1
|
Shi C, Alderman OLG, Tamalonis A, Weber JKR, Benmore CJ. The structure of molten calcium ferrite under various redox conditions. Philos Trans A Math Phys Eng Sci 2023; 381:20220352. [PMID: 37634540 DOI: 10.1098/rsta.2022.0352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/21/2023] [Indexed: 08/29/2023]
Abstract
Laser-heated melts based on the 43CaO-57Fe2O3-x eutectic, close to the calcium ferrite (CF) composition, were measured with high-energy X-ray diffraction using aerodynamic levitation over a range of redox states controlled by CO/CO2 gas atmospheres. The iron-oxygen coordination number was found to rise from 4.4 ± 0.3 at 15% Fe3+ to 5.3 ± 0.3 at 87% Fe3+. Empirical potential structure refinement modelling was used to obtain the ferric and ferrous partial pair distribution functions. It was found that the Fe2+ iron-oxygen coordination number is consistently approximately 10% higher in CF than in pure iron oxide, while Fe3+ is essentially identical in all but the most oxygen-rich environments (where it is higher in CF compared with FeOx). The model also shows calcium octahedra to be the dominant species across all redox environments, although the population of CaO7 increases with the availability of oxygen at the expense of CaO4 and CaO5. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 1)'.
Collapse
Affiliation(s)
- Caijuan Shi
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Oliver L G Alderman
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK
| | | | - J K R Weber
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK
- Materials Development, Inc., Arlington Heights, IL, USA
| | - Chris J Benmore
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| |
Collapse
|
2
|
Benmore CJ, Benmore SR, Wilke SK, Menon V, Byrn SR, Weber JKR. X-ray Diffraction of Water in Polyvinylpyrrolidone. Mol Pharm 2023; 20:3645-3652. [PMID: 37306254 PMCID: PMC11064787 DOI: 10.1021/acs.molpharmaceut.3c00265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
PVP is a hydrophilic polymer commonly used as an excipient in pharmaceutical formulations. Here we have performed time-resolved high-energy X-ray scattering experiments on pellets of PVP at different humidity conditions for 1-2 days. A two-phase exponential decay in water sorption is found with a peak in the differential pair distribution function at 2.85 Å, which is attributed to the average (hydrogen bonded) carbonyl oxygen-water oxygen distance. Additional scattering measurements on powders with fixed compositions ranging from 2 to 12.3 wt % H2O were modeled with Empirical Potential Structure Refinement (EPSR). The models reveal approximately linear relations between the carbonyl oxygen-water oxygen coordination number (nOC-OW) and the water oxygen-water oxygen coordination number (nOW-OW) versus water content in PVP. A stronger preference for water-water hydrogen bonding over carbonyl-water bonding is found. At all the concentrations studied the majority of water molecules were found to be randomly isolated, but a wide distribution of coordination environments of water molecules is found within the PVP polymer strands at the highest concentrations. Overall, the EPSR models indicate a continuous evolution in structure versus water content with nOW-OW=1 occurring at ∼12 wt % H2O, i.e., the composition where, on average, each water molecule is surrounded by one other water molecule.
Collapse
Affiliation(s)
- C J Benmore
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S R Benmore
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - S K Wilke
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - V Menon
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - S R Byrn
- Improved Pharma, West Lafayette, Indiana 47906, USA
| | - J K R Weber
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| |
Collapse
|
3
|
Alderman OLG, Benmore CJ, Holland D, Weber JKR. Boron coordination change in barium borate melts and glasses and its contribution to configurational heat capacity, entropy, and fragility. J Chem Phys 2023; 158:2895231. [PMID: 37290074 DOI: 10.1063/5.0153282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/10/2023] [Indexed: 06/10/2023] Open
Abstract
High-energy x-ray diffraction from molten and glassy BaB2O4 and BaB4O7 has been performed using aerodynamic levitation and laser heating over a wide range of temperatures. Remarkably, even in the presence of a heavy metal modifier dominating x-ray scattering, it was possible to extract accurate values for the tetrahedral, sp3, boron fraction, N4, which declines with increasing temperature, using bond valence-based mapping from the measured mean B-O bond lengths while accounting for vibrational thermal expansion. These are used within a boron-coordination-change model to extract enthalpies, ΔH, and entropies, ΔS, of isomerization between sp2 and sp3 boron. The results for BaB4O7, ΔH = 22(3) kJ mol-1 boron, ΔS = 19(2) J mol-1 boron K-1, agree quantitatively with those found previously for Na2B4O7. Analytical expressions for N4(J, T) and associated configurational heat capacity, CPconf(J, T), and entropy, Sconf(J, T), contributions are extended to cover a wide composition range 0 ≤ J = BaO/B2O3 ≤ 3 using a model for ΔH(J) and ΔS(J) derived empirically for lithium borates. Maxima in the CPconf(J, Tg) and fragility index contributions are thereby predicted for J ≲ 1, higher than the maximum observed and predicted in N4(J, Tg) at J ≃ 0.6. We discuss the utility of the boron-coordination-change isomerization model in the context of borate liquids containing other modifiers and the prospect of neutron diffraction to aid in empirical determinations of modifier-dependent effects, illustrated by new neutron diffraction data on Ba11B4O7 glass, its well-known α-polymorph, and lesser-known δ-phase.
Collapse
Affiliation(s)
- O L G Alderman
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, United Kingdom
| | - C J Benmore
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Holland
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - J K R Weber
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| |
Collapse
|
4
|
Benmore CJ, Benmore SR, Edwards AD, Shrader CD, Bhat MH, Cherry BR, Smith P, Gozzo F, Shi C, Smith D, Yarger JL, Byrn SR, Weber JKR. A High Energy X-ray Diffraction Study of Amorphous Indomethacin. J Pharm Sci 2022; 111:818-824. [PMID: 34890631 PMCID: PMC11064786 DOI: 10.1016/j.xphs.2021.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 11/18/2022]
Abstract
Amorphous pharmaceuticals often possess a wide range of molecular conformations and bonding arrangements. The x-ray pair distribution function (PDF) method is a powerful technique for the characterization of variations in both intra-molecular and inter-molecular packing arrangements. Here, the x-ray PDF of amorphous Indomethacin is shown to be particularly sensitive to the preferred orientations of the chlorobenzyl ring found in isomers in the crystalline state. In some cases, the chlorobenzyl ring has no preferred torsional angle in the amorphous form, while in others evidence of distinct isomer orientations are observed. Amorphous samples with no preferred torsion angles of the chlorobenzyl ring are found to favor enhanced inter-molecular hydrogen bonding, and this is reflected in the intensity of the first sharp diffraction peak. These significant variations in structure rule out amorphous Indomethacin as a possible standard for x-ray PDF measurements. At high humidity, time resolved PDF's for >40 h reveal water molecules forming hydrogen bonds with Indomethacin molecules. A simple linear hydrogen bond model indicates that water molecules in the wet amorphous form have similar hydrogen bond strengths to those found between Indomethacin dimers or chains in the dry amorphous form.
Collapse
Affiliation(s)
- C J Benmore
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, United States of America; Arizona State University, Tempe, AZ 85281, United States of America.
| | - S R Benmore
- Materials Development, Inc., Arlington Heights, IL 60004, United States of America
| | - A D Edwards
- Arizona State University, Tempe, AZ 85281, United States of America
| | - C D Shrader
- Arizona State University, Tempe, AZ 85281, United States of America
| | - M H Bhat
- Arizona State University, Tempe, AZ 85281, United States of America
| | - B R Cherry
- Arizona State University, Tempe, AZ 85281, United States of America
| | - P Smith
- Improved Pharma, West Lafayette, IN 47906, United States of America
| | - F Gozzo
- Excelsus Structural Solutions, Park Innovaare, 5234 Villigen, Switzerland
| | - C Shi
- Data Science Consulting, Tiger Analytics, Santa Clara, CA 95054
| | - D Smith
- Improved Pharma, West Lafayette, IN 47906, United States of America; Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47906, United States of America
| | - J L Yarger
- Arizona State University, Tempe, AZ 85281, United States of America
| | - S R Byrn
- Improved Pharma, West Lafayette, IN 47906, United States of America; Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47906, United States of America
| | - J K R Weber
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, United States of America; Materials Development, Inc., Arlington Heights, IL 60004, United States of America
| |
Collapse
|
5
|
Benmore CJ, González GB, Alderman OLG, Wilke SK, Yarger JL, Leinenweber K, Weber JKR. Hard x-ray methods for studying the structure of amorphous thin films and bulk glassy oxides. J Phys Condens Matter 2021; 33:194001. [PMID: 33540391 DOI: 10.1088/1361-648x/abe352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
High-energy photon diffraction minimizes many of the corrections associated with laboratory x-ray diffractometers, and enables structure factor measurements to be made over a wide range of momentum transfers. The method edges us closer toward an ideal experiment, in which coordination numbers can be extracted without knowledge of the sample density. Three case studies are presented that demonstrate new hard x-ray methods for studying the structure of glassy and amorphous materials. First, the methodology and analysis of high-energy grazing incidence on thin films is discussed for the case of amorphous In2O3. The connectivity of irregular InO6polyhedra are shown to exist in face-, edge- and corner-shared configurations in the approximate ratio of 1:2:3. Secondly, the technique of high-energy small and wide angle scattering has been carried out on laser heated and aerodynamically levitated samples of silica-rich barium silicate (20BaO:80SiO2), from the single phase melt at 1500oC to the phase separated glass at room temperature. Based on Ba-O coordination numbers of 6 to 7, it is argued that the although the potential of Ba is ionic, it is weak enough to cause the liquid-liquid immiscibility to become metastable. Lastly, high-energy small and wide angle scattering has also been applied to high water content (up to 12 wt.%) samples of hydrous SiO2glass quenched from 1500oC at 4 GPa. An increase of Si1-O2correlations at 4.3 Å is found to be consistent with an increase in the population of three-membered SiO4rings at the expense of larger rings.
Collapse
Affiliation(s)
- C J Benmore
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, United States of America
- Arizona State University, Tempe, AZ 85287, United States of America
| | - G B González
- Department of Physics, DePaul University, Chicago, Illinois 60614, United States of America
| | - O L G Alderman
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, United Kingdom
| | - S K Wilke
- Materials Development, Inc., Evanston, IL 60202, United States of America
| | - J L Yarger
- Arizona State University, Tempe, AZ 85287, United States of America
| | - K Leinenweber
- Arizona State University, Tempe, AZ 85287, United States of America
| | - J K R Weber
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, United States of America
- Materials Development, Inc., Evanston, IL 60202, United States of America
| |
Collapse
|
6
|
Wilson M, Ribeiro MCC, Wilding MC, Benmore C, Weber JKR, Alderman O, Tamalonis A, Parise JB. Structure and Liquid Fragility in Sodium Carbonate. J Phys Chem A 2018; 122:1071-1076. [PMID: 29243931 DOI: 10.1021/acs.jpca.7b10712] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The relationship between local structure and dynamics is explored for molten sodium carbonate. A flexible fluctuating-charge model, which allows for changes in the shape and charge distribution of the carbonate molecular anion, is developed. The system shows the evolution of highly temperature-dependent complex low-dimensional structures which control the dynamics (and hence the liquid fragility). By varying the molecular anion charge distribution, the key interactions responsible for the formation of these structures can be identified and rationalized. An increase in the mean charge separation within the carbonate ions increases the connectivity of the emerging structures and leads to an increase in the system fragility.
Collapse
Affiliation(s)
- Mark Wilson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Mauro C C Ribeiro
- Laboratório de Espectroscopia Molecular, Instituto de Química, Universidade de Sa̅o Paulo , Av. Prof. Lineu Prestes 748, Sa̅o Paulo 05508-000, Brazil
| | - Martin C Wilding
- Department of Chemistry, University College London , 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Chris Benmore
- X-ray Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - J K R Weber
- X-ray Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.,Materials Development Inc. , Arlington Heights, Illinois 60004, United States
| | - Oliver Alderman
- X-ray Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.,Materials Development Inc. , Arlington Heights, Illinois 60004, United States
| | - Anthony Tamalonis
- Materials Development Inc. , Arlington Heights, Illinois 60004, United States
| | - J B Parise
- SUNY , Stony Brook, New York 11794, United States
| |
Collapse
|
7
|
Wilding MC, Wilson M, Ribeiro MCC, Benmore CJ, Weber JKR, Alderman OLG, Tamalonis A, Parise JB. The structure of liquid alkali nitrates and nitrites. Phys Chem Chem Phys 2017; 19:21625-21638. [PMID: 28766680 DOI: 10.1039/c7cp03465b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
State of the art high energy X-ray diffraction experiments and simulation models (employing a description of charge transfer) are applied to pure molten alkali nitrates and nitrites and uncover significant emerging structure.
Collapse
Affiliation(s)
| | - Mark Wilson
- Department of Chemistry
- Physical and Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
| | - Mauro C. C. Ribeiro
- Laboratório de Espectroscopia Molecular
- Instituto de Química
- Universidade de Sāo Paulo
- Sāo Paulo
- Brazil
| | | | - J. K. R. Weber
- X-ray Science Division
- Argonne National Laboratory
- Argonne
- USA
- Materials Development Inc
| | - O. L. G. Alderman
- X-ray Science Division
- Argonne National Laboratory
- Argonne
- USA
- Materials Development Inc
| | | | | |
Collapse
|
8
|
Weber JKR, Tamalonis A, Benmore CJ, Alderman OLG, Sendelbach S, Hebden A, Williamson MA. Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials. Rev Sci Instrum 2016; 87:073902. [PMID: 27475566 DOI: 10.1063/1.4955210] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/22/2016] [Indexed: 06/06/2023]
Abstract
An aerodynamic levitator with carbon dioxide laser beam heating was integrated with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. The chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The sample environment was integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. The system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions.
Collapse
Affiliation(s)
- J K R Weber
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - A Tamalonis
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - C J Benmore
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - O L G Alderman
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - S Sendelbach
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - A Hebden
- Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M A Williamson
- Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| |
Collapse
|
9
|
Wilding MC, Wilson M, Alderman OLG, Benmore C, Weber JKR, Parise JB, Tamalonis A, Skinner L. Low-Dimensional Network Formation in Molten Sodium Carbonate. Sci Rep 2016; 6:24415. [PMID: 27080401 PMCID: PMC4832186 DOI: 10.1038/srep24415] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 03/17/2016] [Indexed: 11/10/2022] Open
Abstract
Molten carbonates are highly inviscid liquids characterized by low melting points and high solubility of rare earth elements and volatile molecules. An understanding of the structure and related properties of these intriguing liquids has been limited to date. We report the results of a study of molten sodium carbonate (Na2CO3) which combines high energy X-ray diffraction, containerless techniques and computer simulation to provide insight into the liquid structure. Total structure factors (F(x)(Q)) are collected on the laser-heated carbonate spheres suspended in flowing gases of varying composition in an aerodynamic levitation furnace. The respective partial structure factor contributions to F(x)(Q) are obtained by performing molecular dynamics simulations treating the carbonate anions as flexible entities. The carbonate liquid structure is found to be heavily temperature-dependent. At low temperatures a low-dimensional carbonate chain network forms, at T = 1100 K for example ~55% of the C atoms form part of a chain. The mean chain lengths decrease as temperature is increased and as the chains become shorter the rotation of the carbonate anions becomes more rapid enhancing the diffusion of Na(+) ions.
Collapse
Affiliation(s)
- Martin C Wilding
- Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Mark Wilson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Oliver L G Alderman
- X-ray Science Division, Argonne National Laboratory, Argonne IL60439, USA.,Materials Development, Inc., Arlington Heights IL 60004, USA
| | - Chris Benmore
- X-ray Science Division, Argonne National Laboratory, Argonne IL60439, USA
| | - J K R Weber
- X-ray Science Division, Argonne National Laboratory, Argonne IL60439, USA.,Materials Development, Inc., Arlington Heights IL 60004, USA
| | - John B Parise
- Geosciences Department and Department of Chemistry, Stony Brook University, NY 11794-2100, USA
| | | | - Lawrie Skinner
- X-ray Science Division, Argonne National Laboratory, Argonne IL60439, USA.,Materials Development, Inc., Arlington Heights IL 60004, USA.,Geosciences Department and Department of Chemistry, Stony Brook University, NY 11794-2100, USA
| |
Collapse
|
10
|
Weber JKR, Benmore CJ, Suthar KJ, Tamalonis AJ, Alderman OLG, Sendelbach S, Kondev V, Yarger J, Rey CA, Byrn SR. Using containerless methods to develop amorphous pharmaceuticals. Biochim Biophys Acta Gen Subj 2016; 1861:3686-3692. [PMID: 27062908 DOI: 10.1016/j.bbagen.2016.03.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 11/29/2022]
Abstract
BACKGROUND Many pipeline drugs have low solubility in their crystalline state and require compounding in special dosage forms to increase bioavailability for oral administration. The use of amorphous formulations increases solubility and uptake of active pharmaceutical ingredients. These forms are rapidly gaining commercial importance for both pre-clinical and clinical use. METHODS Synthesis of amorphous drugs was performed using an acoustic levitation containerless processing method and spray drying. The structure of the products was investigated using in-situ high energy X-ray diffraction. Selected solvents for processing drugs were investigated using acoustic levitation. The stability of amorphous samples was measured using X-ray diffraction. Samples processed using both spray drying and containerless synthesis were compared. RESULTS We review methods for making amorphous pharmaceuticals and present data on materials made by containerless processing and spray drying. It was shown that containerless processing using acoustic levitation can be used to make phase-pure forms of drugs that are known to be difficult to amorphize. The stability and structure of the materials was investigated in the context of developing and making clinically useful formulations. CONCLUSIONS Amorphous compounds are emerging as an important component of drug development and for the oral delivery of drugs with low solubility. Containerless techniques can be used to efficiently synthesize small quantities of pure amorphous forms that are potentially useful in pre-clinical trials and for use in the optimization of clinical products. GENERAL SIGNIFICANCE Developing new pharmaceutical products is an essential enterprise to improve patient outcomes. The development and application of amorphous pharmaceuticals to increase absorption is rapidly gaining importance and it provides opportunities for breakthrough research on new drugs. There is an urgent need to solve problems associated with making formulations that are both stable and that provide high bioavailability. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo.
Collapse
Affiliation(s)
- J K R Weber
- MDI, Arlington, Heights, IL, USA; Argonne National Laboratory, Argonne, IL, USA.
| | - C J Benmore
- Argonne National Laboratory, Argonne, IL, USA; Arizona State University, Tempe, AZ, USA
| | - K J Suthar
- Argonne National Laboratory, Argonne, IL, USA
| | | | - O L G Alderman
- MDI, Arlington, Heights, IL, USA; Argonne National Laboratory, Argonne, IL, USA
| | | | - V Kondev
- Argonne National Laboratory, Argonne, IL, USA
| | - J Yarger
- Arizona State University, Tempe, AZ, USA
| | - C A Rey
- C. Rey, Inc., Evanston, IL, USA
| | - S R Byrn
- Purdue University, Lafayette, IN, USA
| |
Collapse
|
11
|
Benmore CJ, Skinner LB, Lee B, Weber JKR, Parise JB, Williamson M. Topological ordering in liquid UO2. J Phys Condens Matter 2016; 28:015102. [PMID: 26656592 DOI: 10.1088/0953-8984/28/1/015102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A molecular dynamics model of liquid UO2 that is in good agreement with recent high-energy x-ray diffraction data has been analyzed using the Bhatia-Thornton formalism. A pre-peak appears in the topological structure factor S NN(Q) at Q = 1.85(1)Å(-1) which is not present in the more common, element specific Faber-Ziman partial structure factors. A radical Voronoi tessellation of the 3D molecular dynamics model shows the presence of a wide distribution of clusters, consistent with presence of highly mobile oxygen atoms. However, 4-fold Voronoi polyhedra (n 4) are found to dominate the structure and the majority of clusters can be described by the distribution n 3 ⩽ n 4 ⩾ n 5. It is argued that an open network of 4-fold Voronoi polyhedra could explain the origin of the pre-peak in S NN(Q) and the topological ordering observed in liquid UO2.
Collapse
Affiliation(s)
- C J Benmore
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | | | | | | | | | | |
Collapse
|
12
|
Alderman OLG, Ferlat G, Baroni A, Salanne M, Micoulaut M, Benmore CJ, Lin A, Tamalonis A, Weber JKR. Liquid B2O3 up to 1700 K: x-ray diffraction and boroxol ring dissolution. J Phys Condens Matter 2015; 27:455104. [PMID: 26499978 DOI: 10.1088/0953-8984/27/45/455104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Using high energy x-ray diffraction, the structure factors of glassy and molten B2O3 were measured with high signal-to-noise, up to a temperature of T = 1710(20) K. The observed systematic changes with T are shown to be consistent with the dissolution of hexagonal [B3O6] boroxol rings, which are abundant in the glass, whilst the high-T (>~1500 K) liquid can be more closely described as a random network structure based on [BO3] triangular building blocks. We therefore argue that diffraction data are in fact qualitatively sensitive to the presence of small rings, and support the existence of a continuous structural transition in molten B2O3, for which the temperature evolution of the 808 cm−1 Raman scattering band (boroxol breathing mode) has long stood as the most emphatic evidence. Our conclusions are supported by both first-principles and polarizable ion model molecular dynamics simulations which are capable of giving good account of the experimental data, so long as steps are taken to ensure a ring fraction similar to that expected from Raman spectroscopy. The mean thermal expansion of the B-O bond has been measured directly to be αBO = 3.7(2) × 10−6 K−1, which accounts for a few percent of the bulk expansion just above the glass transition temperature, but accounts for greater than one third of the bulk expansion at temperatures in excess of 1673 K.
Collapse
|
13
|
Tamalonis A, Weber JKR, Neuefeind JC, Carruth J, Skinner LB, Alderman OLG, Benmore CJ. Note: Detector collimators for the nanoscale ordered materials diffractometer instrument at the Spallation Neutron Source. Rev Sci Instrum 2015; 86:096105. [PMID: 26429492 DOI: 10.1063/1.4930279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Five neutron collimator designs were constructed and tested at the nanoscale ordered materials diffractometer (NOMAD) instrument. Collimators were made from High Density PolyEthylene (HDPE) or 5% borated HDPE. In all cases, collimators improved the signal to background ratio and reduced detection of secondary scattering. In the Q-range 10-20 Å(-1), signal to background ratio improved by factors of approximately 1.6 and 2.0 for 50 and 100 mm deep collimators, respectively. In the Q-range 40-50 Å(-1), the improvement factors were 1.8 and 2.7. Secondary scattering as measured at Q ∼ 9.5 Å(-1) was significantly decreased when the collimators were installed.
Collapse
Affiliation(s)
- A Tamalonis
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - J K R Weber
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - J C Neuefeind
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - J Carruth
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - L B Skinner
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - O L G Alderman
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA
| | - C J Benmore
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| |
Collapse
|
14
|
Skinner LB, Benmore CJ, Weber JKR, Williamson MA, Tamalonis A, Hebden A, Wiencek T, Alderman OLG, Guthrie M, Leibowitz L, Parise JB. Molten uranium dioxide structure and dynamics. Science 2014; 346:984-7. [PMID: 25414311 DOI: 10.1126/science.1259709] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.
Collapse
Affiliation(s)
- L B Skinner
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA. Mineral Physics Institute, Stony Brook University, Stony Brook, NY 11794-2100, USA. Materials Development, Inc., 3090 Daniels Court, Arlington Heights, IL 60004, USA.
| | - C J Benmore
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - J K R Weber
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA. Materials Development, Inc., 3090 Daniels Court, Arlington Heights, IL 60004, USA
| | - M A Williamson
- Chemical Science and Engineering, Argonne National Laboratory, Argonne, IL 60439, USA
| | - A Tamalonis
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - A Hebden
- Chemical Science and Engineering, Argonne National Laboratory, Argonne, IL 60439, USA
| | - T Wiencek
- Nuclear Engineering, Argonne National Laboratory, Argonne, IL 60439, USA
| | - O L G Alderman
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA. Materials Development, Inc., 3090 Daniels Court, Arlington Heights, IL 60004, USA
| | - M Guthrie
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
| | - L Leibowitz
- Chemical Science and Engineering, Argonne National Laboratory, Argonne, IL 60439, USA
| | - J B Parise
- Mineral Physics Institute, Stony Brook University, Stony Brook, NY 11794-2100, USA. Photon Sciences, Brookhaven National Laboratory, Upton, NY 11973, USA
| |
Collapse
|
15
|
Skinner LB, Benmore CJ, Weber JKR, Du J, Neuefeind J, Tumber SK, Parise JB. Low cation coordination in oxide melts. Phys Rev Lett 2014; 112:157801. [PMID: 24785072 DOI: 10.1103/physrevlett.112.157801] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Indexed: 06/03/2023]
Abstract
The complete set of partial pair distribution functions for a rare earth oxide liquid are measured by combining aerodynamic levitation, neutron and x-ray diffraction on Y2O3, and Ho2O3 melts at 2870 K. The average Y-O (or Ho-O) coordination of these isomorphic melts is measured to be 5.5(2), which is significantly less than the octahedral coordination of crystalline Y2O3 (or Ho2O3). Investigation of La2O3, ZrO2, and Al2O3 melts by x-ray diffraction and molecular dynamics simulations also show lower-than-crystal cation-oxygen coordination. These measurements suggest a general trend towards lower coordination compared to their crystalline counterparts. It is found that the coordination drop is larger for lower field strength, larger radius cations and is negligible for high field strength (network forming) cations, such as SiO2. These findings have broad implications for predicting the local structure and related physical properties of metal-oxide melts and oxide glasses.
Collapse
Affiliation(s)
- L B Skinner
- Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100, USA and X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA and Materials Development Inc., Arlington Heights, Illinois 60004, USA
| | - C J Benmore
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J K R Weber
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA and Materials Development Inc., Arlington Heights, Illinois 60004, USA
| | - J Du
- Materials Science & Engineering, University of North Texas, Denton, Texas 76203, USA
| | - J Neuefeind
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S K Tumber
- Materials Development Inc., Arlington Heights, Illinois 60004, USA
| | - J B Parise
- Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100, USA
| |
Collapse
|
16
|
Skinner LB, Benmore CJ, Weber JKR, Wilding MC, Tumber SK, Parise JB. A time resolved high energy X-ray diffraction study of cooling liquid SiO2. Phys Chem Chem Phys 2013; 15:8566-72. [PMID: 23588490 DOI: 10.1039/c3cp44347g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- L B Skinner
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | | | | | | | | | | |
Collapse
|
17
|
Wilding MC, Wilson M, Benmore CJ, Weber JKR, McMillan PF. Structural changes in supercooled Al2O3–Y2O3 liquids. Phys Chem Chem Phys 2013; 15:8589-605. [DOI: 10.1039/c3cp51209f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Skinner LB, Benmore CJ, Weber JKR, Tumber S, Lazareva L, Neuefeind J, Santodonato L, Du J, Parise JB. Structure of Molten CaSiO3: Neutron Diffraction Isotope Substitution with Aerodynamic Levitation and Molecular Dynamics Study. J Phys Chem B 2012; 116:13439-47. [DOI: 10.1021/jp3066019] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- L. B. Skinner
- Mineral Physics Institute & Department of Geosciences, Stony Brook University, Stony Brook, New York 11794-2100, United States
| | - C. J. Benmore
- X-ray Science Division, Advanced
Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - J. K. R. Weber
- X-ray Science Division, Advanced
Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Materials Development, Inc., Arlington Heights, Illinois 60004, United States
| | - S. Tumber
- Materials Development, Inc., Arlington Heights, Illinois 60004, United States
| | - L. Lazareva
- Mineral Physics Institute & Department of Geosciences, Stony Brook University, Stony Brook, New York 11794-2100, United States
| | - J. Neuefeind
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee,
United States
| | - L. Santodonato
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee,
United States
| | - J. Du
- Dept. of
Material Science and
Engineering, University of North Texas,
Denton, Texas 76203, United States
| | - J. B. Parise
- Mineral Physics Institute & Department of Geosciences, Stony Brook University, Stony Brook, New York 11794-2100, United States
- Light Source Division, Brookhaven National Laboratory, Upton, New York 11973,
United States
| |
Collapse
|
19
|
Abstract
The luminescent properties of divalent europium ions can be exploited to produce storage phosphors for x-ray imaging applications. The relatively high cost and limited availability of divalent europium halides makes it desirable to synthesize them from the readily available trivalent salts. In this work, samples of pure EuCl(3) and fluoride glass melts doped with EuCl(3) were processed at 700-800 °C in an inert atmosphere furnace. The Eu oxidation state in the resulting materials was determined using fluorescence and Mössbauer spectroscopy. Heat treatment of pure EuCl(3) for 10 min at 710 °C resulted in a material comprising approximately equal amounts of Eu(2+) and Eu(3+). Glasses made using mixtures of EuCl(2) and EuCl(3) in the starting material contained both oxidation states. This paper describes the sample preparation and analysis and discusses the results in the context of chemical equilibria in the melts.
Collapse
Affiliation(s)
- J K R Weber
- Materials Development, Inc., Arlington Heights, IL 60004, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
Greaves GN, Wilding MC, Hennet L, Langstaff D, Kargl F, Benmore CJ, Weber JKR. Comment on "liquid-liquid phase transition in supercooled yttria-alumina". Phys Rev Lett 2011; 106:119601-119602. [PMID: 21469907 DOI: 10.1103/physrevlett.106.119601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Revised: 06/01/2010] [Indexed: 05/30/2023]
|
21
|
Affiliation(s)
- M. C. Wilding
- Institute of Mathematical and Physical Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3BZ, U.K., X-ray Science Division, Argonne National Laboratory, Illinois 60439, and Materials Development, Inc., Arlington Heights, Illinois 60004
| | - C. J. Benmore
- Institute of Mathematical and Physical Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3BZ, U.K., X-ray Science Division, Argonne National Laboratory, Illinois 60439, and Materials Development, Inc., Arlington Heights, Illinois 60004
| | - J. K. R. Weber
- Institute of Mathematical and Physical Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3BZ, U.K., X-ray Science Division, Argonne National Laboratory, Illinois 60439, and Materials Development, Inc., Arlington Heights, Illinois 60004
| |
Collapse
|
22
|
Lubinsky AR, Johnson JA, Schweizer S, Weber JKR, Nishikawa RM, Domenicali P, Fantone SD. Scanning translucent glass-ceramic x-ray storage phosphors. Proc SPIE Int Soc Opt Eng 2010; 7622:76223W. [PMID: 23264857 PMCID: PMC3526193 DOI: 10.1117/12.843346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A simple benchtop apparatus has been built, to measure the x-ray imaging properties of fluorozirconate-based glass-ceramic x-ray storage phosphor materials. The MTF degradation due to stimulating light spreading in the plate is lower in comparison to optically turbid screens resulting in higher image MTF. In addition, the degree of transparency, or the amount of light scattering at the wavelength of the stimulating (laser) light is adjustable by means of the glass preparation process. The amount of stimulating exposure required for plate readout is generally higher than in previous systems, but well within the range of commercially available laser systems, for practical readout times. The effects of flare or unwanted readout due to back-reflection from the imaging plate is also less than in previous systems.A novel telecentric scanning system has been developed that is able to rapidly read out the latent image stored in the translucent imaging plates. This system features a reflective primary scan mirror to achieve telecentricity, optical correction for scan line bow, and the design should enable the construction of a relatively inexpensive scanner system for the translucent x-ray storage plates.
Collapse
Affiliation(s)
- A. R. Lubinsky
- Department of Radiology, SUNY, Stony Brook, NY 11794-8460
| | - J. A. Johnson
- Department of Materials Science and Engineering, University of Tennessee Space Institute, 411 B. H. Goethert Parkway, Tullahoma, TN 37388
| | - S. Schweizer
- Fraunhofer Center for Silicon Photovoltaics, Walter-Hülse-Str. 1, 06120 Halle (Saale), Germany, and Centre for Innovation Competence SiLi-nano, Martin Luther University of Halle-Wittenberg, K.-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale), Germany
| | - J. K. R. Weber
- Materials Development, Inc., 3090 Daniels Court, Arlington Heights, IL 60004-7708
| | - R. M. Nishikawa
- Department of Radiology, University of Chicago, Chicago, IL 60637
| | - P. Domenicali
- Optikos Corporation, 107 Audubon Road, Wakefield, MA 01880
| | - S. D. Fantone
- Optikos Corporation, 107 Audubon Road, Wakefield, MA 01880
| |
Collapse
|
23
|
Abstract
Crystallization phenomena of fluorochlorozirconate glasses were investigated by means of differential scanning calorimetry and inelastic neutron scattering. The precipitation of barium chloride nanoparticles from the glass matrix upon heat treatment was found to be suppressed when re-melting the glass with a reducing agent but not if the agent was present in the initial synthesis. Addition of small amounts of oxide to the predominantly fluoride melt was found to maintain the presence of nanoparticles but not to induce the predicted phase transition of the barium chloride nanoparticles from hexagonal to orthorhombic structure. Inelastic neutron scattering performed on an 'as-made' glass and a heat-treated glass showed an increase in 'hardness', consistent with a more ordered structure.
Collapse
Affiliation(s)
- JA Johnson
- University of Tennessee Space Institute, Tullahoma, TN 37388, USA
| | - JKR Weber
- Materials Development, Incorporated, 820 Davis Street, Suite 129, Evanston, IL 60201, USA
| | - AI Kolesnikov
- Neutron Scattering Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - S Schweizer
- Fraunhofer Center for Silicon Photovoltaics, Walter-Hülse-Straße 1, 06120 Halle (Saale), Germany
- Institute of Physics, Martin Luther University of Halle-Wittenberg, Heinrich-Damerow-Straße 4, 06120 Halle (Saale), Germany
| |
Collapse
|
24
|
Weber JKR, Rey CA, Neuefeind J, Benmore CJ. Acoustic levitator for structure measurements on low temperature liquid droplets. Rev Sci Instrum 2009; 80:083904. [PMID: 19725664 DOI: 10.1063/1.3196177] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops of 1-3 mm in diameter at temperatures in the range -40 to +40 degrees C. The levitator comprised (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) an acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1 kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of approximately 22 kHz and could produce sound pressure levels of up to 160 dB. The force applied by the acoustic field could be modulated to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids.
Collapse
Affiliation(s)
- J K R Weber
- Materials Development, Inc., Arlington Heights, Illinois 60004, USA.
| | | | | | | |
Collapse
|
25
|
Mei Q, Benmore CJ, Weber JKR. Structure of liquid SiO2: a measurement by high-energy x-ray diffraction. Phys Rev Lett 2007; 98:057802. [PMID: 17358901 DOI: 10.1103/physrevlett.98.057802] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Indexed: 05/08/2023]
Abstract
The x-ray structure factor for liquid SiO2 has been measured by laser heating of an aerodynamically levitated droplet. The main structural changes of the melt compared to the room temperature glass are associated with an increase in the size of the SiO4 tetrahedra, indicating a small reduction in the average Si-O-Si bond torsion angle and an expansion of the network between 5 and 9 A. Strong directional bonds with little high temperature broadening and a high degree of intermediate range order are found to persist in the liquid state.
Collapse
Affiliation(s)
- Q Mei
- Intense Pulsed Neutron Source Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | | | | |
Collapse
|
26
|
Rix JE, Weber JKR, Santodonato LJ, Hill B, Walker LM, McPherson R, Wenzel J, Hammons SE, Hodges J, Rennich M, Volin KJ. Automated sample exchange and tracking system for neutron research at cryogenic temperatures. Rev Sci Instrum 2007; 78:013907. [PMID: 17503933 DOI: 10.1063/1.2426878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
An automated system for sample exchange and tracking in a cryogenic environment and under remote computer control was developed. Up to 24 sample "cans" per cycle can be inserted and retrieved in a programed sequence. A video camera acquires a unique identification marked on the sample can to provide a record of the sequence. All operations are coordinated via a LABVIEW program that can be operated locally or over a network. The samples are contained in vanadium cans of 6-10 mm in diameter and equipped with a hermetically sealed lid that interfaces with the sample handler. The system uses a closed-cycle refrigerator (CCR) for cooling. The sample was delivered to a precooling location that was at a temperature of approximately 25 K, after several minutes, it was moved onto a "landing pad" at approximately 10 K that locates the sample in the probe beam. After the sample was released onto the landing pad, the sample handler was retracted. Reading the sample identification and the exchange operation takes approximately 2 min. The time to cool the sample from ambient temperature to approximately 10 K was approximately 7 min including precooling time. The cooling time increases to approximately 12 min if precooling is not used. Small differences in cooling rate were observed between sample materials and for different sample can sizes. Filling the sample well and the sample can with low pressure helium is essential to provide heat transfer and to achieve useful cooling rates. A resistive heating coil can be used to offset the refrigeration so that temperatures up to approximately 350 K can be accessed and controlled using a proportional-integral-derivative control loop. The time for the landing pad to cool to approximately 10 K after it has been heated to approximately 240 K was approximately 20 min.
Collapse
Affiliation(s)
- J E Rix
- Containerless Research, Inc., Evanston, Illinois 60202, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Kohara S, Suzuya K, Takeuchi K, Loong CK, Grimsditch M, Weber JKR, Tangeman JA, Key TS. Glass Formation at the Limit of Insufficient Network Formers. Science 2004; 303:1649-52. [PMID: 15016995 DOI: 10.1126/science.1095047] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Inorganic glasses normally exhibit a network of interconnected, covalent-bonded, structural elements that has no long-range order. In silicate glasses, the network formers are based on SiO4 tetrahedra interconnected through oxygen atoms at the corners. Conventional wisdom implies that alkaline and alkaline-earth orthosilicate materials cannot be vitrified, because they do not contain sufficient network-forming SiO2 to establish the needed interconnectivity. We studied a bulk magnesium orthosilicate glass obtained by containerless melting and cooling. We found that the role of network former was largely taken on by corner and edge sharing of highly distorted, ionic Mg-O species that adopt 4-, 5-, and 6-coordination with oxygen. The results suggest that similar glassy phases may be found in the containerless environment of interstellar space.
Collapse
Affiliation(s)
- S Kohara
- Japan Synchrotron Radiation Research Institute, Mikazuki, Sayo, Hyogo 679-5198, Japan
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Benmore C, Weber JKR, Tangeman JA, Siewenie J, Heira KJ. Structure of binary CaO-Al 2O 3and SrO-Al 2O 3liquids by combined levitation-neutron diffraction. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302093522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
29
|
Abstract
Rutherford backscattering spectroscopy (RBS) and microscopy demonstrate that the approximately 1400°C oxidation of levitated droplets of a natural Fe2+-bearing aluminosilicate (basalt) melt occurs by chemical diffusion of Fe2+ and Ca2+ to the free surface of the droplet; internal oxidation of the melt results from the required counterflux of electron holes. Diffusion of an oxygen species is not required. Oxidation causes the droplets to go subsolidus; magnetite (Fe3O4) forms at the oxidation-solidification front with a morphology suggestive of a Liesegang-band nucleation process.
Collapse
Affiliation(s)
- RF Cooper
- R. F. Cooper and J. B. Fanselow, Departments of Materials Science and Engineering and Geology and Geophysics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706, USA. J. K. R. Weber and D. R. Merkley, Intersonics Incorporated, 3453 Commercial Avenue, Northbrook, IL 60062, USA. D. B. Poker, Oak Ridge National Laboratory, Mail Stop 6048, Post Office Box 2008, Oak Ridge, TN 37831, USA
| | | | | | | | | |
Collapse
|
30
|
Krishnan S, Anderson CD, Weber JKR, Nordine PC, Hofmeister WH, Bayuzick RJ. Optical properties and spectral emissivities at 632.8 nm in the titanium-aluminum system. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf02669604] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|