Browsing by Author "Rehm, C"

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    2nd Asia-Oceania Instrument Scientist Workshops, Manly, July 19, 2015
    (Taylor & Francis Online, 2015-11-17) Hester, JR; Holt, SA; Imperia, P; Piltz, RO; Rehm, C; Rule, KC; Mole, RA; McIntyre, GJ
    No abstract available
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    About the versatility of the state-of-the-art USANS instrument Kokkaburra
    (International Conference on Neutron Scattering, 2017-07-12) Rehm, C; de Campo, L
    Being opened for external users in 2014 the ultra-small-angle neutron scattering (USANS) instrument KOOKABURRA has since then proven to be a state-of-the-art instrument for the determination of large-scale structures. In our contribution we will discuss the instrument layout and highlight its performance as evidenced by successful USANS experiments on a variety of sample materials like, e.g., sulfide ore minerals, opals, and other complex systems.
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    Challenges of kinetic measurements with a Bonse-Hart neutron diffractometer
    (International Conference on Neutron Scattering, 2017-07-12) Garvey, CJ; de Campo, L; Rehm, C; Muzny, CD; Hanley, HJM
    Here we report on kinetic studies of the structural effects of applied shear on the gelation of silica using the Bonse-Hart type double crystal diffractometer (USANS) Kookaburra (ANSTO, Lucas Heights Australia). This instrument is able to cover a range of scattering vectors, 2.8 x 10-5 Å-1 < q < 4x 10-2 Å-1. The gelation process may be viewed structurally as the aggregation of sol particles into larger fractal aggregates, which then form a percolative network (final gel). In previous SANS work, it was shown that shear interrupted the formation of the network, inducing a new, shear dependent structure where there are structural changes on the micron length scale. Here we use USANS to understand the structural pathway that the gel follows to the steady shear state. USANS measurements are made point by point with each rotation step of the analyzer crystal (rocking curve), with counting statistics aimed at resolving a signal above the background. To gather a comprehensive rocking curve, a single measurement will take of the order of hours, putting the ability to cover interesting kinetics beyond the realm of an ordinary beamtime allocation. Here, USANS measurements were made on the gelling system, where each measurement consists of a restricted number of points in the rocking curve, with points selected according to their ability to characterize the intermediate structure.
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    Characterization of porosity in sulfide ore minerals: a USANS/SANS study
    (GeoScience World, 2014-11-18) Xia, F; Zhao, J; Etschmann, BE; Brugger, J; Garvey, CJ; Rehm, C; Lemmel, H; Ilavsky, J; Han, YS; Pring, A
    Porosity plays a key role in the formation and alteration of sulfide ore minerals, yet our knowledge of the nature and formation of the residual pores is very limited. Herein, we report the application of ultra-small-angle neutron scattering and small-angle neutron scattering (USANS/SANS) to assess the porosity in five natural sulfide minerals (violarite, marcasite, pyrite, chalcopyrite, and bornite) possibly formed by hydrothermal mineral replacement reactions and two synthetic sulfide minerals (violarite and marcasite) prepared experimentally by mimicking natural hydrothermal conditions. USANS/SANS data showed very different pore size distributions for these minerals. Natural violarite and marcasite tend to possess less pores in the small size range (<100 nm) compared with their synthetic counterparts. This phenomenon is consistent with a higher degree of pore healing or diagenetic compaction experienced by the natural violarite and marcasite. Surprisingly, nanometer-sized (<20 nm) pores were revealed for a natural pyrite cube from La Rioga, Spain, and the sample has a pore volume fraction of ~7.7%. Both chalcopyrite and bornite from the massive sulfide assemblage of the Olympic Dam deposit in Roxby Downs, South Australia, were found to be porous with a similar pore volume fraction (~15%), but chalcopyrite tends to have a higher proportion of nanometer-size pores centered at ~4 nm while bornite tends to have a broader pore size distribution. The specific surface area is generally low for these minerals ranging from 0.94 to 6.28 m2/g, and the surfaces are generally rough as surface fractal behavior was observed for all these minerals. This investigation has demonstrated that USANS/SANS is a very useful tool for analyzing porosity in ore minerals. We believe that with this quantified porosity information a deeper understanding of the complex fluid flow behavior within the porous minerals can be expected. © 2014, Mineralogical Society of America.
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    Crystallographic characterization of fluorapatite glass-ceramics synthesized from industrial waste
    (Cambridge University Press, 2017-09-15) Loy, CW; Matori, KA; Zainuddin, N; Whitten, AE; Rehm, C; de Campo, L; Sokolova, AV; Schmid, S
    A series of phase transformations of a novel fluoroaluminosilicate glass forming a range of fluorapatite glass-ceramics on sintering are reported. The sintering process induces formation of fluorapatite, mullite, and anorthite phases within the amorphous silicate matrices of the glass-ceramics. The fluoroaluminosilicate glass, SiO2–Al2O3–P2O5–CaO–CaF2, is prepared from waste materials, such as rice husk ash, pacific oyster shells, and disposable aluminium cans. The thermally induced crystallographic and microstructure evolution of the fluoroaluminosilicate glass towards the fluorapatite glass-ceramics, with applications in dental and bone restoration, are investigated by powder X-ray diffraction and small-angle neutron-scattering techniques. © Cambridge University Press.
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    DCD USANS and SESANS: a comparison of two neutron scattering techniques applicable for the study of large-scale structures
    (Wiley-Blackwell, 2013-04-01) Rehm, C; Barker, J; Bouwman, WG; Pynn, R
    This paper provides a comparison of the capabilities of two techniques for extending the range of conventional small-angle neutron scattering (SANS) towards the micrometre length scale, namely the double-crystal diffraction ultra-small-angle neutron scattering (DCD USANS) technique, which uses perfect silicon crystals in Bragg reflection, and spin-echo SANS (SESANS), a method that uses the spin precessions of a polarized neutron beam. Both methods encode the scattering angle to very high precision. Based on round-robin test measurements, the strengths and weaknesses of the two techniques are discussed with respect to the measurement of the particle size of monodisperse scatterers, and potential performance gains for state-of-the-art DCD USANS and SESANS instruments are investigated. © 2013, Wiley-Blackwell.
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    H2O/D2O contrast variation for ultra-small-angle neutron scattering to minimize multiple scattering effects of colloidal particle suspensions
    (MDPI, 2018-09-07) Otsuki, A; de Campo, L; Garvey, CJ; Rehm, C
    This study investigated the use of solvent contrast (H2O/D2O ratio) as a means to optimize the ultra-small-angle neutron scattering (USANS) signal. By optimizing the signal, it was possible to reduce the undesirable effects of coherent multiple scattering while still maintaining a measurable scattered intensity. This result will further enable the use of USANS as a probe of the interactions between colloidal particles and their structures within concentrated suspensions as well as particle dispersion/aggregation. As a model system, we prepared silica colloidal particle suspensions at different solid concentrations. USANS curves were measured using the classical Bonse–Hart double crystal diffractometer while varying the scattering length density of the aqueous phase, thus varying the contrast to the silica particles. As a means of assessing the impact of multiple scattering effects on different q-values, we analyzed the scattered intensity at different contrasts at three different q values. The data were then used to determine the match point of the silica particle suspensions from the expected square root dependence of the scattered intensity with solvent composition, to analyze any differences associated with the solid concentration change, and to determine the optimum H2O/D2O ratio in terms of high transmission (TSAS > 80%) and high enough scattering intensity associated with the contrast of the system. Through this investigation series, we confirmed that adjusting the contrast of the solvent (H2O/D2O) is a good methodology to reduce multiple scattering while maintaining a strong enough scattering signal from a concentrated suspension of silica particles for both USANS and rheometric USANS (rheo-USANS) experiments.© The Authors - This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
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    Hierarchical architecture of cellulose and its interaction with other plant cell wall polysaccharides
    (Australian Institute of Nuclear Science and Engineering (AINSE), 2018-11-18) Martínez-Sanz, M; Lopez-Sanchez, P; Mikkelsen, D; Flanagan, BM; Gidley, MJ; de Campo, L; Rehm, C; Gilbert, EP
    Plant cell walls (PCWs) are extremely complex structures in which cellulose microfibrils are hier archically assembled and embedded in a multi-component matrix. While the cellulose microfibrils represent the basic building unit providing mechanical strength [1], the matrix components are able to tune the properties of each specific tissue [2-3], increasing the flexibility or limiting the transport of moisture, for instance. The synthesis of cellulose hydrogels by means of bacterial fermentation is an efficient approach to mimic the cell wall biosynthesis process and investigate the interactions established between cellu lose and matrix polysaccharides by incorporating the latter into the culture medium. We have char acterised cellulose hydrogels and their composites with PCW polysaccharides by means of SANS and SAXS, combined with complementary techniques such as X-ray diffraction, spectroscopy and microscopy. Furthermore, the production of partially deuterated cellulose hydrogels by using a deuterated glucose-based feedstock is presented as a strategy to enhance the neutron scattering length density contrast [4]. The application of a multi-technique characterisation approach enabled elucidation of the complex hierarchical architecture of cellulose hydrogels and led to the development of a multi-scale model based on core-shell structures [4-8]. The model describes the multi-phase structure of cellulose microfibrils and ribbons, as well as the essential role of water at the different structural levels. In addition, USANS experiments are presented as a promising method to characterise the structure of native cellulose in the longitudinal direction, providing information on the microfibril length and ribbon twisting periodicity. PCW polysaccharides such as xyloglucan, arabinoxylan, mixed linkage glucans and pectins during cellulose synthesis have a distinct structural role and interaction mechanism with cellulose (interfering with the crystallisation process and strongly interacting with the cellulose microfibrils, or establishing interactions at the ribbons’ surface level). These results highlight the ability of small angle scattering techniques to provide valuable insights on cellulose biosynthesis and interactions with PCW polysaccharides. © The Authors.
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    Ionic liquid based nanoparticle emulsions as a corrosion inhibitor
    (Australian Institute of Nuclear Science and Engineering, 2016-11-29) Mata, JP; Taghavikish, M; Subianto, S; Dutta, NK; de Campo, L; Rehm, C; Choudhury, NR
    In this contribution, we report the facile preparation of cross-linked polymerizable ionic liquid (PIL)-based nanoparticles via thiol–ene photopolymerization in a miniemulsion. The synthesized PIL nanoparticles with a diameter of about 200 nm were fully characterized with regard to their chemical structures, morphologies, and properties using different techniques, such as Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy [1]. To gain an in-depth understanding of the physical and morphological structures of the PIL nanoparticles in an emulsion, small angle neutron scattering and ultra-small-angle neutron scattering were used. Neutron scattering studies revealed valuable information regarding the formation of cylindrical ionic micelles in the spherical nanoparticles, which is a unique property of this system. Furthermore, the PIL nanoparticle emulsion was utilized as an inhibitor in a self-assembled nanophase particle (SNAP) coating. The corrosion protection ability of the resultant coating was examined using potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that the PIL nanoparticle emulsion in the SNAP coating acts as an inhibitor of corrosion and is promising for fabricating advanced coatings with improved barrier function and corrosion protection [1].
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    Ionic liquid based nanoparticle emulsions as a corrosion inhibitor
    (International Conference on Neutron Scattering, 2017-07-12) Mata, JP; Taghavikish, M; Subianto, S; Dutta, NK; de Campo, L; Rehm, C; Choudhury, NR
    In this contribution, we report the facile preparation of cross-linked polymerizable ionic liquid (PIL)-based nanoparticles via thiol–ene photopolymerization in aminiemulsion. The synthesized PIL nanoparticles with a diameter of about 200 nmwere fully characterized with regard to their chemical structures, morphologies, and properties using different techniques, such as Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electronmicroscopy, and transmission electron microscopy [1]. To gain an in-depth understanding of the physical and morphological structures of the PIL nanoparticles in an emulsion, small-angle neutron scattering and ultra-small-angle neutron scattering were used. Neutron scattering studies revealed valuable information regarding the formation of cylindrical ionic micelles in the spherical nanoparticles, which is a unique property of this system. Furthermore, the PIL nanoparticle emulsion was utilized as an inhibitorin a self-assembled nanophase particle (SNAP) coating. The corrosion protectionability of the resultant coating was examined using potentio dynamic polarization and electrochemical impedance spectroscopy. The results show that the PIL nanoparticle emulsion in the SNAP coating acts as an inhibitor of corrosion and is promising for fabricating advanced coatings with improved barrier function and corrosion protection [1].
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    Kookaburra, the ultra-small-angle neutron scattering instrument at ANSTO: design and recent applications
    (Australian Nuclear Science and Technology Organisation, 2021-11-25) Mata, JP; de Campo, L; Rehm, C
    The double-crystal ultra-small-angle neutron scattering (USANS) diffractometer KOOKABURRA at ANSTO was made available for user experiments in 2014. KOOKABURRA allows the characterisation of microstructures covering length scales in the range of 0.1–20 µm. Use of the first- and second-order reflections coming off a doubly curved highly oriented mosaic pyrolytic graphite pre-monochromator at a fixed Bragg angle, in conjunction with two interchangeable pairs of Si(111) and Si(311) quintuple-reflection channel-cut crystals, permits operation of the instrument at two individual wavelengths, 4.74 and 2.37 Å (see more details https://www.ansto.gov.au/our-facilities/australian-centre-for-neutron-scattering/neutron-scattering-instruments/kookaburra). This unique feature among reactor-based USANS instruments allows optimal accommodation of a broad range of samples, both weakly and strongly scattering, in one sample setup [1,2]. The versatility and capabilities of KOOKABURRA have already resulted in a number of research papers, including studies on hard matter systems like rocks and coal [3,4], as well as soft matter systems like hydrogels or milk [5,6]. This clearly demonstrates that this instrument has a major impact in the field of large-scale structure determination. Some of the recent examples will be presented here. References: [1] Rehm, C. et al, J. Appl. Cryst., 2013, 46 1699-1704. [2] Rehm, C. et al, J. Appl. Cryst., 2018, 51, 1-8. [3] Blach, T. et al, Journal of Coal Geology, 2018, 186, 135-144. [4] Sakurovs, R.et al, Energy & Fuels, 2017, 31(1), 231-238. [5] Whittaker, J. et al, Int. J. Biol. Macromol., 2018, 114, 998-1007. [6] Li, Z. et al, Food Hydrocolloid, 2018, 79, 170-178.
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    KOOKABURRA: the ultra-small-angle neutron scattering instrument at OPAL
    (Wiley-Blackwell, 2013-12-01) Rehm, C; Brûlé, A; Freund, AK; Kennedy, SJ
    The new double crystal ultra-small-angle neutron scattering instrument Kookaburra, currently under construction at the ANSTO OPAL reactor, will allow characterization of microstructures covering length scales in the range of 0.1 to 10 microm. Using the 002 and 004 reflections of a doubly curved mosaic highly oriented pyrolytic graphite premonochromator crystal at a fixed Bragg angle of 45degrees in conjunction with two pairs of Si(111) and Si(311) quintuple-reflection channel-cut crystals will allow operation of the instrument at two different wavelengths, thus optimally accommodating weakly and strongly scattering samples in one sample position. The versatility, the estimated neutron fluxes and the low background noise of Kookaburra suggest that this state-of-the-art instrument will have a major impact in the field of large-scale structure determination. © 2013, Wiley-Blackwell.
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    Large-scale structure investigations via neutron scattering techniques
    (Australian Institute of Nuclear Science and Engineering, 2016-11-29) Rehm, C; de Campo, L
    Modern materials science and engineering relies increasingly on detailed knowledge of the microstructure and interactions in soft and hard materials. Contemporary research areas comprise, e.g., biology and the life sciences, porosity, particle sizes as well as complex fluids. At the Australian Nuclear Science and Technology Organisation (ANSTO) we apply small-angle neutron scattering (SANS) as a major technique for probing structures and interfaces of bulk samples of such substances on length scales ranging between approximately 0.001 um and 1 um using the QUOKKA [1] instrument, whereas the ultra small-angle neutron scattering (USANS) instrument KOOKABURRA [2] advances large scale structure determination of complex systems of interest in the size range of 0.1 um to 10 um. Both techniques provide information on bulk properties with minimum sample preparation, and can be used to analyse material in a non-destructive manner. This presentation will discuss SANS and USANS techniques available at ANSTO for the study of large-scale structures, and present combined SANS/USANS data sets measured on selected samples.
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    Liquid crystals with hierarchical ordering
    (International Conference on Neutron Scattering, 2017-07-12) de Campo, L; Moghaddam, M; Sokolova, AV; Rehm, C; Mittelbach, R; Varslot, T; Castle, T; Garvey, CJ; Kirby, N; Hyde, ST
    We present liquid crystal geometries experimentally found for star-polyphilic molecules as the basic building block. Star-polyphiles are small molecules, bearing three mutually immiscible chains attached to a common center [1,2,3]. Like conventional lipids or surfactants (that usually have two immisciblechains), such molecules self-assemble to form lamellar, hexagonal, micellar cubic and bicontinuous cubic structures. However, the presence of the third immiscible chain significantly increases structural complexity and hierarchical ordering can occur.
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    Microstructural evolution of dental glass-ionomer cements during setting reaction followed using SANS and USANS
    (International Conference on Neutron Scattering, 2017-07-12) Loy, CW; Matori, KA; Zainuddin, N; Whitten, AE; Rehm, C; de Campo, L; Schmid, S
    Glass-ionomer cement (GIC) is a biocompatible material which is clinically used for dental filling. The main challenges for further developing GIC in dental applications are improving the mechanical strength and controlling the setting reaction. During the setting reaction, poly (acrylic acid) attacks the fluoroaluminosilicate glass particles to form a siliceous hydrogel layer, glass core and polyalkenoate matrix in paste form. The siliceous hydrogel layer undergoes dehydration to yield a strong cross-linkage to bind both polymer and glass particles into a cement structure. This study presents the application of small angle neutron scattering (SANS) and ultra small angle neutron scattering (USANS) with contrast variation techniques to study the microstructure evolution of a complex GIC paste during 48 hours of the setting reaction. A few GIC pastes are prepared from medical grade poly (acrylic acid), SiO2–Al2O3–P2O5–Na2O–CaO–CaF2-based fluoroaluminosilicate glasses and a mixture of H2O:D2O solvent following the ISO9917-1:2007 cement preparation method. The combination of SANS (Bilby@ACNS) and USANS (Kookaburra@ACNS) provides microstructure information of GIC paste over the length scale of 1 nm to 10 µm. The microstructure change of each phase in GIC pastes is investigated at different contrast conditions by varying the H2O:D2O ratio for both neutron scattering experiments. The macro- and nano-scale features of the polymer-glass-hydrogel phases in GIC paste during the setting reaction as well as their impact on mechanical strengths are presented in this study.
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    Phase space optimisation of the USANS instrument Kookaburra at the ANSTO OPAL reactor
    (Elsevier, 2011-04-01) Freund, AK; Rehm, C
    An optimisation of the USANS instrument Kookaburra has been conducted determining the most efficient type of premonochromator crystal and scattering geometry. The approach has been based on representations in phase space combining direct and reciprocal space diagrams. Results are presented for several scenarios involving flat and curved, perfect and mosaic crystals, horizontal and vertical scattering planes. The highest peak current density of 1.7 x 10(5) cm(-2) s(-1) is provided for a wavelength of 4.43 angstrom by a doubly curved pyrolytic graphite premonochromator diffracting in a horizontal plane and producing a beam size of about 50 cm(2) at the sample position. The smallest background is achieved for a wavelength of 2.56 angstrom and a vertical scattering plane using a bent perfect premonochromator crystal and optionally a collimator to decrease the divergence of the beam exiting the cold neutron guide. For this wavelength a peak current density of 6.6 x 10(4) cm(-2) s(-1) is collected into a sample area of 10 cm(2). The bent perfect crystal design is of particular advantage for small samples. (C) 2010 Elsevier B.V.
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    Polymeric ionic liquid nanoparticle emulsions as a corrosion inhibitor in anticorrosion coatings
    (American Chemical Society, 2016-07-06) Taghavikish, M; Subianto, S; Dutta, NK; de Campo, L; Mata, JP; Rehm, C; Choudhury, NR
    In this contribution, we report the facile preparation of cross-linked polymerizable ionic liquid (PIL)-based nanoparticles via thiol–ene photopolymerization in a miniemulsion. The synthesized PIL nanoparticles with a diameter of about 200 nm were fully characterized with regard to their chemical structures, morphologies, and properties using different techniques, such as Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. To gain an in-depth understanding of the physical and morphological structures of the PIL nanoparticles in an emulsion, small-angle neutron scattering and ultra-small-angle neutron scattering were used. Neutron scattering studies revealed valuable information regarding the formation of cylindrical ionic micelles in the spherical nanoparticles, which is a unique property of this system. Furthermore, the PIL nanoparticle emulsion was utilized as an inhibitor in a self-assembled nanophase particle (SNAP) coating. The corrosion protection ability of the resultant coating was examined using potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that the PIL nanoparticle emulsion in the SNAP coating acts as an inhibitor of corrosion and is promising for fabricating advanced coatings with improved barrier function and corrosion protection. Open Access © 2016 American Chemical Society
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    Pushing small-angle neutron scattering at OPAL to smaller Q
    (Australian Institute of Physics, 2008-01-30) Rehm, C
    The Bragg Institute at ANSTO plans to install a low-Q neutron scattering instrument at the newly built research reactor OPAL. Such instrument will extend the Q-range of the already existing SANS instrument Quokka by two orders of magnitude. At a recently held workshop two options for the new instrument were identified: the classical Crystal-USANS method and the newer Spin-Echo SANS technique.
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    Structural evolution of photocrosslinked silk fibroin and silk fibroin-based hybrid hydrogels: a small angle and ultra-small angle scattering investigation
    (Elsevier, 2018-07-15) Whittaker, JL; Balu, R; Knott, RB; de Campo, L; Mata, JP; Rehm, C; Hill, AJ; Dutta, NK; Choudhury, NR
    Regenerated Bombyx mori silk fibroin (RSF) is a widely recognized protein for biomedical applications; however, its hierarchical gel structure is poorly understood. In this paper, the hierarchical structure of photocrosslinked RSF and RSF-based hybrid hydrogel systems: (i) RSF/Rec1-resilin and (ii) RSF/poly(N-vinylcaprolactam (PVCL) is reported for the first time using small-angle scattering (SAS) techniques. The structure of RSF in dilute to concentrated solution to fabricated hydrogels were characterized using small angle X-ray scattering (SAXS), small angle neutron scattering (SANS) and ultra-small angle neutron scattering (USANS) techniques. The RSF hydrogel exhibited three distinctive structural characteristics: (i) a Porod region in the length scale of 2 to 3 nm due to hydrophobic domains (containing β-sheets) which exhibits sharp interfaces with the amorphous matrix of the hydrogel and the solvent, (ii) a Guinier region in the length scale of 4 to 20 nm due to hydrophilic domains (containing turns and random coil), and (iii) a Porod-like region in the length scale of few micrometers due to water pores/channels exhibiting fractal-like characteristics. Addition of Rec1-resilin or PVCL to RSF and subsequent crosslinking systematically increased the nanoscale size of hydrophobic and hydrophilic domains, whereas decreased the homogeneity of pore size distribution in the microscale. The presented results have implications on the fundamental understanding of the structure–property relationship of RSF-based hydrogels. © 2018 Elsevier B.V.
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    Structure evolution of nanodiamond aggregates: a SANS and USANS study
    (International Union of Crystallography, 2022-02-21) Kabir, II; Osborne, JC; Lu, W; Mata, JP; Rehm, C; Yeoh, GH; Erez, T
    Ultra-small-angle neutron scattering (USANS) and small-angle neutron scattering (SANS) measurements, covering length scales from micrometres to nanometres, were made to investigate the structure of nanodiamonds (NDs) and their suspensions. These nanodiamonds were produced by two different techniques, namely by the detonation method and by the laser ablation of a carbon-hydrocarbon mixture. The (U)SANS results indicated the presence of structures four orders of magnitude larger than the dimensions of a single ND particle, consisting of aggregations of ND particles. This aggregation of the ND particles was studied by employing the contrast variation technique. Two different solvents, namely H2O and dimethyl sulfoxide (and their deuterated counterparts), were used to understand the role of hydrogen in the shape and size of the aggregates. The analysis of experimental data from SANS measurements also reveals the ND particles to have an ellipsoidal structure. Using a defined shape model and the SANS contrast variation technique, it was possible to characterize the non-diamond outer shell of the particles and determine the outer layer thickness. This clarification of the structure of the NDs will allow better preparation of suspensions/samples for various applications. Understanding the structure of NDs at multiple length scales also provides crucial knowledge of particle-particle interaction and its effect on the aggregation structures. © International Union of Crystallography - Open Access CC BY licence.