Publications
117 results found
Svanberg-Larsson J, Nelson GW, Steinvall SE, et al., 2016, A Comparison of Explicitly-terminated Diamond Electrodes Decorated with Gold Nanoparticles, Electroanalysis, Vol: 28, Pages: 88-95, ISSN: 1521-4109
This work compares electrodeposited and drop-cast (DC) AuNPs on oxygen and hydrogen terminated boron-doped diamond (BDDO and BDDH). The samples were characterized using a range of electrochemical and physical surface methods and investigated as mercury sensors. Overall, AuNPs deposited by either method were found to be more electrochemically active on BDDH than BDDO, although more DC-AuNPs were adsorbed onto BDDO than BDDH. The mercury sensing experiments, carried out using square-wave anodic stripping voltammetry (SWASV) showed that lower Hg concentrations were detected with AuNPs/BDDH than AuNPs/BDDO regardless of deposition method, thus demonstrating a benefit of using BDDH for electroanalysis.
Walker RJ, Pougin A, Oropeza FE, et al., 2016, Surface Termination and CO<sub>2</sub> Adsorption onto Bismuth Pyrochlore Oxides, CHEMISTRY OF MATERIALS, Vol: 28, Pages: 90-96, ISSN: 0897-4756
- Author Web Link
- Cite
- Citations: 18
Harrison RH, Steele JAM, Chapman R, et al., 2015, Modular and versatile spatial functionalization of tissue engineering scaffolds through fiber-initiated controlled radical polymerization, Advanced Functional Materials, Vol: 25, Pages: 5748-5757, ISSN: 1616-301X
Native tissues are typically heterogeneous and hierarchically organized, and generating scaffolds that can mimic these properties is critical for tissue engineering applications. By uniquely combining controlled radical polymerization (CRP), end‐functionalization of polymers, and advanced electrospinning techniques, a modular and versatile approach is introduced to generate scaffolds with spatially organized functionality. Poly‐ε‐caprolactone is end functionalized with either a polymerization‐initiating group or a cell‐binding peptide motif cyclic Arg‐Gly‐Asp‐Ser (cRGDS), and are each sequentially electrospun to produce zonally discrete bilayers within a continuous fiber scaffold. The polymerization‐initiating group is then used to graft an antifouling polymer bottlebrush based on poly(ethylene glycol) from the fiber surface using CRP exclusively within one bilayer of the scaffold. The ability to include additional multifunctionality during CRP is showcased by integrating a biotinylated monomer unit into the polymerization step allowing postmodification of the scaffold with streptavidin‐coupled moieties. These combined processing techniques result in an effective bilayered and dual‐functionality scaffold with a cell‐adhesive surface and an opposing antifouling non‐cell‐adhesive surface in zonally specific regions across the thickness of the scaffold, demonstrated through fluorescent labelling and cell adhesion studies. This modular and versatile approach combines strategies to produce scaffolds with tailorable properties for many applications in tissue engineering and regenerative medicine.
Regoutz A, Egdell RG, Morgan DJ, et al., 2015, Electronic and surface properties of Ga-doped In2O3 ceramics, APPLIED SURFACE SCIENCE, Vol: 349, Pages: 970-982, ISSN: 0169-4332
Kahk JM, Villar-Garcia IJ, Grechy L, et al., 2015, A study of the pressure profiles near the first pumping aperture in a high pressure photoelectron spectrometer, Journal of Electron Spectroscopy and Related Phenomena, Vol: 205, Pages: 57-65, ISSN: 1873-2526
In a high-pressure photoelectron spectrometer, the sample is positioned close to a differential pumping aperture, behind which the pressure is several orders of magnitude lower than the pressure in the analysis chamber. To find the optimal sample position, where the path length of the photoelectrons through the high pressure region is minimized as far as possible without compromising knowledge of the actual pressure at the sample surface, an understanding of the pressure variations near the sample and the aperture is required. A computational fluid dynamics study has been carried out to examine the pressure profiles, and the results are compared against experimental spectra whose intensities are analyzed using the Beer–Lambert law. The resultant pressure profiles are broadly similar to the one previously derived from a simplistic molecular flow model, but indicate that as the pressure in the analysis chamber is raised, the region over which the pressure drop occurs becomes progressively narrower.
Mahat MM, Mawad D, Nelson GW, et al., 2015, Elucidating the deprotonation of polyaniline films by X-ray photoelectron spectroscopy, Journal of Materials Chemistry C, Vol: 3, Pages: 7180-7186, ISSN: 2050-7526
Spin-coated polyaniline (PANI) thin films can be made conductive following treatment with a dopant (reducing or oxidising agent). However, de-doping results in loss of electrical properties. We chemically doped PANI films using p-toluene sulfonic acid (pTSA) and camphor sulfonic acid (CSA) and examined their ability to retain these dopants and their conductive properties in physiological media. Changes in the protonation level of these films were assessed by N 1s core line spectra in X-ray photoelectron spectroscopy (XPS). PANI films were found to de-dope with a decrease in the ratio of N 1s photoelectron signal corresponding to positively charged nitrogen (i.e. –NH2+, [double bond, length as m-dash]NH+) to the total N 1s signal. De-doping of PANI films was confirmed by depletion of the dopant fragment (–SO3−) as determined from both XPS and atomic distribution in Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) images. XPS has been successfully used as a tool to elucidate the deprotonation of PANI films and the loss of the dopant from the bulk.
Edwards MOM, Karlsson PG, Eriksson SK, et al., 2015, Increased photoelectron transmission in High-pressure photoelectron spectrometers using "swift acceleration", NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Vol: 785, Pages: 191-196, ISSN: 0168-9002
- Author Web Link
- Cite
- Citations: 19
Poll CG, Payne DJ, 2015, Electrochemical Synthesis of PbO<sub>2</sub>, Pb<sub>3</sub>O<sub>4</sub> and PbO Films on a Transparent Conducting Substrate, ELECTROCHIMICA ACTA, Vol: 156, Pages: 283-288, ISSN: 0013-4686
- Author Web Link
- Cite
- Citations: 29
Oropeza FE, Villar-Garcia IJ, Palgrave RG, et al., 2014, A solution chemistry approach to epitaxial growth and stabilisation of Bi2Ti2O7 films, Journal of Materials Chemistry A, Vol: 2, Pages: 18241-18245, ISSN: 2050-7488
Single crystalline pyrochlore Bi2Ti2O7 films have been grown in three different orientations on yttria-stabilised zirconia at temperatures as low as 600 °C, by using a simple wet chemistry method based on the spin-coating technique. Contrary to free-standing powders and polycrystalline films, epitaxial single crystalline Bi2Ti2O7 is stable relative to other bismuth titanate compounds at temperatures up to 900 °C. A study of core X-ray photoelectron spectra shows Bi2Ti2O7 films contain an oxygen deficiency whose concentration depends on the annealing temperature. Based on low-energy ion scattering spectroscopy, it was determined that crystalline surfaces terminate in BiOx-like structures.
Allen JP, Galea NM, Watson GW, et al., 2014, Valence States in CeVO<sub>4</sub> and Ce<sub>0.5</sub>Bi<sub>0.5</sub>VO<sub>4</sub> Probed by Density Functional Theory Calculations and X-ray Photoemission Spectroscopy, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 118, Pages: 25330-25339, ISSN: 1932-7447
- Author Web Link
- Cite
- Citations: 14
Eriksson SK, Hahlin M, Kahk JM, et al., 2014, A versatile photoelectron spectrometer for pressures up to 30 mbar, REVIEW OF SCIENTIFIC INSTRUMENTS, Vol: 85, ISSN: 0034-6748
- Author Web Link
- Cite
- Citations: 37
Mudd JJ, Lee T-L, Munoz-Sanjose V, et al., 2014, Valence-band orbital character of CdO: A synchrotron-radiation photoelectron spectroscopy and density functional theory study, PHYSICAL REVIEW B, Vol: 89, ISSN: 1098-0121
- Author Web Link
- Cite
- Citations: 25
Kahk JM, Poll CG, Oropeza FE, et al., 2014, Understanding the electronic structure of IrO2 using hard-X-ray photoelectron spectroscopy and density-functional theory, Physical Review Letters, Vol: 112, ISSN: 0031-9007
The electronic structure of IrO2 has been investigated using hard x-ray photoelectron spectroscopy and density-functional theory. Excellent agreement is observed between theory and experiment. We show that the electronic structure of IrO2 involves crystal field splitting of the iridium 5d orbitals in a distorted octahedral field. The behavior of IrO2 closely follows the theoretical predictions of Goodenough for conductive rutile-structured oxides [J. B. Goodenough, J. Solid State Chem. 3, 490 (1971)]. Strong satellites associated with the core lines are ascribed to final state screening effects. A simple plasmon model for the satellites applicable to many other metallic oxides appears to be not valid for IrO2.
Oropeza FE, Walker R, Payne DJ, 2014, Electronic structure of bismuth titanates thin films and their application in solar energy conversion, 247th National Spring Meeting of the American-Chemical-Society (ACS), Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
- Author Web Link
- Cite
- Citations: 1
Mudd JJ, Lee T-L, Munoz-Sanjose V, et al., 2014, Hard x-ray photoelectron spectroscopy as a probe of the intrinsic electronic properties of CdO, PHYSICAL REVIEW B, Vol: 89, ISSN: 1098-0121
- Author Web Link
- Cite
- Citations: 26
Kahk JM, Sheridan DL, Kehoe AB, et al., 2014, The electronic structure of silver orthophosphate: experiment and theory, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 2, Pages: 6092-6099, ISSN: 2050-7488
- Author Web Link
- Cite
- Citations: 20
Trantidou T, Payne DJ, Tsiligkiridis V, et al., 2013, The dual role of Parylene C in chemical sensing: Acting as an encapsulant and as a sensing membrane for pH monitoring applications, Sensors and Actuators B - Chemical, Vol: 186, Pages: 1-8, ISSN: 0925-4005
In this work, we demonstrate a new property of Parylene C emphasizing on its application in pH sensing technologies. For many decades the material has been extensively used as a biocompatible inert encapsulant of implantable micro-devices. Toward a new understanding of the material's potential, we explore the transformation of Parylene C from a passive encapsulation membrane into an active H+ sensing membrane using discrete MOSFETs to evaluate its chemical sensing performance. We employ oxygen plasma treatment to functionalize Parylene's H+ sensing capacity and enhance the chemical sensitivity, drift rates, and reliability of the sensing devices. Moreover, we demonstrate a versatile technique that enables the deployment of the material both as an encapsulant and as a sensing membrane in a single platform, in order to benefit from distinguishable and consistent sensitivities, and low leakage currents during pH measurements. Our investigation reveals that the selective modification of Parylene's surface chemistry yields reliable pH sensing devices, ensuring the best combination of sensitivity (16.3 mV/pH) and leakage currents (6–10 nA) over a reasonably wide pH range (4–10), while drift rates remain in low levels (2.5–20 mV/h). We believe that this study opens up new application horizons for Parylene, which is a new promising material in the emerging field of flexible electronics able to deliver low film thicknesses and high biocompatibility, while facilitating the application of mechanical stimulus.
Marshall MSJ, Becerra-Toledo AE, Payne DJ, et al., 2012, Structure and composition of linear TiO<i><sub>x</sub></i> nanostructures on SrTiO<sub>3</sub>(001), PHYSICAL REVIEW B, Vol: 86, ISSN: 1098-0121
- Author Web Link
- Cite
- Citations: 17
Zhang KHL, Payne DJ, Egdell RG, 2012, Cross section and resonance effects in photoemission from Sn-doped In<sub>2</sub>O<sub>3</sub>(111), SOLID STATE COMMUNICATIONS, Vol: 152, Pages: 194-198, ISSN: 0038-1098
- Author Web Link
- Cite
- Citations: 4
Zhang KHL, Lazarov VK, Galindo PL, et al., 2012, Domain Matching Epitaxial Growth of In<sub>2</sub>O<sub>3</sub> Thin Films on α-Al<sub>2</sub>O<sub>3</sub>(0001), CRYSTAL GROWTH & DESIGN, Vol: 12, Pages: 1000-1007, ISSN: 1528-7483
- Author Web Link
- Cite
- Citations: 47
Scanlon DO, Kehoe AB, Watson GW, et al., 2011, Nature of the Band Gap and Origin of the Conductivity of PbO<sub>2</sub> Revealed by Theory and Experiment, PHYSICAL REVIEW LETTERS, Vol: 107, ISSN: 0031-9007
- Author Web Link
- Cite
- Citations: 85
Zhang KHL, Regoutz A, Palgrave RG, et al., 2011, Determination of the Poisson ratio of (001) and (111) oriented thin films of In<sub>2</sub>O<sub>3</sub> by synchrotron-based x-ray diffraction, PHYSICAL REVIEW B, Vol: 84, ISSN: 1098-0121
- Author Web Link
- Cite
- Citations: 19
Payne DJ, Robinson MDM, Egdell RG, et al., 2011, The nature of electron lone pairs in BiVO<sub>4</sub>, APPLIED PHYSICS LETTERS, Vol: 98, ISSN: 0003-6951
- Author Web Link
- Cite
- Citations: 82
Payne DJ, Marquis EA, 2011, Three-Dimensional Spatial Distribution of Cr atoms in Doped Indium Oxide, CHEMISTRY OF MATERIALS, Vol: 23, Pages: 1085-1087, ISSN: 0897-4756
- Author Web Link
- Cite
- Citations: 18
Marshall MSJ, Newell DT, Payne DJ, et al., 2011, Atomic and electronic surface structures of dopants in oxides: STM and XPS of Nb- and La-doped SrTiO<sub>3</sub>(001), PHYSICAL REVIEW B, Vol: 83, ISSN: 1098-0121
- Author Web Link
- Cite
- Citations: 82
Walsh A, Payne DJ, Egdell RG, et al., 2011, Stereochemistry of post-transition metal oxides: revision of the classical lone pair model, CHEMICAL SOCIETY REVIEWS, Vol: 40, Pages: 4455-4463, ISSN: 0306-0012
- Author Web Link
- Cite
- Citations: 512
Koerber C, Krishnakumar V, Klein A, et al., 2010, Electronic structure of In<sub>2</sub>O<sub>3</sub> and Sn-doped In<sub>2</sub>O<sub>3</sub> by hard x-ray photoemission spectroscopy, PHYSICAL REVIEW B, Vol: 81, ISSN: 2469-9950
- Author Web Link
- Cite
- Citations: 111
Scanlon DO, Watson GW, Payne DJ, et al., 2010, Theoretical and Experimental Study of the Electronic Structures of MoO<sub>3</sub> and MoO<sub>2</sub>, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 114, Pages: 4636-4645, ISSN: 1932-7447
- Author Web Link
- Cite
- Citations: 501
Shin D, Foord JS, Payne DJ, et al., 2009, Comparative study of bandwidths in copper delafossites from x-ray emission spectroscopy, PHYSICAL REVIEW B, Vol: 80, ISSN: 2469-9950
- Author Web Link
- Cite
- Citations: 34
Zhang KHL, Payne DJ, Palgrave RG, et al., 2009, Surface Structure and Electronic Properties of In<sub>2</sub>O<sub>3</sub>(111) Single-Crystal Thin Films Grown on Y-Stabilized ZrO<sub>2</sub>(111), CHEMISTRY OF MATERIALS, Vol: 21, Pages: 4353-4355, ISSN: 0897-4756
- Author Web Link
- Cite
- Citations: 49
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.