Browsing by Author "Morrow, Lauren"

Now showing 1 - 4 of 4
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    Easily Regenerated Readily Deployable Absorbent for Heavy Metal Removal from Contaminated Water
    (Springer Nature, 2017) Alagappan, Perry N.; Heimann, Jessica; Morrow, Lauren; Andreoli, Enrico; Barron, Andrew R.
    Although clean and abundant water is the keystone of thriving communities, increasing demand and volatile climate patterns are depleting rivers and aquifers. Moreover, the quality of such water sources is threatened by noxious contaminants, of which heavy metals represents an area of growing concern. Recently, graphene oxide (GO) has been suggested as an adsorbent; however, a support is desirable to ensure a high surface area and an immobile phase. Herein, we described the preparation and characterization of a supported-epoxidized carbon nanotube (SENT) via the growth of multi walled carbon nanotubes (MWNTs) onto a quartz substrate. Subsequent epoxidation provides sufficient functionality to enable adsorbent of heavy metals (Cd2+, Co2+, Cu2+, Hg2+, Ni2+, and Pb2+) from aqueous solution with initial concentrations (60–6000 ppm) chosen to simulate high industrial wastewater contamination. The SENT adsorption efficiency is >99.4% for all metals and the saturation concentration is significantly greater than observed for either GO or acid treated MWNTs. The SENT adsorbent may be readily regenerated under mild conditions using a globally available household chemical, vinegar. 1 g of SENT has the potential to treat 83,000 L of contaminated water down to WHO limits which would be sufficient for 11,000 people.
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    Issues Affecting the Synthetic Scalability of Ternary Metal Ferrite Nanoparticles
    (Hindawi Publishing Corporation, 2015) Morrow, Lauren; Barron, Andrew R.
    Ternary Mn-Zn ferrite (MnxZn1-xFe2O4) nanoparticles (NPs) have been prepared by the thermal decomposition of an oleate complex, sodium dodecylbenzenesulfonate (SDBS) mediated hydrazine decomposition of the chloride salts, and triethylene glycol (TREG) mediated thermal decomposition of the metal acetylacetonates. Only the first method was found to facilitate the synthesis of uniform, isolable NPs with the correct Mn : Zn ratio (0.7 : 0.3) as characterized by small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and inductively coupled plasma-optical emission spectroscopy (ICP-OES). Scaling allowed for retention of the composition and size; however, attempts to prepare Zn-rich ferrites did not result in NP formation. Thermogravimetric analysis (TGA) indicated that the incomplete decomposition of the metal-oleate complexes prior to NP nucleation for Zn-rich compositions is the cause.
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    Metal ferrite nanoparticles as tracers in hydraulically fractured wells
    (2015-02-27) Morrow, Lauren; Barron, Andrew R; Wilson, Lon J; Pasquali, Matteo
    A variety of metal ferrite nanoparticles were synthesized via thermal decomposition reaction and characterized with transmission electron microscopy, small angle X-ray scattering, inductively coupled plasma – optical emission spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and a superconducting quantum interference device in order to develop a cost-effective means of tracing hydraulic fractures in wells. In addition, the nanoparticles were developed as a means of determining sources of contamination in the environment surrounding a well by way of “fingerprinting” the different potential sources. This is achieved through the manipulation of the quantities of metal cations substituted into the crystal structure of magnetite, allowing for the creation of unique and desired magnetic characteristics. In order to determine the feasibility of using nanoparticles as tracers, the quantity needed to be able to detect the nanoparticles as determined, as well as how the magnetic properties change as temperature increases as a function of nanoparticle composition. Finally, the feasibility of making industrial quantities of the nanoparticles was investigated.
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    Temperature dependence on the mass susceptibility and mass magnetization of superparamagnetic Mn–Zn–ferrite nanoparticles as contrast agents for magnetic imaging of oil and gas reservoirs
    (Taylor & Francis, 2018) Morrow, Lauren; Snow, Brendan; Ali, Arfan; Maguire-Boyle, Samuel J.; Almutairi, Zeyad; Potter, David K.; Barron, Andrew R.
    The mass susceptibility (χmass) and mass magnetization (Mmass) were determined for a series of ternary manganese and zinc ferrite nanoparticles (Mn–Zn ferrite NPs, MnxZn1−xFe2O4) with different Mn:Zn ratios (0.08 ≤ x ≤ 4.67), prepared by the thermal decomposition reaction of the appropriate metal acetylacetonate complexes, and for the binary homologs (MxFe3−xO4, where M = Mn or Zn). Alteration of the Mn:Zn ratio in Mn–Zn ferrite NPs does not significantly affect the particle size. At room temperature and low applied field strength the mass susceptibility increases sharply as the Mn:Zn ratio increases, but above a ratio of 0.4 further increase in the amount of manganese results in the mass susceptibility decreasing slightly, reaching a plateau above Mn:Zn ≈ 2. The compositional dependence of the mass magnetization shows less of a variation at room temperature and high applied fields. The temperature dependence of the mass magnetization of Mn–Zn ferrite NPs is significantly less for Mn-rich compositions making them more suitable for downhole imaging at higher temperatures (>100 °C). For non-shale reservoirs, replacement of nMag by Mn-rich Mn–Zn ferrites will allow for significant signal-to-noise enhancement of 6.5× over NP magnetite.