scispace - formally typeset
Open AccessJournal ArticleDOI

Structural transition in alcohol-water binary mixtures: A spectroscopic study

TLDR
In this article, the effects of the hydrogen bond (H-bond) network with alcohol concentration are revealed by a minimum in the peak frequency of the absorption spectrum of coumarin 153 (C153) which occur at alcohol mole fraction ∼0·10 for water-ethanol and at ∼ 0·04 for tertiary butanol (TBA) mixtures.
Abstract
The strengthening of the hydrogen bonding (H-bond) network as well as transition from the tetrahedral-like water network to the zigzag chain structure of alcohol upon increasing the alcohol concentration in ethanol-water and tertiary butanol (TBA) — water mixtures have been studied by using both steady state and time resolved spectroscopy. Absorption and emission characteristics of coumarin 153 (C153), a widely used non-reactive solvation probe, have been monitored to investigate the structural transition in these binary mixtures. The effects of the hydrogen bond (H-bond) network with alcohol concentration are revealed by a minimum in the peak frequency of the absorption spectrum of C153 which occur at alcohol mole fraction ∼0·10 for water-ethanol and at ∼0·04 for water-TBA mixtures. These are the mole fractions around which several thermodynamic properties of these mixtures show anomalous change due to the enhancement of H-bonding network. While the strengthening of H-bond network is revealed by the absorption spectra, the emission characteristics show the typical non-ideal alcohol mole fraction dependence at all concentrations. The time resolved anisotropy decay of C153 has been found to be bi-exponential at all alcohol mole fractions. The sharp change in slopes of average rotational correlation time with alcohol mole fraction indicates the structural transition in the environment around the rotating solute. The changes in slopes occur at mole fraction ∼0·10 for TBA-water and at ∼0·2 for ethanol-water mixtures, which are believed to reflect alcohol mole fraction induced structural changes in these alcohol-water binary mixtures.

read more

Content maybe subject to copyright    Report

Citations
More filters
Book

Water in Biological and Chemical Processes: From Structure and Dynamics to Function

TL;DR: Water in Biology: Dynamical View and Function: 6. Biological water 7. Explicit role of water in biological functions 8. Hydration of proteins 9. Can we understand protein hydration layer: lessons from computer simulations as mentioned in this paper.
Journal ArticleDOI

Raman Spectroscopy of Water-Ethanol Solutions: The Estimation of Hydrogen Bonding Energy and the Appearance of Clathrate-like Structures in Solutions.

TL;DR: This work presents the Raman scattering spectra of water, ethanol, and water-ethanol solutions with 20 and 70 vol % of ethanol thoroughly measured and analyzed at temperatures varying from -10 to +70 °C and finds the energy of hydrogen bonding in 20 vol% of ethanol was found the highest among all the samples.
Journal ArticleDOI

Concentration and temperature dependence of the refractive index of ethanol-water mixtures: Influence of intermolecular interactions.

TL;DR: The temperature and concentration dependence of the refractive index, nD(x, T) , in ethanol-water mixtures agrees with previous data in the ethanol-rich concentration range and shows anomalies at lower water concentrations but no anomaly at 41 mol% water.
Journal ArticleDOI

Theoretical and Computational Analysis of Static and Dynamic Anomalies in Water−DMSO Binary Mixture at Low DMSO Concentrations

TL;DR: The findings are mapped to an interacting lattice model which substantiates the continuum percolation model as the reason for low concentration anomalies in binary mixtures where the solutes involved have both hydrophilic and hydrophobic moieties.
Journal ArticleDOI

Co-Nonsolvency of Poly(n-isopropylacrylamide) in Deuterated Water/Ethanol Mixtures

TL;DR: In this paper, small-angle neutron scattering was used to investigate poly(N-isopropylacrylamide) (PNIPAM) polymer solutions in d-water/d-ethanol mixtures.
References
More filters
Book

Water:A Comprehensive Treatise

Felix Franks
Journal ArticleDOI

Subpicosecond Measurements of Polar Solvation Dynamics: Coumarin 153 Revisited

TL;DR: In this article, the authors used time-resolved emission measurements of the solute coumarin 153 (C153) to probe the time dependence of solvation in 24 common solvents at room temperature.
Journal ArticleDOI

Picosecond solvation dynamics of coumarin 153: The importance of molecular aspects of solvation

TL;DR: In this paper, a probe molecule coumarin 153 (Cu153) and picosecond spectroscopic techniques were used to examine the solvation dynamics in polar liquids and showed that the frequency of the electronic spectrum of this probe provides a convenient measure of solvation energetics.
Journal ArticleDOI

Molecular segregation observed in a concentrated alcohol–water solution

TL;DR: In this article, the authors used neutron diffraction with isotope substitution to probe the molecular-scale structure of a concentrated alcohol-water mixture (7:3 molar ratio) and found that most of the water molecules exist as small hydrogen-bonded strings and clusters in a 'fluid' of close-packed methyl groups, with water clusters bridging neighbouring methanol hydroxyl groups through hydrogen bonding.
Related Papers (5)