Near-infrared study of the state of water in aqueous solutions of tetraalkylammonium and -phosphonium bromides and alkali halides at 10, 25, and 40.deg.

1973 ◽  
Vol 77 (26) ◽  
pp. 3071-3077 ◽  
Author(s):  
P. R. Philip ◽  
C. Jolicoeur
Keyword(s):  
Aqueous Solutions ◽  
Near Infrared ◽  
Alkali Halides ◽  
The State ◽  
Infrared Study ◽  
State Of Water

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.

The state of water in soft contact lenses explored with near infrared spectroscopy and Aquaphotomics

NIR news ◽  
2017 ◽  
Vol 28 (6) ◽  
pp. 9-12
Author(s):  
Jelena Munćan
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Contact Lenses ◽  
Water Structure ◽  
The State ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
State Of Water ◽  
Three State Model

The structure of water in hydrogel materials of soft contact lenses was investigated by near infrared spectroscopy and Aquaphotomics. Near infrared spectroscopy offers rapid, reagent free, and nondestructive characterization of hydrogel materials, while Aquaphotomics provides detailed insight into the complex water structure inside the hydrogel consisting of many water molecular species. These findings push the limits of our knowledge beyond the current “three-state” model of water in hydrogels, while at the same time provide information about the state of the polymer itself thus justifying the “water molecular-mirror” concept of Aquaphotomics.

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

scholarly journals THE VAPOUR PRESSURES OF AQUEOUS SOLUTIONS WITH SPECIAL REFERENCE TO THE PROBLEM OF THE STATE OF WATER IN BIOLOGICAL FLUIDS

1931 ◽  
Vol 14 (5) ◽  
pp. 661-683 ◽  
Author(s):  
Arthur Grollman
Keyword(s):  
Aqueous Solutions ◽  
Vapour Pressure ◽  
Biological Fluids ◽  
The State ◽  
Mixed Solution ◽  
Appreciable Change ◽  
Degree Of Hydration ◽  
Gum Acacia ◽  
Inorganic Substances ◽  
State Of Water

Data for the depression of vapour pressure are presented for the following aqueous solutions: NaCl (0.03 to 0.1 molar), KCl (0.03 to 0.1 molar), urea (0.05 to 0.5 molar), sucrose (0.05 to 0.10 molar), lactic and succinic acids, creatine, CaCl2 (0.05 molar), and mixtures of these substances with one another and with certain other solutions (gelatin, gum acacia, sea water, LiCl, etc.). The relation of the depression of vapour pressure of a mixed solution to that of solutions of the individual constituents was investigated in order to ascertain to what extent such studies may be used for the determination of the degree of hydration, or of the state of water, in solutions. Organic substances (urea, sucrose, etc.) showed anomalous results which were markedly affected and unpredictable in mixed solutions. They are, therefore, unsuited for the study of water binding. In the case of solutions of inorganic substances—LiCl and CaCl2—the principle of the additive nature of colligative properties is also only approximately true—except perhaps in very dilute solutions. The limitations of the colligative method for determining the degree of hydration have been defined in accord with the above findings. Studies of the vapour pressures of mixtures of gelatin or gum acacia with NaCl or KCl demonstrated that hydration in gelatin is relatively small at pH = 7 and undetectable in gum acacia solutions. The view, therefore, that hydrophilic colloids are strongly hydrated has not been substantiated. The passage from the sol to the gel state also was not accompanied in gelatin or in blood by any appreciable change in the degree of hydration of the hydrophilic colloids present in these substances.

Fourier Transform Infrared Study on the State of Water Sorbed to Poly(ethylene glycol) Films†

Langmuir ◽  
2001 ◽  
Vol 17 (6) ◽  
pp. 1889-1895 ◽  
Author(s):  
Hiromi Kitano ◽  
Ken Ichikawa ◽  
Makoto Ide ◽  
Mitsuhiro Fukuda ◽  
Wataru Mizuno
Keyword(s):  
Fourier Transform ◽  
Ethylene Glycol ◽  
Fourier Transform Infrared ◽  
The State ◽  
Poly Ethylene Glycol ◽  
Infrared Study ◽  
State Of Water ◽  
Poly Ethylene

Infrared study of the state of water in the hydration shell of DNA

1970 ◽  
Vol 48 (10) ◽  
pp. 1536-1542 ◽  
Author(s):  
Michael Falk ◽  
A. G. Poole ◽  
C. G. Goymour
Keyword(s):  
Liquid Water ◽  
Low Temperatures ◽  
Hydration Shell ◽  
The State ◽  
Water Molecules ◽  
Surrounding Water ◽  
Infrared Study ◽  
Hydration Shells ◽  
State Of Water ◽  
Bond Strengths

The state of water in the hydration shell of DNA was studied by infrared spectroscopy. The stretching bands of isotopically dilute HDO adsorbed on DNA have nearly the same band profiles as those of HDO in liquid water. This indicates a distribution of hydrogen-bond strengths similar to that in liquid water. At low temperatures, the spectra show that an inner layer of about 10 water molecules per nucleotide is incapable of crystallization, even when the surrounding water crystallizes into ice I. The biopolymer hydration shells are not "ice-like" in the sense of crystalline ordering into an ice-like structure.

Analysis of the state of water in polyvinylpyrrolidone aqueous solutions using DSC method

2012 ◽  
Vol 538 ◽  
pp. 43-47 ◽  
Author(s):  
Yoshitomo Furushima ◽  
Kazuhiko Ishikiriyama ◽  
Yoshiyuki Ueno ◽  
Hiroyuki Sugaya
Keyword(s):  
Aqueous Solutions ◽  
The State ◽  
State Of Water ◽  
Dsc Method
Sign in / Sign up

Export Citation Format

Share Document