Imperial College London

Prof Milo Shaffer

Faculty of Natural SciencesDepartment of Chemistry

Professor of Materials Chemistry
 
 
 
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Contact

 

+44 (0)20 7594 5825m.shaffer

 
 
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Assistant

 

Mr John Murrell +44 (0)20 7594 2845

 
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Location

 

M221Royal College of ScienceSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

258 results found

Au H, Rubio N, Shaffer MSP, 2018, Brominated graphene as a versatile precursor for multifunctional grafting, CHEMICAL SCIENCE, Vol: 9, Pages: 209-217, ISSN: 2041-6520

JOURNAL ARTICLE

Brandley E, Greenhalgh ES, Shaffer MSP, Li Qet al., 2018, Mapping carbon nanotube orientation by fast fourier transform of scanning electron micrographs, Carbon, Vol: 137, Pages: 78-87, ISSN: 0008-6223

© 2018 The Authors A novel method of applying a two-dimensional Fourier transform (2D-FFT) to SEM was developed to map the CNT orientation in pre-formed arrays. Local 2D-FFTs were integrated azimuthally to determine an orientation distribution function and the associated Herman parameter. This approach provides data rapidly and over a wide range of lengthscales. Although likely to be applicable to a wide range of anisotropic nanoscale structures, the method was specifically developed to study CNT veils, a system in which orientation critically controls mechanical properties. Using this system as a model, key parameters for the 2D-FFT analysis were optimised, including magnification and domain size; a model set of CNT veils were pre-strained to 5%, 10% and 15%, to vary the alignment degree. The algorithm confirmed a narrower orientation distribution function and increasing Herman parameter, with increasing pre-strain. To validate the algorithm, the local orientation was compared to that derived from a common polarised Raman spectroscopy. Orientation maps of the Herman parameter, derived by both methods, showed good agreement. Quantitatively, the mean Herma n parameter calculated using the polarised Raman spectroscopy was 0.42 ± 0.004 compared to 0.32 ± 0.002 for the 2D-FFT method, with a correlation coefficient of 0.73. Possible reasons for the modest and systematic discrepancy were discussed.

JOURNAL ARTICLE

De Luca F, Clancy A, Rubio Carrero N, Anthony DB, De Luca H, Shaffer M, Bismarck Aet al., 2018, Increasing carbon fiber composite strength with a nanostructured“brick-and-mortar” interphase, Materials Horizons, ISSN: 2051-6355

Conventional fiber-reinforced composites suffer from the formation of critical clusters of correlated fiber breaks, leading to sudden composite failure in tension. To mitigate this problem, an optimized “brick-and-mortar” nanostructured interphase was developed, in order to absorb energy at fiber breaks and alleviate local stress concentrations whilst maintaining effective load transfer. The coating was designed to exploit crack bifurcation and platelet interlocking mechanisms known in natural nacre. However, the architecture was scaled down by an order of magnitude to allow a highly ordered conformal coating to be deposited around conventional structural carbon fibers, whilst retaining the characteristic phase proportions and aspect ratios of the natural system. Drawing on this bioinspiration, a Layer-by-Layer assembly method was used to coat multiple fibers simultaneously, providing an efficient and potentially scalable route for production. Single fiber pull out and fragmentation tests showed improved interfacial characteristics for energy absorption and plasticity. Impregnated fiber tow model composites demonstrated increases in absolute tensile strength (+15%) and strain-to-failure (+30%), as compared to composites containing conventionally sized fibers.

JOURNAL ARTICLE

De Luca F, Sernicola G, Shaffer MSP, Bismarck Aet al., 2018, "Brick-and-Mortar" Nanostructured Interphase for Glass-Fiber-Reinforced Polymer Composites, ACS APPLIED MATERIALS & INTERFACES, Vol: 10, Pages: 7352-7361, ISSN: 1944-8244

JOURNAL ARTICLE

Ellis T, Chiappi M, Garcia-Trenco A, Al-Ejji M, Sarkar S, Georgiou TK, Shaffer MSP, Tetley TD, Schwander S, Ryan MP, Porter AEet al., 2018, Multi-Metallic Microparticles Increase the Potency of Rifampicin Against Intracellular Mycobacterium tuberculosis., ACS Nano

Mycobacterium tuberculosis (M.tb) has the extraordinary ability to adapt to the administration of antibiotics through the development of resistance mechanisms. By rapidly exporting drugs from within the cytosol, these pathogenic bacteria diminish antibiotic potency and drive the presentation of drug tolerant tuberculosis (TB). The membrane integrity of M.tb is pivotal in retaining these drug-resistant traits. Silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs) are established antimicrobial agents that effectively compromise membrane stability, giving rise to increased bacterial permeability to antibiotics. In this work, biodegradable multi-metallic microparticles (MMPs), containing Ag NPs and ZnO NPs, were developed for use in pulmonary delivery of antituberculous drugs to the endosomal system of M.tb-infected macrophages. Efficient uptake of MMPs by M.tb-infected THP1 cells was demonstrated using an in vitro macrophage infection model, with direct interaction between MMPs and M.tb visualised with the use of electron FIB-SEM tomography. The release of Ag NPs and ZnO NPs within the macrophage endosomal system increased the potency of the model antibiotic rifampicin by as much as 76%, realised through an increase in membrane disorder of intracellular M.tb. MMPs were effective at independently driving membrane destruction of extracellular bacilli located at the exterior face of THP1 macrophages. This MMP system presents as an effective drug delivery vehicle that could be used for the transport of antituberculous drugs such as rifampicin to infected alveolar macrophages, whilst increasing drug potency. By increasing M.tb membrane permeability, such a system may prove effectual in improving treatment of drug-susceptible TB in addition to M.tb strains considered drug-resistant.

JOURNAL ARTICLE

Finley JM, Yu H, Longana ML, Pimenta S, Shaffer MSP, Potter KDet al., 2018, Exploring the pseudo-ductility of aligned hybrid discontinuous composites using controlled fibre-type arrangements, COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING, Vol: 107, Pages: 592-606, ISSN: 1359-835X

JOURNAL ARTICLE

Fisher SJ, Shaffer MSP, 2018, Rapid quantitative mapping of multi-walled carbon nanotube concentration in nanocomposites, COMPOSITES SCIENCE AND TECHNOLOGY, Vol: 160, Pages: 161-168, ISSN: 0266-3538

JOURNAL ARTICLE

Garcia-Trenco A, Regoutz A, White ER, Payne DJ, Shaffer MSP, Williams CKet al., 2018, PdIn intermetallic nanoparticles for the Hydrogenation of CO2 to Methanol, APPLIED CATALYSIS B-ENVIRONMENTAL, Vol: 220, Pages: 9-18, ISSN: 0926-3373

JOURNAL ARTICLE

Javaid A, Ho KKC, Bismarck A, Steinke JHG, Shaffer MSP, Greenhalgh ESet al., 2018, Improving the multifunctional behaviour of structural supercapacitors by incorporating chemically activated carbon fibres and mesoporous silica particles as reinforcement, Journal of Composite Materials, ISSN: 0021-9983

© 2018, The Author(s) 2018. Novel structural supercapacitors have been fabricated which can simultaneously carry mechanical loads as well as store electrochemical energy. Structural supercapacitors are fabricated by impregnating activated carbon fibre mat electrodes and glass fibre mat separator with crosslinked polymer electrolytes using the resin infusion under flexible tooling method. Mesoporous silica particles are also used as reinforcements to further improve the electrochemical and mechanical performance of structural supercapacitors. The fabricated structural supercapacitors have been characterised through chronoamperometry method and impedance spectroscopy to evaluate the electrochemical performance and in-plane shear properties to evaluate the mechanical performance. A multifunctional structural supercapacitor, exhibiting simultaneously a power density of 34 W kg −1 , an energy density of 0.12 Wh kg −1 and a shear modulus of 1.75 GPa, has been fabricated.

JOURNAL ARTICLE

Kennedy OW, Coke ML, White ER, Shaffer MSP, Warburton PAet al., 2018, MBE growth and morphology control of ZnO nanobelts with polar axis perpendicular to growth direction, MATERIALS LETTERS, Vol: 212, Pages: 51-53, ISSN: 0167-577X

JOURNAL ARTICLE

Leung AHM, Pike SD, Clancy AJ, Yau HC, Lee WJ, Orchard KL, Shaffer MSP, Williams CKet al., 2018, Layered zinc hydroxide monolayers by hydrolysis of organozincs, CHEMICAL SCIENCE, Vol: 9, Pages: 2135-2146, ISSN: 2041-6520

JOURNAL ARTICLE

Robinson RK, Birrell MA, Adcock JJ, Wortley MA, Dubuis ED, Chen S, McGilvery CM, Hu S, Shaffer MSP, Bonvini SJ, Maher SA, Mudway IS, Porter AE, Carlsten C, Tetley TD, Belvisi MGet al., 2018, Mechanistic link between diesel exhaust particles and respiratory reflexes, JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY, Vol: 141, Pages: 1074-+, ISSN: 0091-6749

JOURNAL ARTICLE

Woodward RT, Markoulidis F, De Luca F, Anthony DB, Malko D, McDonald TO, Shaffer MSP, Bismarck Aet al., 2018, Carbon foams from emulsion-templated reduced graphene oxide polymer composites: electrodes for supercapacitor devices, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 6, Pages: 1840-1849, ISSN: 2050-7488

JOURNAL ARTICLE

Zhu Y, Radlauer MR, Schneiderman DK, Shaffer MSP, Hillmyer MA, Williams CKet al., 2018, Multiblock Polyesters Demonstrating High Elasticity and Shape Memory Effects, MACROMOLECULES, Vol: 51, Pages: 2466-2475, ISSN: 0024-9297

JOURNAL ARTICLE

Anthony DB, Qian H, Clancy AJ, Greenhalgh ES, Bismarck A, Shaffer MSPet al., 2017, Applying a potential difference to minimise damage to carbon fibres during carbon nanotube grafting by chemical vapour deposition, NANOTECHNOLOGY, Vol: 28, ISSN: 0957-4484

JOURNAL ARTICLE

Buckley DJ, Hodge SA, De Marco M, Hu S, Anthony DB, Cullen PL, McKeigue K, Skipper NT, Shaffer MSP, Howard CAet al., 2017, Trajectory of the Selective Dissolution of Charged Single-Walled Carbon Nanotubes, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 121, Pages: 21703-21712, ISSN: 1932-7447

JOURNAL ARTICLE

Clancy AJ, Anthony DB, Fisher SJ, Leese HS, Roberts CS, Shaffer MSPet al., 2017, Reductive dissolution of supergrowth carbon nanotubes for tougher nanocomposites by reactive coagulation spinning, NANOSCALE, Vol: 9, Pages: 8764-8773, ISSN: 2040-3364

JOURNAL ARTICLE

Clancy AJ, Serginson JM, Greenfield JL, Shaffer MSPet al., 2017, Systematic comparison of single-walled carbon nanotube/poly(vinyl acetate) graft-to reactions, POLYMER, Vol: 133, Pages: 263-271, ISSN: 0032-3861

JOURNAL ARTICLE

De Marco M, Menzel R, Bawaked SM, Mokhtar M, Obaid AY, Basahel SN, Shaffer MSPet al., 2017, Hybrid effects in graphene oxide/carbon nanotube-supported layered double hydroxides: enhancing the CO2 sorption properties, CARBON, Vol: 123, Pages: 616-627, ISSN: 0008-6223

JOURNAL ARTICLE

Garcia-Trenco A, White ER, Regoutz A, Payne DJ, Shaffer MSP, Williams CKet al., 2017, Pd2Ga-Based Colloids as Highly Active Catalysts for the Hydrogenation of CO2 to Methanol, ACS CATALYSIS, Vol: 7, Pages: 1186-1196, ISSN: 2155-5435

JOURNAL ARTICLE

Gonzalez Carter DA, Leo BF, Ruenraroengsak P, Chen S, Goode A, Theodorou I, Chung KF, Carzaniga R, Shaffer M, Dexter D, Ryan M, Porter Aet al., 2017, Silver nanoparticles reduce brain inflammation and related neurotoxicity through induction of H2S-synthesizing enzymes, Scientific Reports, Vol: 7, ISSN: 2045-2322

Silver nanoparticles (AgNP) are known to penetrate into the brain and cause neuronal death. However, there is a paucity in studies examining the effect of AgNP on the resident immune cells of the brain, microglia. Given microglia are implicated in neurodegenerative disorders such as Parkinson’s disease (PD), it is important to examine how AgNPs affect microglial inflammation to fully assess AgNP neurotoxicity. In addition, understanding AgNP processing by microglia will allow better prediction of their long term bioreactivity. In the present study, the in vitro uptake and intracellular transformation of citrate-capped AgNPs by microglia, as well as their effects on microglial inflammation and related neurotoxicity were examined. Analytical microscopy demonstrated internalization and dissolution of AgNPs within microglia and formation of non-reactive silver sulphide (Ag2S) on the surface of AgNPs. Furthermore, AgNP-treatment up-regulated microglial expression of the hydrogen sulphide (H2S)-synthesizing enzyme cystathionine-γ-lyase (CSE). In addition, AgNPs showed significant anti-inflammatory effects, reducing lipopolysaccharide (LPS)-stimulated ROS, nitric oxide and TNFα production, which translated into reduced microglial toxicity towards dopaminergic neurons. Hence, the present results indicate that intracellular Ag2S formation, resulting from CSE-mediated H2S production in microglia, sequesters Ag+ ions released from AgNPs, significantly limiting their toxicity, concomitantly reducing microglial inflammation and related neurotoxicity.

JOURNAL ARTICLE

Hart M, White ER, Chen J, McGilvery CM, Pickard CJ, Michaelides A, Sella A, Shaffer MSP, Salzmann CGet al., 2017, Encapsulation and Polymerization of White Phosphorus Inside Single-Wall Carbon Nanotubes, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, Vol: 56, Pages: 8144-8148, ISSN: 1433-7851

JOURNAL ARTICLE

Hodge SA, Buckley DJ, Yau HC, Skipper NT, Howard CA, Shaffer MSPet al., 2017, Chemical routes to discharging graphenides, NANOSCALE, Vol: 9, Pages: 3150-3158, ISSN: 2040-3364

JOURNAL ARTICLE

Hu S, Laker ZPL, Leese HS, Rubio N, De Marco M, Au H, Skilbeck MS, Wilson NR, Shaffer MSPet al., 2017, Thermochemical functionalisation of graphenes with minimal framework damage, CHEMICAL SCIENCE, Vol: 8, Pages: 6149-6154, ISSN: 2041-6520

JOURNAL ARTICLE

Miller TS, Suter TM, Telford AM, Picco L, Payton OD, Russell-Pavier F, Cullen PL, Sella A, Shaffer MSP, Nelson J, Tileli V, McMillan PF, Howard CAet al., 2017, Single Crystal, Luminescent Carbon Nitride Nanosheets Formed by Spontaneous Dissolution, NANO LETTERS, Vol: 17, Pages: 5891-5896, ISSN: 1530-6984

JOURNAL ARTICLE

Pike SD, Garcia-Trenco A, White ER, Leung AHM, Weiner J, Shaffer MSP, Williams CKet al., 2017, Colloidal Cu/ZnO catalysts for the hydrogenation of carbon dioxide to methanol: investigating catalyst preparation and ligand effectst, CATALYSIS SCIENCE & TECHNOLOGY, Vol: 7, Pages: 3842-3850, ISSN: 2044-4753

JOURNAL ARTICLE

Pike SD, White ER, Regoutz A, Sammy N, Payne DJ, Williams CK, Shaffer MSPet al., 2017, Reversible Redox Cycling of Well-Defined, Ultrasmall Cu/Cu2O Nanoparticles, ACS NANO, Vol: 11, Pages: 2714-2723, ISSN: 1936-0851

JOURNAL ARTICLE

Rocha VG, García-Tuñón E, Botas C, Markoulidis F, Feilden E, D'Elia E, Ni N, Shaffer M, Saiz Eet al., 2017, Multimaterial 3D Printing of Graphene-Based Electrodes for Electrochemical Energy Storage Using Thermoresponsive Inks., ACS Appl Mater Interfaces, Vol: 9, Pages: 37136-37145

The current lifestyles, increasing population, and limited resources result in energy research being at the forefront of worldwide grand challenges, increasing the demand for sustainable and more efficient energy devices. In this context, additive manufacturing brings the possibility of making electrodes and electrical energy storage devices in any desired three-dimensional (3D) shape and dimensions, while preserving the multifunctional properties of the active materials in terms of surface area and conductivity. This paves the way to optimized and more efficient designs for energy devices. Here, we describe how three-dimensional (3D) printing will allow the fabrication of bespoke devices, with complex geometries, tailored to fit specific requirements and applications, by designing water-based thermoresponsive inks to 3D-print different materials in one step, for example, printing the active material precursor (reduced chemically modified graphene (rCMG)) and the current collector (copper) for supercapacitors or anodes for lithium-ion batteries. The formulation of thermoresponsive inks using Pluronic F127 provides an aqueous-based, robust, flexible, and easily upscalable approach. The devices are designed to provide low resistance interface, enhanced electrical properties, mechanical performance, packing of rCMG, and low active material density while facilitating the postprocessing of the multicomponent 3D-printed structures. The electrode materials are selected to match postprocessing conditions. The reduction of the active material (rCMG) and sintering of the current collector (Cu) take place simultaneously. The electrochemical performance of the rCMG-based self-standing binder-free electrode and the two materials coupled rCMG/Cu printed electrode prove the potential of multimaterial printing in energy applications.

JOURNAL ARTICLE

Rubio N, Au H, Leese HS, Hu S, Clancy AJ, Shaffer MSPet al., 2017, Grafting from versus Grafting to Approaches for the Functionalization of Graphene Nanoplatelets with Poly(methyl methacrylate), MACROMOLECULES, Vol: 50, Pages: 7070-7079, ISSN: 0024-9297

JOURNAL ARTICLE

Thong AZ, Shaffer MSP, Horsfield AP, 2017, HOMO-LUMO coupling: the fourth rule for highly effective molecular rectifiers, NANOSCALE, Vol: 9, Pages: 8119-8125, ISSN: 2040-3364

JOURNAL ARTICLE

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