1
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Bui K, Wemyss AM, Zhang R, Nguyen GTM, Vancaeyzeele C, Vidal F, Plesse C, Wan C. Tailoring Electromechanical Properties of Natural Rubber Vitrimers by Cross-Linkers. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c01229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Khoa Bui
- International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, CV4 7AL Coventry, U.K
- CY Cergy-Paris Université, LPPI, 95000 CERGY, France
| | - Alan M. Wemyss
- International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, CV4 7AL Coventry, U.K
| | - Runan Zhang
- Department of Mechanical Engineering, University of Bath, BA2 7AY Bath, U.K
| | | | | | | | - Cedric Plesse
- CY Cergy-Paris Université, LPPI, 95000 CERGY, France
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, CV4 7AL Coventry, U.K
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2
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Hu X, Zhang R, Wemyss AM, Du A, Bao X, Geng X, Wan C. Damping and Electromechanical Behavior of Ionic-Modified Brominated Poly(isobutylene-co-isoprene) Rubber Containing Petroleum Resin C5. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.1c04790] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiao Hu
- International Institute for Nanocomposites Manufacturing, WMG, University of Warwick, Coventry CV4 7AL, U.K
- School of Engineering, University of Warwick, Coventry CV4 7AL, U.K
| | - Runan Zhang
- Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, U.K
| | - Alan M. Wemyss
- International Institute for Nanocomposites Manufacturing, WMG, University of Warwick, Coventry CV4 7AL, U.K
| | - Aihua Du
- Key Lab of Rubber-Plastics, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Xujin Bao
- Department of Materials, Loughborough University, Loughborough LE11 3TU, U.K
| | - Xueyu Geng
- School of Engineering, University of Warwick, Coventry CV4 7AL, U.K
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing, WMG, University of Warwick, Coventry CV4 7AL, U.K
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3
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Ekeocha J, Ellingford C, Pan M, Wemyss AM, Bowen C, Wan C. Challenges and Opportunities of Self-Healing Polymers and Devices for Extreme and Hostile Environments. Adv Mater 2021; 33:e2008052. [PMID: 34165832 DOI: 10.1002/adma.202008052] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 12/21/2020] [Indexed: 06/13/2023]
Abstract
Engineering materials and devices can be damaged during their service life as a result of mechanical fatigue, punctures, electrical breakdown, and electrochemical corrosion. This damage can lead to unexpected failure during operation, which requires regular inspection, repair, and replacement of the products, resulting in additional energy consumption and cost. During operation in challenging, extreme, or harsh environments, such as those encountered in high or low temperature, nuclear, offshore, space, and deep mining environments, the robustness and stability of materials and devices are extremely important. Over recent decades, significant effort has been invested into improving the robustness and stability of materials through either structural design, the introduction of new chemistry, or improved manufacturing processes. Inspired by natural systems, the creation of self-healing materials has the potential to overcome these challenges and provide a route to achieve dynamic repair during service. Current research on self-healing polymers remains in its infancy, and self-healing behavior under harsh and extreme conditions is a particularly untapped area of research. Here, the self-healing mechanisms and performance of materials under a variety of harsh environments are discussed. An overview of polymer-based devices developed for a range of challenging environments is provided, along with areas for future research.
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Affiliation(s)
- James Ekeocha
- International Institute for Nanocomposites Manufacturing (IINM), University of Warwick, Coventry, CV4 7AL, UK
| | - Christopher Ellingford
- International Institute for Nanocomposites Manufacturing (IINM), University of Warwick, Coventry, CV4 7AL, UK
| | - Min Pan
- Department of Mechanical Engineering, University of Bath, Bath, BA2 7AY, UK
| | - Alan M Wemyss
- International Institute for Nanocomposites Manufacturing (IINM), University of Warwick, Coventry, CV4 7AL, UK
| | - Christopher Bowen
- Department of Mechanical Engineering, University of Bath, Bath, BA2 7AY, UK
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM), University of Warwick, Coventry, CV4 7AL, UK
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4
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Little A, Wemyss AM, Haddleton DM, Tan B, Sun Z, Ji Y, Wan C. Synthesis of Poly(Lactic Acid- co-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation. Polymers (Basel) 2021; 13:2458. [PMID: 34372058 PMCID: PMC8348705 DOI: 10.3390/polym13152458] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 01/29/2023] Open
Abstract
The rise in demand for biodegradable plastic packaging with high barrier properties has spurred interest in poly(lactic acid-co-glycolic acid) (PLGA) copolymers with a relatively high glycolide content. In this work, we examined how reaction conditions affect the synthesis of PLGA25 (L:G 25:75) through the ring-opening polymerisation of d-l-lactide (L) and glycolide (G), using tin 2-ethylhexanoate (Sn(Oct)2) as the catalyst and 1-dodecanol as the initiator. The effects of varying the initiator concentration, catalyst concentration, reaction time, and temperature on the molecular weight, monomer conversion, and thermal properties of PLGA25 were investigated. Increasing the reaction temperature from 130 to 205 °C significantly reduced the time required for high monomer conversions but caused greater polymer discolouration. Whilst increasing the [M]:[C] from 6500:1 to 50,000:1 reduced polymer discolouration, it also resulted in longer reaction times and higher reaction temperatures being required to achieve high conversions. High Mn and Mw values of 136,000 and 399,000 g mol-1 were achieved when polymerisations were performed in the solid state at 150 °C using low initiator concentrations. These copolymers were analysed using high temperature SEC at 80 °C, employing DMSO instead of HFIP as the eluent.
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Affiliation(s)
- Alastair Little
- International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry CV4 7AL, UK; (A.L.); (A.M.W.)
| | - Alan M. Wemyss
- International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry CV4 7AL, UK; (A.L.); (A.M.W.)
| | | | - Bowen Tan
- PJIM Polymer Scientific Co., Ltd., Shanghai 201102, China; (B.T.); (Z.S.); (Y.J.)
| | - Zhaoyang Sun
- PJIM Polymer Scientific Co., Ltd., Shanghai 201102, China; (B.T.); (Z.S.); (Y.J.)
| | - Yang Ji
- PJIM Polymer Scientific Co., Ltd., Shanghai 201102, China; (B.T.); (Z.S.); (Y.J.)
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry CV4 7AL, UK; (A.L.); (A.M.W.)
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5
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Wemyss AM, Ellingford C, Morishita Y, Bowen C, Wan C. Dynamic Polymer Networks: A New Avenue towards Sustainable and Advanced Soft Machines. Angew Chem Int Ed Engl 2021; 60:13725-13736. [PMID: 33411416 PMCID: PMC8248167 DOI: 10.1002/anie.202013254] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/07/2020] [Indexed: 12/11/2022]
Abstract
While the fascinating field of soft machines has grown rapidly over the last two decades, the materials they are constructed from have remained largely unchanged during this time. Parallel activities have led to significant advances in the field of dynamic polymer networks, leading to the design of three-dimensionally cross-linked polymeric materials that are able to adapt and transform through stimuli-induced bond exchange. Recent work has begun to merge these two fields of research by incorporating the stimuli-responsive properties of dynamic polymer networks into soft machine components. These include dielectric elastomers, stretchable electrodes, nanogenerators, and energy storage devices. In this Minireview, we outline recent progress made in this emerging research area and discuss future directions for the field.
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Affiliation(s)
- Alan M Wemyss
- International Institute for Nanocomposites Manufacturing (IINM)WMGUniversity of WarwickCoventryCV4 7ALUK
| | - Christopher Ellingford
- International Institute for Nanocomposites Manufacturing (IINM)WMGUniversity of WarwickCoventryCV4 7ALUK
| | - Yoshihiro Morishita
- Core Technology Research DepartmentAdvanced Materials DivisionBridgestone CorporationJapan
| | - Chris Bowen
- Department of Mechanical EngineeringUniversity of BathBathBA2 7AYUK
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM)WMGUniversity of WarwickCoventryCV4 7ALUK
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6
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Wemyss AM, Ellingford C, Morishita Y, Bowen C, Wan C. Dynamic Polymer Networks: A New Avenue towards Sustainable and Advanced Soft Machines. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202013254] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Alan M Wemyss
- International Institute for Nanocomposites Manufacturing (IINM) WMG University of Warwick Coventry CV4 7AL UK
| | - Christopher Ellingford
- International Institute for Nanocomposites Manufacturing (IINM) WMG University of Warwick Coventry CV4 7AL UK
| | - Yoshihiro Morishita
- Core Technology Research Department Advanced Materials Division Bridgestone Corporation Japan
| | - Chris Bowen
- Department of Mechanical Engineering University of Bath Bath BA2 7AY UK
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM) WMG University of Warwick Coventry CV4 7AL UK
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7
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Efstathiou S, Wemyss AM, Patias G, Al-Shok L, Grypioti M, Coursari D, Ma C, Atkins CJ, Shegiwal A, Wan C, Haddleton DM. Self-healing and mechanical performance of dynamic glycol chitosan hydrogel nanocomposites. J Mater Chem B 2021; 9:809-823. [DOI: 10.1039/d0tb02390f] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Evaluation of Schiff base nanocomposite hydrogels properties using a benzaldehyde multifunctional amphiphilic polyacrylamide crosslinker in conjunction with glycol chitosan.
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Affiliation(s)
| | - Alan M. Wemyss
- Department of Chemistry
- University of Warwick
- Coventry
- UK
- International Institute for Nanocomposites Manufacturing (IINM)
| | | | - Lucas Al-Shok
- Department of Chemistry
- University of Warwick
- Coventry
- UK
| | | | | | - Congkai Ma
- Department of Chemistry
- University of Warwick
- Coventry
- UK
| | | | | | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM)
- WMG
- University of Warwick
- UK
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8
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Tejpal S, Wemyss AM, Bastie CC, Klein-Seetharaman J. Lemon Extract Reduces Angiotensin Converting Enzyme (ACE) Expression and Activity and Increases Insulin Sensitivity and Lipolysis in Mouse Adipocytes. Nutrients 2020; 12:E2348. [PMID: 32781523 PMCID: PMC7468735 DOI: 10.3390/nu12082348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/31/2020] [Accepted: 08/03/2020] [Indexed: 01/06/2023] Open
Abstract
Obesity is associated with insulin resistance and cardiovascular complications. In this paper, we examine the possible beneficial role of lemon juice in dieting. Lemon extract (LE) has been proposed to improve serum insulin levels and decrease angiotensin converting enzyme (ACE) activity in mouse models. ACE is also a biomarker for sustained weight loss and ACE inhibitors improve insulin sensitivity in humans. Here, we show that LE impacts adipose tissue metabolism directly. In 3T3-L1 differentiated adipocyte cells, LE improved insulin sensitivity as evidenced by a 3.74 ± 0.54-fold increase in both pAKT and GLUT4 levels. LE also induced lipolysis as demonstrated by a 16.6 ± 1.2 fold-change in pHSL protein expression levels. ACE gene expression increased 12.0 ± 0.1 fold during differentiation of 3T3-L1 cells in the absence of LE, and treatment with LE decreased ACE gene expression by 80.1 ± 0.5% and protein expression by 55 ± 0.37%. We conclude that LE's reduction of ACE expression causes increased insulin sensitivity and breakdown of lipids in adipocytes.
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Affiliation(s)
- Shilpa Tejpal
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill, Coventry CV4 7AL, UK;
| | - Alan M. Wemyss
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry CV4 7AL, UK;
| | - Claire C. Bastie
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill, Coventry CV4 7AL, UK;
| | - Judith Klein-Seetharaman
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill, Coventry CV4 7AL, UK;
- Department of Chemistry, Colorado School of Mines, Golden, CO 80401, USA
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9
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Ma C, Han T, Kang M, Liarou E, Wemyss AM, Efstathiou S, Tang BZ, Haddleton D. Aggregation-Induced Emission Active Polyacrylates via Cu-Mediated Reversible Deactivation Radical Polymerization with Bioimaging Applications. ACS Macro Lett 2020; 9:769-775. [PMID: 35648566 DOI: 10.1021/acsmacrolett.0c00281] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The introduction of aggregation-induced emission (AIE) moieties into polymers results in smart materials with AIE characteristics, expanding their scope of applications. Herein, well-defined polymers with controlled molecular weight, low dispersity, and high end-group fidelity are produced via copper(0)-mediated reversible-deactivation radical polymerizations (Cu(0)-RDRPs). An AIE-containing initiator tetraphenylethene bromoisobutyrate (TPEBIB) has been synthesized, fully characterized, and utilized for the construction of different polyacrylate homopolymers and block copolymers bearing the TPE group with a range of molecular weights and architectures. All of the polymers exhibited AIE behavior. Notably, the hydrophobic TPE-poly(tert-butyl acrylate) (TPE-PtBA)-containing block copolymers are transformed to TPE-poly(acrylic acid) (TPE-PAA)-based amphiphilic copolymers by facile deprotection, enabling pH-tunable self-assembly in aqueous media to give fluorescent nanoparticles with various sizes. The low cytotoxicity, high specificity, and excellent photostability render them promising candidates as lysosome-specific probes in biological imaging applications.
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Affiliation(s)
- Congkai Ma
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Ting Han
- Center for AIE Research, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Miaomiao Kang
- Center for AIE Research, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Evelina Liarou
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Alan M. Wemyss
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Spyridon Efstathiou
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Ben Zhong Tang
- Center for AIE Research, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - David Haddleton
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
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10
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Ellingford C, Zhang R, Wemyss AM, Zhang Y, Brown OB, Zhou H, Keogh P, Bowen C, Wan C. Self-Healing Dielectric Elastomers for Damage-Tolerant Actuation and Energy Harvesting. ACS Appl Mater Interfaces 2020; 12:7595-7604. [PMID: 31944651 DOI: 10.1021/acsami.9b21957] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The actuation and energy-harvesting performance of dielectric elastomers are strongly related to their intrinsic electrical and mechanical properties. For future resilient smart transducers, a fast actuation response, efficient energy-harvesting performance, and mechanical robustness are key requirements. In this work, we demonstrate that poly(styrene-butadiene-styrene) (SBS) can be converted into a self-healing dielectric elastomer with high permittivity and low dielectric loss, which can be deformed to large mechanical strains; these are key requirements for actuation and energy-harvesting applications. Using a one-step click reaction at room temperature for 20 min, methyl-3-mercaptopropionate (M3M) was grafted to SBS and reached 95.2% of grafting ratios. The resultant M3M-SBS can be deformed to a high mechanical strain of 1000%, with a relative permittivity of εr = 7.5 and a low tan δ = 0.03. When used in a dielectric actuator, it can provide 9.2% strain at an electric field of 39.5 MV m-1 and can also generate an energy density of 11 mJ g-1 from energy harvesting. After being subjected to mechanical damage, the self-healed elastomer can recover 44% of its breakdown strength during energy harvesting. This work demonstrates a facile route to produce self-healing, high permittivity, and low dielectric loss elastomers for both actuation and energy harvesting, which is applicable to a wide range of diene elastomer systems.
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Affiliation(s)
- Christopher Ellingford
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Runan Zhang
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Alan M Wemyss
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Yan Zhang
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Oliver B Brown
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Hongzhao Zhou
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Patrick Keogh
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Christopher Bowen
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
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11
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Zhang J, Liarou E, Town J, Li Y, Wemyss AM, Haddleton DM. Aqueous copper-mediated reversible deactivation radical polymerization (RDRP) utilizing polyetheramine derived initiators. Polym Chem 2020. [DOI: 10.1039/d0py00555j] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Polyetheramines (Jeffamines™) are used in Copper-mediated reversible deactivation radical polymeriation (Cu-RDRP) in water for the synthesis of temperature-responsive block copolymers.
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Affiliation(s)
- Jirui Zhang
- Department of Chemistry
- University of Warwick
- Coventry
- UK
| | | | - James Town
- Department of Chemistry
- University of Warwick
- Coventry
- UK
| | - Yongguang Li
- Department of Chemistry
- University of Warwick
- Coventry
- UK
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12
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Zhou Y, Wemyss AM, Brown OB, Huang Q, Wan C. Structure and electrochemical properties of hierarchically porous carbon nanomaterials derived from hybrid ZIF-8/ZIF-67 bi-MOF coated cyclomatrix poly(organophosphazene) nanospheres. NEW J CHEM 2020. [DOI: 10.1039/d0nj00040j] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hierarchically porous carbon nanostructures with intrinsically doped heteroatoms and metal elements are attractive for electrochemical energy storage applications.
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Affiliation(s)
- Yutao Zhou
- International Institute for Nanocomposites Manufacturing (IINM)
- WMG
- University of Warwick
- UK
| | - Alan M. Wemyss
- International Institute for Nanocomposites Manufacturing (IINM)
- WMG
- University of Warwick
- UK
| | - Oliver B. Brown
- International Institute for Nanocomposites Manufacturing (IINM)
- WMG
- University of Warwick
- UK
| | - Qianye Huang
- Energy Innovation Centre (EIC)
- WMG
- University of Warwick
- UK
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM)
- WMG
- University of Warwick
- UK
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13
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Liarou E, Staniforth M, Town JS, Marathianos A, Grypioti M, Li Y, Chang Y, Efstathiou S, Hancox E, Wemyss AM, Wilson P, Jones BA, Aljuaid M, Stavros VG, Haddleton DM. UV irradiation of Cu-based complexes with aliphatic amine ligands as used in living radical polymerization. Eur Polym J 2020. [DOI: 10.1016/j.eurpolymj.2019.109388] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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14
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Marathianos A, Liarou E, Anastasaki A, Whitfield R, Laurel M, Wemyss AM, Haddleton DM. Photo-induced copper-RDRP in continuous flow without external deoxygenation. Polym Chem 2019. [DOI: 10.1039/c9py00945k] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Photo-induced Cu-RDRP of acrylates in a continuous flow reactor without the need for deoxygenation or externally added reagents.
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Affiliation(s)
| | - Evelina Liarou
- Department of Chemistry
- University of Warwick Library Road
- Coventry
- UK
| | | | | | - Matthew Laurel
- Department of Chemistry
- University of Warwick Library Road
- Coventry
- UK
| | - Alan M. Wemyss
- Department of Chemistry
- University of Warwick Library Road
- Coventry
- UK
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15
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Atkins CJ, Patias G, Town JS, Wemyss AM, Eissa AM, Shegiwal A, Haddleton DM. A simple and versatile route to amphiphilic polymethacrylates: catalytic chain transfer polymerisation (CCTP) coupled with post-polymerisation modifications. Polym Chem 2019. [DOI: 10.1039/c8py01641k] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Amphiphilic polymers have become key figures in the fields of pharmacology, medicine, agriculture and cosmetics.
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Affiliation(s)
| | | | - James S. Town
- Department of Chemistry
- University of Warwick
- Coventry
- UK
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16
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Patias G, Wemyss AM, Efstathiou S, Town JS, Atkins CJ, Shegiwal A, Whitfield R, Haddleton DM. Controlled synthesis of methacrylate and acrylate diblock copolymers via end-capping using CCTP and FRP. Polym Chem 2019. [DOI: 10.1039/c9py01133a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This work demonstrates a method for preparing acrylic-methacrylic diblock copolymers via end-capping.
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Affiliation(s)
| | | | | | - James S. Town
- University of Warwick
- Department of Chemistry
- Coventry
- UK
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17
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Abstract
We have previously reported a novel method for measuring the spectral properties and orientation of fluorescent probes in solution, which we denoted fluorescence-detected linear dichroism (FDLD). In this work, we expand the scope of the technique by recording the FDLD spectra of the small organic fluorophores: anthracene, 4',6-diamidino-2-phenylindole (DAPI), 1,6-diphenylhexatriene (DPH), and 4-methylphenyl benzoate (MPB), oriented on stretched oxidised polyethylene film. Much like what was observed in solution, we found that the FDLD produced a large signal enhancement compared with absorbance LD, which lowers the sample requirement for measurement. We also found that FDLD has an increased sensitivity towards the immediate environment of the chromophore, revealing oligomeric structures on the film. We believe that FDLD has the potential to reveal important properties of molecules that are obscured or unattainable when using other methods.
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Affiliation(s)
- A M Wemyss
- Department of Chemistry and MOAC Doctoral Training Centre, University of Warwick, Coventry, CV4 7AL, UK.
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18
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Ellingford C, Zhang R, Wemyss AM, Bowen C, McNally T, Figiel Ł, Wan C. Intrinsic Tuning of Poly(styrene-butadiene-styrene)-Based Self-Healing Dielectric Elastomer Actuators with Enhanced Electromechanical Properties. ACS Appl Mater Interfaces 2018; 10:38438-38448. [PMID: 30360080 DOI: 10.1021/acsami.8b13785] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The electromechanical properties of a thermoplastic styrene-butadiene-styrene (SBS) dielectric elastomer was intrinsically tuned by chemical grafting with polar organic groups. Methyl thioglycolate (MG) reacted with the butadiene block via a one-step thiol-ene "click" reaction under UV at 25 °C. The MG grafting ratio reached 98.5 mol % (with respect to the butadiene alkenes present) within 20 min and increased the relative permittivity to 11.4 at 103 Hz, with a low tan δ. The actuation strain of the MG-grafted SBS dielectric elastomer actuator was 10 times larger than the SBS-based actuator, and the actuation force was 4 times greater than SBS. The MG-grafted SBS demonstrated an ability to achieve both mechanical and electrical self-healing. The electrical breakdown strength recovered to 15% of its original value, and the strength and elongation at break recovered by 25 and 21%, respectively, after 3 days. The self-healing behavior was explained by the introduction of polar MG groups that reduce viscous loss and strain relaxation. The weak CH/π bonds through the partially charged (δ+) groups adjacent to the ester of MG and the δ- center of styrene enable polymer chains to reunite and recover properties. Intrinsic tuning can therefore enhance the electromechanical properties of dielectric elastomers and provides new actuator materials with self-healing mechanical and dielectric properties.
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Affiliation(s)
| | - Runan Zhang
- Department of Mechanical Engineering , University of Bath , Bath BA2 2ET , U.K
| | | | - Christopher Bowen
- Department of Mechanical Engineering , University of Bath , Bath BA2 2ET , U.K
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Dorrington G, Chmel NP, Norton SR, Wemyss AM, Lloyd K, Praveen Amarasinghe D, Rodger A. Light scattering corrections to linear dichroism spectroscopy for liposomes in shear flow using calcein fluorescence and modified Rayleigh-Gans-Debye-Mie scattering. Biophys Rev 2018; 10:1385-1399. [PMID: 30255222 PMCID: PMC6233352 DOI: 10.1007/s12551-018-0458-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 09/13/2018] [Indexed: 12/02/2022] Open
Abstract
The interpretation of data from absorbance spectroscopy experiments of liposomes in flow systems is often complicated by the fact that there is currently no easy way to account for scattering artefacts. This has proved particularly problematic for linear dichroism (LD) spectroscopy, which may be used to determine binding modes of small molecules, peptides and proteins to liposomes if we can extract the absorbance signal from the combined absorbance/scattering experiment. Equations for a modified Rayleigh-Gans-Debye (RGD) approximation to the turbidity (scattering) LD spectrum are available in the literature though have not been implemented. This review summarises the literature and shows how it can be implemented. The implementation proceeds by first determining volume loss that occurs when a spherical liposome is subjected to flow. Calcein fluorescence can be used for this purpose since at high concentrations (> 60 mM) it has low intensity fluorescence with maxima at 525 and 563 nm whereas at low concentrations (<1 mM) the fluorescence intensity is enhanced and the band shifts to 536 nm. The scattering calculation process yields the average axis ratios of the distorted liposome ellipsoids and extent of orientation of the liposomes in flow. The scattering calculations require methods to estimate liposome integrity, volume loss, and orientation when subjected to shear stresses under flow.
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Affiliation(s)
- Glen Dorrington
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- MOAC Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
| | - Nikola P Chmel
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- MOAC Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
| | - Stephen R Norton
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- MOAC Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
| | - Alan M Wemyss
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- MOAC Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
| | - Katherine Lloyd
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- MOAC Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
| | - D Praveen Amarasinghe
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- MOAC Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
| | - Alison Rodger
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
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20
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Wemyss AM, Chmel NP, Lobo DP, Sutherland JA, Dafforn TR, Rodger A. Fluorescence detected linear dichroism spectroscopy: A selective and sensitive probe for fluorophores in flow-oriented systems. Chirality 2018; 30:227-237. [PMID: 29314266 DOI: 10.1002/chir.22795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/22/2017] [Accepted: 10/27/2017] [Indexed: 11/06/2022]
Abstract
Fluorescence detection typically enhances sensitivity and selectivity for fluorescent analytes. The potential for combining fluorescence detection with flow orientation of the sample in the normal configuration of linear dichroism experiments is explored in this work by measuring the fluorescence emitted from flow-orientated DNA-bound ligands and M13 bacteriophage. Data for ethidium bromide, Hoechst 33258, and 4,6-diamidino-2-phenyindole are presented. The theoretical basis of the technique is also presented for instruments running in both the fixed direct-current mode, which is the normal operation mode of circular dichroism spectropolarimeters, and also in fixed high-tension voltage mode. The role of the stray light reaching the detector that results in a spectral shape in fixed direct current mode that resembles the shape of a linear dichroism spectrum, rather than the expected reduced linear dichroism, is also explored.
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Affiliation(s)
- Alan M Wemyss
- Department of Chemistry and MOAC Doctoral Training Centre, University of Warwick, Coventry, UK
| | - Nikola P Chmel
- Department of Chemistry and MOAC Doctoral Training Centre, University of Warwick, Coventry, UK
| | - Daniela P Lobo
- Department of Chemistry and MOAC Doctoral Training Centre, University of Warwick, Coventry, UK
| | - John A Sutherland
- Department of Chemistry and Physics, Augusta University, Augusta, Georgia, USA
| | | | - Alison Rodger
- Department of Chemistry and MOAC Doctoral Training Centre, University of Warwick, Coventry, UK.,Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
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Abstract
Antibiotics save many lives, but their efficacy is under threat: overprescription, population growth, and global travel all contribute to the rapid origination and spread of resistant strains. Exacerbating this threat is the fact that no new major classes of antibiotics have been discovered in the last 30 years: this is the "discovery void." We discuss the traditional molecular targets of antibiotics as well as putative novel targets.
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Affiliation(s)
| | | | - Alan M. Wemyss
- Molecular Organisation and Assembly in Cells Doctoral Training Centre
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22
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Lobo DP, Wemyss AM, Smith DJ, Straube A, Betteridge KB, Salmon AHJ, Foster RR, Elhegni HE, Satchell SC, Little HA, Pacheco-Gómez R, Simmons MJ, Hicks MR, Bates DO, Rodger A, Dafforn TR, Arkill KP. Direct detection and measurement of wall shear stress using a filamentous bio-nanoparticle. Nano Res 2015; 8:3307-3315. [PMID: 27570611 PMCID: PMC4996322 DOI: 10.1007/s12274-015-0831-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 05/24/2023]
Abstract
The wall shear stress (WSS) that a moving fluid exerts on a surface affects many processes including those relating to vascular function. WSS plays an important role in normal physiology (e.g. angiogenesis) and affects the microvasculature's primary function of molecular transport. Points of fluctuating WSS show abnormalities in a number of diseases; however, there is no established technique for measuring WSS directly in physiological systems. All current methods rely on estimates obtained from measured velocity gradients in bulk flow data. In this work, we report a nanosensor that can directly measure WSS in microfluidic chambers with sub-micron spatial resolution by using a specific type of virus, the bacteriophage M13, which has been fluorescently labeled and anchored to a surface. It is demonstrated that the nanosensor can be calibrated and adapted for biological tissue, revealing WSS in micro-domains of cells that cannot be calculated accurately from bulk flow measurements. This method lends itself to a platform applicable to many applications in biology and microfluidics.
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Affiliation(s)
- Daniela P Lobo
- Department of Chemistry and Warwick Analytical Science Centre, University of Warwick, Coventry CV4 7AL, UK
| | - Alan M Wemyss
- Department of Chemistry and Warwick Analytical Science Centre, University of Warwick, Coventry CV4 7AL, UK; MOAC Doctoral Training Centre, University of Warwick, Coventry CV4 7AL, UK
| | - David J Smith
- Mathematics, University of Birmingham, Edgbaston, Birmingham, West Midlands B15 2TT, UK
| | - Anne Straube
- Centre for Mechanochemical Cell Biology, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Kai B Betteridge
- Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Andrew H J Salmon
- Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Rebecca R Foster
- Clinical Sciences, Whitson Street, University of Bristol, Bristol BS1 3NY, UK
| | - Hesham E Elhegni
- Clinical Sciences, Whitson Street, University of Bristol, Bristol BS1 3NY, UK
| | - Simon C Satchell
- Clinical Sciences, Whitson Street, University of Bristol, Bristol BS1 3NY, UK
| | - Haydn A Little
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, West Midlands B15 2TT, UK
| | - Raúl Pacheco-Gómez
- Biosciences, University of Birmingham, Edgbaston, Birmingham, West Midlands B15 2TT, UK
| | - Mark J Simmons
- Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, West Midlands B15 2TT, UK
| | - Matthew R Hicks
- Biosciences, University of Birmingham, Edgbaston, Birmingham, West Midlands B15 2TT, UK
| | - David O Bates
- School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| | - Alison Rodger
- Department of Chemistry and Warwick Analytical Science Centre, University of Warwick, Coventry CV4 7AL, UK
| | - Timothy R Dafforn
- Biosciences, University of Birmingham, Edgbaston, Birmingham, West Midlands B15 2TT, UK
| | - Kenton P Arkill
- Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
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