Infrared band intensities in ammonium hydroxide and ammonium salts*

Sethna, P. P.; Downing, Harry D.; Pinkley, Lary W.; Williams, D. Dudley

doi:10.1364/josa.68.000429

Cited by 12 publications

(9 citation statements)

References 7 publications

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“…The bands at 1629 cm –1 [1632 cm –1 ] in the CoFeNP [a-CoFeNP] spectrum can be assigned to the in-plane and out-of-plane bending vibration from the absorbed water (H–O) . For both samples, the band at 1400 cm –1 corresponds to the strong NH 4 + vibrations associated with the coprecipitation agent used during the synthesis . It is worthwhile to note the smaller ratio between the intensities of the NH 4 + and M–O characteristics peaks in the a-CoFeNP samples, which had been submitted to annealing.…”

Section: Resultsmentioning

confidence: 99%

“…38 For both samples, the band at 1400 cm −1 corresponds to the strong NH 4 + vibrations associated with the coprecipitation agent used during the synthesis. 39 It is worthwhile to note the smaller ratio between the intensities of the NH 4 + and M−O characteristics peaks in the a-CoFeNP samples, which had been submitted to annealing. The discrete peaks observed in both spectra at 1167, 1116, and 1090 cm −1 are because of the Fe−Co alloy system.…”

Section: Coclmentioning

confidence: 97%

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Spinel Cobalt Ferrite Nanoparticles for Sensing Phosphate Ions in Aqueous Media and Biological Samples

et al. 2020

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Phosphate ions perform a variety of functions in metabolic processes and are essential for all living organisms. The determination of the concentration of phosphate ions is useful in clinical diagnosis of various diseases as an inadequate phosphate level could lead to many health problems. In the search for a cost-effective method of fast monitoring, we investigated the use of cobalt ferrite nanoparticles (CoFeNPs) in the selective recognition of phosphate ions dissolved in aqueous media and more complex samples, such as human blood serum. We prepared these NPs by a chemical coprecipitation route and subjected them to annealing at 600 °C for 1 h. The successful formation of the NPs was confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and hysteresis loop measurements. The NPs exhibited a ferrimagnetic behavior, a spineltype crystalline structure, and hexagonal shape in the nanoscale range. We demonstrated that CoFeNPs containing immobilized fluorescent-labeled single-chain DNA (ssDNA*) probes can be applied for the fast selective detection of phosphate ions dissolved in a liquid medium. We have explored the fact that phosphate groups can displace ssDNA* probes attached to the nanoparticles, therefore causing a perceptible change in the fluorescence signal of the supernatant liquid. This detection method has been tested for the sensing of phosphate ions present both in aqueous solutions and in biological samples, with excellent selectivity and a low limit of detection (∼1.75 nM).

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Section: Resultsmentioning

confidence: 99%

Section: Coclmentioning

confidence: 97%

Spinel Cobalt Ferrite Nanoparticles for Sensing Phosphate Ions in Aqueous Media and Biological Samples

et al. 2020

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“…Ammonium hydroxide has been shown to exist as a solution of NH 3 molecules that are hydrogen bonded with water molecules rather than separate NH 4 + and OH − ions in solution. 30 The dissociation constant for ammonium hydroxide in water is ∼1.710 × 10 −5 at room temperature. 31 Thus, for the concentrations used in this study, we expect that no more than about 2% of the NH 3 dipoles will become protonated to form the NH 4 + cation.…”

Section: Resultsmentioning

confidence: 99%

Ionic Concentration Effects on Reverse Micelle Size and Stability: Implications for the Synthesis of Nanoparticles

et al. 2012

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We present a systematic investigation and analysis of the structure and stability of reverse micelle systems with the addition of NH(4)OH, ZrOCl(2), and Al(NO(3))(3) salts. We demonstrate that the reverse micelle size decreases with increasing salt additions until one reaches a critical concentration, which characterizes the onset of system destabilization. The concept of an electrical double layer, as it applies to reverse micelles, is considered for explaining features of destabilization, including the initial decrease in reverse micelle size, the destabilization concentration, and the effect of cation valence. We propose that the reduction in size prior to instability is caused by compression of the reverse micelle electrical double layers, as higher concentrations of salts are present. The reduced thickness of the electrical double layers allows the decaying potentials to move into closer proximity to each other before generating enough repulsion to balance the forces for reverse micelle formation and form a new equilibrium average reverse micelle size. The point of reverse micelle instability has been related to the formation of a two-phase system as a result of the inability to further compress the salt co-ions in the core of the reverse micelles, which would cause an excessive repulsive force between the overlapping potentials. We have extracted a critical potential of -89 nV between the two overlapping potentials for the AOT/water/isooctane (ω(0) = 10) systems studied. All these effects have important implications for the preparation of nanopowders by reverse micelle synthesis. If the reverse micelles are unstable before the precipitates are formed, then the advantage of reverse micelle synthesis is immediately lost.

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“…2− [30,34,35]. Based on XRPD and FT-IR results, the chemistry involved in the NH 3 removal process is formulated as the following equations:…”

Section: Structure Of H 3 Po 4 /C and H 3 Po 4 /A Characterized By X-ray Diffraction (Xrpd)mentioning

confidence: 99%

Effects of Moisture on NH3 Capture Using Activated Carbon and Acidic Porous Polymer Modified by Impregnation with H3PO4: Sorbent Material Characterized by Synchrotron XRPD and FT-IR

2022

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The performances of reactive adsorbents, H3PO4/C (activated carbon) and H3PO4/A (Amberlyst 35), in removing NH3 from a waste-gas stream were investigated using a breakthrough column. Accelerated aging tests investigated the effects of the water content on the performance of the adsorbents. Results of breakthrough tests show that the adsorption capacity greatly decreased with the drying time of H3PO4/C preparation. Synchrotron XRPD indicated increased amorphous phosphorus species formation with drying time. Nitrogen adsorption-desorption isotherms results further suggested that the evaporation of water accommodated in macropores decreases adsorption capacity besides the formation of the amorphous species. Introducing water moisture to the NH3 stream increases the adsorption capacity concomitant with the conversion of some NH4H2PO4 to (NH4)2HPO4. Due to the larger pore of cylindrical type and more hydrophilic for acidic porous polymer support, as opposed to slit-type for the activated carbon, the adsorption capacity of H3PO4/A is about 3.4 times that of H3PO4/C. XRPD results suggested that NH3 reacts with aqueous H3PO4 to form NH4H2PO4, and no significant macropore-water evaporation was observed when acidic porous polymer support was used, as evidenced by N2 isotherms characterizing used H3PO4/A.

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Infrared band intensities in ammonium hydroxide and ammonium salts*

Cited by 12 publications

References 7 publications

Spinel Cobalt Ferrite Nanoparticles for Sensing Phosphate Ions in Aqueous Media and Biological Samples

Spinel Cobalt Ferrite Nanoparticles for Sensing Phosphate Ions in Aqueous Media and Biological Samples

Ionic Concentration Effects on Reverse Micelle Size and Stability: Implications for the Synthesis of Nanoparticles

Effects of Moisture on NH3 Capture Using Activated Carbon and Acidic Porous Polymer Modified by Impregnation with H3PO4: Sorbent Material Characterized by Synchrotron XRPD and FT-IR

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