A near-infrared study of changes in the solvent upon solute-solute interactions in aqueous solutions of tetraalkylammonium salts

1978 ◽  
Vol 82 (9) ◽  
pp. 1051-1056 ◽  
Author(s):  
Carmel Jolicoeur ◽  
Jean Paquette ◽  
Michel Lucas
Keyword(s):  
Aqueous Solutions ◽  
Near Infrared ◽  
Tetraalkylammonium Salts ◽  
Infrared Study ◽  
Solute Interactions

A near-infrared study of hydrogen bonding in human albumin aqueous solutions

1990 ◽  
Vol 172 (3-4) ◽  
pp. 312-316 ◽  
Author(s):  
R. Lamanna ◽  
M. Delmelle ◽  
S. Cannistraro
Keyword(s):  
Hydrogen Bonding ◽  
Aqueous Solutions ◽  
Near Infrared ◽  
Human Albumin ◽  
Infrared Study

Effects of salts on the kinetics of oxidation of alkenes by thallic salts in aqueous solutions

1981 ◽  
Vol 46 (3) ◽  
pp. 693-700 ◽  
Author(s):  
Milan Strašák ◽  
Jaroslav Majer
Keyword(s):  
Aqueous Solutions ◽  
Phase Transfer ◽  
Heterogeneous Reaction ◽  
Qualitative Model ◽  
Kinetic Effect ◽  
Tetraalkylammonium Salts ◽  
Reaction Conditions ◽  
Kinetics Of Oxidation ◽  
Kinetics Of ◽  
Heterogeneous Reaction Conditions

The kinetics of oxidation of alkenes by thallic sulphate in aqueous solutions, involving the two reaction steps-the hydroxythallation and the dethallation - was studied, and the effect of salts on the kinetics was examined; this made it possible to specify more precisely the reaction mechanism and to suggest a qualitative model of the reaction coordinate. It was found that in homogeneous as well as in heterogeneous reaction conditions, the reaction can be accelerated appreciably by adding tetraalkylammonium salts. These salts not only operate as catalysts of the phase transfer, but also exert a significant kinetic effect, which can be explained with a simplification in terms of a stabilization of the transition state of the reaction.

A Near‐Infrared Study of the NS 14 Bipolar Nebula

1998 ◽  
Vol 509 (2) ◽  
pp. 749-760 ◽  
Author(s):  
Eric M. Howard ◽  
Judith L. Pipher ◽  
William J. Forrest
Keyword(s):  
Near Infrared ◽  
Infrared Study

Using near infrared measurements to evaluate NaCl and KCl in water

2019 ◽  
Vol 27 (2) ◽  
pp. 147-155
Author(s):  
Reisha D Peters ◽  
Scott D Noble
Keyword(s):  
Aqueous Solutions ◽  
Near Infrared ◽  
Average Error ◽  
Spectral Measurements ◽  
Salt Solutions ◽  
Saturation Point ◽  
Test Set ◽  
Solution Type ◽  
All Solutions ◽  
Infrared Measurements

Spectral differences between aqueous solutions of NaCl and KCl have received minimal attention in previous research due to strong similarities between the two salts and the lack of motivation to differentiate between them. Correlations between salinity and absorbance have been developed previously with varying degrees of linearity but have not been tested to saturation. This work will demonstrate that correlating spectral measurements and the concentration of NaCl and KCl in water can be extended up to the saturation point of both salts and that solutions of these salts with unknown concentrations can be distinguished. Spectral data for samples of NaCl and KCl in single-salt solutions were collected up to saturation and correlations were developed for differentiating between solutions of the two species. These correlations were able to correctly identify the solution type for all solutions in the test set and estimate their concentrations with an average error of 0.9%.

Plucking a hydrogen bond: A near infrared study of all four intermolecular modes in (DF)2

1996 ◽  
Vol 105 (16) ◽  
pp. 6645-6664 ◽  
Author(s):  
Scott Davis ◽  
David T. Anderson ◽  
David J. Nesbitt
Keyword(s):  
Hydrogen Bond ◽  
Near Infrared ◽  
Infrared Study

scholarly journals Water Properties of Soft Contact Lenses: A Comparative Near-Infrared Study of Two Hydrogel Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jelena Munćan ◽  
Ivana Mileusnić ◽  
Jovana Šakota Rosić ◽  
Aleksandra Vasić-Milovanović ◽  
Lidija Matija
Keyword(s):  
Water Content ◽  
Near Infrared ◽  
Contact Lenses ◽  
Polymer Network ◽  
The State ◽  
Vinyl Pyrrolidone ◽  
Soft Contact ◽  
Infrared Study ◽  
Soft Contact Lenses ◽  
State Of Water

The functionality of soft contact lenses depends strongly on the water content and their water-transport ability. This study was conducted in order to examine the state of water in two sets of soft contact lenses: VSO38, pHEMA Filcon I 1, and VSO50, copolymer of HEMA and VP Filcon II 1 (HEMA = 2-hydroxy-ethyl methacrylate; VP = vinyl pyrrolidone). Hydrogel lenses were studied using near-infrared spectroscopy and the novel Aquaphotomics approach in order to determine the state of water in materials based on their near-infrared spectra. Aquaphotomics approach investigates absorption at specific vibrational bands of water’s covalent and hydrogen bonds which can provide information on how the water structure changes with the structural change of the polymer network. Principal component analysis and specific star-chart “aquagram” were used to analyse water spectral pattern in hydrogel materials. The findings show that material VSO38 has water predominantly organized in bound state, while material with higher water content, VSO50, has more free and weakly hydrogen bonded water. Our findings define in detail exact water species existing and interacting with the polymer network. The results show qualitative and quantitative possibilities of Aquaphotomics for better modelling and understanding water behaviour in hydrogel materials.

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