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13 results on '"Coulston, Roger J."'

2. Supramolecular hydrogel microcapsules via cucurbit[8]uril host–guest interactions with triggered and UV-controlled molecular permeability† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5sc01440a Click here for additional data file

Author

Yu, Ziyi, Zhang, Jing, Coulston, Roger J., Parker, Richard M., Biedermann, Frank, Liu, Xin, Scherman, Oren A., and Abell, Chris

Subjects
Chemistry
Abstract

Host–guest assembly at the interface of microfluidic droplets offers a versatile strategy to construct supramolecular hydrogel microcapsules with “smart” cargo release., Host–guest assembly in droplet-based microfluidics opens a new avenue for fabricating supramolecular hydrogel microcapsules with high monodispersity and controlled functionality. In this paper, we demonstrate a single emulsion microdroplet platform to prepare microcapsules with supramolecular hydrogel skins from host molecule cucurbit[8]uril and guest polymer anthracene-functionalized hydroxyethyl cellulose. In contrast to construction of microcapsules from a droplet-in-droplet double emulsion, here the electrostatic attraction between charged polymer and surfactant facilitates formation of defined supramolecular hydrogel skins in a single emulsion. Furthermore, by taking advantage of dynamic interactions and the tunable cross-linked supramolecular hydrogel network, it is possible to prepare microcapsules with triggered and UV-controlled molecular permeability. These could be potentially used in a delivery system for e.g. agrochemicals, nutraceuticals or cosmetics.

Published
2015

3. Electrostatically Directed Self-Assembly of Ultrathin Supramolecular Polymer Microcapsules

Author

Parker, Richard M, Zhang, Jing, Zheng, Yu, Coulston, Roger J, Smith, Clive A, Salmon, Andrew R, Yu, Ziyi, Scherman, Oren A, Abell, Chris, Parker, Richard [0000-0002-4096-9161], Yu, Ziyi [0000-0003-4420-5836], Scherman, Oren [0000-0001-8032-7166], Abell, Chris [0000-0001-9174-1987], and Apollo - University of Cambridge Repository

Subjects
microcapsules, microstructures, microfluidics, self-assembly, Full Papers, supramolecular materials
Abstract

Supramolecular self-assembly offers routes to challenging architectures on the molecular and macroscopic scale. Coupled with microfluidics it has been used to make microcapsules-where a 2D sheet is shaped in 3D, encapsulating the volume within. In this paper, a versatile methodology to direct the accumulation of capsule-forming components to the droplet interface using electrostatic interactions is described. In this approach, charged copolymers are selectively partitioned to the microdroplet interface by a complementary charged surfactant for subsequent supramolecular cross-linking via cucurbit[8]uril. This dynamic assembly process is employed to selectively form both hollow, ultrathin microcapsules and solid microparticles from a single solution. The ability to dictate the distribution of a mixture of charged copolymers within the microdroplet, as demonstrated by the single-step fabrication of distinct core-shell microcapsules, gives access to a new generation of innovative self-assembled constructs.

Published
2015

7. Harnessing the energy of molecular recognition in a nanomachine having a photochemical on/off switch

Author

Coulston, Roger J., Onagi, Hideki, Lincoln, Stephen F., and Easton, Christopher J.

Subjects
Cyclodextrins -- Chemical properties, Amides -- Chemical properties, Isomerism -- Chemical properties, Isomerism -- Structure, Chemistry
Abstract

A molecular machine is described where the work output resulting from molecular recognition is harnessed to constrain the geometry of an amide bond. A more advanced form of device exists as two isomers are interconverted photochemically, but only one of the isomers display the molecular recognition and performs the work, so the photoisomerization turns the machine on and off.

Published
2006

12. One-Step Fabrication of Supramolecular Microcapsules from Microfluidic Droplets.

Author

Jing Zhang, Coulston, Roger J., Jones, Samuel T., Jin Geng, Scherman, Oren A., and Abell, Chris

Subjects
*MICROENCAPSULATION, *ARTIFICIAL cells, *MICROFLUIDICS, *SUPRAMOLECULAR chemistry, *GOLD nanoparticles, *RAMAN spectroscopy, *NANOCOMPOSITE materials
Abstract

Although many techniques exist for preparing microcapsules, it is still challenging to fabricate them in an efficient and scalable process without compromising functionality and encapsulation efficiency. We demonstrated a simple one-step approach that exploits a versatile host-guest system and uses microfluidic droplets to generate porous microcapsules with easily customizable functionality. The capsules comprise a polymer-gold nanoparticle composite held together by cucurbit[8]uril ternary complexes. The dynamic yet highly stable micrometer-sized structures can be loaded in one step during capsule formation and are amenable to on-demand encapsulant release. The internal chemical environment can be probed with surface enhanced Raman spectroscopy. [ABSTRACT FROM AUTHOR]

Published
2012
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13. Supramolecular gold nanoparticle–polymer composites formed in water with cucurbit[8]urilThis article is part of the ‘Emerging Investigators’ themed issue for ChemComm.Electronic supplementary information (ESI) available: Experimental details and full characterisation including the synthesis of all ligands and functionalised AuNPs as well as UV/vis and DLS data. See DOI: 10.1039/c0cc03250f

Author

Coulston, Roger J., Jones, Samuel T., Lee, Tung-Chun, Appel, Eric A., and Scherman, Oren A.

Subjects
*SUPRAMOLECULAR chemistry, *COLLOIDAL gold, *POLYMERIC composites, *WATER, *MACROCYCLIC compounds, *ACRYLAMIDE, *CHEMICAL processes
Abstract

A gold nanoparticle–polymer composite material has been prepared in water using cucurbit[8]uril as a supramolecular “handcuff” to hold together viologen-functionalised gold nanoparticles and a naphthol-functionalised acrylamide copolymer. [ABSTRACT FROM AUTHOR]

Published
2010

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