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Stevens MC, Taylor NM, Guo X, Hussain H, Mahmoudi N, Cattoz BN, Leung AHM, Dowding PJ, Vincent B, Briscoe WH. Diblock bottlebrush polymer in a non-polar medium: Self-assembly, surface forces, and superlubricity. J Colloid Interface Sci 2024; 658:639-647. [PMID: 38134672 DOI: 10.1016/j.jcis.2023.12.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 08/31/2023] [Revised: 11/08/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
Whilst bottlebrush polymers have been studied in aqueous media for their conjectured role in biolubrication, surface forces and friction mediated by bottlebrush polymers in non-polar media have not been previously reported. Here, small-angle neutron scattering (SANS) showed that a diblock bottlebrush copolymer (oligoethyleneglycol acrylate/ethylhexyl acrylate; OEGA/EHA) formed spherical core-shell aggregates in n-dodecane (a model oil) in the polymer concentration range 0.1-2.0 wt%, with a radius of gyration Rg ∼ 7 nm, comprising 40-65 polymer molecules per aggregate. The surface force apparatus (SFA) measurements revealed purely repulsive forces between surfaces bearing inhomogeneous polymer layers of thickness L ∼ 13-23 nm, attributed to adsorption of a mixture of polymer chains and surface-deformed micelles. Despite the surface inhomogeneity, the polymer layers could mediate effective lubrication, demonstrating superlubricity with the friction coefficient as low as µ ∼ 0.003. The analysis of velocity-dependence of friction using the Eyring model shed light on the mechanism of the frictional process. That is, the friction mediation was consistent with the presence of nanoscopic surface aggregates, with possible contributions from a gel-like network formed by the polymer chains on the surface. These unprecedented results, correlating self-assembled polymer micelle structure with the surface forces and friction the polymer layers mediate, highlight the potential of polymers with the diblock bottlebrush architecture widespread in biological living systems, in tailoring desired surface interactions in non-polar media.
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Affiliation(s)
- Michael C Stevens
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Nicholas M Taylor
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK; Syngenta, Jealott's Hill International Research Centre, Bracknell RG42 6EY, UK
| | - Xueying Guo
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Hadeel Hussain
- Diamond Light Source Ltd, I07 Beamline, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Najet Mahmoudi
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX, UK
| | - Beatrice N Cattoz
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Alice H M Leung
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Peter J Dowding
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Brian Vincent
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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Kim J, Cattoz B, Leung AHM, Parish JD, Becer CR. Enabling Reversible Addition-Fragmentation Chain-Transfer Polymerization for Brush Copolymers with a Poly(2-oxazoline) Backbone. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00497] [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: 11/30/2022]
Affiliation(s)
- Jungyeon Kim
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Beatrice Cattoz
- Infineum UK Ltd., Milton Hill Business & Technology Centre, Abingdon, Oxfordshire OX13 6BB, United Kingdom
| | - Alice H. M. Leung
- Infineum UK Ltd., Milton Hill Business & Technology Centre, Abingdon, Oxfordshire OX13 6BB, United Kingdom
| | - James D. Parish
- Infineum UK Ltd., Milton Hill Business & Technology Centre, Abingdon, Oxfordshire OX13 6BB, United Kingdom
| | - C. Remzi Becer
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
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Leung AHM, Pike SD, Clancy AJ, Yau HC, Lee WJ, Orchard KL, Shaffer MSP, Williams CK. Layered zinc hydroxide monolayers by hydrolysis of organozincs. Chem Sci 2018; 9:2135-2146. [PMID: 29719687 PMCID: PMC5896490 DOI: 10.1039/c7sc04256f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/16/2018] [Indexed: 11/21/2022] Open
Abstract
Organometallic precursors provide a new and clean route to solutions of 2D materials relevant for applications including catalysis, electronics and sensing.
2D inorganic materials and their exfoliated counterparts are both of fundamental interest and relevant for applications including catalysis, electronics and sensing. Here, a new bottom-up synthesis route is used to prepare functionalised nanoplatelets, in apolar organic solvents, via the hydrolysis of organometallic reagents; the products can be prepared in high yield, at room temperature. In particular, a series of layered zinc hydroxides, coordinated by aliphatic carboxylate ligands, were produced by the hydrolysis of diethyl zinc and zinc carboxylate mixtures, optimally at a molar ratio of [COOR]/[Zn] = 0.6. Layered zinc hydroxides coordinated by oleate ligands form high concentration solutions of isolated monolayers (3 nm thick x ∼ 26 nm) in apolar organic solvents (up to 23 mg mL–1 in toluene), as confirmed by both atomic force and transmission electron microscopies of deposited species. The high solubility of the product allows the synthetic pathway to be monitored directly in situ through 1H NMR spectroscopy. The high solubility also provides a route to solution deposition of active functional materials, as illustrated by the formation of nanoporous films of optically transparent porous zinc oxide (1 μm thickness) after annealing at 500 °C. This new organometallic route to 2D materials obviates common complications of top-down exfoliation syntheses, including sonochemical-degradation and low yields of aggregated polydispersed layers, and may potentially be extended to a wide range of systems.
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Affiliation(s)
- Alice H M Leung
- Chemistry Research Laboratory , University of Oxford , 12 Mansfield Road , Oxford , UK OX1 3TA .
| | - Sebastian D Pike
- Chemistry Research Laboratory , University of Oxford , 12 Mansfield Road , Oxford , UK OX1 3TA .
| | - Adam J Clancy
- Department of Chemistry , Imperial College London , London , UK SW7 2AZ .
| | - Hin Chun Yau
- Department of Chemistry , Imperial College London , London , UK SW7 2AZ .
| | - Won Jun Lee
- Department of Chemistry , Imperial College London , London , UK SW7 2AZ .
| | | | - Milo S P Shaffer
- Department of Chemistry , Imperial College London , London , UK SW7 2AZ . .,Department of Materials , Imperial College London , London , UK SW7 2AZ
| | - Charlotte K Williams
- Chemistry Research Laboratory , University of Oxford , 12 Mansfield Road , Oxford , UK OX1 3TA . .,Department of Chemistry , Imperial College London , London , UK SW7 2AZ .
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Phanopoulos A, Leung AHM, Yow S, Palomas D, White AJP, Hellgardt K, Horton A, Crimmin MR. Binuclear β-diketiminate complexes of copper(i). Dalton Trans 2017; 46:2081-2090. [DOI: 10.1039/c6dt04246e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The reaction of a series of dinucleating bis(β-diketiminate) pro-ligands with mesitylcopper in the presence and absence of mono and diphosphines has allowed the isolation of a new series of dicopper(i) complexes.
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Affiliation(s)
| | | | - Shuhui Yow
- Department of Chemistry
- Imperial College London
- London
- UK
| | - David Palomas
- Department of Chemistry
- Imperial College London
- London
- UK
| | | | - Klaus Hellgardt
- Department of Chemical Engineering
- Imperial College London
- London
- UK
| | - Andrew Horton
- PTI/DX Emerging Technologies
- Shell Global Solutions International B.V
- 1030 BN Amsterdam
- The Netherlands
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Pike SD, García-Trenco A, White ER, Leung AHM, Weiner J, Shaffer MSP, Williams CK. Colloidal Cu/ZnO catalysts for the hydrogenation of carbon dioxide to methanol: investigating catalyst preparation and ligand effects. Catal Sci Technol 2017. [DOI: 10.1039/c7cy01191a] [Citation(s) in RCA: 17] [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: 01/04/2023]
Abstract
This paper reports on the influences of the catalyst preparation method and ligand effects for a series of highly active Cu/ZnO colloidal catalysts for the hydrogenation of CO2 to methanol.
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Affiliation(s)
| | - Andrés García-Trenco
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
| | | | - Alice H. M. Leung
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
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Pike SD, García-Trenco A, White ER, Leung AHM, Weiner J, Shaffer MSP, Williams CK. Correction: Colloidal Cu/ZnO catalysts for the hydrogenation of carbon dioxide to methanol: investigating catalyst preparation and ligand effects. Catal Sci Technol 2017. [DOI: 10.1039/c7cy90083j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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
Correction for ‘Colloidal Cu/ZnO catalysts for the hydrogenation of carbon dioxide to methanol: investigating catalyst preparation and ligand effects’ by Sebastian D. Pike et al., Catal. Sci. Technol., 2017, DOI: 10.1039/c7cy01191a.
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