A new form of hydroxyaluminum phthalocyanine by acid treatment. Characterization and photoactivity

1988 ◽  
Vol 66 (7) ◽  
pp. 1609-1616 ◽  
Author(s):  
LÊ H. Dao ◽  
Gérard Perrier ◽  
Kenneth Cole
Keyword(s):  
Acid Treatment ◽  
Near Infrared ◽  
Absorption Spectrometry ◽  
Acid Solutions ◽  
Solar Cell Device ◽  
Visible Absorption ◽  
X Ray ◽  
Photoelectrochemical Solar Cell ◽  
Aqueous Acid ◽  
New Form

A new polymorph of hydroxyaluminum phthalocyanine (PcAlOH) was obtained when PcAlOH thin film was exposed to aqueous acid solutions. The new polymorph, which is characterized by infrared, near-infrared, and visible absorption spectrometry and X-ray diffractometry, shows enhanced photoactivity in a photoelectrochemical solar cell device.

Ion-Exchange Paper—X-Ray Emission Procedure for Determination of Microgram Quantities of Mercury

1964 ◽  
Vol 47 (2) ◽  
pp. 391-394
Author(s):  
William B Link ◽  
Keith S Heine ◽  
J H Jones ◽  
Percy Wattlington
Keyword(s):  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Emission Spectroscopy ◽  
Barium Sulfate ◽  
Magnesium Stearate ◽  
Magnesium Carbonate ◽  
Acid Solutions ◽  
X Ray ◽  
Aqueous Acid

Abstract A method has been developed for determining 1 μg of mercury in 100 ml of aqueous acid solution with a precision of ± 0.25 μg. In the method, the mercury is adsorbed by anion resinloaded paper and determined by X-ray emission spectroscopy. The method gave 75—125% recoveries of 1 μg of mercury from acid solutions containing 10 g of sodium sulfate, sodium chloride, iron oxide, magnesium carbonate, and calcium carbonate, and satisfactory recoveries from the HCl extract of carbon, barium sulfate, chromic oxide, bentonite, kaolin, talc, titanium dioxide, and magnesium stearate. Substantial changes in flow rate or acid concentration seem to have little effect on mercury absorption from HC1 solution. Mercury in zinc oxide or bismuth oxychloride cannot be determined by this technique.

Redox-triggered reversible modulation of intense near-infrared and visible absorption using paddlewheel-type diruthenium(III) complex

2021 ◽  
Author(s):  
Yusuke Kataoka ◽  
Nanako Imasaki ◽  
Natsumi Yano ◽  
Minoru Mitsumi ◽  
Makoto Handa
Keyword(s):  
Single Crystal ◽  
Near Infrared ◽  
Visible Absorption ◽  
X Ray ◽  
Diruthenium Complex

A new paddlewheel-type diruthenium complex with 2-amino-3-(trifluoromethyl)pyridine (amtfmp) [Ru2(amtfmp)4Cl2] ([1]), which shows intense and characteristic near-infrared (NIR) and visible absorption, has been developed and structurally characterized by single crystal X-ray...

Preparation of a Reduced Layered Tungstic Acid HxW2O7 via Acid Treatment of Bi2W2O9 in the Presence of Sn2+ Ions

2007 ◽  
Vol 1056 ◽  
Author(s):  
Seiichi Tahara ◽  
Takakazu Minato ◽  
Nobuhiro Kumada ◽  
Shigenobu Hayashi ◽  
Yoshiyuki Sugahara
Keyword(s):  
Acid Treatment ◽  
Tungstic Acid ◽  
Visible Absorption Spectrum ◽  
Xps Analysis ◽  
Selective Leaching ◽  
X Ray Diffraction ◽  
Octahedral Structure ◽  
Visible Absorption ◽  
X Ray ◽  
Uv Visible

ABSTRACTA reduced layered tungstic acid with a double-octahedral structure was prepared by acid treatment of an Aurivillius-type Bi2W2O9 in the presence of Sn2+ ions. While the color of the product formed by acid treatment with no Sn2+ ions present, H2W2O7, was yellow, a blue powder was obtained after the acid treatment in the presence of Sn2+ ions. No notable change in the morphology was observed after acid treatment. The X-ray diffraction pattern of the product acid-treated in the presence of Sn2+ ions was very similar to that of H2W2O7. Essentially all the Bi3+ ions were lost upon acid treatment, indicating the occurrence of selective leaching of bismuth oxide sheets in Bi2W2O9. A UV-visible absorption spectrum and XPS analysis demonstrated that the W6+ ions were partially reduced to W5+ ions, and the number of protons in the product was correspondingly 2.4 per [W2O7]. These results suggest the successful formation of a reduced layered tungstic acid, H2.4W2O7.

scholarly journals Synthesis and Dual-Mode Electrochromism of Anisotropic Monoclinic Nb12O29 Colloidal Nanoplatelets

2020 ◽  
Author(s):  
Hsin-Che Lu ◽  
Sandeep Ghosh ◽  
Naman Katyal ◽  
Graeme Henkelman ◽  
Vikram S. Lankanpal ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Photoelectron Spectroscopy ◽  
Near Infrared ◽  
Colloidal Synthesis ◽  
Solar Modulation ◽  
Raman Signal ◽  
Dual Mode ◽  
Visible Absorption ◽  
X Ray ◽  
Ion Intercalation

<div>Transition metal oxide nanocrystals with dual-mode electrochromism hold promise for smart windows enabling spectrally selective solar modulation. We have developed the colloidal synthesis of anisotropic monoclinic Nb12O29 nanoplatelets (NPLs) to investigate the dual-mode electrochromism of niobium oxide nanocrystals. The precursor for synthesizing NPLs was prepared by mixing NbCl5 and oleic acid to form a complex that was subsequently heated to form an oxide-like structure capped by oleic acid, denoted as niobium oxo cluster. By initiating the synthesis using niobium oxo clusters, preferred growth of NPLs over other polymorphs was observed. The structure of the synthesized NPLs was examined by X-ray diffraction in conjunction with simulations, revealing that the NPLs are monolayer monoclinic Nb12O29, thin in the [100] direction and extended along the b and c directions. Besides having monolayer thickness, NPLs show decreased intensity of Raman signal from Nb-O bonds with higher bond order when compared to bulk monoclinic Nb12O29, as interpreted by calculations. Progressive electrochemical reduction of NPL films led to absorbance in the near-infrared region (stage 1) followed by absorbance in both the visible and near-infrared regions (stage 2), thus exhibiting dual-mode electrochromism. The mechanisms underlying these two processes were distinguished electrochemically by cyclic voltammetry to determine the extent to which ion intercalation limits the kinetics, and by verifying the presence of localized electrons following ion intercalation using X-ray photoelectron spectroscopy. Both results support that the near-infrared absorption results from capacitive charging and the onset of visible absorption in the second stage is caused by ion intercalation.</div>

scholarly journals Synthesis and Dual-Mode Electrochromism of Anisotropic Monoclinic Nb12O29 Colloidal Nanoplatelets

2020 ◽  
Author(s):  
Hsin-Che Lu ◽  
Sandeep Ghosh ◽  
Naman Katyal ◽  
Graeme Henkelman ◽  
Vikram S. Lankanpal ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Photoelectron Spectroscopy ◽  
Near Infrared ◽  
Colloidal Synthesis ◽  
Solar Modulation ◽  
Raman Signal ◽  
Dual Mode ◽  
Visible Absorption ◽  
X Ray ◽  
Ion Intercalation

<div>Transition metal oxide nanocrystals with dual-mode electrochromism hold promise for smart windows enabling spectrally selective solar modulation. We have developed the colloidal synthesis of anisotropic monoclinic Nb12O29 nanoplatelets (NPLs) to investigate the dual-mode electrochromism of niobium oxide nanocrystals. The precursor for synthesizing NPLs was prepared by mixing NbCl5 and oleic acid to form a complex that was subsequently heated to form an oxide-like structure capped by oleic acid, denoted as niobium oxo cluster. By initiating the synthesis using niobium oxo clusters, preferred growth of NPLs over other polymorphs was observed. The structure of the synthesized NPLs was examined by X-ray diffraction in conjunction with simulations, revealing that the NPLs are monolayer monoclinic Nb12O29, thin in the [100] direction and extended along the b and c directions. Besides having monolayer thickness, NPLs show decreased intensity of Raman signal from Nb-O bonds with higher bond order when compared to bulk monoclinic Nb12O29, as interpreted by calculations. Progressive electrochemical reduction of NPL films led to absorbance in the near-infrared region (stage 1) followed by absorbance in both the visible and near-infrared regions (stage 2), thus exhibiting dual-mode electrochromism. The mechanisms underlying these two processes were distinguished electrochemically by cyclic voltammetry to determine the extent to which ion intercalation limits the kinetics, and by verifying the presence of localized electrons following ion intercalation using X-ray photoelectron spectroscopy. Both results support that the near-infrared absorption results from capacitive charging and the onset of visible absorption in the second stage is caused by ion intercalation.</div>

scholarly journals NEAR-INFRARED AND X-RAY QUASI-PERIODIC OSCILLATIONS IN NUMERICAL MODELS OF Sgr A*

2012 ◽  
Vol 746 (1) ◽  
pp. L10 ◽  
Author(s):  
Joshua C. Dolence ◽  
Charles F. Gammie ◽  
Hotaka Shiokawa ◽  
Scott C. Noble
Keyword(s):  
Near Infrared ◽  
Numerical Models ◽  
Periodic Oscillations ◽  
X Ray ◽  
Sgr A

scholarly journals Electronic Structure of n-Cycloparaphenylenes Directly Observed by Photoemission Spectroscopy

2021 ◽  
Author(s):  
Kaname Kanai ◽  
Takuya Inoue ◽  
Takaya Furuichi ◽  
Kaito Shinoda ◽  
Takashi Iwahashi ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electronic Structures ◽  
Photoemission Spectroscopy ◽  
Cyclic Structure ◽  
Visible Absorption ◽  
X Ray ◽  
Inverse Photoemission

A series of n-cycloparaphenylenes ([n]CPP) were studied by ultraviolet photoemission, inverse photoemission, ultraviolet-visible absorption, and X-ray photoemission spectroscopy to detect their unique electronic structures. [n]CPP has a cyclic structure in...

scholarly journals Characterization and mapping of hematite ore mineral classes using hyperspectral remote sensing technique: a case study from Bailadila iron ore mining region

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ibrahim Shaik ◽  
S. K. Begum ◽  
P. V. Nagamani ◽  
Narayan Kayet
Keyword(s):  
Infrared Absorption ◽  
Near Infrared ◽  
Spectral Feature ◽  
Absorption Feature ◽  
X Ray ◽  
Remote Sensing Technique ◽  
Ore Minerals ◽  
Feature Fitting ◽  
Hematite Ore

AbstractThe study demonstrates a methodology for mapping various hematite ore classes based on their reflectance and absorption spectra, using Hyperion satellite imagery. Substantial validation is carried out, using the spectral feature fitting technique, with the field spectra measured over the Bailadila hill range in Chhattisgarh State in India. The results of the study showed a good correlation between the concentration of iron oxide with the depth of the near-infrared absorption feature (R2 = 0.843) and the width of the near-infrared absorption feature (R2 = 0.812) through different empirical models, with a root-mean-square error (RMSE) between < 0.317 and < 0.409. The overall accuracy of the study is 88.2% with a Kappa coefficient value of 0.81. Geochemical analysis and X-ray fluorescence (XRF) of field ore samples are performed to ensure different classes of hematite ore minerals. Results showed a high content of Fe > 60 wt% in most of the hematite ore samples, except banded hematite quartzite (BHQ) (< 47 wt%).

scholarly journals Coherence tomography with broad bandwidth extreme ultraviolet and soft X-ray radiation

2021 ◽  
Vol 127 (4) ◽  
Author(s):  
S. Skruszewicz ◽  
S. Fuchs ◽  
J. J. Abel ◽  
J. Nathanael ◽  
J. Reinhard ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Near Infrared ◽  
Extreme Ultraviolet ◽  
Infrared Light ◽  
Imaging Method ◽  
Optical Coherence ◽  
Axial Resolution ◽  
Cross Sectional ◽  
X Ray ◽  
Broad Bandwidth

AbstractWe present an overview of recent results on optical coherence tomography with the use of extreme ultraviolet and soft X-ray radiation (XCT). XCT is a cross-sectional imaging method that has emerged as a derivative of optical coherence tomography (OCT). In contrast to OCT, which typically uses near-infrared light, XCT utilizes broad bandwidth extreme ultraviolet (XUV) and soft X-ray (SXR) radiation (Fuchs et al in Sci Rep 6:20658, 2016). As in OCT, XCT’s axial resolution only scales with the coherence length of the light source. Thus, an axial resolution down to the nanometer range can be achieved. This is an improvement of up to three orders of magnitude in comparison to OCT. XCT measures the reflected spectrum in a common-path interferometric setup to retrieve the axial structure of nanometer-sized samples. The technique has been demonstrated with broad bandwidth XUV/SXR radiation from synchrotron facilities and recently with compact laboratory-based laser-driven sources. Axial resolutions down to 2.2 nm have been achieved experimentally. XCT has potential applications in three-dimensional imaging of silicon-based semiconductors, lithography masks, and layered structures like XUV mirrors and solar cells.

Evaluation of swelling properties and drug release from mechanochemical pre-gelatinized glutinous rice starch matrix tablets by near infrared spectroscopy

2021 ◽  
pp. 096703352098235
Author(s):  
Tomomi Takaku ◽  
Yusuke Hattori ◽  
Tetsuo Sasaki ◽  
Tomoaki Sakamoto ◽  
Makoto Otsuka
Keyword(s):  
Drug Release ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Matrix Tablets ◽  
Rice Starch ◽  
Release Time ◽  
Swelling Properties ◽  
X Ray ◽  
Glutinous Rice ◽  
Pharmaceutical Properties

The effect of grinding on the pharmaceutical properties of matrix tablets consisting of ground glutinous rice starch (GRS) and theophylline (TH) was predicted by near infrared (NIR) spectroscopy. Ground GRS samples were prepared by grinding GRS in a planetary ball mill for 0-120 min, measured by X-ray diffractometry (XRD) and NIR, and then evaluated for crystallinity (%XRD) based on XRD profiles. Tablets containing TH (5 w/w%), ground GRS (94 w/w%), and magnesium stearate (1 w/w%) were formed by compression. Gel-forming and drug-release processes of the tablets were measured using a dissolution instrument with X-ray computed tomography (XCT). Swelling ratio (SWE) and mean drug-release time (MDT) were evaluated based on XCT and drug-release profiles, respectively. Calibration models for predicting percent %XRD, MDT, and SWE were constructed based on the NIR of ground GRS using partial least-squares. The results indicated the possibility of controlling the pharmaceutical properties of matrix tablets by altering the pre-gelatinization of GRS based on changes in their NIR spectra during the milling process.

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