Vibrational spectral studies of solutions at elevated temperatures and pressures. 11. A Raman spectral study of aqueous iron(III) chloride solutions between 25 and 300 °C

1989 ◽  
Vol 67 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Katsuo Murata ◽  
Donald E. Irish ◽  
Gerald E. Toogood
Keyword(s):  
Raman Spectroscopy ◽  
Dielectric Constant ◽  
Dominant Species ◽  
Elevated Temperatures ◽  
Spectral Studies ◽  
Iron Species ◽  
Chloride Solutions ◽  
Increasing Temperature ◽  
Raman Spectral ◽  
Temperature Factors

The Raman spectra of acidified aqueous iron(III) chloride solutions have been measured between 25 and 300 °C. When Fe3+ concentrations are in the range 0.75 to 1.0 mol kg−1 and Cl−/Fe3+ ratios, R, in the range 3 to 9.5, the dominant species at 25 °C is trans-[Fe(H2O)4Cl2]+; at 300 °C the sole iron-containing species is tetrahedral [Formula: see text]. Conversion of [Fe(H2O)4Cl2]+ into [Formula: see text] appears not to involve intermediate iron species. In the presence of excess chloride the reaction [Formula: see text] is presumed to occur; ΔH for this reaction has been estimated as +65 ± 8 kJ mol−1. In addition to increasing temperature, factors which favour [Formula: see text] over other iron species include increasing acidity, increasing R, and decreasing dielectric constant. Keywords: high temperature aqueous solutions, iron(III) chloride, Raman spectroscopy.

Raman spectral studies of nucleic acids. 36. Structure in solution of the RNA.cntdot.DNA hybrid (rA)8.cntdot.(dT)8 determined by NMR and Raman spectroscopy

1990 ◽  
Vol 112 (11) ◽  
pp. 4508-4512 ◽  
Author(s):  
Masato Katahira ◽  
Sang Jong Lee ◽  
Yuji Kobayashi ◽  
Hiromu Sugeta ◽  
Yoshimasa Kyogoku ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Nucleic Acids ◽  
Spectral Studies ◽  
Raman Spectral ◽  
Structure In Solution

Permittivity Study of a CuCl Residue at 13–450 °C and Elucidation of the Microwave Intensification Mechanism for Its Dechlorination

2019 ◽  
Vol 38 (2019) ◽  
pp. 135-142
Author(s):  
Guo Zhanyong ◽  
Li Fachaung ◽  
Su Guang ◽  
Zhai Demei ◽  
Cheng Fang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Microwave Irradiation ◽  
Loss Factor ◽  
Elevated Temperatures ◽  
Temperature Dependent ◽  
Positive Interaction ◽  
Increasing Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Metallurgy Process

AbstractPermittivity is a vitally important parameter for describing the absorbing and heating characteristics of a material under microwave irradiation, and it is also strongly dependent on temperature. However, the literature contains little information on this topic and even less particular permittivity data at elevated temperatures. In this paper, the permittivity of a CuCl residue at temperatures from 13 to 450 °C at 2.45 GHz was measured using the cavity perturbation method. The relationship of its real part (ε′) and imaginary part (ε″) with temperature (T) was deduced. In addition, the temperature-dependent tangent (tan δ) and the penetration depth (d) of microwaves into the material were calculated. The results of the permittivity study show that the dielectric constant (ε′) of the CuCl residue increased linearly with increasing temperature. In contrast, the dielectric loss factor (ε″) and loss tangent first maintained on a steady value between 13 and 300 °C and then substantially increased from 300 to 450 °C. The positive interaction of the dielectric property and temperature showed the reasonableness of our earlier metallurgy process, where the CuCl residue for dechlorination was roasted at 350–450 °C under microwave irradiation.

Vibrational Spectral Studies of Solutions at Elevated Temperatures and Pressures. III. A Furnace Assembly for Raman Spectral Studies to 300°C and 15 MPa

1982 ◽  
Vol 36 (2) ◽  
pp. 137-140 ◽  
Author(s):  
D. E. Irish ◽  
T. Jarv ◽  
C. I. Ratcliffe
Keyword(s):  
High Temperature ◽  
Aqueous Solutions ◽  
Elevated Temperatures ◽  
Chemical Processes ◽  
Spectral Studies ◽  
Raman Spectral

The design of a furnace assembly for maintaining aqueous solutions at temperatures up to 300°C and controlled pressures of up to 15 MPa is described. The apparatus is being used to monitor the chemical processes taking place in high-temperature aqueous solutions. Spectra of the Zn(NO3)2/H2O system and the HCl/H2O system are presented as examples.

Raman spectral studies of solutions at elevated temperatures and pressures.13. Sodium formate – water

1993 ◽  
Vol 71 (10) ◽  
pp. 1728-1733 ◽  
Author(s):  
Richard J. Bartholomew ◽  
Donald E. Irish
Keyword(s):  
Raman Spectra ◽  
Elevated Temperatures ◽  
Sodium Formate ◽  
Fermi Resonance ◽  
Spectral Studies ◽  
Coupling Constant ◽  
Ambient Conditions ◽  
Modes Of Vibration ◽  
Resonance Doublet ◽  
Raman Spectral

Raman spectra of the formate anion in water (H2O and D2O) have been measured for four concentrations under ambient conditions and for two concentrations at temperatures ranging from 49 to 239 °C and a pressure of 10 MPa. Five of the six fundamental modes of vibration are polarized. This result is inconsistent with C2ν symmetry. The Fermi resonance doublet clearly results from the interaction of 2ν5 and ν1. The latter mode decreases in frequency as the temperature rises, thus increasing the coupling and hence the intensity of the 2ν5 component. The coupling constant, W, and the positions of the unperturbed bands [Formula: see text] and [Formula: see text] have been calculated. No evidence to support a bifurcated structure for the solvated anion was found.

Raman Spectral Studies of 2-Mercaptobenzothiazole Accelerator Systems

1974 ◽  
Vol 47 (4) ◽  
pp. 911-923 ◽  
Author(s):  
R. S. Kapur ◽  
J. L. Koenig ◽  
J. R. Shelton
Keyword(s):  
Raman Spectroscopy ◽  
Laser Raman Spectroscopy ◽  
Spectral Studies ◽  
Significant Evidence ◽  
Laser Raman ◽  
Raman Spectral

Abstract A mechanism for the formation of the rubber-bound intermediate in the vulcanization of elastomers has been proposed. The active sulfurating agent is a polysulfide. Laser Raman spectroscopy has been used to provide significant evidence for this mechanism in the presence of cis-1,4-poly(butadiene).

scholarly journals Strengthening epoxy adhesives at elevated temperatures based on dynamic disulfide bonds

2020 ◽  
Vol 1 (9) ◽  
pp. 3182-3188
Author(s):  
Hsing-Ying Tsai ◽  
Yasuyuki Nakamura ◽  
Takehiro Fujita ◽  
Masanobu Naito
Keyword(s):  
Glass Transition ◽  
Disulfide Bonds ◽  
Epoxy Resins ◽  
Elevated Temperatures ◽  
Adhesive Properties ◽  
Epoxy Adhesives ◽  
Transition Points ◽  
Increasing Temperature

Epoxy resins incorporating aromatic disulfide bonds demonstrated improved adhesive properties with increasing temperature below their glass transition points.

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