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Jones F, Jones P, Ogden MI, Richmond WR, Rohl AL, Saunders M. The interaction of EDTA with barium sulfate. J Colloid Interface Sci 2007; 316:553-61. [PMID: 17904573 DOI: 10.1016/j.jcis.2007.09.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/31/2007] [Accepted: 09/03/2007] [Indexed: 10/22/2022]
Abstract
Ethylenediaminetetraacetic acid (EDTA) is a known complexing agent that interacts with a host of cations. In this paper, various techniques are used to elucidate the mechanism of interaction between EDTA and barium sulfate surfaces. It is shown that complexation with metal ions is not sufficient to explain the inhibition of barite crystallization but that other processes such as chemisorption must also occur. EDTA is shown to always adsorb as the mono-protonated species - suggesting that the molecule is able to lose a proton when it adsorbs at lower pH. Molecular modelling shows that the interaction of the surface barium ions with the carboxylate group is an important one. Finally, in situ turbidity measurements provide information about the mechanism of nucleation/growth modification. It is found that the EDTA molecule inhibits barium sulfate nucleation and that this could be its primary means of inhibiting precipitation of barium sulfate.
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Hoang TA, Ang HM, Rohl AL. Effects of temperature on the scaling of calcium sulphate in pipes. POWDER TECHNOL 2007. [DOI: 10.1016/j.powtec.2006.11.013] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Jones F, Richmond WR, Rohl AL. Molecular modeling of phosphonate molecules onto barium sulfate terraced surfaces. J Phys Chem B 2007; 110:7414-24. [PMID: 16599519 DOI: 10.1021/jp054916+] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The adsorption of phosphonate molecules onto mineral surfaces is of interest due to their use as scale inhibitors. Molecular modeling is an important tool that can aid the fundamental understanding of how these inhibitors operate. This paper presents an empirical molecular mechanics study of the adsorption of a series of straight chain phosphonate molecules onto barium sulfate. It has been found that inhibition can be predicted for this straight chain series of molecules, which differ by the number of phosphonate groups present as well as by the chain length. Even more importantly, the modeling results can predict which faces will be preferred, and this has been verified by scanning and transmission electron microscopy on the resultant barite particles. It has been found that, in general, lattice matching results in the lowest replacement energy for all of the organic molecules investigated. The agreement between the experiment and the model confirms that the dominant mechanism of interaction for the additives on barium sulfate is via the deprotonated phosphonate groups with the barium ions on the surface.
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Paglia G, Buckley CE, Rohl AL. Comment on “Examination of Spinel and Nonspinel Structural Models for γ-Al2O3by DFT and Rietveld Refinement Simulations”. J Phys Chem B 2006; 110:20721-3; author reply 20724-6. [PMID: 17034265 DOI: 10.1021/jp061648m] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Carter DJ, Rohl AL, Gale JD. Ab Initio Simulations of the (101) Surfaces of Potassium Dihydrogenphosphate (KDP). J Chem Theory Comput 2006; 2:797-800. [PMID: 26626685 DOI: 10.1021/ct060012w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have used density functional calculations to examine the (101) surfaces of KDP, under vacuum, nitrogen, and aqueous conditions, and these simulations are found to agree well with nanoscale experimental studies demonstrating that the density functional calculations are providing a good description of the surfaces of this complex inorganic salt.
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Benedict JB, Cohen DE, Lovell S, Rohl AL, Kahr B. What is Syncrystallization? States of the pH Indicator Methyl Red in Crystals of Phthalic Acid. J Am Chem Soc 2006; 128:5548-59. [PMID: 16620129 DOI: 10.1021/ja0601181] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The concept of syncrystallization was reinvestigated by focusing on phthalic acid (PA) grown with methyl red (MR). Crystals are alternately red and yellow in adjacent growth sectors. X-ray structures of MR and its cocrystals, revealing MR in the neutral, zwitterionic, and protonated states, as well as measurements of linear birefringence and linear dichroism of mixed crystals, were used to investigate mechanisms of PA coloring. These experiments were complemented by force field calculations of the lowest energy stable surfaces of expressed facets and energies of MR on and in crystals, as well as molecular orbital calculations of MR. Two MR species were detected in PA having distinct energies, polarizations, and face selectivities. Assignments of structures to these MRs, previously thought to be neutral and protonated, required a nuanced analysis of hydrogen bonds. The essential difference between yellow and red species is whether the MR carboxylic acid proton is inter- or intramolecularly hydrogen bound. Inferences about mixed crystal structure drawn from an examination of cocrystals of PA and MR are inconsistent with polarization spectroscopy signaling caution when using stoichiometric compounds as models of dilute solid solutions. Upon heating mixed crystals, linear dichroism diminishes and oriented, elongated pools of MR separate and pass through the bulk in directions perpendicular to the direction of elongation. These bâtonnets subsequently crystallize leaving macroscopic oriented crystals of a MR-rich phase within PA. No evidence was found for the simultaneous crystallization of MR and PA; however, the MR reorientation on heating as well as the separation and recrystallization of a MR-rich phase are distinct processes that could be embraced by the literal meaning of syncrystallization.
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Fleming SD, Morton JR, Rohl AL, Ward CB. Interatomic Potentials for Simulating MnO2Polymorphs. MOLECULAR SIMULATION 2005. [DOI: 10.1080/08927020412331298702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Barbon A, Bellinazzi M, Benedict JB, Brustolon M, Fleming SD, Jang SH, Kahr B, Rohl AL. Luminescent Probes of Crystal Growth: Surface Charge and Polar Axis Sense in Dye-Doped Potassium Hydrogen Phthalate. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200453839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Barbon A, Bellinazzi M, Benedict JB, Brustolon M, Fleming SD, Jang SH, Kahr B, Rohl AL. Luminescent Probes of Crystal Growth: Surface Charge and Polar Axis Sense in Dye-Doped Potassium Hydrogen Phthalate. Angew Chem Int Ed Engl 2004; 43:5328-31. [PMID: 15382151 DOI: 10.1002/anie.200453839] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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35
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Frincu MC, Fleming SD, Rohl AL, Swift JA. The Epitaxial Growth of Cholesterol Crystals from Bile Solutions on Calcite Substrates. J Am Chem Soc 2004; 126:7915-24. [PMID: 15212540 DOI: 10.1021/ja0488030] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Epitaxial relationships between the surfaces of inorganic and bioorganic crystals can be an important factor in crystal nucleation and growth processes in a variety of biological environments. Crystalline cholesterol monohydrate (ChM), a constituent of both gallstone and atherosclerotic plaques, is often found in association with assorted mineral phases. Using in situ atomic force microscopy (AFM) and well-characterized model bile solutions, the nucleation and epitaxial growth of ChM on calcite (104) surfaces in real-time is demonstrated. The growth rates of individual cholesterol islands formed on calcite substrates were determined at physiological temperatures. Evidence of Ostwald's ripening was also observed under these experimental conditions. The energetics of various (104) calcite/(001) ChM interfaces were calculated to determine the most stable interfacial structure. These simulations suggest that the interface is fully hydrated and that cholesterol hydroxyl groups are preferentially positioned above carbonate ions in the calcite surface. This combination of experimental and theoretical work provides a clearer picture of how preexisting mineral seeds might provide a viable growth template that can reduce the energetic barrier to cholesterol nucleation under some physiological conditions.
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38
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Carter DJ, Ogden MI, Rohl AL. Incorporation of Cyano Transition Metal Complexes in KCl Crystals—Experimental and Computational Studies. Aust J Chem 2003. [DOI: 10.1071/ch02260] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Experimental and computational studies of the incorporation of hexacyanoferrate(II), hexacyanocobaltate(III), and hexacyanoferrate(III) into potassium chloride crystals are described. The experimental results showed that the extent of incorporation follows the trend hexacyanoferrate(II) » hexacyanoferrate(III) > hexacyanocobaltate(III). Computational modelling produced replacement energies that match the experimental trend. The calculated geometry of the incorporated complexes was also found to match well with previous experimental results.
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Fogg AM, Freij AJ, Rohl AL, Ogden MI, Parkinson GM. Toward a Fundamental Understanding of Molecular Recognition: A Synthetic and Computational Study of Morphological Control of Ca3Al2(OH)12. J Phys Chem B 2002. [DOI: 10.1021/jp015528k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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40
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Mingos PMD, Rohl AL. Size and shape characteristics of inorganic molecular ions and their relevance to crystallization problems. Inorg Chem 2002. [DOI: 10.1021/ic00019a039] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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41
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Gale JD, Rohl AL, Milman V, Warren MC. An ab Initio Study of the Structure and Properties of Aluminum Hydroxide: Gibbsite and Bayerite. J Phys Chem B 2001. [DOI: 10.1021/jp011795e] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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Ogden MI, Rohl AL, Gale JD. An ab initio study of the influence of crystal packing on the host-guest interactions of calix[4]arene crystal structures. Chem Commun (Camb) 2001:1626-7. [PMID: 12240414 DOI: 10.1039/b104193m] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the first quantum mechanical calculations of p-tert-butylcalix[4]arene inclusion complexes in the crystalline state with geometrical aspects demonstrating good agreement with experiment, while comparison of the configurations calculated for an isolated complex and in the crystal, illustrate that crystal packing forces contribute to the observed structure of the host-guest assembly.
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Fleming SD, Rohl AL, Parker SC, Parkinson GM. Atomistic Modeling of Gibbsite: Cation Incorporation. J Phys Chem B 2001. [DOI: 10.1021/jp003136s] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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44
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Jones F, Rohl AL, Farrow JB, van Bronswijk W. Molecular modeling of water adsorption on hematite. Phys Chem Chem Phys 2000. [DOI: 10.1039/b003380o] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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45
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Gale JD, Rohl AL, Watling HR, Parkinson GM. Theoretical Investigation of the Nature of Aluminum-Containing Species Present in Alkaline Solution. J Phys Chem B 1998. [DOI: 10.1021/jp983044r] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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46
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Watling HR, Fleming SD, van Bronswijk W, Rohl AL. Ionic structure in caustic aluminate solutions and the precipitation of gibbsite. ACTA ACUST UNITED AC 1998. [DOI: 10.1039/a807420h] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Vyas S, Grimes RW, Gay DH, Rohl AL. Structure, stability and morphology of stoichiometric ceria crystallites. ACTA ACUST UNITED AC 1998. [DOI: 10.1039/a707052g] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Nygren MA, Gay DH, Richard A. Catlow C, Wilson MP, Rohl AL. Incorporation of growth-inhibiting diphosphonates into steps on the calcite cleavage plane surface. ACTA ACUST UNITED AC 1998. [DOI: 10.1039/a806585c] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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49
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Barlow S, Rohl AL, Shi S, Freeman CM, O'Hare D. Molecular Mechanics Study of Oligomeric Models for Poly(ferrocenylsilanes) Using the Extensible Systematic Forcefield (ESFF). J Am Chem Soc 1996. [DOI: 10.1021/ja953680s] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Nyberg M, Nygren MA, Pettersson LGM, Gay DH, Rohl AL. Hydrogen Dissociation on Reconstructed ZnO Surfaces. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp953704h] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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