The scattering of light and phase transition in solutions of tertiary butyl alcohol in water

Vuks, M. F.; Shurupova, L. V.

doi:10.1016/0030-4018(72)90096-x

Cited by 41 publications

(35 citation statements)

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“…Structural relaxation of water molecules surrounding the solute was used to rationalize the observations. In yet another light scattering experiment, Vuks and Shurupova [32] found an additional maximum at x TBA ≈ 0.03 (apart from the theoretically predicted one) and interpreted the same using phase transition. However, their results were later contended [33].…”

Section: Introductionmentioning

confidence: 73%

Fluctuating micro-heterogeneity in water–tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

Banerjee

Furtado

Bagchi

2014

The Journal of Chemical Physics

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Water-tert-butyl alcohol (TBA) binary mixture exhibits a large number of thermodynamic and dynamic anomalies. These anomalies are observed at surprisingly low TBA mole fraction, with xTBA ≈ 0.03 − 0.07. We demonstrate here that the origin of the anomalies lies in the local structural changes that occur due to self-aggregation of TBA molecules. We observe a percolation transition of the TBA molecules at xTBA ≈ 0.05. We note that "islands" of TBA clusters form even below this mole fraction, while a large spanning cluster emerges above that mole fraction. At this percolation threshold, we observe a lambda-type divergence in the fluctuation of the size of the largest TBA cluster, reminiscent of a critical point. Alongside, the structure of water is also perturbed, albeit weakly, by the aggregation of TBA molecules. There is a monotonic decrease in the tetrahedral order parameter of water, while the dipole moment correlation shows a weak non-linearity. Interestingly, water molecules themselves exhibit a reverse percolation transition at higher TBA concentration, xTBA ≈ 0.45, where large spanning water clusters now break-up into small clusters. This is accompanied by significant divergence of the fluctuations in the size of largest water cluster. This second transition gives rise to another set of anomalies around. Both the percolation transitions can be regarded as manifestations of Janus effect at small molecular level.

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Section: Introductionmentioning

confidence: 73%

Fluctuating micro-heterogeneity in water–tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

Banerjee

Furtado

Bagchi

2014

The Journal of Chemical Physics

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“…Furthermore, under certain conditions aqueous TBA solutions show the presence of mesoscopic droplets, with a size of about 100 nm [28][29][30][31][32][33][34][35]. We have recently shown that mesoscopic droplets form only when a hydrophobic compound ("hydrophobe") is added to aqueous TBA solutions in the concentration range of 3 mol % to 8 mol % TBA and at low temperatures (below room temperature), thus clarifying the long-standing issue on the origin of mesoscopic inhomogeneities in such solutions [34,35].…”

Section: Introductionmentioning

confidence: 99%

Phase behavior and mesoscale solubilization in aqueous solutions of hydrotropes

Subramanian

Анисимов

2014

Fluid Phase Equilibria

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Hydrotropes are amphiphilic molecules that are too small to spontaneously form equilibrium structures in aqueous solutions, but form dynamic, non-covalent assemblies, referred to as clusters. In the presence of a hydrophobic compound, these clusters seem to get stabilized leading to the formation of long-lived, highly stable mesoscopic droplets, a phenomenon that we call "mesoscale solubilization". In this work, we focus on the unusual mesoscopic properties of aqueous solutions of a nonionic hydrotrope, namely tertiary butyl alcohol (TBA), on addition of various hydrophobic compounds. Aqueous TBA solutions, in about 3 mol % to 8 mol % TBA concentration range and about 0 °C to 25 °C temperature range, show the presence of short-ranged (~ 0.5 nm), short-lived (tens of picoseconds) molecular clusters which result in anomalies of the thermodynamic properties. These clusters are transient but do not relax by diffusion, thus distinctly different from conventional concentration fluctuations. In this concentration and temperature range, upon the addition of a third (more hydrophobic) component to TBA-water solutions, long-lived mesoscopic droplets of about 100 nm size are observed. In this work, we clarify the ambiguity behind the definition of solubility and elucidate the phenomenon of mesoscale solubilization. A systematic study of the macroscopic and mesoscopic phase behavior of three ternary systems TBA-water-propylene oxide, TBA-water-isobutyl alcohol, and TBA-water-cyclohexane has been carried out. We differentiate between molecular solubility, mesoscale solubilization, and macroscopic phase separation. We have confirmed that practically stable aqueous colloids can be created from small molecules, without addition of surfactants or polymers. Such kind of novel materials may find applications in the design of various processes and products, ranging from pharmaceuticals to cosmetics and agrochemicals.

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“…(1) h i 1 = n V M g (2) This relation is more frequently written in the form with M the Maxwell constant, n the refractive index of the isotropic medium, and q the viscosity.…”

Section: Introductionmentioning

confidence: 99%

ChemInform Abstract: FLOW BIREFRINGENCE MEASUREMENTS IN LOW‐VISCOSITY LIQUIDS WITH THE HELP OF BOUNDARY LAYER SHEAR WAVES, AND ORIENTATIONAL RELAXATION IN N‐ALKYL CARBOXYLIC ACIDS (NORMAL FATTY ACIDS)

Ottmers¹

1974

Chemischer Informationsdienst

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A new measuring method for determining flow birefringence constants by generating shear velocity gradients with the help of Rayleigh boundary layer shear waves (21.3 kHz) will be described. This method has an advantage over previous measuring systems with Couette apparatuses in that disturbing heating influences in the birefringent layer can be avoided by pulsed excitation and faulty depolarizations can be eliminated by narrow‐band filtering. With this technique flow birefringence was investigated in n‐heptanoic, n‐octanoic, n‐nonanoic acid, o‐dichlorobenzene and cinnamaldehyde. The temperature dependency of flow birefringence in the carboxylic acids will be discussed on the basis of the theory of Peterlin and Stuart which leads to a simple relation between flow birefringence and orientational relaxation in low molecular liquids. The results will be compared with flow birefringence measurements in n‐paraffins and with investigations of orientational Rayleigh scattering in n‐alkyl bromides. The comparison leads to a confirmation of Peterlin's and Stuart's theoretical starting point. In addition it will be shown that molecular rearrangement processes in n‐alkyl carboxylic acids beginning with propionic acid are carried out predominantly by dimers, whereby the Arrhenius activation enthalpies of these processes are dependent on the molecular chain length in a way comparable to other simple n‐alkyl families.

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The scattering of light and phase transition in solutions of tertiary butyl alcohol in water

Cited by 41 publications

References 1 publication

Fluctuating micro-heterogeneity in water–tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

Fluctuating micro-heterogeneity in water–tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

Phase behavior and mesoscale solubilization in aqueous solutions of hydrotropes

ChemInform Abstract: FLOW BIREFRINGENCE MEASUREMENTS IN LOW‐VISCOSITY LIQUIDS WITH THE HELP OF BOUNDARY LAYER SHEAR WAVES, AND ORIENTATIONAL RELAXATION IN N‐ALKYL CARBOXYLIC ACIDS (NORMAL FATTY ACIDS)

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