Can supervise: YES
Rafeek, AD, Choi, G & Evans, LA 2018, 'Morphological, spectroscopic and crystallographic studies of calcium phosphate bioceramic powders', JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY, vol. 54, no. 1, pp. 161-168.View/Download from: Publisher's site
Choi, G, Karacan, I, Cazalbou, S, Evans, L, Sinutok, S & Ben-Nissan, B 2017, 'Conversion of calcified algae (Halimeda sp) and hard coral (Porites sp) to Hydroxyapatite', Key Engineering Materials, vol. 758 KEM, pp. 157-161.View/Download from: Publisher's site
© 2017 Trans Tech Publications, Switzerland. Calcium phosphate materials can be produced using a number of wet methods that are based on hydrothermal or co-precipitation methods that might use acidic or basic chemical environments. In our previously published works, we have investigated calcium phosphates such as monetite, hydroxyapatite, and whitlockite which were successfully produced by mechano-chemical methods and/or hydrothermal treatments from a range of marine shells and corals which were obtained from the Great Barrier Reef. The aim of the current work was to analyze and compare the mechanisms of conversion of one hard coral species and one calcified algae species from the Great Barrier Reef.
Evans, LA 2016, 'Magnetic Resonance Cryoporometry Analysis of Red Deer (Cervus elaphus) Antler Bone', Journal of the Australian Ceramic Society, vol. 52, no. 2, pp. 1-8.
Deer antler is a unique example of mammalian long bone because it regenerates annually with an extremely
rapid rate of growth. This study describes a low-field NMR technique combined with cryoporimetric calibration
for the estimation of pore size distribution in antler bone from spin-spin (T2) relaxation data. Pore sizes
determined by the NMR method have been compared with the more traditional methods of gas adsorption and
mercury intrusion experiments. The NMR method has the advantage of being rapid, non-destructive and noninvasive.
It is superior to image analysis because the whole sample is used rather than a cross-section. This
technique is particularly useful for the determination of fine pore structure including pore dimensions at the
nanometre level and may be applied to other bioceramic materials where pore size and interconnectivity of the
pores is important.
Lewis, KC, Boonyang, U, Evans, LA, Siripaisarnpipat, S & Ben-Nissan, B 2006, 'A comparative study of Thai and Australian crocodile bone for use as a potential biomaterial', Bioceramics 18, Pts 1 And 2, Key Engineering Materials, vol. 309-311, no. 1, pp. 15-18.
This study aims to characterize the structure and properties of crocodile bone to assess the potential for use in biomedical applications. Crocodile bone samples obtained from Thailand (Crocodylus siamensis) and Australia (Crocodylus porosus), being the
Evans, LA, McCutcheon, A, Dennis, GR, Mulley, RC & Wilson, MA 2005, 'Pore size analysis of fallow deer (Dama dama) antler bone', Journal Of Materials Science, vol. 40, no. 21, pp. 5733-5739.View/Download from: Publisher's site
Deer antler is of interest to material scientists because it represents bone which can withstand applied stresses of over 300 MPa. In this work we demonstrate the presence of nanopores in this material by nuclear magnetic resonance (NMR) spectroscopy, an
Soil organic acids such as humic and fulvic acids can play an important role in influencing inorganic phosphate availability in P-fertilized soils by inhibiting formation of thermodynamically stable calcium phosphates. Calcium phosphate phases which are important in these systems may include amorphous calcium phosphate (Ca9(PO4)6·nH2O; ACP), dicalcium phosphate dihydrate (CaHPO4·2H2O; DCPD, also known as brushite), octacalcium phosphate (Ca8H2(PO4)6·5H2O; OCP) and the thermodynamically most stable phase, hydroxyapatite (Ca5(PO4)3OH; HAp). In this study, the formation of these phases in the presence of soil humic acids derived from the Sydney Basin in New South Wales, Australia has been examined using the combined techniques of pH-stat autotitration, Fourier transform infrared (FTIR) and laser Raman spectroscopy, as well as X-ray diffraction (XRD) and elemental analyses. Under conditions of high supersaturation at a pH of 7.4 and a temperature of 25 °C, it was found that these soil humics delay the transformation of unstable ACP to thermodynamically more stable OCP and thence to an apatitic phase resembling poorly crystalline HAp. At the lower pH of 5.7, and in the presence of humic acids, ACP was also precipitated initially. However, this was in contrast to the humic-free solutions which produced DCPD. ACP produced in the presence of humic materials persisted longer than DCPD in their absence, before ultimately hydrolyzing to OCP. Modes of humic-calcium phosphate interaction are discussed. It has been concluded that humic materials are geologically relevant inhibitors of calcium phosphate transformation and that they may modify the availability of phosphorus in soils by changing crystallisation behaviour from solution.
Kalman, JR, Nordlund, CA, Patney, HK, Evans, LA & Wilson, MA 2001, 'Order in Carbons Produced by Plasma Arcing in the Presence of Cobalt', Carbon, vol. 39, pp. 137-144.View/Download from: Publisher's site
Alvarez, R & Evans, LA 2000, 'Synthesis of Hydroxyapatite in the Presence of Biologically Significant Molecules', Journal of the Australasian Ceramic Society, vol. 36, no. 1, pp. 53-62.
Alvarez, R, Evans, LA, Milham, PJ & Wilson, M 2000, 'Analysis of Oxygen-18 in Orthophosphate by Electrospray Ionisation Mass Spectrometry', International Journal of Mass Spectrometry, vol. 203, no. 0, pp. 177-186.
Wilson, M, Patney, HK, Lee, GS & Evans, LA 2000, 'Carbon Nanotubes as Advanced Materials', Journal of the Australasian Ceramic Society, vol. 36, no. 1, pp. 21-35.
Evans, LA & Alvarez, R 1999, 'Characterization of the calcium biomineral in the radular teeth of Chiton pelliserpentis', Journal of Biological Inorganic Chemistry, vol. 4, no. 2, pp. 166-170.View/Download from: Publisher's site
The radula in a group of molluscan invertebrates, the chitons (Polyplacophora), is a ribbon-like apparatus used for feeding and which bears a series of distinctive mineralized teeth called the major lateral teeth. While some chiton species deposit only iron biominerals in these teeth, many others deposit both iron and calcium. In this study, the calcium biomineral in the teeth of one of the latter types of species, the Australian east- coast chiton, Chiton pelliserpentis, has been isolated and examined for the first time. Spectroscopic and crystallographic techniques have identified the biomineral as a carbonate-substituted apatite with significant fluoride substitution also likely. Fourier-transform infrared and laser Raman spectroscopy indicated that the carbonate content was less than that of either bovine tibia cortical bone or human tooth enamel. X-ray diffraction analysis showed the biomineral to be poorly crystalline due to small crystal size and appreciable anionic substitution. The lattice parameters were calculated to be a=9.382 Å and c=6.883 Å, which are suggestive of a fluorapatite material. It is postulated that structural and biochemical differences in the tooth organic matrix of different chiton species will ultimately determine if the teeth become partly calcified or iron mineralized only.
Chai, C, Ben-Nissan, B, Pyke, S & Evans, L 1995, 'Sol-Gel Derived Hydroxylapatite Coatings for Biomedical Applications', Materials and Manufacturing Processes, vol. 10, no. 2, pp. 205-216.View/Download from: Publisher's site
This paper presents the preliminary findings of a novel coating technique for the deposition of hydroxylapatite coatings on ceramic substrates. Through the use of sol-gel methods crystalline coatings of hydroxylapatite on substrates of vycor glass, polycrystalline alumina and single crystal magnesia have been successfully produced. The production of sol-gel solutions, coatings and their analysis was examined by X-ray diffraction, scanning electron microscopy and atomic force microscopy. Results thus far indicate that high quality hydroxylapatite coatings can be produced on ceramic substrates, with coatings deposited in this manner offering a number of benefits over other coating methods. © 1995, Taylor & Francis Group, LLC. All rights reserved.
The structure and organization of the organic matrix of the cusps of the major lateral teeth of the chiton Acanthopleura hirtosahave been examined using conventional light and transmission electron microscopy techniques and by using the protein ferritin as an ultrastructural probe. The results show major structural differences in the organic matrix between the surface layers of the anterior (calcified) region and the posterior (magnetite‐mineralized) region and their respective underlying regions. In addition, the central (lepidocrocite‐mineralized) region of the tooth has been examined and shown to consist of bundles of fibres arranged such that they display a tightly interwoven pattern. It is suggested that while the structural organization of surface fibres readily permits the passage of ions required for mineralization, the architecturally discrete distribution of biominerals found in mature chiton teeth is due mostly to spatial delineation of the tooth by matrix macromolecules in the central region of the tooth. 1994 The Royal Swedish Academy of Sciences
Macey, DJ, Webb, J, Evans, LA & St. Pierre, TG 1993, 'Synthesis of nanospace biominerals and macroscopic structures in chiton teeth', Journal of Computer-Assisted Microscopy, vol. 5, no. 1, pp. 103-107.
The authors have studied biomineralization in chitons, common marine invertebrates that are widely distributed throughout the world. Chitons are most noticeable in the intertidal zone where they feed, using quite distinctive biominerally-hardened teeth, by browsing on organisms which encrust the rocks on which they live. Synthesis of nanospace biominerals and macroscopic structures in chiton teeth have been studied.
Evans, LA, Macey, DJ & Webb, J 1992, 'Calcium biomineralization in the radular teeth of the chiton, Acanthopleura hirtosa', Calcified Tissue International, vol. 51, no. 1, pp. 78-82.View/Download from: Publisher's site
A method has been devised for isolating the calcium biomineral from the iron biominerals and organic components present in the major lateral teeth of the chiton Acanthopleura hirtosa. Fourier-transform infrared spectroscopy of the calcium biomineral indicated that it was an apatite material containing carbonate and fluoride ions. Carbonate was not found to be present as a separate phase. The apatite was further separated into low and high density fractions, both of which showed crystallinity intermediate between that of bovine tibia cortical bone and human tooth enamel, as indicated by powder X-ray diffraction analysis. The calcified region of the major lateral teeth was also studied in situ using transmission electron microscopy and electron diffraction analysis, revealing a close spatial relationship between the mineral apatite phase and underlying organic matrix. It is suggested that the architectural arrangement of apatite biomineral and fibrous organic constituents imparts specialized mechanical properties to the tooth making it ideally suited for the task of obtaining food from hard surfaces. © 1992 Springer-Verlag New York Inc.
St. Pierre, TG, Evans, LA & Webb, J 1992, 'Non-stoichiometric magnetite and maghemite in the mature teeth of the chiton Acanthopleura hirtosa', Hyperfine Interactions, vol. 71, no. 1-4, pp. 1275-1278.View/Download from: Publisher's site
Mature radula pieces from the chiton Acanthopleura hirtosa were studied using Mössbauer spectroscopy. The magnetite present in the radulae was found to have a distribution of Verwey transition temperatures in the range 85-100K. It was deduced that the magnetite was non-stoichiometric with an average formula Fe2.98O3. About 10% of the Fe in the radulae was in the form of maghemite and about 19% was in the form of paramagnetic or superparamagnetic phases. © 1992 J.C. Baltzer A.G., Scientific Publishing Company.
Evans, LA, Macey, DJ & Webb, J 1991, 'Distribution and composition of matrix protein in the radula teeth of the chiton Acanthopleura hirtosa', Marine Biology, vol. 109, no. 2, pp. 281-286.View/Download from: Publisher's site
The organic matrix of the major lateral teeth of the chiton Acanthopleura hirtosa was found to consist of approx 10% by weight of protein. Histochemical analysis indicated that the majority of the protein was located in the calcified (anterior) region of the tooth, while the iron-mineralized or posterior region contained relatively small amounts of protein. In comparison, whole radula tissue contained significantly greater amounts of protein than the major lateral teeth alone. This extra protein is required to harden the non-mineralized areas of the radula. High-performance liquid chromatography and biochemical analyses indicated that the protein is rich in aspartic and glutamic acids, while phosphoserine was also detected in appreciable quantities. In addition, the protein component was closely associated with chitin fibres which comprise the remainder of the organic matrix. It is suggested that the calcified region of the tooth exhibits greater organic matrix-mediated control during the biomineralization process than the ironmineralized posterior region. © 1991 Springer-Verlag.
Choi, G & Evans, L 2019, 'Calcified Algae for Tissue Engineering.' in Choi, A & Ben-Nissan, B (eds), Marine-Derived Biomaterials for Tissue Engineering Applications, Springer, Germany, pp. 383-412.View/Download from: Publisher's site
This book presents the latest advances in marine structures and related biomaterials for applications in both soft- and hard-tissue engineering, as well as controlled drug delivery.
MacFarlane, DR, Sun, J, Forsyth, M, Bell, JM, Evans, LA & Skyrabin, IL 1995, 'Polymer electrolytes for electrochromic window applications', SOLID STATE IONICS, 10th International Conference on Solid State Ionics (SSI-10), ELSEVIER SCIENCE BV, SINGAPORE, SINGAPORE, pp. 959-964.View/Download from: Publisher's site
BELL, JM, BARCZYNSKA, J, EVANS, LA, MACDONALD, KA, WANG, J, GREEN, DC & SMITH, GB 1994, 'ELECTROCHROMISM IN SOL-GEL DEPOSITED TIO2 FILMS', OPTICAL MATERIALS TECHNOLOGY FOR ENERGY EFFICIENCY AND SOLAR ENERGY CONVERSION XIII, 13th Conference on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion, in Honor of Professor Adolf Goetzberger, SPIE - INT SOC OPTICAL ENGINEERING, FREIBURG, GERMANY, pp. 324-331.View/Download from: Publisher's site
BELL, JM, SMITH, GB, GREEN, DC, BARCZYNSKA, J, EVANS, L, MACDONALD, KA, VOELKEL, G, WEST, BO & SPICCIA, L 1993, 'ASSESSMENT OF ELECTROCHROMIC DEVICES BASED ON SOL-GEL DEPOSITED FILMS', OPTICAL MATERIALS TECHNOLOGY FOR ENERGY EFFICIENCY AND SOLAR ENERGY CONVERSION XII, Conference on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion 12, SPIE - INT SOC OPTICAL ENGINEERING, SAN DIEGO, CA, pp. 132-142.View/Download from: Publisher's site