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Shimma Y, Sato T, Baglioni P, Ogura T. Hierarchical Emulsion Structure and Functionality Regulated by Coexisting Bicontinuous Microemulsion and Liquid Crystal Domains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:4077-4086. [PMID: 38346388 DOI: 10.1021/acs.langmuir.3c02935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Since microemulsions are usually low viscosity fluids, enhanced rheological properties while maintaining their structure-derived functionality have long been desired from an industrial application point of view. However, for instance, it is practically difficult to thicken bicontinuous microemulsions (BCMEs) without perturbing their alternating domain structure or to emulsify oils using BCME having ultralow interfacial tension as an external phase. In this study, a methodology called a BCLC emulsification technique has been constructed to obtain oil-in-water emulsions stabilized by coexisting BCME and liquid crystal (LC) phases. The produced emulsions based on polyglyceryl-10 diisostearate, polyglyceryl-6 dicaprate, cetyl ethylhexanoate, and water are structurally scrutinized by means of small- and wide-angle X-ray scattering (SWAXS), freeze fracture transmission electron microscopy (FF-TEM), and scanning electron assisted dielectric microscopy (SE-ADM). The data provide experimental evidence that this methodology enables one to control the bending elasticity of the interfacial membranes and consequent long-range order of the BCME domains. Moreover, closely correlated with the interfacial membrane properties, submicrometer-sized fine oil droplets are supported by the LC networks and agglomerated into spongy or network-like phase-separation patterns. The resulting nonfluidic, jelly emulsions are particularly useful in cosmetics because of combined BCME-derived high cleansing performance and excellent usability owing to the enhanced viscosity. The thickening mechanisms are essentially different from those of common lamellar-gel-stabilized oil-in-water emulsions, which utilize crystalline lamellar gel networks as oil droplet stabilizers.
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Affiliation(s)
- Yuko Shimma
- ALBION Co., Ltd., 2-24-11 Higashi-Nihonbashi, Chuo-ku, Tokyo 103-0004, Japan
| | - Takaaki Sato
- Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Piero Baglioni
- Department of Chemistry and CSGI, University of Florence, 50019 Sesto Fiorentino, Florence, Italy
| | - Taku Ogura
- NIKKOL GROUP, Nikko Chemicals Co., Ltd., 1-4-8 Nihonbashibakurocho, Chuo-ku, Tokyo 103-0002, Japan
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Negem M, Miller D, Irvine J, Heakal FET. Water/oil nanoemulsion-based synthesis of Bi xSn 6-2xS y (0.33 ≤ × ≤ 2.95) semiconductor QDs for efficient photocatalytic degradation of MB dye. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:58998-59012. [PMID: 37000392 DOI: 10.1007/s11356-023-26596-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 03/17/2023] [Indexed: 05/10/2023]
Abstract
The development of efficient photocatalysts for the photodegradation of organic dyes in wastewater is highly worthwhile. Herein, the nanoemulsion tactic was utilized to synthesize BixSn6-2xSy (0.33 ≤ x ≤ 2.95) photocatalysts with morphological structures that changed from nanowhiskers to quantum dots (QDs). The optical properties of these materials were examined by UV-visible absorbance spectroscopy and photoluminescence, while Mott-Schottky analysis was utilized to study their electronic properties. BixSn6-2xSy materials exhibit appreciable absorption in the UV-visible light range with a direct band gap that increases from 1.23 to 1.46 eV. Both crystal structure and composition greatly affect the photocatalytic activity of BixSn6-2xSy semiconductors. Among the various synthesized photocatalysts, BiSn4S4.5 can efficiently photodegrade methylene blue dye (MB) in the shortest time under UV-visible light. The photocatalytic activity is positively affected by the change of crystal structure from orthorhombic to cubic symmetry. Based on the Mott-Schottky plots, the flat band potential (Efb) and the semiconductor behavior of the fabricated BixSn6-2xSy nanomaterials were determined. The obtained Efb values for SnS, Bi0.33Sn5.34S5.8, BiSn4S5.5, and Bi2.14Sn1.71S4.7 are -0.18 V, -0.42 V, -0.53 V, and -0.51 V (vs. Ag/AgCl), respectively. The Efb value is clearly shifted towards more negative potential values with increasing the Bi molar ratio (x). However, Bi2.95Sn0.1S4.5 semiconductor was found to be of n-type character, having a positive Efb value of +0.66 V (vs. Ag/AgCl). Photocurrent and EIS responses confirm the high stability and photocatalytic activity of BiSn4S5.5, which also achieves the lowest charge transfer resistance. The modified electronic properties of the BixSn6-2xSy semiconductors significantly improve their photocatalytic activity, rendering them to be promising absorbers for sunlight harvesting applications.
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Affiliation(s)
- Mosaad Negem
- Chemistry Department, Faculty of Science, Fayoum University, Fayoum, Egypt
| | - David Miller
- School of Chemistry, EaSTChem, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - John Irvine
- School of Chemistry, EaSTChem, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
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Mahmoudabadbozchelou M, Karniadakis GE, Jamali S. nn-PINNs: Non-Newtonian physics-informed neural networks for complex fluid modeling. SOFT MATTER 2021; 18:172-185. [PMID: 34859251 DOI: 10.1039/d1sm01298c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Time- and rate-dependent material functions in non-Newtonian fluids in response to different deformation fields pose a challenge in integrating different constitutive models into conventional computational fluid dynamic platforms. Considering their relevance in many industrial and natural settings alike, robust data-driven frameworks that enable accurate modeling of these complex fluids are of great interest. The main goal is to solve the coupled Partial Differential Equations (PDEs) consisting of the constitutive equations that relate the shear stress to the deformation and fully capture the behavior of the fluid under various flow protocols with different boundary conditions. In this work, we present non-Newtonian physics-informed neural networks (nn-PINNs) for solving systems of coupled PDEs adopted for complex fluid flow modeling. The proposed nn-PINN method is employed to solve the constitutive models in conjunction with conservation of mass and momentum by benefiting from Automatic Differentiation (AD) in neural networks, hence avoiding the mesh generation step. nn-PINNs are tested for a number of different complex fluids with different constitutive models and for several flow protocols. These include a range of Generalized Newtonian Fluid (GNF) empirical constitutive models, as well as some phenomenological models with memory effects and thixotropic timescales. nn-PINNs are found to obtain the correct solution of complex fluids in spatiotemporal domains with good accuracy compared to the ground truth solution. We also present applications of nn-PINNs for complex fluid modeling problems with unknown boundary conditions on the surface, and show that our approach can successfully recover the velocity and stress fields across the domain, including the boundaries, given some sparse velocity measurements.
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Affiliation(s)
| | - George Em Karniadakis
- Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912, USA
| | - Safa Jamali
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, USA.
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Rheology-Informed Neural Networks (RhINNs) for forward and inverse metamodelling of complex fluids. Sci Rep 2021; 11:12015. [PMID: 34103602 PMCID: PMC8187644 DOI: 10.1038/s41598-021-91518-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/27/2021] [Indexed: 11/24/2022] Open
Abstract
Reliable and accurate prediction of complex fluids’ response under flow is of great interest across many disciplines, from biological systems to virtually all soft materials. The challenge is to solve non-trivial time and rate dependent constitutive equations to describe these structured fluids under various flow protocols. We present Rheology-Informed Neural Networks (RhINNs) for solving systems of Ordinary Differential Equations (ODEs) adopted for complex fluids. The proposed RhINNs are employed to solve the constitutive models with multiple
ODEs by benefiting from Automatic Differentiation in neural networks. In a direct solution, the RhINNs platform accurately predicts the fully resolved solution of constitutive equations for a Thixotropic-Elasto-Visco-Plastic (TEVP) complex fluid for a series of flow protocols. From a practical perspective, an exhaustive list of experiments are required to identify model parameters for a multi-variant constitutive TEVP model. RhINNs are found to learn these non-trivial model parameters for a complex material using a single flow protocol, enabling accurate modeling with limited number of experiments and at an unprecedented rate. We also show the RhINNs are not limited to a specific model and can be extended to include various models and recover complex manifestations of kinematic heterogeneities and transient shear banding of thixotropic fluids.
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Yu G, Walker M, Wilson MR. Atomistic simulation studies of ionic cyanine dyes: self-assembly and aggregate formation in aqueous solution. Phys Chem Chem Phys 2021; 23:6408-6421. [PMID: 33705506 DOI: 10.1039/d0cp06205g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cyanine dyes are known to form large-scale aggregates of various morphologies via spontaneous self-assembly in aqueous solution, akin to chromonic liquid crystals. Atomistic molecular dynamics simulations have been performed on four cyanine dyes: pseudoisocyanine chloride (PIC), pinacyanol chloride (PCYN), 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine chloride (TTBC) and 1,1'-disulfopropyl-3,3'-diethyl-5,5',6,6'-tetrachloro-benzimidazolylcarbocyanine sodium salt (BIC). Simulations employed an optimised general AMBER force field and demonstrate the organisation of the dyes into stacked structures at dilute concentrations. The thermodynamics of self-assembly was studied by calculating potentials of mean force for n-mers (n = 2, 3 or 4), from which the free energies of association are determined. We report binding free energies in the range of 8 to 15kBT for dimerisation, concordant with typical values for ionic chromonics (7 to 14kBT), and examine the enthalpic and entropic contributions to the aggregation process. The self-assembly of these dyes yields two distinct classes of structures. We observe the formation of H-aggregate stacks for PCYN, with further complexity in these assemblies for PIC; where the aggregates contain shift and Y junction defects. TTBC and BIC associate into a J-aggregate sheet structure of unimolecular thickness, and is composed of a brickwork arrangement between molecules. These sheet structures are characteristic of the smectic chromonic mesophase, and such assemblies provide a route to the emergence of nanoscale tubular architectures.
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Affiliation(s)
- Gary Yu
- Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham, UK.
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Kim HW, Won SH, Kuzmin V, Kim BS, Shin ST. Molecular Ordering Behavior of Lyotropic Chromonic Liquid Crystals on a Polyimide Alignment Layer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5778-5786. [PMID: 32388988 DOI: 10.1021/acs.langmuir.0c00486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Coating-type polarizing films with a high dichroic ratio (DR) and polarization efficiency in the visible region were fabricated using a solution of ternary lyotropic chromonic liquid crystals (LCLCs). Optical characteristics of these anisotropic LCLC polarizing films were then determined. DR increased with increasing LCLC concentrations. Molecular ordering of these LCLCs on a rubbed polyimide (PI) layer increased because LCLC molecules' orientation was enhanced by the dielectric anisotropy effect from rubbing the surface of the PI. In addition, this study demonstrated how the interaction between liquid crystal aggregates and the PI surface with different LCLC solutions correlated with LCLC molecular orientations on the PI which is significantly dependent on whether the coating direction of the LCLC solution was parallel or perpendicular to the PI rubbing direction. It was found that the ordering direction at high LCLC concentrations was determined by shearing direction of the LCLC solution coating, whereas the ordering direction at low LCLC concentrations was governed by the dielectric anisotropy effect from the PI rubbing direction.
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Affiliation(s)
- Hyeong Wook Kim
- Department of Applied Physics, Korea University, 2511, Sejong-ro, Sejong 30019, Republic of Korea
| | - Sang Hee Won
- Department of Applied Physics, Korea University, 2511, Sejong-ro, Sejong 30019, Republic of Korea
| | - Valery Kuzmin
- Light Polymers Inc., 298 Lawrence Avenue, South San Francisco, California 94080, United States
| | - Bo Sung Kim
- Department of Applied Physics, Korea University, 2511, Sejong-ro, Sejong 30019, Republic of Korea
- Light Polymers Inc., 298 Lawrence Avenue, South San Francisco, California 94080, United States
| | - Sung Tae Shin
- Department of Applied Physics, Korea University, 2511, Sejong-ro, Sejong 30019, Republic of Korea
- Light Polymers Inc., 298 Lawrence Avenue, South San Francisco, California 94080, United States
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7
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Molecular dynamics simulation of supercritical CO2 microemulsion with ionic liquid domains: Structures and properties. Chin J Chem Eng 2019. [DOI: 10.1016/j.cjche.2019.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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Danov KD, Kralchevsky PA, Stoyanov SD, Cook JL, Stott IP. Analytical modeling of micelle growth. 2. Molecular thermodynamics of mixed aggregates and scission energy in wormlike micelles. J Colloid Interface Sci 2019; 551:227-241. [DOI: 10.1016/j.jcis.2019.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 10/26/2022]
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9
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Gordon V, Bakhtiari L, Kovach K. From molecules to multispecies ecosystems: the roles of structure in bacterial biofilms. Phys Biol 2019; 16:041001. [PMID: 30913545 DOI: 10.1088/1478-3975/ab1384] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Biofilms are communities of sessile microbes that are bound to each other by a matrix made of biopolymers and proteins. Spatial structure is present in biofilms on many lengthscales. These range from the nanometer scale of molecular motifs to the hundred-micron scale of multicellular aggregates. Spatial structure is a physical property that impacts the biology of biofilms in many ways. The molecular structure of matrix components controls their interaction with each other (thereby impacting biofilm mechanics) and with diffusing molecules such as antibiotics and immune factors (thereby impacting antibiotic tolerance and evasion of the immune system). The size and structure of multicellular aggregates, combined with microbial consumption of growth substrate, give rise to differentiated microenvironments with different patterns of metabolism and gene expression. Spatial association of more than one species can benefit one or both species, while distances between species can both determine and result from the transport of diffusible factors between species. Thus, a widespread theme in the biological importance of spatial structure in biofilms is the effect of structure on transport. We survey what is known about this and other effects of spatial structure in biofilms, from molecules up to multispecies ecosystems. We conclude with an overview of what experimental approaches have been developed to control spatial structure in biofilms and how these and other experiments can be complemented with computational work.
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Affiliation(s)
- Vernita Gordon
- Department of Physics, University of Texas at Austin, Austin TX 78712, United States of America. Center for Nonlinear Dynamics, University of Texas at Austin, Austin TX 78712, United States of America. Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin TX 78712, United States of America. Author to whom any correspondence should be addressed
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10
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Tilton RD. Opportunities for complex fluids engineering
w
ith nanoparticulate polymer brushes. AIChE J 2018. [DOI: 10.1002/aic.16427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Robert D. Tilton
- Center for Complex Fluids Engineering, Dept. of Chemical Engineering Carnegie Mellon University Pittsburgh Pennsylvania 15213
- Center for Complex Fluids Engineering, Dept. of Biomedical Engineering Carnegie Mellon University Pittsburgh Pennsylvania 15213
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11
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Serrano-Luginbühl S, Ruiz-Mirazo K, Ostaszewski R, Gallou F, Walde P. Soft and dispersed interface-rich aqueous systems that promote and guide chemical reactions. Nat Rev Chem 2018. [DOI: 10.1038/s41570-018-0042-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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12
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Nastishin Y, Savaryn V, Lychkovskyy E, Yakovlev MY, Vankevych P, Krupych O, Hrabchak V, Boiko O, Nazarenko V, Lavrentovich O. Effect of UV-light irradiation on phase diagram of lyotropic chromonic liquid crystal. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2017.12.079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Wensink HH, Morales Anda L. Elastic moduli of a smectic membrane: a rod-level scaling analysis. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:075101. [PMID: 29313832 DOI: 10.1088/1361-648x/aaa646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chiral rodlike colloids exposed to strong depletion attraction may self-assemble into chiral membranes whose twisted director field differs from that of a 3D bulk chiral nematic. We formulate a simple microscopic variational theory to determine the elastic moduli of rods assembled into a bidimensional smectic membrane. The approach is based on a simple Onsager-Straley theory for a non-uniform director field that we apply to describe rod twist within the membrane. A microscopic approach enables a detailed estimate of the individual Frank elastic moduli (splay, twist and bend) as well as the twist penetration depth of the smectic membrane in relation to the rod density and shape. We find that the elastic moduli are distinctly different from those of a bulk nematic fluid, with the splay elasticity being much stronger and the curvature elasticity much weaker than for rods assembled in a three-dimensional nematic fluid. We argue that the use of the simplistic one-constant approximation in which all moduli are assumed to be of equal magnitude is not appropriate for modelling the structure-property relation of smectic membranes.
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Affiliation(s)
- H H Wensink
- Laboratoire de Physique des Solides-UMR 8502, CNRS & Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
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14
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15
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Khizhnyak SD, Komarov PV, Ovchinnikov MM, Zherenkova LV, Pakhomov PM. Mechanism of gelation in low-concentration aqueous solutions of silver nitrate with l-cysteine and its derivatives. SOFT MATTER 2017; 13:5168-5184. [PMID: 28664947 DOI: 10.1039/c7sm00772h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We discuss the results of experimental studies of the processes of gelation in aqueous solutions of silver nitrate with l-cysteine and its derivatives. We focus on understanding what determines if these small molecules will self-assemble in water at their extremely low concentration to form a gel. A mechanism of gel formation in a cysteine-silver solution (CSS) is proposed. The analysis of the results indicates that filamentary aggregates of a gel network are formed via interaction of NH3+ and C(O)O- groups that belong to neighboring silver mercaptide (SM) aggregates. In turn, formation of sulphur-silver bonds between silver mercaptide molecules is responsible for self-assembling these molecules into SM aggregates which can be considered as supramonomers. Free polar groups located on the surfaces of the aggregates can form hydrogen bonds with water molecules, which explains the unique ability of CSS hydrogels to trap water at low concentrations of low-molecular-weight hydrogelators.
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Affiliation(s)
- Svetlana D Khizhnyak
- Department of Physical Chemistry and General Physics, Tver State University, Tver, 170100, Russia
| | - Pavel V Komarov
- Department of Physical Chemistry and General Physics, Tver State University, Tver, 170100, Russia and Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, 119991, Russia.
| | | | - Lubov V Zherenkova
- Department of Physical Chemistry and General Physics, Tver State University, Tver, 170100, Russia
| | - Pavel M Pakhomov
- Department of Physical Chemistry and General Physics, Tver State University, Tver, 170100, Russia
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Ross JL. The Dark Matter of Biology. Biophys J 2017; 111:909-16. [PMID: 27602719 PMCID: PMC5018137 DOI: 10.1016/j.bpj.2016.07.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/06/2016] [Accepted: 07/26/2016] [Indexed: 02/04/2023] Open
Abstract
The inside of the cell is full of important, yet invisible species of molecules and proteins that interact weakly but couple together to have huge and important effects in many biological processes. Such “dark matter” inside cells remains mostly hidden, because our tools were developed to investigate strongly interacting species and folded proteins. Example dark-matter species include intrinsically disordered proteins, posttranslational states, ion species, and rare, transient, and weak interactions undetectable by biochemical assays. The dark matter of biology is likely to have multiple, vital roles to regulate signaling, rates of reactions, water structure and viscosity, crowding, and other cellular activities. We need to create new tools to image, detect, and understand these dark-matter species if we are to truly understand fundamental physical principles of biology.
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Affiliation(s)
- Jennifer L Ross
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts.
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17
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Nandigrami P, Grove B, Konya A, Selinger RLB. Gradient-driven diffusion and pattern formation in crowded mixtures. Phys Rev E 2017; 95:022107. [PMID: 28297895 DOI: 10.1103/physreve.95.022107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Indexed: 11/07/2022]
Abstract
Gradient-driven diffusion in crowded, multicomponent mixtures is a topic of high interest because of its role in biological processes such as transport in cell membranes. In partially phase-separated solutions, gradient-driven diffusion affects microstructure, which in turn affects diffusivity; a key question is how this complex coupling controls both transport and pattern formation. To examine these mechanisms, we study a two-dimensional multicomponent lattice gas model, where "tracer" molecules diffuse between a source and a sink separated by a solution of sticky "crowder" molecules that cluster to form dynamically evolving obstacles. In the high-temperature limit, crowders and tracers are miscible, and transport may be predicted analytically. At intermediate temperatures, crowders phase separate into clusters that drift toward the tracer sink. As a result, steady-state tracer diffusivity depends nonmonotonically on both temperature and crowder density, and we observe a variety of complex microstructures. In the low-temperature limit, crowders rapidly aggregate to form obstacles that are kinetically arrested; if crowder density is near the percolation threshold, resulting tracer diffusivity shows scaling behavior with the same scaling exponent as the random resistor network model. Though highly idealized, this simple model reveals fundamental mechanisms governing coupled gradient-driven diffusion, phase separation, and microstructural evolution in crowded mixtures.
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Affiliation(s)
| | - Brandy Grove
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Andrew Konya
- Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA
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18
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Dagys L, Klimavicius V, Balevicius V. Processing of CP MAS kinetics: Towards NMR crystallography for complex solids. J Chem Phys 2016. [DOI: 10.1063/1.4962579] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Gupta S, Wang WS, Vanapalli SA. Microfluidic viscometers for shear rheology of complex fluids and biofluids. BIOMICROFLUIDICS 2016; 10:043402. [PMID: 27478521 PMCID: PMC4947045 DOI: 10.1063/1.4955123] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 06/21/2016] [Indexed: 05/20/2023]
Abstract
The rich diversity of man-made complex fluids and naturally occurring biofluids is opening up new opportunities for investigating their flow behavior and characterizing their rheological properties. Steady shear viscosity is undoubtedly the most widely characterized material property of these fluids. Although widely adopted, macroscale rheometers are limited by sample volumes, access to high shear rates, hydrodynamic instabilities, and interfacial artifacts. Currently, microfluidic devices are capable of handling low sample volumes, providing precision control of flow and channel geometry, enabling a high degree of multiplexing and automation, and integrating flow visualization and optical techniques. These intrinsic advantages of microfluidics have made it especially suitable for the steady shear rheology of complex fluids. In this paper, we review the use of microfluidics for conducting shear viscometry of complex fluids and biofluids with a focus on viscosity curves as a function of shear rate. We discuss the physical principles underlying different microfluidic viscometers, their unique features and limits of operation. This compilation of technological options will potentially serve in promoting the benefits of microfluidic viscometry along with evincing further interest and research in this area. We intend that this review will aid researchers handling and studying complex fluids in selecting and adopting microfluidic viscometers based on their needs. We conclude with challenges and future directions in microfluidic rheometry of complex fluids and biofluids.
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Affiliation(s)
- Siddhartha Gupta
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409, USA
| | - William S Wang
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409, USA
| | - Siva A Vanapalli
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409, USA
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Martínez MDP, Milano J, Eddrief M, Marangolo M, Bustingorry S. Modeling magnetization curves in magnetic thin films with striped patterns. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:136001. [PMID: 26941191 DOI: 10.1088/0953-8984/28/13/136001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this work, we study magnetic thin films presenting magnetic stripe patterns. A fingerprint of such domains is a linear behavior of the in-plane magnetization curves below a given saturation field. We present free energy models for the in-plane magnetization curves which permit us to extract key geometrical information about the stripe patterns, such as the maximum canted angle of the magnetization and the domain wall width. As an example, we discuss in this work magnetization curves for Fe(1-x)Ga(x) magnetic films which present a stripe pattern with a period of 160 nm and we found a typical maximum canted angle of 85° and a domain wall width around 30 nm.
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Affiliation(s)
- M Di Pietro Martínez
- Instituto Balseiro, Universidad Nacional de Cuyo, Av. Bustillo 9500, (R8402AGP) San Carlos de Bariloche, RN, Argentina
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Stubenrauch C, Gießelmann F. Gelled Complex Fluids: Combining Unique Structures with Mechanical Stability. Angew Chem Int Ed Engl 2016; 55:3268-75. [DOI: 10.1002/anie.201506603] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Cosima Stubenrauch
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Frank Gießelmann
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
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Stubenrauch C, Gießelmann F. Gelierte komplexe Fluide - die Verbindung einzigartiger Strukturen mit mechanischer Stabilität. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201506603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cosima Stubenrauch
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Deutschland
| | - Frank Gießelmann
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Deutschland
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23
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Qiao B, Ferru G, Olvera de la Cruz M, Ellis RJ. Molecular Origins of Mesoscale Ordering in a Metalloamphiphile Phase. ACS CENTRAL SCIENCE 2015; 1:493-503. [PMID: 27163014 PMCID: PMC4827664 DOI: 10.1021/acscentsci.5b00306] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Indexed: 05/19/2023]
Abstract
Controlling the assembly of soft and deformable molecular aggregates into mesoscale structures is essential for understanding and developing a broad range of processes including rare earth extraction and cleaning of water, as well as for developing materials with unique properties. By combined synchrotron small- and wide-angle X-ray scattering with large-scale atomistic molecular dynamics simulations we analyze here a metalloamphiphile-oil solution that organizes on multiple length scales. The molecules associate into aggregates, and aggregates flocculate into meso-ordered phases. Our study demonstrates that dipolar interactions, centered on the amphiphile headgroup, bridge ionic aggregate cores and drive aggregate flocculation. By identifying specific intermolecular interactions that drive mesoscale ordering in solution, we bridge two different length scales that are classically addressed separately. Our results highlight the importance of individual intermolecular interactions in driving mesoscale ordering.
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Affiliation(s)
- Baofu Qiao
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, Argonne, Illinois 60439, United States
- E-mail:
| | - Geoffroy Ferru
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, Argonne, Illinois 60439, United States
| | - Monica Olvera de la Cruz
- Department of Materials
Science and Engineering and Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Ross J. Ellis
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, Argonne, Illinois 60439, United States
- E-mail:
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24
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Asgari M. A molecular model for the free energy, bending elasticity, and persistence length of wormlike micelles. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2015; 38:98. [PMID: 26362658 DOI: 10.1140/epje/i2015-15098-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 07/15/2015] [Accepted: 08/05/2015] [Indexed: 06/05/2023]
Abstract
An expression for the elastic free-energy density of a wormlike micelle is derived taking into account interactions between its constituent molecules. The resulting expression is quadratic in the curvature and torsion of the centerline of micelle and thus resembles free-energy density functions for polymer chains and helical filaments such as DNA. The model is applied on a wormlike micelle in the shape of a circular arc, open or closed. Conditions under which linear chains in dilute systems transform into toroidal rings are analyzed. Two concrete anisotropic soft-core interaction potentials are used to calculate the elastic moduli present in the derived model, in terms of the density of the molecules and their dimensions. Expressions for the persistence length of the wormlike micelle are found based on the flexural rigidities so obtained. Similar to previous observations, our results indicate that the persistence length of a wormlike micelle increases as the aspect ratio of its constituent molecules increases. A detailed application of the model on wormlike micelles of toroidal geometry, along with employing statistical-thermodynamical concepts of self-assembly is performed, and the results are found to be well consistent with the literature. Steps to obtain the material parameters through possible experiments are discussed.
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Affiliation(s)
- Meisam Asgari
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, H3A0C3, Montreal, QC, Canada.
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25
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Goodfellow BW, Yu Y, Bosoy CA, Smilgies DM, Korgel BA. The Role of Ligand Packing Frustration in Body-Centered Cubic (bcc) Superlattices of Colloidal Nanocrystals. J Phys Chem Lett 2015; 6:2406-2412. [PMID: 26266710 DOI: 10.1021/acs.jpclett.5b00946] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper addresses the assembly of body centered-cubic (bcc) superlattices of organic ligand-coated nanocrystals. First, examples of bcc superlattices of dodecanethiol-capped Au nanocrystals and oleic acid-capped PbS and PbSe nanocrystals are presented and examined by transmission electron microscopy (TEM) and grazing incidence small-angle X-ray scattering (GISAXS). These superlattices tend to orient on their densest (110) superlattice planes and exhibit a significant amount of {112} twinning. The same nanocrystals deposit as monolayers with hexagonal packing, and these thin films can coexist with thicker bcc superlattice layers, even though there is no hexagonal plane in a bcc lattice. Both the preference of bcc in bulk films over the denser face-centered cubic (fcc) superlattice structure and the transition to hexagonal monolayers can be rationalized in terms of packing frustration of the ligands. A model is presented to calculate the difference in entropy associated with capping ligand packing frustration in bcc and fcc superlattices.
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Affiliation(s)
- Brian W Goodfellow
- †McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712-1062, United States
| | - Yixuan Yu
- †McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712-1062, United States
| | - Christian A Bosoy
- †McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712-1062, United States
| | - Detlef-M Smilgies
- ‡Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853, United States
| | - Brian A Korgel
- †McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712-1062, United States
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26
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Modelling the interfacial behaviour of dilute light-switching surfactant solutions. J Colloid Interface Sci 2015; 445:16-23. [DOI: 10.1016/j.jcis.2014.12.040] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/07/2014] [Accepted: 12/10/2014] [Indexed: 11/17/2022]
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27
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Espinosa Silva YR, Grigera JR. Micelle stability in water under a range of pressures and temperatures; do both have a common mechanism? RSC Adv 2015. [DOI: 10.1039/c5ra09377e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Using molecular dynamics simulations, we present a description compatible with experimental data of the self-assembly aggregation of SDS molecules in H2O and D2O for a wide range of pressures and temperatures.
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Affiliation(s)
| | - J. Raul Grigera
- CEQUINOR
- University of La Plata and CONICET
- B1900 La Plata
- Argentina
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28
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Nikiforidis CV, Gilbert EP, Scholten E. Organogel formation via supramolecular assembly of oleic acid and sodium oleate. RSC Adv 2015. [DOI: 10.1039/c5ra05336f] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To create materials with novel functionalities, the formation of gels within hydrophobic media has become popular.
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Affiliation(s)
- Constantinos V. Nikiforidis
- Top Institute Food & Nutrition
- 6700AN Wageningen
- The Netherlands
- Physics and Physical Chemistry of Foods
- Wageningen University
| | | | - Elke Scholten
- Top Institute Food & Nutrition
- 6700AN Wageningen
- The Netherlands
- Physics and Physical Chemistry of Foods
- Wageningen University
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29
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Guzman-Sepulveda JR, Douglass KM, Amin S, Lewis NE, Dogariu A. Passive optical mapping of structural evolution in complex fluids. RSC Adv 2015. [DOI: 10.1039/c4ra11627e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Low-coherence optical scattering allows probing the complex structure of self-assembling systems over extended ranges of the temperature and concentrations.
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Affiliation(s)
| | - Kyle M. Douglass
- CREOL
- The College of Optics and Photonics
- University of Central Florida
- Orlando
- USA
| | | | | | - Aristide Dogariu
- CREOL
- The College of Optics and Photonics
- University of Central Florida
- Orlando
- USA
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30
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Haavisto S, Koponen AI, Salmela J. New insight into rheology and flow properties of complex fluids with Doppler optical coherence tomography. Front Chem 2014; 2:27. [PMID: 24904920 PMCID: PMC4032874 DOI: 10.3389/fchem.2014.00027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 04/28/2014] [Indexed: 11/28/2022] Open
Abstract
Flow properties of complex fluids such as colloidal suspensions, polymer solutions, fiber suspensions and blood have a vital function in many technological applications and biological systems. Yet, the basic knowledge on their properties is inadequate for many practical purposes. One important reason for this has been the lack of effective experimental methods that would allow detailed study of the flow behavior of especially opaque multi-phase fluids. Optical Coherence Tomography (OCT) is an emerging technique capable of simultaneous measurement of the internal structure and motion of most opaque materials, with resolution in the micrometer scale and measurement frequency up to 100 kHz. This mini-review will examine the recent results on the use of Doppler-OCT in the context of flows and rheological properties of complex fluids outside biomedical field.
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Affiliation(s)
| | | | - Juha Salmela
- Fibres and Biobased Materials, Rheology and Process Flows, VTT Technical Research Centre of FinlandJyväskylä, Finland
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31
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Gao Y, Helgeson ME. Texture analysis microscopy: quantifying structure in low-fidelity images of dense fluids. OPTICS EXPRESS 2014; 22:10046-10063. [PMID: 24787886 DOI: 10.1364/oe.22.010046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Optical images are often corrupted by noise, low contrast, uneven illumination and artefacts, which may pose significant challenges to image analysis, particularly for dense fluids. Traditionally, noise removal and contrast enhancement are achieved by global arithmetic operations on the image as a whole, and/or by image convolution with various kernels. However, these methods work under very limited conditions and can compromise detail within the image. Here, we develop a new technique, texture analysis microscopy (TAM), to overcome these challenges based on the method of image correlation. TAM recasts an image by the statistical similarities between a raw image and a template feature (e.g. a Gaussian) that best approximates features in the image. We demonstrate the superiority of TAM by applying it to low-fidelity images under conditions where traditional methods fail or have deteriorative performance, for analyses including structural correlations, particle identification and sizing.
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32
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Danov KD, Kralchevsky PA, Ananthapadmanabhan KP. Micelle-monomer equilibria in solutions of ionic surfactants and in ionic-nonionic mixtures: a generalized phase separation model. Adv Colloid Interface Sci 2014; 206:17-45. [PMID: 23558017 DOI: 10.1016/j.cis.2013.02.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/16/2013] [Accepted: 02/19/2013] [Indexed: 12/01/2022]
Abstract
On the basis of a detailed physicochemical model, a complete system of equations is formulated that describes the equilibrium between micelles and monomers in solutions of ionic surfactants and their mixtures with nonionic surfactants. The equations of the system express mass balances, chemical and mechanical equilibria. Each nonionic surfactant is characterized by a single thermodynamic parameter--its micellization constant. Each ionic surfactant is characterized by three parameters, including the Stern constant that quantifies the counterion binding. In the case of mixed micelles, each pair of surfactants is characterized with an interaction parameter, β, in terms of the regular solution theory. The comparison of the model with experimental data for surfactant binary mixtures shows that β is constant--independent of the micelle composition and electrolyte concentration. The solution of the system of equations gives the concentrations of all monomeric species, the micelle composition, ionization degree, surface potential and mean area per head group. Upon additional assumptions for the micelle shape, the mean aggregation number can be also estimated. The model gives quantitative theoretical interpretation of the dependence of the critical micellization concentration (CMC) of ionic surfactants on the ionic strength; of the CMC of mixed surfactant solutions, and of the electrolytic conductivity of micellar solutions. It turns out, that in the absence of added salt the conductivity is completely dominated by the contribution of the small ions: monomers and counterions. The theoretical predictions are in good agreement with experimental data.
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Affiliation(s)
- Krassimir D Danov
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, Sofia 1164, Bulgaria
| | - Peter A Kralchevsky
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, Sofia 1164, Bulgaria.
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33
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Disclike vs. cylindrical micelles: Generalized model of micelle growth and data interpretation. J Colloid Interface Sci 2014; 416:258-73. [DOI: 10.1016/j.jcis.2013.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 11/03/2013] [Accepted: 11/06/2013] [Indexed: 11/18/2022]
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34
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Skilling KJ, Citossi F, Bradshaw TD, Ashford M, Kellam B, Marlow M. Insights into low molecular mass organic gelators: a focus on drug delivery and tissue engineering applications. SOFT MATTER 2014; 10:237-56. [PMID: 24651822 DOI: 10.1039/c3sm52244j] [Citation(s) in RCA: 254] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In recent years low molecular mass organic gelators (LMOGs) have gained increasing interest as an alternative biomaterial to polymer derived gels, with potential applications in drug delivery and tissue engineering. LMOGs are small organic molecules which self-assemble in water or organic solvents forming a 3D network that entraps the liquid phase resulting in gel formation. In this review, we report the classification of LMOGs into hydrogelators and gelators of organic solvents and we discuss the techniques commonly used to characterise the gels of these gelators with particular reference to specific applications of LMOGs in drug delivery and tissue engineering.
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Affiliation(s)
- Kathryn J Skilling
- School of Pharmacy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
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35
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Kralchevsky PA, Danov KD, Anachkov SE, Georgieva GS, Ananthapadmanabhan KP. Extension of the ladder model of self-assembly from cylindrical to disclike surfactant micelles. Curr Opin Colloid Interface Sci 2013. [DOI: 10.1016/j.cocis.2013.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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36
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37
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Lin HP, Cheng YR, Lin CR, Li FY, Chen CL, Wong ST, Cheng S, Liu SB, Wan BZ, Mou CY, Tang CY, Lin CY. The Synthesis and Application of the Mesoporous Molecular Sieves MCM-41 - A Review. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.199900067] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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38
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Jusufi A. Molecular simulations of self-assembly processes of amphiphiles in dilute solutions: the challenge for quantitative modelling. Mol Phys 2013. [DOI: 10.1080/00268976.2013.826394] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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39
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Pratap AP, Bhowmick DN. Pseudo Ternary Diagrams of Pesticide Microemulsion Systems. TENSIDE SURFACT DET 2013. [DOI: 10.3139/113.100211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
In application of pesticide formulations, use of microemulsion systems offer several advantages over conventional systems such as wettable powders, emulsifiable concentrates (EC's), oil in water emulsions (O/W emulsions), water in oil emulsions (W/O emulsions) and aqueous suspension concentrates. Microemulsion systems are preferred for their long-term thermodynamic stability, low viscosity and ultimate economy. Microemulsion system also enables the usage of the least expensive solvent such as water. Formulation of agrochemical microemulsion is not a straightforward process. However, the pseudo ternary plot is a convenient mean of determining the compositions of microemulsion, macroemulsion and solubilized systems. Identification of specific regions in a pseudo ternary plot makes it possible to arrive at economical composition for microemulsion and solubilized systems. Such compositions gave maximum stability with the optimum usage of surfactants. These microemulsion and solubilized systems when diluted with the inexpensive solvent such as water gave macroemulsion and microemulsion respectively, which were stable over an extended period of time. This paper provides the basis for a simple procedure for the preparation of microemulsion systems employing water, oil, surfactant and cosurfactant.
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40
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Komarov PV, Mikhailov IV, Alekseev VG, Khizhnyak SD, Pakhomov PM. Self-assembly and gel formation processes in an aqueous solution of L-cysteine and silver nitrate. J STRUCT CHEM+ 2012. [DOI: 10.1134/s002247661205023x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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Mills EA, Regan MH, Stanic V, Collings PJ. Large Assembly Formation via a Two-Step Process in a Chromonic Liquid Crystal. J Phys Chem B 2012; 116:13506-15. [DOI: 10.1021/jp306135w] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elizabeth A. Mills
- Department of Physics & Astronomy, Swarthmore College, Swarthmore, Pennsylvania 19081, United States
| | - Margaret H. Regan
- Department of Physics & Astronomy, Swarthmore College, Swarthmore, Pennsylvania 19081, United States
| | - Vesna Stanic
- Photon Sciences Directorate, Brookhaven National Laboratory, Upton, New York 11973,
United States
| | - Peter J. Collings
- Department of Physics & Astronomy, Swarthmore College, Swarthmore, Pennsylvania 19081, United States
- Department
of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania
19014, United States
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42
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Anyfantakis M, Fell D, Butt HJ, Auernhammer GK. Time-dependent Dynamic Receding Contact Angles Studied during the Flow of Dilute Aqueous Surfactant Solutions through Fluorinated Microtubes. CHEM LETT 2012. [DOI: 10.1246/cl.2012.1232] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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43
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Ramini SK, Kuzyk MG. A self healing model based on polymer-mediated chromophore correlations. J Chem Phys 2012; 137:054705. [DOI: 10.1063/1.4739295] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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44
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Khodadadi Z, Mousavi-Khoshdel SM, Gharibi H, Hashemianzadeh SM, Javadian S. Monte Carlo simulation of binary surfactant/contaminant/water systems. J Mol Graph Model 2012; 36:20-9. [PMID: 22503859 DOI: 10.1016/j.jmgm.2012.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 03/05/2012] [Accepted: 03/06/2012] [Indexed: 10/28/2022]
Abstract
Surfactant-enhanced remediation (SER) is an effective approach for the removal of absorbed hydrophobic organic compounds (HOCs) from contaminated soils. The solubilization of contaminants by mixed surfactants with attractive and repulsive head-head interactions was studied by measuring the micelle-water partition coefficient (K(C)) and molar solubilization ratio (MSR) using the lattice Monte Carlo method. The effect of surfactant mixing on the MSR and K(C) of contaminants displayed the following trend: C₄ > C₃ > C₂. Synergistic binary surfactant mixtures showed greater solubilization capacities for contaminants than the corresponding individual surfactants. Mixed micellization parameters, including the interaction parameter β, and activity coefficient f(i), were evaluated with Rubingh's approach. Synergistic mixed-surfactant systems can improve the performance of surfactant-enhanced remediation of soils and groundwater by decreasing the amount of applied surfactant and the cost of remediation.
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Affiliation(s)
- Zahra Khodadadi
- Department of Physical Chemistry, Tarbiat Modarres University, P.O. Box: 14115-175, Tehran, Iran
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45
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Mondal J, Yethiraj A. Effect of secondary structure on the self-assembly of amphiphilic molecules: A multiscale simulation study. J Chem Phys 2012; 136:084902. [DOI: 10.1063/1.3689298] [Citation(s) in RCA: 13] [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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46
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Komarov PV, Mikhailov IV, Alekseev VG, Khizhnyak SD, Pakhomov PM. Full-atom molecular dynamics study of structure and stability of filament-like aggregates formed by silver mercaptide molecules. COLLOID JOURNAL 2011. [DOI: 10.1134/s1061933x11030057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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47
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Zhang J, Xu XD, Chen LJ, Luo Q, Wu NW, Wang DX, Zhao XL, Yang HB. Platinum Acetylide Complexes Containing Iptycene as Cores: A New Family of Unexpected Efficient Organometallic Gelators. Organometallics 2011. [DOI: 10.1021/om2002987] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jing Zhang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Xing-Dong Xu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Li-Jun Chen
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Qi Luo
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Nai-Wei Wu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, People's Republic of China
| | - De-Xian Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xiao-Li Zhao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Hai-Bo Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, People's Republic of China
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48
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Aleksa V, Kausteklis J, Klimavicius V, Gdaniec Z, Balevicius V. Raman and NMR spectroscopy study of liquid crystalline ionogel phase in ionic liquid/H2O mixtures: The states of water. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2010.12.060] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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49
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Samanta A, Paul BK, Guchhait N. Studies of bio-mimetic medium of ionic and non-ionic micelles by a simple charge transfer fluorescence probe N,N-dimethylaminonapthyl-(acrylo)-nitrile. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:1525-1534. [PMID: 21393054 DOI: 10.1016/j.saa.2011.01.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 01/11/2011] [Accepted: 01/26/2011] [Indexed: 05/30/2023]
Abstract
In this report we have studied micellization process of anionic, cationic and non-ionic surfactants using N,N-dimethylaminonapthyl-(acrylo)-nitrile (DMANAN) as an external fluorescence probe. Micropolarity, microviscosity, critical micellar concentration of these micelles based on steady state absorption and fluorescence and time resolved emission spectroscopy of the probe DMANAN show that the molecule resides in the micelle-water interface for ionic micelles and in the core for the non-ionic micelle. The effect of variation of pH of the micellar solution as well as fluorescence quenching measurements of DMANAN provide further support for the location of the probe in the micelles.
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Affiliation(s)
- Anuva Samanta
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, India
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50
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Park HS, Kang SW, Tortora L, Kumar S, Lavrentovich OD. Condensation of self-assembled lyotropic chromonic liquid crystal sunset yellow in aqueous solutions crowded with polyethylene glycol and doped with salt. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4164-4175. [PMID: 21391644 DOI: 10.1021/la200505y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We use optical and fluorescence microscopy, densitometry, cryo-transmission electron microscopy (cryo-TEM), spectroscopy, and synchrotron X-ray scattering to study the phase behavior of the reversible self-assembled chromonic aggregates of an anionic dye Sunset Yellow (SSY) in aqueous solutions crowded with an electrically neutral polymer polyethylene glycol (PEG) and doped with the salt NaCl. PEG causes the isotropic SSY solutions to condense into a liquid-crystalline region with a high concentration of SSY aggregates, coexisting with a PEG-rich isotropic (I) region. PEG added to the homogeneous nematic (N) phase causes separation into the coexisting N and I domains; the SSY concentration in the N domains is higher than the original concentration of PEG-free N phase. Finally, addition of PEG to the highly concentrated homogeneous N phase causes separation into the coexisting columnar hexagonal (C) phase and I phase. This behavior can be qualitatively explained by the depletion (excluded volume) effects that act at two different levels: at the level of aggregate assembly from monomers and short aggregates and at the level of interaggregate packing. We also show a strong effect of a monovalent salt NaCl on phase diagrams that is different for high and low concentrations of SSY. Upon the addition of salt, dilute I solutions of SSY show appearance of the condensed N domains, but the highly concentrated C phase transforms into a coexisting I and N domains. We suggest that the salt-induced screening of electric charges at the surface of chromonic aggregates leads to two different effects: (a) increase of the scission energy and the contour length of aggregates and (b) decrease of the persistence length of SSY aggregates.
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Affiliation(s)
- Heung-Shik Park
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States
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