department of Nuclear Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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39
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Chen SH, Chen WR, Mallamace F. The glass-to-glass transition and its end point in a copolymer micellar system. Science 2003; 300:619-22. [PMID: 12714739 DOI: 10.1126/science.1082364] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We present experimental evidence, obtained from small-angle neutron scattering and photon correlation measurements, indicating the existence of two types of structurally arrested (glassy) states in a copolymer micellar system with a short-range interparticle attractive interaction. Within a certain range of micellar volume fractions, a sharp transition between these two types of glass is observed by varying the temperature. Furthermore, we found an end point of this transition line beyond which the two glasses become identical in their local structure and their long-time dynamics. These findings confirm the recent mode-coupling theory predictions regarding the phase behavior of the structurally arrested states for this type of system.
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Affiliation(s)
- Sow-Hsin Chen
- Department of Nuclear Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
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40
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Debord SB, Lyon LA. Influence of Particle Volume Fraction on Packing in Responsive Hydrogel Colloidal Crystals. J Phys Chem B 2003. [DOI: 10.1021/jp026783n] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saet Byul Debord
- Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, Georgia 30332-0400
| | - L. Andrew Lyon
- Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, Georgia 30332-0400
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41
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Zaccarelli E, Foffi G, Dawson KA, Buldyrev SV, Sciortino F, Tartaglia P. Confirmation of anomalous dynamical arrest in attractive colloids: a molecular dynamics study. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:041402. [PMID: 12443202 DOI: 10.1103/physreve.66.041402] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2002] [Indexed: 05/24/2023]
Abstract
Previous theoretical simulation and experimental studies have indicated that particles with a short-ranged attraction exhibit a range of dynamical arrest phenomena. These include very pronounced reentrance in the dynamical arrest curve, a logarithmic singularity in the density correlation functions, and the existence of "attractive" and "repulsive" glasses. Here we carry out extensive molecular dynamics calculations on dense systems interacting via a square-well potential. This is one of the simplest systems with the required properties, and may be regarded as canonical for interpreting the phase diagram, and now also the dynamical arrest. We confirm the theoretical predictions for reentrance, logarithmic singularity, and give a direct evidence of the existence, independent of theory, of two distinct glasses. We now regard the previous predictions of these phenomena as having been established.
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Affiliation(s)
- E Zaccarelli
- Dipartimento di Fisica, Istituto Nazionale di Fisica della Materia, and INFM Center for Statistical Mechanics and Complexity, Università di Roma La Sapienza, Piazzale Aldo Moro 5, I-00185 Rome, Italy
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42
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Dawson KA. The glass paradigm for colloidal glasses, gels, and other arrested states driven by attractive interactions. Curr Opin Colloid Interface Sci 2002. [DOI: 10.1016/s1359-0294(02)00052-3] [Citation(s) in RCA: 204] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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43
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Götze W, Sperl M. Logarithmic relaxation in glass-forming systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:011405. [PMID: 12241362 DOI: 10.1103/physreve.66.011405] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2002] [Indexed: 05/23/2023]
Abstract
Within the mode-coupling theory for ideal glass transitions, an analysis of the correlation functions of glass-forming systems for states near higher-order glass-transition singularities is presented. It is shown that the solutions of the equations of motion can be asymptotically expanded in polynomials of the logarithm of time t. In leading order, a ln(t) law is obtained, and the leading corrections are given by a fourth-order polynomial. The correlators interpolate between three scenarios. First, there are surfaces in parameter space where the dominant corrections to the ln(t) law vanish, so that the logarithmic decay governs the structural relaxation process. Second, the dynamics due to the higher-order singularity can describe the initial and intermediate part of the alpha process thereby reducing the range of validity of von Schweidler's law and leading to strong alpha relaxation stretching. Third, the ln(t) law can replace the critical decay law of the beta process, leading to a particularly large crossover interval between the end of the transient and the beginning of the alpha process. This may lead to susceptibility spectra below the band of microscopic excitations exhibiting two peaks. Typical results of the theory are demonstrated for models dealing with one and two correlation functions.
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Affiliation(s)
- W Götze
- Physik Department, Technische Universität München, D-85747 Garching, Germany
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44
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Foffi G, Dawson KA, Buldyrev SV, Sciortino F, Zaccarelli E, Tartaglia P. Evidence for an unusual dynamical-arrest scenario in short-ranged colloidal systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 65:050802. [PMID: 12059519 DOI: 10.1103/physreve.65.050802] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2002] [Indexed: 05/23/2023]
Abstract
Extensive molecular dynamics simulation studies of particles interacting via a short-ranged attractive square-well potential are reported. The calculated loci of constant diffusion coefficient D in the temperature-packing fraction plane show a reentrant behavior, i.e., an increase of diffusivity on cooling, confirming an important part of the high volume-fraction dynamical-arrest scenario earlier predicted by theory for particles with short-ranged potentials. The more efficient localization mechanism induced by the short-range bonding provides, on average, additional free volume as compared to the hard-sphere case and results in faster dynamics.
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Affiliation(s)
- G Foffi
- Irish Centre for Colloid Science and Biomaterials, Department of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
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45
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Pham KN, Puertas AM, Bergenholtz J, Egelhaaf SU, Moussaïd A, Pusey PN, Schofield AB, Cates ME, Fuchs M, Poon WCK. Multiple glassy states in a simple model system. Science 2002; 296:104-6. [PMID: 11935020 DOI: 10.1126/science.1068238] [Citation(s) in RCA: 656] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Experiments, theory, and simulation were used to study glass formation in a simple model system composed of hard spheres with short-range attraction ("sticky hard spheres"). The experiments, using well-characterized colloids, revealed a reentrant glass transition line. Mode-coupling theory calculations and molecular dynamics simulations suggest that the reentrance is due to the existence of two qualitatively different glassy states: one dominated by repulsion (with structural arrest due to caging) and the other by attraction (with structural arrest due to bonding). This picture is consistent with a study of the particle dynamics in the colloid using dynamic light scattering.
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Affiliation(s)
- K N Pham
- Department of Physics and Astronomy, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK
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46
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Hellweg T, Kratz K, Pouget S, Eimer W. Internal dynamics in colloidal PNIPAM microgel particles immobilised in mesoscopic crystals. Colloids Surf A Physicochem Eng Asp 2002. [DOI: 10.1016/s0927-7757(01)01077-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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47
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48
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49
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Jund P, Jullien R, Campbell I. Random walks on fractals and stretched exponential relaxation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 63:036131. [PMID: 11308733 DOI: 10.1103/physreve.63.036131] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2000] [Indexed: 05/23/2023]
Abstract
Stretched exponential relaxation [exp-(t/tau)(beta(K))] is observed in a large variety of systems but has not been explained so far. Studying random walks on percolation clusters in curved spaces whose dimensions range from 2 to 7, we show that the relaxation is accurately a stretched exponential and is directly connected to the fractal nature of these clusters. Thus we find that in each dimension the decay exponent beta(K) is related to well-known exponents of the percolation theory in the corresponding flat space. We suggest that the stretched exponential behavior observed in many complex systems (polymers, colloids, glasses...) is due to the fractal character of their configuration space.
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Affiliation(s)
- P Jund
- Laboratoire des Verres, Université Montpellier 2, place E. Bataillon, 34095 Montpellier, France
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Dawson K, Foffi G, Fuchs M, Götze W, Sciortino F, Sperl M, Tartaglia P, Voigtmann T, Zaccarelli E. Higher-order glass-transition singularities in colloidal systems with attractive interactions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 63:011401. [PMID: 11304254 DOI: 10.1103/physreve.63.011401] [Citation(s) in RCA: 242] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2000] [Indexed: 05/23/2023]
Abstract
The transition from a liquid to a glass in colloidal suspensions of particles interacting through a hard core plus an attractive square-well potential is studied within the mode-coupling-theory framework. When the width of the attractive potential is much shorter than the hard-core diameter, a reentrant behavior of the liquid-glass line and a glass-glass-transition line are found in the temperature-density plane of the model. For small well-width values, the glass-glass-transition line terminates in a third-order bifurcation point, i.e., in a A3 (cusp) singularity. On increasing the square-well width, the glass-glass line disappears, giving rise to a fourth-order A4 (swallow-tail) singularity at a critical well width. Close to the A3 and A4 singularities the decay of the density correlators shows stretching of huge dynamical windows, in particular logarithmic time dependence.
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Affiliation(s)
- K Dawson
- Irish Centre for Colloid Science and Biomaterials, University College Dublin, Belfield
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