Author
Leigh T. Canham
Other affiliations: Defence Research Agency, Defence Science and Technology Laboratory, University of St Andrews
Bio: Leigh T. Canham is an academic researcher from University of Birmingham. The author has contributed to research in topics: Porous silicon & Silicon. The author has an hindex of 42, co-authored 160 publications receiving 18268 citations. Previous affiliations of Leigh T. Canham include Defence Research Agency & Defence Science and Technology Laboratory.
Papers published on a yearly basis
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TL;DR: In this article, a metal-assisted chemical etch reaction was performed on metallurgical-grade silicon powders using the HF-ferric chloride (FeCl3) process.
Abstract: Nanostructured mesoporous silicon powders are being developed for a diverse range of applications including drug delivery, therapeutics, biosensors, and explosives. Such powders are easily produced through mechanical milling of membranes taken from electrochemically anodized silicon wafers. Where applications require highvolume, low-cost production, however, wafer feedstock is not viable and alternative feedstocks such as metallurgical-grade silicon powders become more attractive. Porosification of powders can be achieved using electro-less processing such as stain etching. Although much of the stain-etch literature has been developed around silicon wafers, the process, involving immersion of the silicon in an aqueous solution of hydrofluoric and nitric acids, has been readily transferred to powders. 1,2 Scalable synthesis methodologies have been reported for powders, 3 albeit with limitations on achievable surface area (143 m 2 /g), pore volume (0.3 ml/g), and yield (5%). Encouraging results have been reported 4 on the use of alternative oxidants, containing transition metals, for porosification of wafers, thus avoiding issues such as quiescence periods, inhomogeneity and irreproducibility usually associated with hydrofluoric-nitric acid processing. Metal-assisted chemical etching of silicon wafers has been the subject of two reviews. 5,6 For the first time, to our knowledge, we have applied metal-assisted etching using the hydrofluoric acid (HF)-ferric chloride (FeCl3) process, 7,8 in modified form, to metallurgical-grade silicon powders. The metal-assisted etch reaction can be described as
53 citations
TL;DR: The levels of alkaline phosphatase expression, a specific biomarker for mesenchymal stem cell differentiation, show that the scaffolds have the ability to mediate such processes, and that the location of the Si plays a key role in levels of expression.
Abstract: The impact of mesoporous silicon (PSi) particles—embedded either on the surface, or totally encapsulated within electrospun poly (e-caprolactone) (PCL) fibers—on its properties as a tissue engineering scaffold is assessed. Our findings suggest that the resorbable porous silicon component can sensitively accelerate the necessary calcification process in such composites. Calcium phosphate deposition on the scaffolds was measured via in vitro calcification assays both at acellular and cellular levels. Extensive attachment of fibroblasts, human adult mesenchymal stem cells, and mouse stromal cells to the scaffold were observed. Complementary cell differentiation assays and ultrastructural measurements were also carried out; the levels of alkaline phosphatase expression, a specific biomarker for mesenchymal stem cell differentiation, show that the scaffolds have the ability to mediate such processes, and that the location of the Si plays a key role in levels of expression.
51 citations
49 citations
TL;DR: In this article, the temporal variation of the visible photoluminescence from rapid thermally oxidized porous silicon prepared from n+ substrates was studied, and it was shown that the blue (fast band) emission becomes prevalent only after samples are stored in ambient air.
Abstract: We have studied the temporal variation of the visible photoluminescence from rapid thermally oxidized porous silicon prepared from n+ substrates. In contrast to the red (slow band) emission, which is observable immediately after high‐temperature oxidation, the blue (fast band) emission is shown to become prevalent only after samples are stored in ambient air. The intensity of the blue emission increases with progressive aging, the magnitude of the increase being dependent on the temperature at which the material is oxidized. Thermal treatment of aged rapid thermally oxidized material can reduce and even quench the blue photoluminescence. Quenching is reversible in that the photoluminescence re‐appears after further aging at room temperature.
48 citations
Patent•
20 Feb 2002
TL;DR: In this article, an internal therapeutic product consisting of an anti-cancer component selected from one or both of: a radionucleotide, a cytotoxic drug, and a silicon component was presented for the treatment of cancer.
Abstract: The invention relates to the treatment of cancer. In particular the invention relates to an internal therapeutic product comprising: (i) an anti-cancer component selected from one or both of: a radionucleotide, a cytotoxic drug; and (ii) a silicon component selected from one or more of: resorbable silicon, biocompatible silicon, bioactive silicon, porous silicon, polycrystalline silicon, amorphous silicon, and bulk crystalline silicon, the internal therapeutic product being for the treatment of cancer.
47 citations
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TL;DR: In this article, the authors focus on the properties of quantum dots and their ability to join the dots into complex assemblies creates many opportunities for scientific discovery, such as the ability of joining the dots to complex assemblies.
Abstract: Current research into semiconductor clusters is focused on the properties of quantum dots-fragments of semiconductor consisting of hundreds to many thousands of atoms-with the bulk bonding geometry and with surface states eliminated by enclosure in a material that has a larger band gap. Quantum dots exhibit strongly size-dependent optical and electrical properties. The ability to join the dots into complex assemblies creates many opportunities for scientific discovery.
10,737 citations
TL;DR: Dye-sensitized solar cells (DSCs) offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency as mentioned in this paper, and many DSC research groups have been established around the world.
Abstract: Dye-sensitized solar cells (DSCs) offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. DSC research groups have been established around the worl ...
8,707 citations
TL;DR: This observation shows that quantum confinement in layered d-electron materials like MoS(2), a prototypical metal dichalcogenide, provides new opportunities for engineering the electronic structure of matter at the nanoscale.
Abstract: Novel physical phenomena can emerge in low-dimensional nanomaterials. Bulk MoS2, a prototypical metal dichalcogenide, is an indirect bandgap semiconductor with negligible photoluminescence. When the MoS2 crystal is thinned to monolayer, however, a strong photoluminescence emerges, indicating an indirect to direct bandgap transition in this d-electron system. This observation shows that quantum confinement in layered d-electron materials like MoS2 provides new opportunities for engineering the electronic structure of matter at the nanoscale.
7,886 citations
TL;DR: In this article, the authors present methods of severe plastic deformation and formation of nanostructures, including Torsion straining under high pressure, ECA pressing, and multiple forging.
5,763 citations
TL;DR: Nanotechnology is a multidisciplinary field, which covers a vast and diverse array of devices derived from engineering, biology, physics and chemistry that can provide essential breakthroughs in the fight against cancer.
Abstract: Nanotechnology is a multidisciplinary field, which covers a vast and diverse array of devices derived from engineering, biology, physics and chemistry. These devices include nanovectors for the targeted delivery of anticancer drugs and imaging contrast agents. Nanowires and nanocantilever arrays are among the leading approaches under development for the early detection of precancerous and malignant lesions from biological fluids. These and other nanodevices can provide essential breakthroughs in the fight against cancer.
4,241 citations