A Precise Calorimetric Study of 18-Crown-6 Complexes with Sodium, Potassium, Rubidium, Caesium, and Ammonium Ions in Aqueous Solution

1992 ◽  
Vol 65 (4) ◽  
pp. 1173-1175 ◽  
Author(s):  
Kazuhiko Ozutsumi ◽  
Shin-ichi Ishiguro
Keyword(s):  
Aqueous Solution ◽  
Calorimetric Study ◽  
Ammonium Ions ◽  
Sodium Potassium

scholarly journals Photo-Induced Decomposition of 2-Chloroaniline in Aqueous Solution

2002 ◽  
Vol 57 (5-6) ◽  
pp. 512-515 ◽  
Author(s):  
Ermin Katrin Winarno ◽  
Nikola Getoff
Keyword(s):  
Aqueous Solution ◽  
Degradation Products ◽  
Chloride Ions ◽  
Pure Oxygen ◽  
Ammonium Ions ◽  
Probable Reaction Mechanism ◽  
Specific Analysis ◽  
Probable Reaction ◽  
Uv Dose ◽  
Induced Decomposition

A study was performed on the oxidizing degradation of 2-chloroaniline (used as a model pollutant in water) by photolysis (λ = 254 nm). The change of spectrum and substrate concentration of treated solutions was measured spectrophotometrically as well as by HPLC. The yields of the degradation products (chloride ions, ammonium ions, formaldehyde, etc.) were studied as a function of UV-dose. Their initial quantumyields (Qi) were determined by specific analysis. It was shown that the substrate photolysis in the presence of N2O is most efficient, followed by degradation in media saturated with pure oxygen and air. A probable reaction mechanism for the photo-induced degradation of 2-ClA is presented.

Adsorption of alkylammonium cations by montmorillonite

Clay Minerals ◽  
1967 ◽  
Vol 7 (1) ◽  
pp. 1-17 ◽  
Author(s):  
B. K. G. Theng ◽  
D. J. Greenland ◽  
J. P. Quirk
Keyword(s):  
Aqueous Solution ◽  
Single Layer ◽  
Tertiary Amines ◽  
X Ray Diffraction ◽  
Ammonium Ions ◽  
X Ray ◽  
Inorganic Cations ◽  
Quaternary Ammonium Ions ◽  
Contact Distance ◽  
Alkyl Groups

AbstractThe adsorption of various alkylammonium cations from aqueous solution by sodium and calcium montmorillonite has been studied. Adsorption occurred through an exchange reaction between the inorganic cations on the clay and the alkylammonium ions in solution. The affinity of the clay for these cations was linearly related to molecular weight, with the exception of the smaller methyl-ammonium and the larger quaternary ammonium ions. Comparison of primary, secondary and tertiary amines containing the same alkyl groups showed that the affinity of the clay was greatest for the primary amine and least for the tertiary. This behaviour has been interpreted in terms of the size and shape of the cations. X-ray diffraction analysis showed that no more than a single layer of adsorbed cations was present in the inter-lamellar space at maximum adsorption. Comparison between Δ-values and the thickness of the adsorbed ions showed that there was a contraction in the apparent contact distance of these cations. The amount of contraction could be accounted for by ‘keying’ of the adsorbed ions into the montmorillonite surface.

Sign in / Sign up

Export Citation Format

Share Document