Browsing School of Natural Sciences by Subject "Nanoscience & Materials"
Now showing items 1-20 of 21
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ACC and vaterite as metastable intermediates in the solution based crystallization of CaCO3
(Springer International Publishing, 2017)Amorphous calcium carbonate (ACC) and vaterite are not very common in abiotic systems, but they play a very significant role in biomineralization processes and are key in the global carbon cycle. Despite their importance, ... -
Amorphous dysprosium carbonate: characterization, stability, and crystallization pathways
(2013)The crystallization of amorphous dysprosium carbonate (ADC) has been studied in air (21–750 °C) and in solution (21–250 °C). This poorly ordered precursor, Dy2(CO3)3·4H2O, was synthesized in solution at ambient temperature. ... -
Citrate Effects on Amorphous Calcium Carbonate (ACC) Structure, Stability, and Crystallization
(2015)Understanding the role of citrate in the crystallization kinetics of amorphous calcium carbonate (ACC) is essential to explain the formation mechanisms, stabilities, surface properties, and morphologies of CaCO3 biominerals. ... -
The effect of aspartic acid and glycine on amorphous calcium carbonate (ACC) structure, stability and crystallization
(Elsevier, 2014)The effect of organic molecules on CaCO3 crystallization, in particular on the formation of the initial amorphous calcium carbonate (ACC) phase, is poorly understood despite this knowledge being crucial for designing ... -
The effect of heating on the morphology of crystalline neodymium hydroxycarbonate, NdCO3OH
(2014)The crystallization of hexagonal NdCO3OH through hydrothermal synthesis carried out at slow (reaching the desired temperature within 100 min) and quick (50 min) rates of heating but at variable temperatures (165–220ºC) are ... -
Formation of calcium sulfate through the aggregation of sub-3 nanometre primary species
(2016)The formation pathways of gypsum remain uncertain. Here, using truly in situ and fast time-resolved small-angle X-ray scattering, we quantify the four-stage solution-based nucleation and growth of gypsum (CaSO4·2H2O), an ... -
Inhibition of Calcite Growth: Combined Effects of Mg2+ and SO42–
(2016)Magnesium and sulfate are each known to affect calcite growth and dissolution, but little is known about their combined effects on calcite growth rates. We grew calcite using the constant composition approach at ambient ... -
Is bicarbonate stable in and on the calcite surface?
(2016)We have used density functional theory with the COSMO-RS implicit solvent model to predict the pKa for the deprotonation of bicarbonate to carbonate, i.e. HCO3− <=> CO32− + H+, when HCO3− is included in, and adsorbed on, ... -
Neutron and X-ray diffraction and empirical potential structure refinement modelling of magnesium stabilised amorphous calcium carbonate
(2014)Amorphous calcium carbonate (ACC) plays a key role in biomineralisation processes in sea organisms. Neutron and X-ray diffraction have been performed for a sample of magnesium-stabilised ACC, which was prepared with a Mg:Ca ... -
Organic synthesis on Mars by electrochemical reduction of CO2
(American Association for the Advancement of Science, 2018)The sources and nature of organic carbon on Mars have been a subject of intense research. Steele et al. (2012) showed that 10 martian meteorites contain macromolecular carbon phases contained within pyroxene- and olivine-hosted ... -
Physicochemical and Additive Controls on the Multistep Precipitation Pathway of Gypsum
(MDPI, 2017)Synchrotron-based small- and wide-angle X-ray scattering (SAXS/WAXS) was used to examine in situ the precipitation of gypsum (CaSO4·2H2O) from solution. We determined the role of (I) supersaturation, (II) temperature and ... -
Reaction pathways and textural aspects of the replacement of anhydrite by calcite at 25 °C
(2017)The replacement of sulfate minerals by calcium carbonate polymorphs (carbonation) has important implications in various geological processes occurring in Earth surface environments. In this paper we report the results of ... -
Reaction Pathways toward the Formation of Bastnäsite: Replacement of Calcite by Rare Earth Carbonates
(2021)The interaction of rare earth bearing (La, Nd, Dy) aqueous solutions with calcite crystals at ambient and hydrothermal conditions (25–220 °C) results in the solvent-mediated surface precipitation and subsequent pseudomorphic ... -
The role of amorphous precursors in the crystallization of La and Nd carbonates
(2015)Crystalline La and Nd carbonates can be formed from poorly-ordered nanoparticulate precursors, termed amorphous lanthanum carbonate (ALC) and amorphous neodymium carbonate (ANC). When reacted in air or in aqueous solutions ... -
The role of REE3+ in the crystallization of lanthanites
(2014)The formation of crystalline rare earth element (REE) (e.g. La, Ce, Pr, Nd) carbonates from aqueous solutions was examined at ambient temperature using UV-Vis spectrophotometry, combined with X-ray diffraction, high-resolution ... -
A route for the direct crystallization of dolomite
(2015)The direct crystallization of dolomite from an aqueous solution at temperatures between 60–220 °C was followed in situ through time-resolved synchrotron-based energy-dispersive X-ray diffraction combined with offline ... -
Salinity-Dependent Adhesion Response Properties of Aluminosilicate (K-Feldspar) Surfaces
(2017)Flooding sandstone oil reservoirs with low salinity water can lead to a significant increase in oil recovery, a phenomenon called “the low salinity effect”. Although there are many factors that contribute to this response, ... -
SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions.
(2021)Bentonite is a key barrier for the isolation of high-level radioactive waste within Deep Geological Repository. However, bentonite may be altered by contact with cementitious materials and their alkaline pore fluids. This ... -
Shallow sampling by multi-shot laser ablation and its application within U-Pb zircon geochronology
(2020)The interaction of incident laser radiation and sample substrate is complex and difficult to predict. Natural zircons are often both structurally and chemically heterogeneous in 3-dimensional space. Encountering growth-related, ... -
Structural properties and transformations of precipitated FeS
(2012)Nanocrystalline iron sulfides form in diverse anoxic environments. The initial precipitate is commonly referred to as nanocrystalline mackinawite (FeS) or amorphous FeS. In order to better understand the structure of the ...