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Hayward DW, Magro G, Hörmann A, Prévost S, Schweins R, Richardson RM, Gradzielski M. A temperature-controlled electric field sample environment for small-angle neutron scattering experiments. Rev Sci Instrum 2021; 92:033903. [PMID: 33820030 DOI: 10.1063/5.0040675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
A new sample environment is introduced for the study of soft matter samples in electric fields using small-angle neutron scattering instruments. The sample environment is temperature controlled and features external electrodes, allowing standard quartz cuvettes to be used and conducting samples or samples containing ions to be investigated without the risk of electrochemical reactions occurring at the electrodes. For standard 12.5 mm quartz cuvettes, the maximum applied field is 8 kV/cm, and the applied field may be static or alternating (up to 10 kHz for 8 kV/cm and up to 60 kHz for 4 kV/cm). The electric fields within the sample are calculated and simulated under a number of different conditions, and the capabilities of the setup are demonstrated using a variety of liquid crystalline samples. Measurements were performed as a function of temperature and time spent in the electric field. Finally, the advantages, drawbacks, and potential optimization of the sample environment are discussed with reference to applications in the fields of complex soft matter, biology, and electrorheology.
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Affiliation(s)
- Dominic W Hayward
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straβe des 17. Juni 124, D-10623 Berlin, Germany
| | - Germinal Magro
- School of Physics, University of Bristol, Tyndall Avenue, BS8 1TL Bristol, United Kingdom
| | - Anja Hörmann
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straβe des 17. Juni 124, D-10623 Berlin, Germany
| | - Sylvain Prévost
- Institut Laue-Langevin, 71 Avenue des Martyrs, F-38042 Grenoble Cedex 9, France
| | - Ralf Schweins
- Institut Laue-Langevin, 71 Avenue des Martyrs, F-38042 Grenoble Cedex 9, France
| | - Robert M Richardson
- School of Physics, University of Bristol, Tyndall Avenue, BS8 1TL Bristol, United Kingdom
| | - Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straβe des 17. Juni 124, D-10623 Berlin, Germany
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Nallet F. Scattering studies in self-organised diblock copolymer systems. Colloid Polym Sci 2017. [DOI: 10.1007/s00396-017-4082-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wang G, Garvey CJ, Zhao H, Huang K, Kong L. Toward the Fabrication of Advanced Nanofiltration Membranes by Controlling Morphologies and Mesochannel Orientations of Hexagonal Lyotropic Liquid Crystals. Membranes (Basel) 2017; 7:membranes7030037. [PMID: 28753973 PMCID: PMC5618122 DOI: 10.3390/membranes7030037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/10/2017] [Accepted: 07/12/2017] [Indexed: 01/27/2023]
Abstract
Water scarcity has been recognized as one of the major threats to human activity, and, therefore, water purification technologies are increasingly drawing attention worldwide. Nanofiltration (NF) membrane technology has been proven to be an efficient and cost-effective way in terms of the size and continuity of the nanostructure. Using a template based on hexagonal lyotropic liquid crystals (LLCs) and partitioning monomer units within this structure for subsequent photo-polymerisation presents a unique path for the fabrication of NF membranes, potentially producing pores of uniform size, ranging from 1 to 5 nm, and large surface areas. The subsequent orientation of this pore network in a direction normal to a flat polymer film that provides ideal transport properties associated with continuous pores running through the membrane has been achieved by the orientation of hexagonal LLCs through various strategies. This review presents the current progresses on the strategies for structure retention from a hexagonal LLCs template and the up-to-date techniques used for the reorientation of mesochanels for continuity through the whole membrane.
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Affiliation(s)
- Guang Wang
- Institute for Frontier Materials, Deakin University, Locked Bag 20000, Geelong 3220, Australia.
| | - Christopher J Garvey
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC 2232, Australia.
| | - Han Zhao
- School of Mechanical Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, China.
| | - Kang Huang
- School of Mechanical Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, China.
| | - Lingxue Kong
- Institute for Frontier Materials, Deakin University, Locked Bag 20000, Geelong 3220, Australia.
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Abstract
When immiscible liquids are subject to electric fields interfacial forces arise due to a difference in the permittivity or the conductance of the liquids, and these forces lead to shape change in droplets or to interfacial instabilities. In this topical review we discuss recent advances in the theory and experiments of liquids in electric fields with an emphasis on liquids which are initially miscible and demix under the influence of an external field. In purely dielectric liquids demixing occurs if the electrode geometry leads to sufficiently large field gradients. In polar liquids field gradients are prevalent due to screening by dissociated ions irrespective of the electrode geometry. We examine the conditions for these 'electro prewetting' transitions and highlight few possible systems where they might be important, such as in stabilization of colloids and in gating of pores in membranes.
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Affiliation(s)
- Yael Katsir
- Department of Chemical Engineering and the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, 84105 Beer-Sheva, Israel
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Abstract
We found that the polymeric vesicles from the self-assembly of amphiphilic block copolymer polystyrene-block-poly(acrylic acid) (PS144-b-PAA22) in the dioxane/water mixture can be deformed, broken and finally divided into smaller ones via the external electrostatic field. The higher the electrostatic field intensity, the smaller the vesicles. More importantly, this fission phenomenon induced by electrostatic field can be used to control the release behavior of the vesicles. Our experimental results show that the Nile Red (NR) molecules encapsulated inside the cavity of vesicles can be accurately released by controlling the electrostatic field intensity and the release time. These findings not only enrich the knowledge for the external field induced transformation of polymer structures, but also provide a new and highly convenient approach for the controllable release of polymersomes in solution.
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Affiliation(s)
- Ming Wu
- State
Key Laboratory of Polymer Physics and Chemistry, Changchun Institute
of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
- University
of
Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Yutian Zhu
- State
Key Laboratory of Polymer Physics and Chemistry, Changchun Institute
of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
| | - Wei Jiang
- State
Key Laboratory of Polymer Physics and Chemistry, Changchun Institute
of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
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Zhang Q, Xu R, Kan D, He X. Molecular dynamics simulation of electric-field-induced self-assembly of diblock copolymers. J Chem Phys 2016; 144:234901. [DOI: 10.1063/1.4953689] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Qiuzhi Zhang
- Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Rui Xu
- Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Di Kan
- Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Xuehao He
- Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
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Abstract
Electric fields can induce the orientation of the phase interfaces of block copolymers and provide a potential method to tune polymer phase structures for nanomaterial manufacture. In this work, we applied self-consistent field theory to study the self-assembly of a diblock copolymer confined between two parallel neutral substrates on which a set of electrodes was imposed to form a patterned electric field. The results showed that an alternatively distributed electric field can induce the formation of a parallel lamellar phase structure, which exists stably only in the system with selective substrates. The phase structure was proved to be sensitive to the characteristics of the electric field distribution, such as the strength of the electric field, the size and position of the electrodes, and the corresponding phase diagram was calculated in detail. The transition pathway of the phase structure from the perpendicular layered phase to the parallel layered phase was further analysed using the minimum energy path method. It is shown that the path and the active energy barrier of the phase transition depend on the electric field strength. Compound electric field patterns that can be designed to control the formation of novel and complex microphase structures were also examined.
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Affiliation(s)
- Di Kan
- Department of Chemistry, School of Science, Tianjin University, 300072 Tianjin, China.
| | - Xuehao He
- Department of Chemistry, School of Science, Tianjin University, 300072 Tianjin, China.
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Wu J, Wang X, Ji Y, He L, Li S. Phase diagrams of diblock copolymers in electric fields: a self-consistent field theory study. Phys Chem Chem Phys 2016; 18:10309-19. [PMID: 27020849 DOI: 10.1039/c5cp08030d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigated the phase diagrams of diblock copolymers in external electrostatic fields by using real-space self-consistent field theory. The lamella, cylinder, sphere, and ellipsoid structures were observed and analyzed by their segment distributions, which were arranged to two types of phase diagrams to examine the phase behavior in weak and strong electric fields. One type was constructed on the basis of Flory-Huggins interaction parameter and volume fraction. We identified an ellipsoid structure with a body-centered cuboid arrangement as a stable phase and discussed the shift of phase boundaries in the electric fields. The other type of phase diagrams was established on the basis of the dielectric constants of two blocks in the electric fields. We then determined the regions of ellipsoid phase in the phase diagrams to examine the influence of dielectric constants on the phase transition between ellipsoidal and hexagonally packed cylinder phases. A general agreement was obtained by comparing our results with those described in previous experimental and theoretical studies.
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Affiliation(s)
- Ji Wu
- Department of Physics, Wenzhou University, Wenzhou, Zhejiang 325035, China.
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Pena-Francesch A, Montero L, Borrós S. Tailoring the LCST of thermosensitive hydrogel thin films deposited by iCVD. Langmuir 2014; 30:7162-7167. [PMID: 24874567 DOI: 10.1021/la5003594] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Using the iCVD (initiated chemical vapor deposition) polymerization technique, we generated a library of thermosensitive thin film hydrogels in the physiological temperature range. The library shows how a specific hydrogel with a desired temperature response can be synthesized via the copolymerization of three main components: (a) the main thermosensitive monomer, which determines the temperature range of the LCST; (b) the comonomer, which modulates the temperature according to its hydrophilic/hydrophobic behavior; and (c) the cross-linker, which determines the swelling degree and the polymer chain mobility of the resulting hydrogel. The thermosensitive thin films included in the library have been characterized by the water contact angle (WCA), revealing a switchable hydrophobic/hydrophilic behavior depending on the temperature and a decrease in the WCA with the incorporation of hydrophilic moieties. Moreover, a more accurate characterization by quartz crystal microbalance (QCM) is performed. With temperature and flow control, the switchable swelling properties of the thermosensitive thin films (due to the polymer mixture transition) can be recorded and analyzed in order to study the effects of the comonomer moieties on the lower critical solution temperature (LCST). Thus, the LCST tailoring method has been successfully used in this paper, and thermoresponsive thin films (50 nm in thickness) have been deposited by iCVD, exhibiting LCSTs in the 32-49 °C range. Due to the presented method's ability to tailor the LCST in the physiological temperature range, the developed thermoresponsive films present potential biosensing and drug delivery applications in the biomedical field.
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Affiliation(s)
- Abdon Pena-Francesch
- Grup d'Enginyeria de Materials, Institut Químic de Sarrià-Universitat Ramon Llull , Via Augusta 390, 08017 Barcelona, Spain
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Ian W, Guojun L. Self-assembly and chemical processing of block copolymers: a roadmap towards a diverse array of block copolymer nanostructures. Sci China Life Sci 2013. [PMID: 23740360 DOI: 10.1007/s11427-013-4499-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 05/27/2013] [Indexed: 11/28/2022]
Abstract
Block copolymers can yield a diverse array of nanostructures. Their assembly structures are influenced by their inherent structures, and the wide variety of structures that can be prepared especially becomes apparent when one considers the number of routes available to prepare block copolymer assemblies. Some examples include self-assembly, directed assembly, coupling, as well as hierarchical assembly, which can yield assemblies having even higher structural order. These assembly routes can also be complemented by processing techniques such as selective crosslinking and etching, the former technique leading to permanent structures, the latter towards sculpted and the combination of the two towards permanent sculpted structures. The combination of these pathways provides extremely versatile routes towards an exciting variety of architectures. This review will attempt to highlight destinations reached by LIU Guojun and coworkers following these pathways.
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Affiliation(s)
- Wyman Ian
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
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Wyman I, Liu G. Self-assembly and chemical processing of block copolymers: A roadmap towards a diverse array of block copolymer nanostructures. Sci China Chem 2013. [DOI: 10.1007/s11426-013-4951-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Liedel C, Pester CW, Ruppel M, Urban VS, Böker A. Beyond Orientation: The Impact of Electric Fields on Block Copolymers. MACROMOL CHEM PHYS 2012; 213:259-69. [DOI: 10.1002/macp.201100590] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Xiao X, Huang Y, Feng J, Liu H, Hu Y. Microphase Separation of a Diblock Copolymer Dispersed in Nanorod Arrays Grafted on a Plate: A Monte Carlo Study. MACROMOL THEOR SIMUL 2011. [DOI: 10.1002/mats.201000064] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
We present an electric-field-triggered sphere-to-cylinder transition of negatively charged block copolymer micelles with a radically low electric field of 30 V/cm. The system investigated is dilute solutions of strong polyelectrolyte containing ionic-b-neutral block copolymers (i.e., poly(styrenesulfonate-b-methylbutylene)). We have carried out in situ small-angle X-ray scattering experiments equipped with a dc power supply, combined with electron microscopy and atomic force microscopy. The application of small electrical fields across the solutions of spherical micelles results in the transient morphology of interconnected spheres, which are eventually transformed into a cylindrical shape with time. The E-field-induced cylindrical micelles revert to spherical micelles when the E field is switched off.
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Affiliation(s)
- Sun Ju Lee
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea 790-784
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