Charles Sorrell | The University of New South Wales (original) (raw)

Papers by Charles Sorrell

International journal of engineering. Transactions A: basics, Mar 9, 2018

Research Square (Research Square), Feb 3, 2023

Journal of the Australian Ceramic Society, Oct 6, 2021

arXiv (Cornell University), Sep 3, 2019

Journal of Materials Science, Nov 1, 2022

arXiv (Cornell University), Dec 11, 2020

arXiv (Cornell University), Apr 22, 2021

SN applied sciences, Feb 15, 2019

Chemischer Informationsdienst, May 24, 1977

Chemischer Informationsdienst, Apr 25, 1978

Advanced Engineering Materials

The present work reports a detailed interpretation of the role of Ga and Mn dopants, solid solubi... more The present work reports a detailed interpretation of the role of Ga and Mn dopants, solid solubility mechanisms, charge compensation mechanisms, intervalence charge transfer, antibacterial performance, and cell attachment and proliferation. Sol–gel undoped and doped (1, 5, and 9 mol%) CeO2films are spin‐coated on 3D printed Ti6Al4V biomedical alloy substrates and annealed at 650 °C for 2 h in air. Material characterization includes scanning electron microscopy (SEM), 3D scanning laser confocal microscopy, glancing angle X‐ray diffraction (GAXRD), and X‐ray photoelectron spectroscopy (XPS). In vitro testing includes inhibition of bacterial growth, simulated body fluid (SBF) testing, and cell attachment and proliferation studies. The most significant outcome is that the bioactivity of ceria derives directly from the Ce3+concentration, which itself results from solid solubility (substitutional and interstitial) and charge compensation and redox. This challenges the common assumption o...

Applied Surface Science, 2021

Abstract Although the intrinsic properties of biocatalytic nanomaterials have led to their increa... more Abstract Although the intrinsic properties of biocatalytic nanomaterials have led to their increasing importance for biomedical applications, their applicability has been hindered by the disadvantages of (1) environmentally deleterious synthesis procedures, (2) non-biocompatibility of conventional surface functionalising agents, (3) lack of stealth properties, and (4) blockage of biocatalytically active surface sites during synthesis, functionalisation, and application. The present work reports a new green stealth engineering strategy, using environmentally-friendly natural materials green synthesis technique, and stimuli-responsive molecules for the development of biocompatible ceria-based nanocatalysts with lifetime biocatalytic properties. This green and stealth technique has the advantages of being an integrated, one-pot, room-temperature synthesis and surface-modification method involving surfactant-free precipitation, aqueous silanisation, and metal-free O-PET-ATRP surface functionalisation approach. The surface functionalisation represents a stealth and targeted-design approach that leverages a zwitterionic charge-switchable glycopolymeric stealth coating that serves the four functions of being (1) biologically benign, (2) plasma-protein-repulsive in the physiological environment, (3) charge-switchable between physiological environment and tumour microenvironment, and (4) target-specific in the tumour microenvironment. Critically, lifetime catalytic activity is engineered through the avoidance of adsorption of the functionalising and processing species on lattice sites instead of active sites. These processes were monitored by various analytical techniques in order to elucidate the mechanisms of action of the nanoceria while overcoming environmental, processing, and physiological barriers in nanoceria. The outcomes of this new green and stealth engineering strategy provide lifetime retention of nanoceria’s surface-active-sites, thereby optimising the catalytic redox activity in the physiological environment of pH 7.4 (antioxidant) and tumour microenvironment pH of 6.2 (prooxidant) for neuroblastoma and other therapies. Importantly, this novel approach in the design and engineering of new materials with optimal performance has the potential to enable widespread applicability in the biomedical field.

Journal of Colloid and Interface Science, 2021

HYPOTHESIS The air-solution interface of supersaturated calcium hydrogen carbonate (Ca(HCO3)2) re... more HYPOTHESIS The air-solution interface of supersaturated calcium hydrogen carbonate (Ca(HCO3)2) represents the highest saturation state due to evaporation/CO2-degassing, where calcite crystals are expected to nucleate and grow along the interface. Hence, it should be possible to form a free-standing mineral-only calcium carbonate (CaCO3) microfilm at the air-solution interface of Ca(HCO3)2. The air-solution interface of phosphate buffered saline (PBS) could represent a phase boundary to introduce a hybrid microstructure of CaCO3 and carbonate-rich dicalcium hydroxide phosphate (carbonate-rich hydroxylapatite). EXPERIMENTS Supersaturated Ca(HCO3)2 was prepared at high pressure and heated to form CaCO3 microfilms, which were converted to bone-like microfilms at the air-solution interface of PBS by dissolution-recrystallisation. The microfilms were characterised by scanning electron microscopy, 3D confocal microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, laser Raman microspectroscopy, and X-ray photoelectron spectroscopy. An in situ X-ray diffraction (XRD) system that simulates the aforementioned interfacial techniques was developed to elucidate the microfilms formation mechanisms. FINDINGS The CaCO3 and bone-like microfilms were free-standing, contiguous, and crystalline. The bone-like microfilms exhibited a hybrid structure consisting of a surface layer of remnant calcite and a carbonate-rich hydroxylapatite core of plates. The present work shows that the air-solution interface can be used to introduce hybrid microstructures to mineral microfilms.

Advanced Materials, 2019

Holey 2D metal oxides have shown great promise as functional materials for energy storage and cat... more Holey 2D metal oxides have shown great promise as functional materials for energy storage and catalysts. Despite impressive performance, their processing is challenged by the requirement of templates plus capping agents or high temperatures; these materials also exhibit excessive thicknesses and low yields. The present work reports a metal‐based coordination polymer (MCP) strategy to synthesize polycrystalline, holey, metal oxide (MO) nanosheets with thicknesses as low as two‐unit cells. The process involves rapid exfoliation of bulk‐layered, MCPs (Ce‐, Ti‐, Zr‐based) into atomically thin MCPs at room temperature, followed by transformation into holey 2D MOs upon the removal of organic linkers in aqueous solution. Further, this work represents an extra step for decorating the holey nanosheets using precursors of transition metals to engineer their band alignments, establishing a route to optimize their photocatalysis. The work introduces a simple, high‐yield, room‐temperature, and t...

Sensors and Actuators B: Chemical, 2015

ABSTRACT ZnO sol–gel films, with and without embedded Pt nanoparticles, were used as seeding laye... more ABSTRACT ZnO sol–gel films, with and without embedded Pt nanoparticles, were used as seeding layers for the hydrothermal growth of ZnO nanorods. The morphology of the nanorods was controlled by adjusting the chemistry and processing, yielding samples with high transparencies and exposed surface areas. The prepared samples were assessed for performance as optical gas sensors in terms of absorbance variation and response time and these data were correlated with the structural properties. The nanorods grown on ZnO films containing Pt nanoparticles showed excellent H 2-sensing properties owing to the high exposed surface areas of the ZnO nanorods and to the catalytic effect the underlying Pt nanoparticles.

Ceramics International, 2013

Minerals, Oct 17, 2020

The effects of curing temperature, blast furnace slag content, and Ms on the initial and final se... more The effects of curing temperature, blast furnace slag content, and Ms on the initial and final setting times, and compressive strengths of geopolymer paste and mortars are examined. The present work demonstrates that ambient-cured geopolymer pastes and mortars can be fabricated without requiring high alkalinity activators or thermal curing, provided that the ratios of Class F fly ash (40-90 wt%), blast furnace slag (10-60 wt%), and low alkalinity sodium silicate (Ms = 1.5, 1.7, 2.0) are appropriately balanced. Eighteen mix designs were assessed against the criteria for setting time and compressive strength according to ASTM C150 and AS 3972. Using these data, flexible and reproducible mix designs in terms of the fly ash/slag ratio and Ms were mapped and categorised. The optimal mix designs are 30-40 wt% slag with silicate modulus (Ms) = 1.5-1.7. These data were used to generate predictive models for initial and final setting times and for ultimate curing times and ultimate compressive strengths. These projected data indicate that compressive strengths >100 MPa can be achieved after ambient curing for >56 days of mixes of ≥40 wt% slag.