Imperial College London

ProfessorMaryRyan

Faculty of EngineeringDepartment of Materials

Vice-Dean (Research), Faculty of Engineering
 
 
 
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Contact

 

+44 (0)20 7594 6755m.p.ryan

 
 
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Location

 

B338Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
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211 results found

Koronfel MA, Goode AE, Gomez-Gonzalez MA, Weker JN, Simoes TA, Brydson R, Quinn P, Toney MF, Hart A, Porter AE, Ryan MPet al., 2019, Chemical Evolution of CoCrMo Wear Particles: An in Situ Characterization Study, Journal of Physical Chemistry C, Vol: 123, Pages: 9894-9901, ISSN: 1932-7447

Copyright © 2019 American Chemical Society. The unexpected high failure rates of CoCrMo hip implants are associated with the release of a large number of inflammatory wear particles. CoCrMo is nominally a stable material; however, previous chemical speciation studies on CoCrMo wear particles obtained from periprosthetic tissue revealed only trace amounts of Co remaining despite Co being the major component of the alloy. The unexpected high levels of Co dissolution in vivo raised significant clinical concerns particularly related to the Cr speciation in the dissolution process. At high electrochemical potentials, the alloy's Cr-rich passive film breaks down (transpassive polarization), facilitating alloy dissolution. The potential release of the carcinogenic Cr(VI) species in vivo has been a subject of debate. While the large-scale Co dissolution observed on in vivo produced particles could indicate a highly oxidizing in vivo environment, Cr(VI) species were not previously detected in periprosthetic tissue samples (except in the specific case of post-mortem tissue of diabetic patients). However, Cr(VI) is likely to be an unstable (transient) species in biological environments, and studies on periprosthetic tissue do not provide information about intermediate reaction products or the exposure history of the wear particles. Here, an in situ spectromicroscopy approach was developed, utilizing the high chemical resolution of synchrotron radiation, to study CoCrMo reactivity as a function of time and oxidizing conditions. The results reveal limited Co dissolution from CoCrMo particles, which increases dramatically at a critical electrochemical potential. Furthermore, in situ XAS detected only Cr(III) dissolution, even at potentials where Cr(VI) is known to be produced, suggesting that Cr(VI) species are extremely transient in simulated biological environments where the oxidation zone is small.

JOURNAL ARTICLE

Hadden JHL, Ryan MP, Riley DJ, 2019, Examining the charging behaviour of nickel hydroxide nanomaterials, ELECTROCHEMISTRY COMMUNICATIONS, Vol: 101, Pages: 47-51, ISSN: 1388-2481

JOURNAL ARTICLE

Guo L, Lovell E, Wilson N, Burdett P, Cohen LF, Ryan MPet al., 2019, The electrochemical behaviour of magnetocaloric alloys La(Fe,Mn,Si)(13)H-x under magnetic field conditions, CHEMICAL COMMUNICATIONS, Vol: 55, Pages: 3642-3645, ISSN: 1359-7345

JOURNAL ARTICLE

Theodorou IG, Ruenraroengsak P, Gonzalez-Carter DA, Jiang Q, Yague E, Aboagye EO, Coombes RC, Porter AE, Ryan MP, Xie Fet al., 2019, Towards multiplexed near-infrared cellular imaging using gold nanostar arrays with tunable fluorescence enhancement, NANOSCALE, Vol: 11, Pages: 2079-2088, ISSN: 2040-3364

JOURNAL ARTICLE

Theodorou IG, Jiang Q, Malms L, Xie X, Coombes RC, Aboagye EO, Porter AE, Ryan MP, Xie Fet al., 2018, Fluorescence enhancement from single gold nanostars: towards ultra-bright emission in the first and second near-infrared biological windows, NANOSCALE, Vol: 10, Pages: 15854-15864, ISSN: 2040-3364

JOURNAL ARTICLE

Qin H, Wu D, Sathian J, Xie X, Ryan M, Xie Fet al., 2018, Tuning the upconversion photoluminescence lifetimes of NaYF4:Yb3+, Er3+ through lanthanide Gd3+ doping, SCIENTIFIC REPORTS, Vol: 8, ISSN: 2045-2322

JOURNAL ARTICLE

Wang T, Centeno A, Darvill D, Pang JS, Ryan MP, Xie Fet al., 2018, Tuneable fluorescence enhancement of nanostructured ZnO arrays with controlled morphology, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 20, Pages: 14828-14834, ISSN: 1463-9076

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, Multimetallic Microparticles Increase the Potency of Rifampicin against Intracellular Mycobacterium tuberculosis, ACS NANO, Vol: 12, Pages: 5228-5240, ISSN: 1936-0851

JOURNAL ARTICLE

Pramana SS, Cavallaro A, Li C, Handoko AD, Chan KW, Walker RJ, Regoutz A, Herrin JS, Yeo BS, Payne DJ, Kilner JA, Ryan MP, Skinner SJet al., 2018, Crystal structure and surface characteristics of Sr-doped GdBaCo2O6-delta double perovskites: oxygen evolution reaction and conductivity, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 6, Pages: 5335-5345, ISSN: 2050-7488

JOURNAL ARTICLE

Botelho D, Leo BF, Massa C, Sarkar S, Tetley T, Chung KF, Chen S, Ryan MP, Porter A, Atochina-Vasserman EN, Zhang J, Schwander S, Gow AJet al., 2018, Exposure to Silver Nanospheres Leads to Altered Respiratory Mechanics and Delayed Immune Response in an in Vivo Murine Model, FRONTIERS IN PHARMACOLOGY, Vol: 9, ISSN: 1663-9812

JOURNAL ARTICLE

Zhang Y, Cao M, Lv H, Wei J, Gu Y, Liu D, Zhang W, Ryan MP, Wu Xet al., 2018, Electrodeposited nanometer-size IrO2/Ti electrodes with 0.3 mg IrO2 cm(-2) for sludge dewatering electrolysers, ELECTROCHIMICA ACTA, Vol: 265, Pages: 507-513, ISSN: 0013-4686

JOURNAL ARTICLE

Cal E, Qi J, Preedy O, Chen S, Boldrin D, Branford WR, Vandeperre L, Ryan MPet al., 2018, Functionalised magnetic nanoparticles for uranium adsorption with ultra-high capacity and selectivity, Journal of Materials Chemistry A, Vol: 6, Pages: 3063-3073, ISSN: 2050-7496

The removal of radioactive contaminants from the environment for safe and efficient waste disposal is a critical challenge, requiring the development of novel selective and high-capacity sequestering materials. In this paper the design of superparamagnetic iron oxide nanoparticles (SPIONs) as highly efficient magnetic-sorbent structures for uranium (U(VI)) separation is described. The nanosorbent was developed by surface functionalisation of single crystalline magnetite (Fe3O4) nanoparticles with a phosphate-based complex coating. This new design allowed for the development of a magnetically separable ultra-effective sorbent, with a measured U(VI) sorption capacity of ∼2333 mg U per g Fe (1690 mg U per g Fe3O4 NP), significantly higher than everything previously reported. Based on TEM analysis, it is proposed that these properties are the result of a multi-layer ligand structure, which enables a high degree of U-incorporation compared to conventional surface-ligand systems. Moreover, the phosphate-NP construct ((PO)x-Fe3O4) shows exceptionally high specificity for the sequestration of U(VI) in solution at pH 7. Adsorption tests in the presence of competing ions, such as Sr(II), Ca(II) and Mg(II), showed high selectivity of the nanoparticles for U(VI) and extremely rapid kinetics of contaminant removal from solution, with the total amount of uranyl ions being removed after only 60 seconds of contact with the NPs. The results presented in this paper highlight the potential of such a phosphate-functionalised magnetic nanosorbent as a highly effective material for the remediation of U(VI) from contaminated water and industrial scenarios.

JOURNAL ARTICLE

Hassan Sk M, Abdullah AM, Ryan MP, Ko M, Williams DE, Laycock N, Ingham Bet al., 2018, Mo-mediated corrosion behaviour of 1 Cr - Carbon steel in sweet medium under hydrodynamic control, ISSN: 0361-4409

© 2018 by NACE International. The effects of micro-alloying of plain carbon steel with Mo (0.7 wt.%) in the presence of 1 wt.% Cr on the corrosion behaviour and scale protectiveness in CO2 saturated (sweet) brine (0.5 M NaCl) environment, under hydrodynamic conditions, at 80°C in a slightly acidic environment (pH 6.6) were investigated. Potentiostatic current transients suggest that there exists a synergistic interaction of Cr and Mo, which induces more rapid scale crystallization compared to the Mo-free steel. The presence of Mo also suppressed the current passing through corrosion scale. SEM images suggested that 1Cr.0.7Mo steel induced formation of thinner scale with better protectiveness compared to their non-Mo counterparts. From the mechanistic perspective, we suggest that the addition of small amounts of Mo induces formation of a crystalline scale at short times and then it accelerates the growth of that crystalline layer, by modifying the local environment at the steel surface. Modeling of this hypothesis is currently in progress.

CONFERENCE PAPER

Sk MH, Abdullah AM, Qi J, Ko M, Ingham B, Laycock N, Ryan MP, Williams DEet al., 2018, The Effects of Cr/Mo Micro-Alloying on the Corrosion Behavior of Carbon Steel in CO2-Saturated (Sweet) Brine under Hydrodynamic Control, JOURNAL OF THE ELECTROCHEMICAL SOCIETY, Vol: 165, Pages: C278-C288, ISSN: 0013-4651

JOURNAL ARTICLE

Meyer N, Rivera LR, Ellis T, Qi J, Ryan MP, Boccaccini ARet al., 2018, Bioactive and Antibacterial Coatings Based on Zein/Bioactive Glass Composites by Electrophoretic Deposition, COATINGS, Vol: 8, ISSN: 2079-6412

JOURNAL ARTICLE

Luongo G, Campagnolo P, Perez JE, Kosel J, Georgiou TK, Regoutz A, Payne DJ, Stevens MM, Ryan MP, Porter AE, Dunlop IEet al., 2017, Scalable High-Affinity Stabilization of Magnetic Iron Oxide Nanostructures by a Biocompatible Antifouling Homopolymer, ACS APPLIED MATERIALS & INTERFACES, Vol: 9, Pages: 40059-40069, ISSN: 1944-8244

JOURNAL ARTICLE

Theodorou IG, Muller KH, Chen S, Goode AE, Yufit V, Ryan MP, Porter AEet al., 2017, Silver Nanowire Particle Reactivity with Human Monocyte-Derived Macrophage Cells: Intracellular Availability of Silver Governs Their Cytotoxicity, ACS BIOMATERIALS SCIENCE & ENGINEERING, Vol: 3, Pages: 2336-2347, ISSN: 2373-9878

JOURNAL ARTICLE

Theodorou IG, Jawad ZAR, Jiang Q, Aboagye EO, Porter AE, Ryan MP, Xie Fet al., 2017, Gold Nanostar Substrates for Metal-Enhanced Fluorescence through the First and Second Near-Infrared Windows, CHEMISTRY OF MATERIALS, Vol: 29, Pages: 6916-6926, ISSN: 0897-4756

JOURNAL ARTICLE

Qin H, Shamso AE, Centeno A, Theodorou LG, Mihai AP, Ryan MP, Xie Fet al., 2017, Enhancement of the upconversion photoluminescence of hexagonal phase NaYF4:Yb3+,Er3+ nanoparticles by mesoporous gold filmst, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 19, Pages: 19159-19167, ISSN: 1463-9076

JOURNAL ARTICLE

Goode AE, Porter AE, Klosowski MM, Ryan MP, Heutz S, McComb DWet al., 2017, Analytical transmission electron microscopy at organic interfaces, CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE, Vol: 21, Pages: 55-67, ISSN: 1359-0286

JOURNAL ARTICLE

Calderon L, Han TT, McGilvery CM, Yang L, Subramaniam P, Lee K-B, Schwander S, Tetley TD, Georgopoulos PG, Ryan M, Porter AE, Smith R, Chung KF, Lioy PJ, Zhang J, Mainelis Get al., 2017, Release of airborne particles and Ag and Zn compounds from nanotechnology-enabled consumer sprays: Implications for inhalation exposure, ATMOSPHERIC ENVIRONMENT, Vol: 155, Pages: 85-96, ISSN: 1352-2310

JOURNAL ARTICLE

Gonzalez-Carter DA, Leo BF, Ruenraroengsak P, Chen S, Goode AE, Theodorou IG, Chung KF, Carzaniga R, Shaffer MSP, Dexter DT, Ryan MP, Porter AEet al., 2017, Silver nanoparticles reduce brain inflammation and related neurotoxicity through induction of H2S-synthesizing enzymes, SCIENTIFIC REPORTS, Vol: 7, ISSN: 2045-2322

JOURNAL ARTICLE

Pramana SS, Cavallaro A, Qi J, Nicklin CL, Ryan MP, Skinner SJet al., 2017, Understanding surface structure and chemistry of single crystal lanthanum aluminate, SCIENTIFIC REPORTS, Vol: 7, ISSN: 2045-2322

JOURNAL ARTICLE

Chung KF, Seiffert J, Chen S, Theodorou IG, Goode AE, Leo BF, McGilvery CM, Hussain F, Wiegman C, Rossios C, Zhu J, Gong J, Tariq F, Yufit V, Monteith AJ, Hashimoto T, Skepper JN, Ryan MP, Zhang J, Tetley TD, Porter AEet al., 2017, Inactivation, Clearance, and Functional Effects of Lung-Instilled Short and Long Silver Nanowires in Rats, ACS NANO, Vol: 11, Pages: 2652-2664, ISSN: 1936-0851

JOURNAL ARTICLE

Pang J, Theodorou IG, Centeno A, Petrov PK, Alford NM, Ryan MP, Xie Fet al., 2017, Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors, JOURNAL OF MATERIALS CHEMISTRY C, Vol: 5, Pages: 917-925, ISSN: 2050-7526

JOURNAL ARTICLE

Arellano DLG, Bhamrah J, Yang J, Gilchrist JB, McComb DW, Ryan MP, Heutz Set al., 2017, Room-Temperature Routes Toward the Creation of Zinc Oxide Films from Molecular Precursors, ACS OMEGA, Vol: 2, Pages: 98-104, ISSN: 2470-1343

JOURNAL ARTICLE

Hassan Sk M, Abdullah AM, Ko M, Laycock N, Ingham B, Ryan MP, Williams DEet al., 2017, Effect of Cr/Mo on the protectiveness of corrosion scales on carbon steel in sweet medium under high flow regime, Pages: 509-517, ISSN: 1938-6737

© The Electrochemical Society. We investigate the effects of Cr/Mo micro-alloying of plain carbon steel on the corrosion behaviour and scale protectiveness in CO2 saturated (sweet) brine (0.5 M NaCl) environment, under hydrodynamic conditions, at 80oC in a slightly acidic environment (pH 6.6). Potentiostatic current transients indicate positive effects of Cr/Mo micro-alloying on an individual as well as synergistic level of the alloyents. Increase in Cr/Mo content appears to reduce the overall current passing through corrosion scale and encourage faster crystallization. SEM images suggest that Cr/Mo micro-alloying induced formation of thinner scale with better protectiveness. From the mechanistic perspective, we suggest that the addition of small amounts of Cr/Mo modulates the current due to dissolution of iron, as well as the current due to growth of a crystalline layer, by modifying the local environment at the steel surface. Modeling of the hypothesis is currently in progress.

CONFERENCE PAPER

Theodorou IG, Ruenraroengsak P, Gow A, Schwander S, Zhang JJ, Chung KF, Tetley TD, Ryan MP, Porter AEet al., 2016, Effect of pulmonary surfactant on the dissolution, stability and uptake of zinc oxide nanowires by human respiratory epithelial cells, NANOTOXICOLOGY, Vol: 10, Pages: 1351-1362, ISSN: 1743-5390

JOURNAL ARTICLE

Simoes TA, Bryant MG, Brown AP, Milne SJ, Ryan M, Neville A, Brydson Ret al., 2016, Evidence for the dissolution of molybdenum during tribocorrosion of CoCrMo hip implants in the presence of serum protein., Acta Biomater, Vol: 45, Pages: 410-418

We have characterized CoCrMo, Metal-on-Metal (MoM) implant, wear debris particles and their dissolution following cycling in a hip simulator, and have related the results to the tribocorrosion of synthetic wear debris produced by milling CoCrMo powders in solutions representative of environments in the human body. Importantly, we have employed a modified ICP-MS sample preparation procedure to measure the release of ions from CoCrMo alloys during wear simulation in different media; this involved use of nano-porous ultrafilters which allowed complete separation of particles from free ions and complexes in solution. As a result, we present a new perspective on the release of metal ions and formation of metal complexes from CoCrMo implants. The new methodology enables the mass balance of ions relative to complexes and particles during tribocorrosion in hip simulators to be determined. A much higher release of molybdenum ions relative to cobalt and chromium has been measured. The molybdenum dissolution was enhanced by the presence of bovine serum albumin (BSA), possibly due to the formation of metal-protein complexes. Overall, we believe that the results could have significant implications for the analysis and interpretation of metal ion levels in fluids extracted from hip arthroplasty patients; we suggest that metal levels, including molybdenum, be analysed in these fluids using the protocol described here. STATEMENT OF SIGNIFICANCE: We have developed an important new protocol for the analysis of metal ion levels in fluids extracted from hip implant patients and also hip simulators. Using this procedure, we present a new perspective on the release of metal ions from CoCrMo alloy implants, revealing significantly lower levels of metal ion release during tribocorrosion in hip simulators than previously thought, combined with the release of much higher percentages of molybdenum ions relative to cobalt and chromium. This work is of relevance, both from the perspective of th

JOURNAL ARTICLE

Podhorska L, Delcassian D, Goode AE, Agyei M, McComb DW, Ryan MP, Dunlop IEet al., 2016, Mechanisms of Polymer-Templated Nanoparticle Synthesis: Contrasting ZnS and Au, LANGMUIR, Vol: 32, Pages: 9216-9222, ISSN: 0743-7463

JOURNAL ARTICLE

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