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Bouwman WG. Spin-echo small-angle neutron scattering for multiscale structure analysis of food materials. FOOD STRUCTURE 2021. [DOI: 10.1016/j.foostr.2021.100235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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2
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Smith GN, Brok E, Schmiele M, Mortensen K, Bouwman WG, Duif CP, Hassenkam T, Alm M, Thomsen P, Arleth L. The microscopic distribution of hydrophilic polymers in interpenetrating polymer networks (IPNs) of medical grade silicone. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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3
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Bakker JH, Washington AL, Parnell SR, van Well AA, Pappas C, Bouwman WG. Analysis of SESANS data by numerical Hankel transform implementation in SasView. JOURNAL OF NEUTRON RESEARCH 2020. [DOI: 10.3233/jnr-200154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Jurrian H. Bakker
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Adam L. Washington
- ISIS, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, United Kingdom
| | - Steven R. Parnell
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Ad A. van Well
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Catherine Pappas
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Wim G. Bouwman
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
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4
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Hallett JE, Grillo I, Smith GN. A Neutron Scattering Study of the Structure of Poly(dimethylsiloxane)-Stabilized Poly(methyl methacrylate) (PDMS-PMMA) Latexes in Dodecane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2071-2081. [PMID: 32008323 DOI: 10.1021/acs.langmuir.9b03911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hard-sphere particles in nonpolar solvents are an essential tool for colloid scientists. Sterically stabilized poly(methyl methacrylate) (PMMA) particles have long been used as the exemplary hard-sphere system. However, neither the particles themselves nor the poly(12-hydroxystearic acid) (PHSA) stabilizer necessary to prevent aggregation in nonpolar solvents are commercially available. To counter this, several alternatives have been proposed. In recent years, there has been an increased interest in poly(dimethylsiloxane) (PDMS) stabilizers as a commercially available alternative to PHSA, yet the structure of particles made in this way is not as well understood as those produced using PHSA. In this work, we employ small-angle neutron scattering to determine the internal structure of PDMS-stabilized PMMA particles, synthesized with and without an additional crosslinking agent. We report data consistent with a homogeneous PMMA core with a linearly decaying PDMS shell. The thickness of the shell was in excess of 50 nm, thicker than the PHSA layer typically used to stabilize PMMA but consistent with reports of the layer thickness for similar molecular weight PDMS at planar surfaces. We also show that the amount of the hydrogenous material in the particle core of the crosslinked particles notably exceeds the amount of added ethylene glycol dimethacrylate crosslinker, suggesting some entrapment of the PDMS stabilizer in the PMMA matrix.
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Affiliation(s)
- James E Hallett
- H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
| | - Isabelle Grillo
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Gregory N Smith
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
- Niels Bohr Institute, H. C. Ørsted Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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5
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Bernardo G, Melle-Franco M, Washington AL, Dalgliesh RM, Li F, Mendes A, Parnell SR. Different agglomeration properties of PC61BM and PC71BM in photovoltaic inks – a spin-echo SANS study. RSC Adv 2020; 10:4512-4520. [PMID: 35495220 PMCID: PMC9049156 DOI: 10.1039/c9ra08019h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 12/10/2019] [Indexed: 11/21/2022] Open
Abstract
Fullerene derivatives are used in a wide range of applications including as electron acceptors in solution-processable organic photovoltaics.
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Affiliation(s)
- Gabriel Bernardo
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy
- Faculty of Engineering
- University of Porto
- 4200-465 Porto
- Portugal
| | - Manuel Melle-Franco
- CICECO—Aveiro Institute of Materials
- Department of Chemistry
- University of Aveiro
- 3810-193 Aveiro
- Portugal
| | - Adam L. Washington
- ISIS Pulsed Neutron and Muon Source
- STFC
- Rutherford Appleton Laboratory
- Oxon
- UK
| | | | - Fankang Li
- Neutron Technologies Division
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Adélio Mendes
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy
- Faculty of Engineering
- University of Porto
- 4200-465 Porto
- Portugal
| | - Steven R. Parnell
- Faculty of Applied Sciences
- Delft University of Technology
- 2629 JB Delft
- Netherlands
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6
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Symmetric Talbot-Lau neutron grating interferometry and incoherent scattering correction for quantitative dark-field imaging. Sci Rep 2019; 9:18973. [PMID: 31831866 PMCID: PMC6908620 DOI: 10.1038/s41598-019-55420-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/31/2019] [Indexed: 11/30/2022] Open
Abstract
We introduce the application of a symmetric Talbot-Lau neutron grating interferometer which provides a significantly extended autocorrelation length range essential for quantitative dark-field contrast imaging. The highly efficient set-up overcomes the limitation of the conventional Talbot-Lau technique to a severely limited micrometer range as well as the limitation of the other advanced dark-field imaging techniques in the nanometer regime. The novel set-up enables efficient and continuous dark-field contrast imaging providing quantitative small-angle neutron scattering information for structures in a regime from some tens of nanometers to several tens of micrometers. The quantitative analysis enabled in and by such an extended range is demonstrated through application to reference sample systems of the diluted polystyrene particle in aqueous solutions. Here we additionally demonstrate and successfully discuss the correction for incoherent scattering. This correction results to be necessary to achieve meaningful quantitative structural results. Furthermore, we present the measurements, data modelling and analysis of the two distinct kinds of cohesive powders enabled by the novel approach, revealing the significant structural differences of their fractal nature.
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7
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Smith GN, Derry MJ, Hallett JE, Lovett JR, Mykhaylyk OO, Neal TJ, Prévost S, Armes SP. Refractive index matched, nearly hard polymer colloids. Proc Math Phys Eng Sci 2019; 475:20180763. [PMID: 31293354 DOI: 10.1098/rspa.2018.0763] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 05/09/2019] [Indexed: 11/12/2022] Open
Abstract
Refractive index matched particles serve as essential model systems for colloid scientists, providing nearly hard spheres to explore structure and dynamics. The poly(methyl methacrylate) latexes typically used are often refractive index matched by dispersing them in binary solvent mixtures, but this can lead to undesirable changes, such as particle charging or swelling. To avoid these shortcomings, we have synthesized refractive index matched colloids using polymerization-induced self-assembly (PISA) rather than as polymer latexes. The crucial difference is that these diblock copolymer nanoparticles consist of a single core-forming polymer in a single non-ionizable solvent. The diblock copolymer chosen was poly(stearyl methacrylate)-poly(2,2,2-trifluoroethyl methacrylate) (PSMA-PTFEMA), which self-assembles to form PTFEMA core spheres in n-alkanes. By monitoring scattered light intensity, n-tetradecane was found to be the optimal solvent for matching the refractive index of such nanoparticles. As expected for PISA syntheses, the diameter of the colloids can be controlled by varying the PTFEMA degree of polymerization. Concentrated dispersions were prepared, and the diffusion of the PSMA-PTFEMA nanoparticles as a function of volume fraction was measured. These diblock copolymer nanoparticles are a promising new system of transparent spheres for future colloidal studies.
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Affiliation(s)
- Gregory N Smith
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK
| | - Matthew J Derry
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK
| | - James E Hallett
- H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1FD, UK
| | - Joseph R Lovett
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK
| | | | - Thomas J Neal
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK
| | - Sylvain Prévost
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Steven P Armes
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK
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8
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Li F, Parnell SR, Dalgliesh R, Washington A, Plomp J, Pynn R. Data Correction of Intensity Modulated Small Angle Scattering. Sci Rep 2019; 9:8563. [PMID: 31189935 PMCID: PMC6561909 DOI: 10.1038/s41598-019-44493-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/25/2019] [Indexed: 11/29/2022] Open
Abstract
To investigate long length scale structures using neutron scattering, real space techniques have shown certain advantages over the conventional methods working in reciprocal space. As one of the real space measurement techniques, spin echo modulated small angle neutron scattering (SEMSANS) has attracted attention, due to its relaxed constraints on sample environment and the possibility to combine SEMSANS and a conventional small angle neutron scattering instrument. In this report, we present the first implementation of SEMSANS at a pulsed neutron source and discuss important corrections to the data due to the sample absorption. These corrections allow measurements made with different neutron wavelengths and SEMSANS configurations to be overlaid and give confidence that the measurements provide an accurate representation of the density correlations in the sample.
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Affiliation(s)
- Fankang Li
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
| | - Steven R Parnell
- Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, Delft, JB 2629, The Netherlands
| | - Robert Dalgliesh
- ISIS Pulsed Neutron and Muon Source, STFC, Rutherford Appleton Laboratory, Chilton, Oxon, OX11 0QX, UK
| | - Adam Washington
- ISIS Pulsed Neutron and Muon Source, STFC, Rutherford Appleton Laboratory, Chilton, Oxon, OX11 0QX, UK
| | - Jeroen Plomp
- Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, Delft, JB 2629, The Netherlands
| | - Roger Pynn
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.,Center for Exploration of Energy and Matter, Indiana University, Bloomington, IN, 47408, USA
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9
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Smith GN, Cunningham VJ, Canning SL, Derry MJ, Cooper JFK, Washington AL, Armes SP. Spin-echo small-angle neutron scattering (SESANS) studies of diblock copolymer nanoparticles. SOFT MATTER 2018; 15:17-21. [PMID: 30520930 DOI: 10.1039/c8sm01425f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Poly(glycerol monomethacrylate)-poly(benzyl methacrylate) (PGMA-PBzMA) diblock copolymer nanoparticles were synthesized via polymerization-induced self-assembly (PISA) using reversible addition-fragmentation chain-transfer (RAFT) aqueous emulsion polymerization in D2O. Such PISA syntheses produce sterically-stabilized nanoparticles in situ and can be performed at relatively high copolymer concentrations (up to 50 wt%). This PGMA-PBzMA formulation is known to form only spherical nanoparticles in water using aqueous emulsion polymerization (Macromolecules, 2014, 47, 5613-5623), which makes it an ideal model system for exploring new characterization methods. The polymer micelles were characterized using small-angle X-ray scattering (SAXS) and a recently developed form of neutron scattering, spin-echo small-angle neutron scattering (SESANS). As far as we are aware, this is the first report of a study of polymer micelles by SESANS, and the data agree well with reciprocal-space scattering. Using this technique enables characterization of the concentrated, as synthesized dispersions directly without dilution, and this will provide a method to study self-assembled polymer systems that have concentration dependent morphologies, while still maintaining the advantages of scattering techniques.
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Affiliation(s)
- Gregory N Smith
- Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Victoria J Cunningham
- Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Sarah L Canning
- Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Matthew J Derry
- Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - J F K Cooper
- ISIS-STFC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, UK
| | - A L Washington
- ISIS-STFC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, UK
| | - Steven P Armes
- Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
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10
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Smith GN, Ahualli S, Delgado ÁV, Gillespie DAJ, Kemp R, Peach J, Pegg JC, Rogers SE, Shebanova O, Smith N, Eastoe J. Charging Poly(methyl Methacrylate) Latexes in Nonpolar Solvents: Effect of Particle Concentration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:13543-13553. [PMID: 29064706 DOI: 10.1021/acs.langmuir.7b02257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The electrophoresis of a well-established model system of charged colloids in nonpolar solvents has been studied as a function of particle volume fraction at constant surfactant concentration. Dispersions of poly(12-hydroxystearic acid)-stabilized poly(methyl methacrylate) (PMMA) latexes in dodecane were prepared with added Aerosol OT surfactant as the charging agent. The electrophoretic mobility (μ) of the PMMA latexes is found to decrease with particle concentration. The particles are charged by a small molecule charging agent (AOT) at finite concentration, and this makes the origin of this decrease in μ unclear. There are two suggested explanations. The decrease could either be due to the reservoir of available surfactant being exhausted at high particle concentrations or the interactions between the charged particles at high particle number concentrations. Contrast-variation small-angle neutron scattering measurements of PMMA latexes and deuterated AOT-d34 surfactant in latex core contrast-matched solvent were used to study the former, and electrokinetic modeling was used to study the latter. As the same amount of AOT-d34 is found to be incorporated with the latexes at all volume fractions, the solvodynamic and electrical interactions between particles are determined to be the explanation for the decrease in mobility. These measurements show that, for small latexes, there are interactions between the charged particles at all accessible particle volume fractions and that it is necessary to account for this to accurately determine the electrokinetic ζ potential.
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Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Silvia Ahualli
- Department of Applied Physics, School of Science, University of Granada , 18071 Granada, Spain
| | - Ángel V Delgado
- Department of Applied Physics, School of Science, University of Granada , 18071 Granada, Spain
| | - David A J Gillespie
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Roger Kemp
- Merck Chemicals Ltd, University Parkway , Chilworth, Southampton SO16 7QD, United Kingdom
| | - Jocelyn Peach
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Jonathan C Pegg
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Sarah E Rogers
- ISIS-STFC, Rutherford Appleton Laboratory , Chilton, Oxon OX11 0QX, United Kingdom
| | - Olga Shebanova
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus , Chilton, Didcot OX11 0DE, United Kingdom
| | - Nathan Smith
- Merck Chemicals Ltd, University Parkway , Chilworth, Southampton SO16 7QD, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
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11
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Ryu SA, Kim JY, Kim SY, Weon BM. Drying-mediated patterns in colloid-polymer suspensions. Sci Rep 2017; 7:1079. [PMID: 28439069 PMCID: PMC5430651 DOI: 10.1038/s41598-017-00932-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/17/2017] [Indexed: 11/09/2022] Open
Abstract
Drying-mediated patterning of colloidal particles is a physical phenomenon that must be understood in inkjet printing technology to obtain crack-free uniform colloidal films. Here we experimentally study the drying-mediated patterns of a model colloid-polymer suspension and specifically observe how the deposit pattern appears after droplet evaporation by varying particle size and polymer concentration. We find that at a high polymer concentration, the ring-like pattern appears in suspensions with large colloids, contrary to suppression of ring formation in suspensions with small colloids thanks to colloid-polymer interactions. We attribute this unexpected reversal behavior to hydrodynamics and size dependence of colloid-polymer interactions. This finding would be very useful in developing control of drying-mediated self-assembly to produce crack-free uniform patterns from colloidal fluids.
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Affiliation(s)
- Seul-A Ryu
- Soft Matter Physics Laboratory, School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Korea
| | - Jin Young Kim
- Soft Matter Physics Laboratory, School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Korea
| | - So Youn Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Korea
| | - Byung Mook Weon
- Soft Matter Physics Laboratory, School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Korea.
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12
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Smith GN, Finlayson SD, Gillespie DA, Peach J, Pegg JC, Rogers SE, Shebanova O, Terry AE, Armes SP, Bartlett P, Eastoe J. The internal structure of poly(methyl methacrylate) latexes in nonpolar solvents. J Colloid Interface Sci 2016; 479:234-243. [DOI: 10.1016/j.jcis.2016.06.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/08/2016] [Accepted: 06/08/2016] [Indexed: 11/26/2022]
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13
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Parnell SR, Washington AL, Parnell AJ, Walsh A, Dalgliesh RM, Li F, Hamilton WA, Prevost S, Fairclough JPA, Pynn R. Porosity of silica Stöber particles determined by spin-echo small angle neutron scattering. SOFT MATTER 2016; 12:4709-14. [PMID: 27021920 DOI: 10.1039/c5sm02772a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Stöber silica particles are used in a diverse range of applications. Despite their widespread industrial and scientific uses, information on the internal structure of the particles is non-trivial to obtain and is not often reported. In this work we have used spin-echo small angle neutron scattering (SESANS) in conjunction with ultra small angle X-ray scattering (USAXS) and pycnometry to study an aqueous dispersion of Stöber particles. Our results are in agreement with models which propose that Stöber particles have a porous core, with a significant fraction of the pores inaccessible to solvent. For samples prepared from the same master sample in a range of H2O : D2O ratio solutions we were able to model the SESANS results for the solution series assuming monodisperse, smooth surfaced spheres of radius 83 nm with an internal open pore volume fraction of 32% and a closed pore fraction of 10%. Our results are consistent with USAXS measurements. The protocol developed and discussed here shows that the SESANS technique is a powerful way to investigate particles much larger than those studied using conventional small angle scattering methods.
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Affiliation(s)
- S R Parnell
- Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands. and Centre for Exploration of Energy and Matter, Indiana University, Bloomington, 47408, USA
| | - A L Washington
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK and Department of Mechanical Engineering, The University of Sheffield, Sheffield, S1 3DJ, UK
| | - A J Parnell
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
| | - A Walsh
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK
| | - R M Dalgliesh
- ISIS, Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX11 0QX, UK
| | - F Li
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, 47408, USA
| | - W A Hamilton
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, 37831, USA
| | - S Prevost
- ID02 Beamline, European Synchrotron Radiation Facility, F38043, Grenoble, France
| | - J P A Fairclough
- Department of Mechanical Engineering, The University of Sheffield, Sheffield, S1 3DJ, UK
| | - R Pynn
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, 47408, USA and Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, 37831, USA
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14
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Li F, Parnell SR, Bai H, Yang W, Hamilton WA, Maranville BB, Ashkar R, Baxter DV, Cremer JT, Pynn R. Spin echo modulated small-angle neutron scattering using superconducting magnetic Wollaston prisms. J Appl Crystallogr 2016. [DOI: 10.1107/s1600576715021573] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The spin echo modulated small-angle neutron scattering technique has been implemented using two superconducting magnetic Wollaston prisms at a reactor neutron source. The density autocorrelation function measured for a test sample of colloidal silica in a suspension agrees with that obtained previously by other neutron scattering methods on an identically prepared sample. The reported apparatus has a number of advantages over competing technologies: it should allow larger length scales (up to several micrometres) to be probed; it has very small parasitic neutron scattering and attenuation; the magnetic fields within the device are highly uniform; and the neutron spin transport across the device boundaries is very efficient. To understand quantitatively the results of the reported experiment and to guide future instrument development, Monte Carlo simulations are presented, in which the evolution of the neutron polarization through the apparatus is based on magnetic field integrals obtained from finite-element simulations of the various magnetic components. The Monte Carlo simulations indicate that the polarization losses observed in the experiments are a result of instrumental artifacts that can be easily corrected in future experiments.
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15
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Smith GN, Kemp R, Pegg JC, Rogers SE, Eastoe J. Sulfosuccinate and Sulfocarballylate Surfactants As Charge Control Additives in Nonpolar Solvents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:13690-13699. [PMID: 26609708 DOI: 10.1021/acs.langmuir.5b03876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A series of eight sodium sulfonic acid surfactants with differently branched tails (four double-chain sulfosuccinates and four triple-chain sulfocarballylates) were studied as charging agents for sterically stabilized poly(methyl methacrylate) (PMMA) latexes in dodecane. Tail branching was found to have no significant effect on the electrophoretic mobility of the latexes, but the number of tails was found to influence the electrophoretic mobility. Triple-chain, sulfocarballylate surfactants were found to be more effective. Several possible origins of this observation were explored by comparing sodium dioctylsulfosuccinate (AOT1) and sodium trioctylsulfocarballylate (TC1) using identical approaches: the inverse micelle size, the propensity for ion dissociation, the electrical conductivity, the electrokinetic or ζ potential, and contrast-variation small-angle neutron scattering. The most likely origin of the increased ability of TC1 to charge PMMA latexes is a larger number of inverse micelles. These experiments demonstrate a small molecular variation that can be made to influence the ability of surfactants to charge particles in nonpolar solvents, and modifying molecular structure is a promising approach to developing more effective charging agents.
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Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol , Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Roger Kemp
- Merck Chemicals Ltd , University Parkway, Chilworth, Southampton, SO16 7QD, United Kingdom
| | - Jonathan C Pegg
- School of Chemistry, University of Bristol , Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Sarah E Rogers
- ISIS-STFC, Rutherford Appleton Laboratory , Chilton, Oxon, OX11 0QX, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol, BS8 1TS, United Kingdom
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16
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Parnell SR, Washington AL, Li K, Yan H, Stonaha P, Li F, Wang T, Walsh A, Chen WC, Parnell AJ, Fairclough JPA, Baxter DV, Snow WM, Pynn R. Spin echo small angle neutron scattering using a continuously pumped (3)He neutron polarisation analyser. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:023902. [PMID: 25725858 DOI: 10.1063/1.4909544] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 02/08/2015] [Indexed: 06/04/2023]
Abstract
We present a new instrument for spin echo small angle neutron scattering (SESANS) developed at the Low Energy Neutron Source at Indiana University. A description of the various instrument components is given along with the performance of these components. At the heart of the instrument are a series of resistive coils to encode the neutron trajectory into the neutron polarisation. These are shown to work well over a broad range of neutron wavelengths. Neutron polarisation analysis is accomplished using a continuously operating neutron spin filter polarised by Rb spin-exchange optical pumping of (3)He. We describe the performance of the analyser along with a study of the (3)He polarisation stability and its implications for SESANS measurements. Scattering from silica Stöber particles is investigated and agrees with samples run on similar instruments.
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Affiliation(s)
- S R Parnell
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - A L Washington
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - K Li
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - H Yan
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - P Stonaha
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - F Li
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - T Wang
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - A Walsh
- Department of Chemistry, The University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - W C Chen
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - A J Parnell
- Department of Physics and Astronomy, The University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - J P A Fairclough
- Department of Mechanical Engineering, The University of Sheffield, Sheffield S1 3DJ, United Kingdom
| | - D V Baxter
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - W M Snow
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - R Pynn
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
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Ashkar R, Pynn R, Dalgliesh R, Lavrik NV, Kravchenko II. A new approach for probing matter in periodic nanoconfinements using neutron scattering. J Appl Crystallogr 2014. [DOI: 10.1107/s1600576714013387] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The efficacy of spin-echo small-angle neutron scattering (SESANS) combined with an exact dynamical theory (DT) model in resolving the arrangement of spherical colloidal particles in planar confinements, such as the channels of a rectangular diffraction grating, is reported. SESANS data obtained with a suspension of charge-stabilized 180 nm silica particles in contact with a silicon diffraction grating, with ∼650 nm-wide channels, show clear deviations from the signal expected from a homogenous distribution of the suspension. DT fits to the data indicate that the colloidal particles are almost twice as concentrated in the channels as they are in the neighboring bulk suspension, consistent with a structure in which the particles are arranged in close-packed sheets parallel to the walls of the confining channels.
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