Diamond Analytics

Orem, UT, United States

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Orem, UT, United States
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Jensen D.S.,Brigham Young University | Kanyal S.S.,Brigham Young University | Madaan N.,Brigham Young University | Vail M.A.,Diamond Analytics | And 3 more authors.
Surface Science Spectra | Year: 2013

Silicon (100) substrates are ubiquitous in microfabrication and, accordingly, their surface characteristics are important. Herein, we report the analysis of Si (100) via X-ray photoelectron spectroscopy (XPS) using monochromatic Al Kα radiation. Survey scans show that the material is primarily silicon and oxygen with small amounts of carbon, nitrogen, and fluorine contamination. The Si 2p region shows two peaks that correspond to elemental silicon and silicon dioxide. Using these peaks the thickness of the native oxide (SiO2) is estimated using the equation of Strohmeier. The oxygen peak is symmetric. These silicon wafers are used as the substrate for subsequent growth of templated carbon nanotubes in the preparation of microfabricated thin layer chromatography plates. © 2013 American Vacuum Society.


Jensen D.S.,Brigham Young University | Kanyal S.S.,Brigham Young University | Madaan N.,Brigham Young University | Hancock J.M.,Brigham Young University | And 7 more authors.
Surface and Interface Analysis | Year: 2013

We apply a suite of analytical tools to characterize materials created in the production of microfabricated thin layer chromatography plates. Techniques used include X-ray photoelectron spectroscopy (XPS), valence band spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS) in both positive and negative ion modes, Rutherford backscattering spectroscopy (RBS), and helium ion microscopy. Materials characterized include: the Si(100) substrate with native oxide: Si/SiO2, alumina (35 nm) deposited as a diffusion barrier on the Si/SiO2: Si/SiO2/Al2O3, iron (6 nm) thermally evaporated on the Al2O3: Si/SiO 2/Al2O3/Fe, the iron film annealed in H 2 to make Fe catalyst nanoparticles: Si/SiO2/Al 2O3/Fe(NP), and carbon nanotubes (CNTs) grown from the Fe nanoparticles: Si/SiO2/Al2O3/Fe(NP)/CNT. The Fe films and nanoparticles appear in an oxidized state. Some of the analyses of the CNTs/CNT forests appear to be unique: (i) the CNT forest appears to exhibit an interesting 'channeling' phenomenon by RBS, (ii) we observe an odd-even effect in the SIMS spectra of Cn- species for n = 1 - 6, with the n ≥ 6 ions showing a steady decrease in intensity, and (iii) valence band characterization of CNTs using X-radiation is reported. Initial analysis of the CNT forest by XPS shows that it is 100 at.% carbon. After one year, only ca. 0.25 at.% oxygen is observed. The information obtained from the combination of the different analytical tools provides a more complete understanding of our materials than a single technique, which is analogous to the story of 'The Blind Men and the Elephant'. The raw XPS and ToF-SIMS spectra from this study will be submitted to Surface Science Spectra for archiving. Copyright © 2013 John Wiley & Sons, Ltd.


Fekete S.,University of Geneva | Jensen D.S.,Diamond Analytics | Zukowski J.,Diamond Analytics | Guillarme D.,University of Geneva
Journal of Chromatography A | Year: 2015

In this study, reversed phase liquid chromatographic columns packed with superficially porous material made of a carbon core and nanodiamond-polymer shell were evaluated for the analytical characterization of proteins. The emphasis was put on the impact of pore size on the kinetic performance when analyzing large molecules. Three different types of columns possessing an average pore size of 120, 180, and 250. Å were thus evaluated. As expected, the peak capacities were improved with the 180 and above all the 250. Å pore size, while the kinetic performance achieved with the 120. Å were systematically lower.It was also shown that a trifluoroacetic acid (TFA) concentration of 0.3-0.5% was required when analyzing proteins, to achieve suitable peak shapes (limited broadening and tailing) with this material. Elevated temperature (>60. °C) is mandatory when analyzing proteins with silica-based stationary phases, but this was not the case with this particular column made with a carbon core and nanodiamond-polymer shell, since the peak capacities were not improved at high temperature. However, there was a need to increase mobile phase temperature in the range 70-90. °C when analyzing monoclonal antibodies (mAbs), to limit adsorption that often occur in RPLC with this specific class of biomolecules.Finally, the FLARE® wide-pore column was applied to real life samples of native, oxidative stressed and reduced therapeutic proteins as well as reduced, digested mAbs and antibody drug conjugates (ADCs), to highlight the possibilities offered by this column technology. © 2015 Elsevier B.V.


Jensen D.S.,Brigham Young University | Kanyal S.S.,Brigham Young University | Gupta V.,Brigham Young University | Vail M.A.,Diamond Analytics | And 5 more authors.
Journal of Chromatography A | Year: 2012

Some of us recently described the fabrication of thin layer chromatography (TLC) plates from patterned carbon nanotube (CNT) forests via direct infiltration/coating of the CNTs by low pressure chemical vapor deposition (LPCVD) of silicon from SiH4, followed by high temperature oxidation of the CNTs and Si. Herein we present an improved microfabrication process for the preparation of these TLC plates. First, a few nanometers of carbon and/or a thin film of Al2O3 is deposited on the CNTs. This method of priming the CNTs for subsequent depositions appears to be new. X-ray photoelectron spectroscopy confirms the presence of additional oxygen after carbon deposition. After priming, the plates are coated by rapid, conformal deposition of an inorganic material that does not require subsequent oxidation, i.e., by a fast pseudo atomic layer deposition (ψ-ALD) of SiO2 from trimethylaluminum and tris(tert-butoxy)silanol. Unlike devices described previously, faithful reproduction of the features in the masks is still observed after oxidation. A bonded, amino phase on the resulting plates shows fast, highly efficient separations of fluorescent dyes (plate heights in the range of 1.6-7.7μm). Extensive characterization of the new materials by TEM, SEM, EDAX, DRIFT, and XPS is reported. A substantially lower process temperature for the removal of the CNT scaffold is possible as a result of the already oxidized materials used. © 2012 Elsevier B.V.


Jensen D.S.,Brigham Young University | Kanyal S.S.,Brigham Young University | Madaan N.,Brigham Young University | Vail M.A.,Diamond Analytics | And 3 more authors.
Surface Science Spectra | Year: 2013

Carbon nanotubes (CNTs) have unique chemical and physical properties. Herein, we report an XPS analysis of a forest of multiwalled CNTs using monochromatic Al Kα radiation. Survey scans show essentially only one element here: carbon. The carbon 1s peak is centered at 284.5 eV. The C 1s envelope also shows the expected π→π* shake-up peak at ca. 291 eV. The valence band and carbon KVV Auger signals are presented. When patterned, the CNT forests can be used as a template for subsequent deposition of metal oxides to make thin layer chromatography plates. © 2013 American Vacuum Society.


Kanyal S.S.,Brigham Young University | Jensen D.S.,Diamond Analytics | Zhu Z.,Pacific Northwest National Laboratory | Linford M.R.,Brigham Young University
Surface Science Spectra | Year: 2015

The authors report the positive and negative ion time-of-flight secondary ion mass spectrometry spectra obtained with Bi3 2+ primary ions at 50keV of an Fe film annealed in hydrogen at 750°C to form Fe nanoparticles. This surface had been exposed to the air; it had previously been shown by x-ray photoemission spectroscopy to be entirely oxidized. The strongest signal in the positive ion spectrum corresponded to Fe+, with FexOyHz + species also present. A substantial Al+ signal was observed due to exposure of the underlying alumina substrate. The negative ion spectrum showed O-, OH-, and AlO-. © 2015 American Vacuum Society.


Kanyal S.S.,Brigham Young University | Jensen D.S.,Diamond Analytics | Zhu Z.,Pacific Northwest National Laboratory | Linford M.R.,Brigham Young University
Surface Science Spectra | Year: 2015

The authors report the positive and negative ion time-of-flight secondary ion mass spectrometry characterization of a thin film of e-beam evaporated alumina on a silicon substrate using Bi3 ++ primary ions at 50 keV, where this film prevents poisoning of a Fe catalyst in carbon nanotube growth. The positive ion spectrum showed a strong Al+ signal, while the negative ion spectrum showed strong peaks due to AlO-, AlO2 -, AlO3H2 -, and OH-. © 2015 American Vacuum Society.


Kanyal S.S.,Brigham Young University | Jensen D.S.,Diamond Analytics | Zhu Z.,Pacific Northwest National Laboratory | Linford M.R.,Brigham Young University
Surface Science Spectra | Year: 2015

The authors report the positive and negative ion time-of-flight secondary ion mass spectrometry spectra using Bi32+ primary ions at 50 keV of an Fe film (6 nm) that had been thermally evaporated on a thin film of alumina (ca. 35 nm) on a silicon wafer. This surface had been exposed to the air; it had previously been shown by x-ray photoemission spectroscopy (XPS) to be entirely oxidized. The positive ion secondary ion mass spectrometry spectrum shows Fe+, FeH+, and FexOyHz+ species. The negative ion spectrum shows FeOH-, FexOyHz-, and OH- species. © 2015 American Vacuum Society.


PubMed | University of Geneva and Diamond Analytics
Type: | Journal: Journal of chromatography. A | Year: 2015

In this study, reversed phase liquid chromatographic columns packed with superficially porous material made of a carbon core and nanodiamond-polymer shell were evaluated for the analytical characterization of proteins. The emphasis was put on the impact of pore size on the kinetic performance when analyzing large molecules. Three different types of columns possessing an average pore size of 120, 180, and 250 were thus evaluated. As expected, the peak capacities were improved with the 180 and above all the 250 pore size, while the kinetic performance achieved with the 120 were systematically lower. It was also shown that a trifluoroacetic acid (TFA) concentration of 0.3-0.5% was required when analyzing proteins, to achieve suitable peak shapes (limited broadening and tailing) with this material. Elevated temperature (>60C) is mandatory when analyzing proteins with silica-based stationary phases, but this was not the case with this particular column made with a carbon core and nanodiamond-polymer shell, since the peak capacities were not improved at high temperature. However, there was a need to increase mobile phase temperature in the range 70-90C when analyzing monoclonal antibodies (mAbs), to limit adsorption that often occur in RPLC with this specific class of biomolecules. Finally, the FLARE() wide-pore column was applied to real life samples of native, oxidative stressed and reduced therapeutic proteins as well as reduced, digested mAbs and antibody drug conjugates (ADCs), to highlight the possibilities offered by this column technology.


PubMed | Advanced Abrasives Corporation, Diamond Analytics and Brigham Young University
Type: Journal Article | Journal: Analytical and bioanalytical chemistry | Year: 2016

Here, we report the most comprehensive characterization of nanodiamonds (NDs) yet undertaken. Five different samples from three different vendors were analyzed by a suite of analytical techniques, including X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), inductively coupled plasma mass spectrometry (ICP-MS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), Brunauer-Emmett-Teller (BET) surface area measurements, and particle size distribution (PSD) measurements. XPS revealed the elemental compositions of the ND surfaces (83-87 at.% carbon and 12-14 at.% oxygen) with varying amounts of nitrogen (0.4-1.8 at.%), silicon (0.1-0.7 at.%), and tungsten (0.3 at.% only in samples from one vendor). ToF-SIMS and ICP showed metal impurities (Al, Fe, Ni, Cr, etc. with unexpectedly high amounts of W in one vendors samples: ca. 900 ppm). Principal component analyses were performed on the ToF-SIMS and ICP data. DRIFT showed key functional groups (-OH, C=O, C-O, and C=C). BET showed surface areas of 50-214 m(2)/g. XRD and TEM revealed PSD (bimodal distribution and a wide PSD, 5-100 nm, for one vendors samples). XRD also provided particle sizes (2.7-27 nm) and showed the presence of graphite. EELS gave the sp(2)/sp(3) contents of the materials (37-88% sp(3)). PSD measurements were performed via differential sedimentation of the particles (mean particle size ca. 17-50 nm). This comprehensive understanding should allow for improved construction of nanodiamond-based materials.

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