ORCID Profile
0000-0001-5906-4285
Current Organisation
James Cook University
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Organic Chemistry | Natural Products Chemistry | Synthesis Of Macromolecules | Organic Green Chemistry | Macromolecular and Materials Chemistry | Organic Chemical Synthesis | F-Block Chemistry | Physical Chemistry Of Macromolecules | Physical Chemistry (Incl. Structural) | Structural Chemistry and Spectroscopy | Nonlinear Optics and Spectroscopy |
Expanding Knowledge in the Chemical Sciences | Army | Solar-photoelectric | Expanding Knowledge in the Physical Sciences | Integrated circuits and devices
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/CH15623
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0PY00083C
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CP01240E
Abstract: The electrocyclisation and cycloreversion of charge-tagged dithienylethene molecules is explored in the gas phase using tandem ion mobility mass spectrometry.
Publisher: Wiley
Date: 02-07-2008
Publisher: Elsevier BV
Date: 06-2013
Publisher: American Chemical Society (ACS)
Date: 19-01-2005
DOI: 10.1021/MA0488562
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2SM00054G
Publisher: Elsevier BV
Date: 09-2005
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3PY01123B
Publisher: Elsevier BV
Date: 12-2013
Publisher: The Royal Society
Date: 28-10-2020
Abstract: Coral reefs are degrading globally due to increased environmental stressors including warming and elevated levels of pollutants. These stressors affect not only habitat-forming organisms, such as corals, but they may also directly affect the organisms that inhabit these ecosystems. Here, we explore how the dual threat of habitat degradation and microplastic exposure may affect the behaviour and survival of coral reef fish in the field. Fish were caught prior to settlement and pulse-fed polystyrene microplastics six times over 4 days, then placed in the field on live or dead-degraded coral patches. Exposure to microplastics or dead coral led fish to be bolder, more active and stray further from shelter compared to control fish. Effect sizes indicated that plastic exposure had a greater effect on behaviour than degraded habitat, and we found no evidence of synergistic effects. This pattern was also displayed in their survival in the field. Our results highlight that attaining low concentrations of microplastic in the environment will be a useful management strategy, since minimizing microplastic intake by fishes may work concurrently with reef restoration strategies to enhance the resilience of coral reef populations.
Publisher: Wiley
Date: 19-04-2004
Publisher: Wiley
Date: 16-08-2023
Abstract: A series of alternating copolymers of a dithienylethene with di‐ n ‐alkyl‐fluorene (P1‐P3), di‐ n ‐hexylphenylene (P4), 9‐heptadecanylcarbazole (P5) and 4,8‐bis(3,5‐dioctyl‐2‐thienyl)‐1,5‐dithia‐ s ‐indacene (P6) were designed, synthesized and characterized. All of the polymers were soluble in common organic solvents such as chloroform, dichloromethane, toluene and tetrahydrofuran. The side‐chain length affected the solubility of the polymer, molecular weight and the glass transition temperature. Solutions of P1‐P6 showed photochromism with high quantum yields of 6‐π electrocyclization (41‐87%) and cycloreversion (0.4‐1.1%). These polymers also formed uniform thin films and the rates of solid state photoisomerization were measured relative to P4, which had the highest cyclization and cycloreversion rates. The color of the photochromic polymer was tuned according to the comonomer and the maximum absorption wavelength ranged from 569 to 675 nm in the closed isomeric form. All the polymers were thermally stable and showed no signs of photo‐degradation after being exposed to UV‐light for 120 min in air. Based on these promising results, these polymers may be useful for multi‐functional organic electronic devices. This article is protected by copyright. All rights reserved
Publisher: American Chemical Society (ACS)
Date: 14-09-2010
DOI: 10.1021/CM1020355
Publisher: Springer Science and Business Media LLC
Date: 27-08-2020
DOI: 10.1038/S41467-020-18094-4
Abstract: Electrical pumping of organic semiconductor devices involves charge injection, transport, device on/off dynamics, exciton formation and annihilation processes. A comprehensive model analysing those entwined processes together is most helpful in determining the dominating loss pathways. In this paper, we report experimental and theoretical results of Super Yellow (Poly( p -phenylene vinylene) co-polymer) organic light emitting diodes operating at high current density under high voltage nanosecond pulses. We demonstrate complete exciton and charge carrier dynamics of devices, starting from charge injection to light emission, in a time scale spanning from the sub-ns to microsecond region, and compare results with optical pumping. The experimental data is accurately replicated by simulation, which provides a robust test platform for any organic materials. The universality of our model is successfully demonstrated by its application to three other laser active materials. The findings provide a tool to narrow the search for material and device designs for injection lasing.
Publisher: SPIE
Date: 12-05-2003
DOI: 10.1117/12.485990
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/CH15337
Abstract: An organic photochromic compound is explored as a new portable colorimetric sensor for nitroaromatics. This photochromic compound switches from colourless to pink upon exposure to ultraviolet light. In the presence of nitroaromatic explosive derivatives the photoswitching behaviour of the dithienylethene is suppressed, while a potential false positive (toluene) has little effect. The degree of photoswitching inhibition was determined by comparing the integrated visible absorption with the concentration of the analyte to give the pseudo Stern–Volmer constant (KPSV). The KPSVs measured varied from 12900 (p-nitrotoluene) to 236 M–1 (toluene), which were directly related to the analyte absorption at the excitation wavelength.
Publisher: AIP Publishing
Date: 23-12-2019
DOI: 10.1063/1.5131680
Abstract: The correct choice of guest and host molecules in the light-emitting layer is essential for developing high performance phosphorescent organic light emitting devices. However, the effects of the energy level alignment between the guest and the host are yet to be fully elucidated. In this Letter, we use kinetic Monte Carlo simulations to investigate guest-host systems in which the energy gap of the guest and host is fixed, and only the relative energies of the ionization potential/electron affinity are changed to elucidate their effect on charge transport. It was determined that the mobility balance in the blend was sensitive to the energy level alignment, allowing balanced active layer mobility to be achieved despite the hole and electron mobilities being different by around one order of magnitude. It was also found that the mobility of the faster carrier was more sensitive to the energy level alignment than that of the slower carrier due to reduced slower carrier thermalization under deep charge trapping on the guest.
Publisher: American Chemical Society (ACS)
Date: 28-02-2002
DOI: 10.1021/CM011603S
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/CH19336
Abstract: The colorimetric detection of polycyclic aromatic hydrocarbons (PAHs) was investigated for the quick and easy identification of likely oil spill offenders. In this new technology, photochromic compounds were used to sense PAHs by varying their photoswitching capacity. To that end, three photochromes were designed and showed varying degrees of photoswitching inhibition, depending on PAH analyte, photochrome, and excitation wavelength. PAH mixtures that mimic oil spills showed the same varying response and demonstrated the accuracy of this technology. To prove the applicability of this technology, an array was assembled, using the three photochromes at three excitation wavelengths, and tested against authentic crude oil s les. Not only could these s les be differentiated, but also weathering of two distinctly different oil s les showed limited variation in response, demonstrating that this may be a viable technique for in situ oil identification.
Publisher: Wiley
Date: 09-2005
Publisher: American Chemical Society (ACS)
Date: 13-12-2000
DOI: 10.1021/MA001413N
Publisher: Wiley
Date: 06-07-2020
Publisher: American Chemical Society (ACS)
Date: 29-03-2006
DOI: 10.1021/LA053025Q
Abstract: Highly ordered hexagonal arrays of isoporous films prepared from poly(9,9'-dihexylfluorene) and polystyrene-grafted silica nanoparticles (Si-graft-PS) are presented. These close-packed arrays were formed in areas of many square millimeters. The pore size varied from 3.6 to 8.5 microm, depending on the concentration of Si-graft-PS and the processing conditions. Solid-state photoluminescence resulted in a significant red shift of up to 30 nm in these films compared to that in conventional processing techniques. These differences are attributed to enhanced aggregation of the polymers caused by polymer-solvent interactions. These highly ordered polymer films may find use in microelectronic and biological and/or chemical sensor applications.
Publisher: Wiley
Date: 25-03-2022
Abstract: Establishing the toxicity and exposure consequences of microplastics (MPs) on marine organisms relies on the nondestructive isolation of plastics from biological matrices. MPs are commonly extracted from these matrices by chemical digestion using alkali (e.g., potassium hydroxide (KOH) and sodium hydroxide (NaOH)), oxidative (e.g., hydrogen peroxide (H 2 O 2 )) and/or acidic (e.g., nitric acid (HNO 3 )) reagents. Although these digestion conditions can be highly effective for MP extraction, they can also react with the plastics. This can attribute an inaccurate representation of plastic contamination by altering MP visual characteristics (size, shape, color), thereby impeding identification and potentially returning erroneous numbers of ingested particles. In this study, the degradative impacts are assessed of the routinely applied digestion reagents (i) KOH, (ii) NaOH, (iii) H 2 O 2 , and (iv) HNO 3 on polystyrene (PS) based MPs sized between 200 µm and 5 mm. Degradation of the PS MPs is evaluated using FT‐IR, gel permeation chromatography, NMR, photoluminescence spectroscopy, and microscopy. These studies reveal HNO 3 to be the most destructive for PS MPs, while the alkali and oxidative reagents result in negligible changes in plastic properties. These results are recommended to be used as a guideline to update current protocols to ensure the nondestructive treatment of MPs.
Publisher: American Vacuum Society
Date: 05-2004
DOI: 10.1116/1.1649988
Abstract: The performance of polymer thin film transistors, made of different semiconducting polymers, depends mostly on the type of polymer and its deposition conditions. For these polymer field-effect transistors (PFETs), the current transport is limited by the carrier injection from the source electrode into the polymer. The disordered polymer molecules near the injection interface randomize and decrease the injection barrier, resulting in a large variation of the PFET characteristics, such as threshold voltage, leakage current, and mobility. The PFET current–voltage characteristics degrade at temperatures higher than 40 °C and the low frequency noise increases by 0.3 dB/°C.
Publisher: Elsevier BV
Date: 10-2019
Publisher: IOP Publishing
Date: 28-06-2010
Publisher: Informa UK Limited
Date: 30-10-2015
Publisher: Elsevier BV
Date: 06-2002
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CP02818K
Abstract: PMMA polymer films doped with photochromic molecules have been prepared that can be photoswitched between three states and display novel fluorescence behavior.
Publisher: American Chemical Society (ACS)
Date: 11-04-2001
DOI: 10.1021/MA010293W
Publisher: Wiley
Date: 08-07-2018
Abstract: Recent developments in rechargeable battery technology have seen a shift from the well-established Li-ion technology to new chemistries to achieve the high energy density required for extended range electric vehicles and other portable applications, as well as low-cost alternatives for stationary storage. These chemistries include Li-air, Li-S, and multivalent ion technologies including Mg
Publisher: Elsevier BV
Date: 09-2019
Publisher: AIP Publishing
Date: 06-2022
DOI: 10.1063/5.0091142
Abstract: Solution-processing of organic light-emitting diode films has potential advantages in terms of cost and scalability over vacuum-deposition for large area applications. However, solution processed small molecule films can have lower overall device performance. Here, novel molecular dynamics techniques are developed to enable faster simulation of solvent evaporation that occurs during solution processing and give films of thicknesses relevant to real devices. All-atom molecular dynamics simulations are then used in combination with kinetic Monte Carlo transport modeling to examine how differences in morphology stemming from solution or vacuum film deposition affect charge transport and exciton dynamics in films consisting of light-emitting bis(2-phenylpyridine)(acetylacetonate)iridium(III) [Ir(ppy)2(acac)] guest molecules in a 4,4′-bis(N-carbazolyl)biphenyl host. While the structures of the films deposited from vacuum and solution were found to differ, critically, only minor variations in the transport properties were predicted by the simulations even if trapped solvent was present.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2TC00541G
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 05-2004
Publisher: AIP Publishing
Date: 17-07-2023
DOI: 10.1063/5.0152922
Abstract: Phosphorescent organic light emitting diodes (OLEDs) suffer from efficiency roll off, where device efficiency rapidly decays at higher luminance. One strategy to minimize this loss of efficiency at higher luminance is the use of non-uniform or graded guest:host blend ratios within the emissive layer. This work applies a multi-scale modeling framework to elucidate the mechanisms by which a non-uniform blend ratio can change the performance of an OLED. Mobility and exciton data are extracted from a kinetic Monte–Carlo model, which is then coupled to a drift diffusion model for fast s ling of the parameter space. The model is applied to OLEDs with uniform, linear, and stepwise graduations in the blend ratio in the emissive layer. The distribution of the guests in the film was found to affect the mobility of the charge carriers, and it was determined that having a graduated guest profile broadened the recombination zone, leading to a reduction in second order annihilation rates. That is, there was a reduction in triplet–triplet and triplet-polaron annihilation. Reducing triplet–triplet and triplet-polaron annihilation would lead to an improvement in device efficiency.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2004
Publisher: American Chemical Society (ACS)
Date: 08-2002
DOI: 10.1021/MA020140O
Publisher: AIP Publishing
Date: 06-03-2019
DOI: 10.1063/1.5083639
Abstract: Ir(ppy)3:CBP blends have been widely studied as the emissive layer in organic light emitting diodes (OLEDs), yet crucial questions about charge transport within the layer remain unaddressed. Recent molecular dynamics simulations show that the Ir(ppy)3 molecules are not isolated from each other, but at concentrations of as low as 5 wt. % can be part of connected pathways. Such connectivity raises the question of how the iridium(iii) complexes contribute to long-range charge transport in the blend. We implement a kinetic Monte Carlo transport model to probe the guest concentration dependence of charge mobility and show that distinct minima appear at approximately 10 wt. % Ir(ppy)3 due to an increased number of trap states that can include interconnected complexes within the blend film. The depth of the minima is shown to be dependent on the electric field and to vary between electrons and holes due to their different trapping depths arising from the different ionization potentials and electron affinities of the guest and host molecules. Typical guest-host OLEDs use a guest concentration below 10 wt. % to avoid triplet-triplet annihilation, so these results suggest that optimal device performance is achieved when there is significant charge trapping on the iridium(iii) complex guest molecules and minimum interactions of the emissive chromophores that can lead to triplet-triplet annihilation.
Publisher: American Chemical Society (ACS)
Date: 16-12-2020
DOI: 10.1021/ACS.BIOMAC.9B01688
Abstract: Heparin, a sulfated polysaccharide derived from animal sources, is the most commonly used parenteral anticoagulant drug, but it suffers from significant safety and supply issues. Herein, we describe the preparation of heparin mimetic homo- and copolymers via the reversible addition-fragmentation chain transfer (RAFT) polymerization in water of commercially available (non-carbohydrate) sulfonated and carboxylated monomers. The anticoagulant activities of the polymers were assessed by activated partial thromboplastin time (APTT), thrombin clotting time (TCT), and for the more promising polymers, thrombin generation, antifactor Xa, and antifactor IIa assays. Sulfonated homopolymers studied herein displayed low cytotoxicity and significant anticoagulant activity in APTT, TCT, and thrombin generation assays. In addition, copolymers of sodium styrenesulfonate and acrylic acid [poly(SSS-
Publisher: AIP Publishing
Date: 22-04-2021
DOI: 10.1063/5.0044177
Abstract: Emissive layers in phosphorescent organic light-emitting diodes commonly make use of guest–host blends such as Ir(ppy)3:CBP to achieve high external quantum efficiencies. However, while the Ir(ppy)3:CBP blend has been studied experimentally, crucial questions remain regarding how exciton diffusion is dependent on the distribution of the guest in the host, which can currently only be addressed at the atomic level via computational modeling. In this work, kinetic Monte Carlo simulations are utilized to gain insight into exciton diffusion in Ir(ppy)3:CBP blend films. The effects of both guest concentration and exciton density on various system properties are analyzed, including the probability of singlet excitons being converted to triplets, and the probability of those triplets decaying radiatively. Significantly, these simulations suggest that triplet diffusion occurs almost exclusively via guest–guest Dexter transfer and that concentration quenching of triplets induced by guest–guest intermolecular dipole-dipole interactions has a negligible effect at high exciton densities due to the prevalence of triplet–triplet annihilation. Furthermore, results for vacuum deposited morphologies derived from molecular dynamics simulations are compared to the results obtained using a simple cubic lattice approximation with randomly distributed guest molecules. We show that while differences in host-based processes such as singlet diffusion are observed, overall, the results on the fate of the excitons are in good agreement for the two morphology types, particularly for guest-based processes at low guest concentrations where guest clustering is limited.
Publisher: Elsevier BV
Date: 06-2000
Publisher: Wiley
Date: 27-08-2007
Publisher: SPIE
Date: 28-09-2006
DOI: 10.1117/12.687555
Publisher: Elsevier BV
Date: 12-2004
Publisher: Elsevier BV
Date: 09-2015
Publisher: Institution of Engineering and Technology (IET)
Date: 2004
Publisher: American Chemical Society (ACS)
Date: 11-2004
DOI: 10.1021/MA048733H
Publisher: American Chemical Society (ACS)
Date: 12-2004
DOI: 10.1021/CM048617T
Location: Canada
Start Date: 02-2015
End Date: 12-2015
Amount: $270,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 12-2015
Amount: $600,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2021
End Date: 06-2024
Amount: $538,590.00
Funder: Australian Research Council
View Funded Activity