An investigation into the corrosion of Ag coins from the Greek colonies of Southern Italy. Part I: An in situ FT-IR and ERS investigation of the behaviour of Ag in contact with aqueous solutions containing 4-cyanopyridine

The Circle® cell has made possible the quantitative analysis of samples by infrared spectroscopy in aqueous solutions. With the use of this technique, which makes use of an FT-IR spectrometer, a novel analytical method is presented for the quantitative determination of sulfur oxide anions in white liquor. The method is appropriate only for oxidized sulfur species. However, it is shown that when Na2S concentrations are determined by another technique (e.g., ion chromatography or ion-selective electrode), the results can be used to carry out material/species balance on the unoxidized as well as oxidized samples of white liquor. The method is fast, straightforward, and convenient to use, and it does not require further treatments of white liquor solutions. Another advantage of this method is that it lends itself to in situ analysis. It is also general enough to be used for the quantitative analysis of other aqueous solutions. Linear regressions carried out on the SO=4, S20=3, and SO=3 species (in concentration ranges of 0–70, 0–45, and 0–42 g/L as salts, respectively) led to correlation coefficients of higher than 0.99; respective minimum detection limits of 0.01, 0.02, and 0.02 g/L were obtained. The latter can be further improved upon by employing longer-pathlength crystals. The method provides a way of carrying out material species balances, and studying reactions and their kinetics. The process does not use any toxic materials or environmentally unfriendly bleaching agents; it makes use of a combination of temperature, pressure, and molecular oxygen to oxidize white liquor to sulfate.

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FT-IR microspectroscopic analysis of diseased white matter brain tissues

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141214 ◽

1995 ◽

Vol 53 ◽

pp. 968-969

Author(s):

Steven M. Le Vine ◽

David L. Wetzel

Keyword(s):

White Matter ◽

Gray Matter ◽

Twitcher Mouse ◽

Grid Pattern ◽

Marked Contrast ◽

Spatially Resolved ◽

Ft Ir ◽

Ir Microspectroscopy ◽

Chemical Evidence

In situ FT-IR microspectroscopy has allowed spatially resolved interrogation of different parts of brain tissue. In previous work the spectrrscopic features of normal barin tissue were characterized. The white matter, gray matter and basal ganglia were mapped from appropriate peak area measurements from spectra obtained in a grid pattern. Bands prevalent in white matter were mostly associated with the lipid. These included 2927 and 1469 cm-1 due to CH2 as well as carbonyl at 1740 cm-1. Also 1235 and 1085 cm-1 due to phospholipid and galactocerebroside, respectively (Figs 1and2). Localized chemical changes in the white matter as a result of white matter diseases have been studied. This involved the documentation of localized chemical evidence of demyelination in shiverer mice in which the spectra of white matter lacked the marked contrast between it and gray matter exhibited in the white matter of normal mice (Fig. 3).The twitcher mouse, a model of Krabbe’s desease, was also studied. The purpose in this case was to look for a localized build-up of psychosine in the white matter caused by deficiencies in the enzyme responsible for its breakdown under normal conditions.

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Enhanced Adsorption of Bisphenol A from Aqueous Solution with 2-Vinylpyridine Functionalized Magnetic Nanoparticles

Polymers ◽

10.3390/polym10101136 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1136 ◽

Cited By ~ 10

Author(s):

Qiang Li ◽

Fei Pan ◽

Wentao Li ◽

Dongya Li ◽

Haiming Xu ◽

...

Keyword(s):

Bisphenol A ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Magnetic Nanoparticle ◽

Maximum Adsorption Capacity ◽

Salting Out ◽

Functionalized Magnetic Nanoparticles ◽

Ft Ir ◽

Fe3o4 Nanospheres ◽

Enhanced Adsorption

In this study, a novel 2-vinylpyridine functionalized magnetic nanoparticle (Mag-PVP) was successfully prepared. The prepared Mag-PVP was characterized by transmission electronic microscopy (TEM), Fourier transform infrared spectrophotometry (FT-IR), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA), and was used for the adsorption of bisphenol A (BPA) from aqueous solutions. Mag-PVP, which is composed of Fe3O4 nanoparticles and poly divinylbenzene-2-vinylpyridine (with a thickness of 10 nm), exhibited magnetic properties (Ms = 44.6 emu/g) and thermal stability. The maximum adsorption capacity (Qm) of Mag-PVP for BPA obtained from the Langmuir isotherm was 115.87 mg/g at 20 °C, which was more than that of Fe3O4 nanospheres. In the presence of NaCl, the improved adsorption capacity of Mag-PVP was probably attributed to the screening effect of Mag-PVP surface charge and salting-out effect. In the presence of CaCl2 and humic acid (HA), the adsorption capacity of BPA decreased due to competitive adsorption. The adsorption of BPA by Mag-PVP increased slightly with the increase in pH from 3.0 to 5.0 and obtained the largest adsorption amount at pH 5.0, which was probably attributed to hydrogen bonding interactions. Moreover, in actual water, Mag-PVP still showed excellent adsorption performance in removing BPA. The high adsorption capacity and excellent reusability performance in this work indicated that Mag-PVP was an effective adsorbent for removing BPA from aqueous solutions.

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Experimental and Theoretical Studies of Sonically Prepared Cu–Y, Cu–USY and Cu–ZSM-5 Catalysts for SCR deNOx

Catalysts ◽

10.3390/catal11070824 ◽

2021 ◽

Vol 11 (7) ◽

pp. 824

Author(s):

Przemysław J. Jodłowski ◽

Izabela Czekaj ◽

Patrycja Stachurska ◽

Łukasz Kuterasiński ◽

Lucjan Chmielarz ◽

...

Keyword(s):

Ion Exchange ◽

Ultrasonic Irradiation ◽

Active Phase ◽

Spectroscopic Studies ◽

In Situ Drifts ◽

Ft Ir ◽

Diffuse Reflectance Infrared ◽

Experimental And Theoretical Studies

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).

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Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery

Polymers ◽

10.3390/polym13040533 ◽

2021 ◽

Vol 13 (4) ◽

pp. 533 ◽

Cited By ~ 1

Author(s):

Josué A. Torres-Ávalos ◽

Leonardo R. Cajero-Zul ◽

Milton Vázquez-Lepe ◽

Fernando A. López-Dellamary ◽

Antonio Martínez-Richa ◽

...

Keyword(s):

Carbon Nanotubes ◽

Drug Delivery ◽

Methacrylic Acid ◽

Butyl Acrylate ◽

Chemical Vapor ◽

Vis Spectroscopy ◽

Ir And Raman Spectroscopies ◽

Ft Ir

Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTsf) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam. Purified CNTs were analyzed by FE-SEM and HR-TEM. CNTsf contain acyl chloride groups attached to their surface. Purified and functionalized CNTs were studied by FT-IR and Raman spectroscopies. The synthesized nanocomposites were studied by XPS, 13C-NMR, and DSC. Anhydride groups link CNTsf to MAA–BA polymeric chains. The potentiality of the prepared nanocomposites, and of their pure polymer matrices to deliver hydrocortisone, was evaluated in vitro by UV–VIS spectroscopy. The relationship between the chemical structure of the synthesized nanocomposites, or their pure polymeric matrices, and their ability to release hydrocortisone was studied by FT-IR spectroscopy. The hydrocortisone release profile of some of the studied nanocomposites is driven by a change in the inter-associated to self-associated hydrogen bonds balance. The CNTsf used to prepare the studied nanocomposites act as hydrocortisone reservoirs.

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Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

New Journal of Chemistry ◽

10.1039/d1nj00717c ◽

2021 ◽

Author(s):

Liang Wang ◽

Peng Gao ◽

Mengxin Liu ◽

Ziqing Huang ◽

Shixia Lan ◽

...

Keyword(s):

Aqueous Solution ◽

Aqueous Solutions ◽

Adsorption Process ◽

In Situ Polymerization ◽

Selective Removal ◽

Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

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Electronic Structures of Crystalline and Aqueous Solutions of LiBr, NaBr, KBr, and KBrO3: In Situ Br L-Edge Near-edge X-ray Absorption Fine Structure

The Journal of Physical Chemistry B ◽

10.1021/jp0304327 ◽

2003 ◽

Vol 107 (46) ◽

pp. 12562-12565 ◽

Cited By ~ 5

Author(s):

Shuji Matsuo ◽

Ponnusamy Nachimuthu ◽

Dennis W. Lindle ◽

Hisanobu Wakita ◽

Rupert C. C. Perera

Keyword(s):

Fine Structure ◽

Aqueous Solutions ◽

Electronic Structures ◽

X Ray ◽

Absorption Fine ◽

X Ray Absorption

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Diffuse Reflectance FT-IR Characterization of Active Sites under Reaction Conditions: The Production of Oxygenates in the CO/H2 Reaction

Applied Spectroscopy ◽

10.1366/0003702944027345 ◽

1994 ◽

Vol 48 (10) ◽

pp. 1208-1212 ◽

Cited By ~ 7

Author(s):

J. J. Benítez ◽

I. Carrizosa ◽

J. A. Odriozola

Keyword(s):

Infrared Spectra ◽

Active Sites ◽

Diffuse Reflectance ◽

Reaction Conditions ◽

In Situ Drifts ◽

Ft Ir

The reactivity of a Lu2O3-promoted Rh/Al2O3 catalyst in the CO/H2 reaction is reported. Methane, heavier hydrocarbons, methanol, and ethanol are obtained. In situ DRIFTS has been employed to record the infrared spectra under the actual reaction conditions. The structure of the observed COads DRIFTS bands has been resolved into its components. The production of oxygenates (methanol and ethanol) has been correlated with the results of the deconvolution calculation. Specific sites for the production of methanol and ethanol in the CO/H2 reaction over a Rh,Lu2O3/Al2O3 catalyst are proposed.

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