@article { ISI:000228743500067, title = {Miscibility of chitosan-hydroxyethylcellulose blends in aqueous acetic acid solutions at 35 degrees C}, journal = {Journal of Applied Polymer Science}, volume = {96}, number = {5}, year = {2005}, month = {JUN}, pages = {1996-1998}, publisher = {JOHN WILEY \& SONS INC}, type = {Article}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

The miscibility of blends of chitosan and hydroxyethylcellulose in a 2\% acetic acid solution was studied by viscometry, densitometry, and refractometry at 35 degrees C. The data suggest that the blends were completely miscible in all proportions. Further, the membranes were fabricated from concentrated blend solutions. The solid-state compatibility of the blends was confirmed by scanning electron microscopy. (c) 2005 Wiley Periodicals, Inc.

}, keywords = {blends, miscibility, refractive index, viscosity}, issn = {0021-8995}, doi = {10.1002/app.21421}, author = {Wali, A. C. and Naidu, B. V. K. and Mallikarjuna, N. N. and Sainkar, S. R. and Halligudi, Shivaraj B. and Aminabhavi, Tejraj M.} } @article { ISI:000230531100014, title = {Poly(acrylonitrile) ultrafiltration membranes. II. membrane morphology and permeation characteristics}, journal = {Journal of Polymer Science Part B: Polymer Physics}, volume = {43}, number = {15}, year = {2005}, month = {AUG}, pages = {2074-2085}, publisher = {JOHN WILEY \& SONS INC}, type = {Article}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

The rheology and phase-boundary characteristics of various solutions comprising three polyacrylonitrile (PAN) grades dissolved in solutions of N,N-dimethylformamide + salt (LiCl, ZnCl2, or AICl(3)) additives were correlated with the resulting membrane morphology as determined by microscopy and permeability measurements. The phase separation characteristics of the dope solution were not markedly affected by the PAN molecular weight (MW); however, they were affected by the salt additive. For higher MW grades, the effect of salt addition can also be masked by the increased self-association tendency of the polymer chains. PAN-B and -C membranes were clearly less asymmetric in structure than the lower MW PAN-Abased membranes. This is attributed to the higher viscosity/lower diffusivity of the PAN-13 and -C solutions, which results in slower solvent-nonsolvent exchange during the phase inversion process. Two factors reduce the incidence of surface defects (increased bubble points): (a) higher solution viscosity dampens surface perturbations during phase inversion, and (b) phase inversion pathways resulting in more homogenous morphology lead to membranes with higher bubble points. (c) 2005 Wiley Periodicals, Inc.

}, keywords = {bubble point, membranes, Morphology, phase inversion, salts, viscosity}, issn = {0887-6266}, doi = {10.1002/polb.20494}, author = {Phadke, M. A. and Kulkarni, Sudhir S. and Karode, Sandeep K. and Musale, D. A.} } @article { ISI:000242468700074, title = {Synthesis and characterization of cholesteric thermotropic liquid crystalline polyesters}, journal = {Journal of Applied Polymer Science}, volume = {103}, number = {2}, year = {2006}, month = {JAN}, pages = {1232-1237}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Cholesteric liquid crystalline polyesters were successfully synthesized from isosorbide, methyl hydroquinone, and isophthaloyl chloride. Homo/copolyesters were synthesized by the solution polycondensation method, for which a mild organic base such as pyridine was employed. Inherent viscosities of polyesters P-3-P-5 were in the range of 0.31-0.39 dL/g at 25 degrees C in chloroform, and polyesters P-1 and P-2 were insoluble in chloroform. Homo/copolyesters based on isosorbide, methyl hydroquinone, and isophthalic acid had thermal stability at more than 300 degrees C on the basis of 10\% weight loss. The thermotropic liquid crystalline properties were examined by differential scanning calorimetry and polarizing optical microscopy. Wide-angle X-ray diffraction study demonstrated that polyesters P-1, P-2, and P-3 were semicrystalline, whereas the degree of crystallinity of polyesters P-4 and P-5 was less than 5\%. Copolyester P-4 showed formation of a yellow iridescent streak at 209 degrees C on heating and development of a Grand-jean texture at 270 degrees C on heating. These are typical textures of the cholesteric liquid crystalline phase. (c) 2006 Wiley Periodicals, Inc.

}, keywords = {cholesteric liquid crystalline polymers (ChLCP), Differential scanning calorimetry (DSC), optical microscopy, solution polycondensation, Thermogravimetric analysis (TGA), viscosity}, issn = {0021-8995}, doi = {10.1002/app.24610}, author = {Jadhav, Sushilkumar A. and Chougule, Rahul R. and Shinde, Yogesh A. and Chavan, Nayaku} } @article { ISI:000256743300032, title = {Insight into the micellization of dodecyldimethylethylammonium bromide (DDAB) in the presence of bovine serum albumin (BSA)}, journal = {Journal of Colloid and Interface Science}, volume = {323}, number = {2}, year = {2008}, month = {JUL}, pages = {426-434}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

in this work, we report the effect of concentration of bovine serum albumin (BSA) on the micellization of a cationic surfactant, doclecyldimethylethylammonium bromide (DDAB). Several samples covering a wide range of concentrations of protein and surfactant have been investigated. The interactions between the moieties are investigated by measuring fluorescence quenching of BSA molecules. The aggregation number of DDAB micelles is found to be small in the presence of BSA. The formation of DDAB-BSA complex is confirmed by FTIR. Absorbance spectroscopy indicates that at higher concentration, the conformational stability of BSA in DDAB is higher. The viscosity data for protein-surfactant systems confirm conformational changes in protein chains induced by the surfactant. The cmc values for DDAB increase with increasing concentration of BSA. At higher temperatures the micellization-complexation becomes enthalpy-dominated. (c) 2008 Elsevier Inc. All rights reserved.

}, keywords = {Aggregation number, BSA, conductivity, conformational stability, DDAB, FFIR, fluorescence, UV-visible, viscosity}, issn = {0021-9797}, doi = {10.1016/j.jcis.2008.04.026}, author = {Mehta, S. K. and Bhawna and Bhasin, K. K. and Kumar, Anil} } @article { ISI:000264326100007, title = {Dramatic change in viscosities of pure ionic liquids upon addition of molecular solvents}, journal = {Journal of Solution Chemistry}, volume = {38}, number = {5}, year = {2009}, month = {MAY}, pages = {589-600}, publisher = {SPRINGER/PLENUM PUBLISHERS}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Viscosities of binary mixtures of pyridinium based ionic liquids (1-butyl pyridinium tetrafluoroborate, [BP][BF(4)], 1-butyl 3-methyl pyridinium tetrafluoroborate [3-MBP][BF(4)], 1-butyl 4-methyl pyridinium tetrafluoroborate, [4-MBP][BF(4)]), and phosphonium based ionic liquids, (tetrabutyl phosphonium alaninate, [TBP][Ala]; tetrabutyl phosphonium valinate, [TBP][Val]) with the molecular solvents, water, methanol and dichloromethane, have been measured at 298.15 K. A Brookfield ultra-rheometer was employed to measure the reported viscosities. The drop in viscosity in the close vicinity of pure ionic liquid is more prominent in polar solvents like water compared to less polar solvents. The temperature dependence of this observation was also studied for binary mixtures of [4-MBP][BF(4)] with water in range of 298.15-323.15 K. The Vogel-Fulcher-Tamman (VFT) equation was employed to investigate the temperature dependence of the viscosities of pure pyridinium-based ionic liquids in the temperature range from 298.15-323.15 K.

}, keywords = {ionic liquids, Molecular solvents, VFT equations, viscosity}, issn = {0095-9782}, doi = {10.1007/s10953-009-9390-7}, author = {Khupse, Nageshwar D. and Kumar, Anil} } @article { ISI:000268923200029, title = {Solubilization and conformational behavior of zein in aqueous solution of dodecyldimethylethylammonium bromide (DDAB)}, journal = {Colloids and Surfaces A-Physicochemical and Engineering Aspects}, volume = {346}, number = {1-3}, year = {2009}, month = {AUG}, pages = {195-201}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The solubilization and conformational behavior of Zein in the presence of cationic surfactant, dodecyldimethylethylammonium bromide (DDAB) have been studied. The colloidal properties of DDAB in the absence and presence of Zein have also been investigated using physico-chemical and spectroscopy methods. The surfactant appears to bind to Zein at concentrations below the critical micelle concentration (cmc) and the binding becomes weaker at concentrations above the cmc. The interaction between DDAB and Zein depends on the chemical structure and molecular parameters (conformation, molar mass, charge) of the protein. The schematic sketches of the molecular mechanisms of the complex formation between like-charged proteins and surfactants have been proposed. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Absorbance spectroscopy, Aggregation number, conductivity, DDAB, FT-IR, Surface tension, viscosity, Zein}, issn = {0927-7757}, doi = {10.1016/j.colsurfa.2009.06.016}, author = {Mehta, S. K. and Bhawna and Bhasin, K. K. and Kumar, Anil} } @article { ISI:000263021000003, title = {Vinyl-2-pyrrolidone derivatized guar gum based aqueous two-phase system}, journal = {Separation and Purification Technology}, volume = {65}, number = {1, SI}, year = {2009}, month = {FEB}, pages = {9-13}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Aqueous two-phase systems (ATPs) are formed when certain combinations of two polymers or polymer and salt are added to water. Phase separation occurs at certain specific concentrations that have similar densities and low interfacial tensions. The present study involves synthesis and application of a novel derivatized guar in aqueous two-phase system. The derivation of guar gum was performed by grafting of 1-vinyl-2-pyrrolidone by a redox reaction in aqueous medium ceric ammonium nitrate (CAN) and potassium Peroxydisulfate(K2S2O8). The ratio of grafting efficiency (\%GE) and ratio of grafting (\%G) was 56\% and 70.1\% respectively. The grafted copolymers were characterized for percent yield and FTIR absorbance. A new aqueous two-phase extraction protocol was established using a mixture of derivatized guar and dextran. A phase diagram was constructed based on the phase separation exhibited by the system at 25 degrees C. The partition coefficient was determined for standard bovine serum albumin (BSA), lactate oxidase (LO) and phytase. The partitioning coefficients were 0.479, 1.981, and 2.586 respectively in the Dextran (2 mill ion)/V-GG/H2O system. The influence of an ionic salt sodium chloride (NaCl) was investigated on the partitioning of BSA. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Aqueous two phase, graft copolymers, Guar gum, Partition coefficient (K), Phase diagram, Vinyl pyrrolidone, viscosity}, issn = {1383-5866}, doi = {10.1016/j.seppur.2008.03.020}, author = {Kautharapu, Kumar and Pujari, Narahari S. and Golegaonkar, Sandeep B. and Ponrathnam, Surendra and Nene, Sanjay N. and Bhatnagar, D.} } @article { ISI:000279017900002, title = {Ionic liquids: new materials with wide applications}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {49}, number = {5-6, SI}, year = {2010}, month = {MAY}, pages = {635-648}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

Ionic liquids have emerged as possible substitutes for volatile organic solvents and have found many applications in a variety of research areas. In this review, an effort has been made to discuss the special properties of ionic liquids that render these unique solvent media useful in chemical transformations, electrochemical applications, extractions, etc.

}, keywords = {Chemical processes, Electrochemical devices, ionic liquids, Physicochemical properties, Solvent properties, viscosity}, issn = {0376-4710}, author = {Khupse, Nageshwar D. and Kumar, Anil} } @article { ISI:000275937400001, title = {Solvent-induced viscosity changes in ionic liquids - a review}, journal = {Proceedings of the National Academy of Sciences India Section A-Physical Sciences}, volume = {80}, number = {1}, year = {2010}, month = {JAN}, pages = {1-12}, publisher = {NATL ACAD SCIENCES INDIA}, address = {5 LAJPATRAI RD, ALLAHABAD 211002, INDIA}, abstract = {

The high viscosity of several ionic liquids is an undesirable property for their applications in a variety of chemical reactions and electrochemical devices. Addition of a solvent in an ionic liquid is known to reduce its high viscosity to a great extent. In this review, an attempt has been made to examine the published data on the reduction in viscosities of many ionic liquids upon the addition of molecular solvents, including water. A tentative description has been provided for the drop in viscosities under these conditions. Analysis of the viscosity data with the help of empirical equations has been summarized. This critical review also outlines the future outlook of the required studies that might be useful to those who are interested in using ionic liquids for a variety of applications.

}, keywords = {ionic liquids, solvent, viscosity}, issn = {0369-8203}, author = {Khupse, Nageshwar D. and Kumar, Anil} } @article { ISI:000279017900010, title = {Temperature dependent viscosity of mixtures of ionic liquids at different compositions}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {49}, number = {5-6, SI}, year = {2010}, month = {MAY}, pages = {727-730}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

This work presents experimental investigations of viscosities of the mixtures of ionic liquids, viz., [bmim][BF(4)] + [bmim][PF(6)] and [hmim][BF(4)] + [hmim][PF(6)] at different temperatures. The temperature dependence of viscosities of these mixtures has been analysed in the light of Vogel-Fulcher-Tammann (VFT) equation with excellent accuracy. The viscosities of the mixtures have been analysed using a simple mixing rule.

}, keywords = {ionic liquids, viscosity}, issn = {0376-4710}, author = {Khupse, Nageshwar D. and Kurolikar, Shabana R. and Kumar, Anil} } @article { ISI:000292011000004, title = {Eutectic mixture-directed kinetics of Diels-Alder reaction}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {50}, number = {6}, year = {2011}, month = {JUN}, pages = {788-792}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

In the search for environmentally benign solvent media, a new class of solvents composed of mixtures of carbohydrates with urea or methylated urea has been noted to be effective in enhancing the reaction rates of a bimolecular organic reaction like the Diels-Alder reaction of cyclopentadiene with methyl acrylate. The viscosity of these media appears to be an important parameter in controlling the second order kinetics.

}, keywords = {carbohydrates, Cycloaddition, Diels-Alder reaction, Dimethylurea, kinetics, Reaction rates, solvent effects, Urea, viscosity}, issn = {0376-4710}, author = {Nagare, Amit S. and Kumar, Anil} } @article { ISI:000307351500021, title = {High viscosity of ionic liquids causes rate retardation of Diels-Alder reactions}, journal = {Science China-Chemistry}, volume = {55}, number = {8, SI}, year = {2012}, month = {AUG}, pages = {1633-1637}, publisher = {SCIENCE PRESS}, address = {16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA}, abstract = {

Second order rate constants, k (2) have been determined for three bi-molecular Diels-Alder reactions to demonstrate that the high viscosity of ionic liquids can be a detrimental property in carrying out Diels-Alder reactions, if ionic liquids are employed as solvent media. It is possible to enhance the reaction rates of the reaction if a co-solvent is mixed in pure ionic liquid used as a solvent.

}, keywords = {Diels-Alder reactions, ionic liquids, kinetics, viscosity}, issn = {1674-7291}, doi = {10.1007/s11426-012-4684-9}, author = {Kumar, Anil and Pawar, Sanjay S.} } @article { ISI:000327418000001, title = {Unusual salting effects in ionic liquid solutions}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {52}, number = {11}, year = {2013}, month = {NOV}, pages = {1377-1382}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

Unusual salting effects of salting-out agents like LiCl and NaCl and salting-in agents like LiClO4 and NaClO4 in ionic liquid solutions are reported. It is observed that the salting behavior in water can be altered in the presence of ionic liquids. It is demonstrated that the salting-in agents in the presence of the ionic liquids with higher alkyl chain can display unusual fall and rise in the viscosity of the systems. On the other hand, no change in the behavior of the salting-out agents is noted in these ionic liquids. A tentative explanation is proposed for the observed viscosity data in these systems.

}, keywords = {Cationic ring, ionic liquids, Salting effects, viscosity}, issn = {0376-4710}, author = {Nanda, Raju and Kumar, Anil} } @article { ISI:000362834600003, title = {Experimental signature of microheterogeneity in ionic liquid-H2O systems and their perturbation by adding Li+ salts: a pulsed gradient spin-echo NMR approach}, journal = {Chemphyschem}, volume = {16}, number = {14}, year = {2015}, month = {OCT}, pages = {2936-2941}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

Distinct microheterogeneity has been observed in the [OMIM]Br-H2O system, which is interestingly perturbed by the addition of Li+ salts, indicating unusual diffusivity of [OMIM]Br and H2O molecules. However, the diffusional dynamics of water clusters show contrasting salting behavior at higher concentrations of Li+ salts, following the classical salting phenomenon in lower amounts. In contrast, the existing microheterogeneity in the [BMIM]Br-H2O system is weak enough to show any perturbation caused by the Li+ salts on the NMR time scale.

}, keywords = {ionic liquids, lithium, microheterogeneity, salt effect, viscosity}, issn = {1439-4235}, doi = {10.1002/cphc.201500503}, author = {Nanda, Raju and Rajamohanan, P. R. and Kumar, Anil} } @article { ISI:000353289100023, title = {Interesting viscosity changes in the aqueous urea-ionic liquid system: effect of alkyl chain length attached to the cationic ring of an ionic liquid}, journal = {Journal of Solution Chemistry}, volume = {44}, number = {3-4, SI}, year = {2015}, month = {APR}, pages = {742-753}, publisher = {SPRINGER/PLENUM PUBLISHERS}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

In the present article, we demonstrate the effect of urea on the structure of the ionic liquids in their aqueous solutions through viscometric methods. We unravel the structure altering effect of urea in its aqueous solutions of ionic liquids possessing higher alkyl chains. The finding is an attempt to discern the anomalous behavior of urea as shown in the past with the help of many techniques. Interestingly, in the aqueous solutions of the imidazolium based ionic liquids having substitution of -C4H9 and -C6H13 groups on the imidazolium ring, urea exhibits kosmotropic behavior. Further increase in the substituted alkyl group such as -C8H17 alters the urea behavior to be chaotropic.

}, keywords = {Alkyl chain length, ionic liquids, Structure-breaker, Structure-maker, Urea, viscosity}, issn = {0095-9782}, doi = {10.1007/s10953-015-0320-6}, author = {Nanda, Raju and Rai, Gitanjali and Kumar, Anil} } @article { ISI:000365445500001, title = {Water-promoted diels-alder reaction in quaternary ammonium salts}, journal = {Journal of Physical Organic Chemistry}, volume = {28}, number = {11}, year = {2015}, month = {NOV}, pages = {665-673}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

{Prevailing classification of salts based on their effect in solubility and stability of proteins in aqueous solution predicts that tetraalkylammonium salts, guanidinium chloride (GnCl), LiClO4 act as salting-in (S/I) and LiCl, NaCl act as salting-out (S/O) in aqueous conditions. In the same context the behaviour of GnCl, LiClO4 and LiCl are contradictory in polar solvents like ethylene glycol and formamide. In these solvents, expected salt effect shows just opposite nature from their usual expectation. However, in the aqueous solution salts like tetraalkylammonium halide (R4NX

}, keywords = {Delta G(solvation), Diels-Alder reaction, k(s), kinetic study, solubility, tetraalkylammonium salts, viscosity}, issn = {0894-3230}, doi = {10.1002/poc.3469}, author = {Nagare, Amit S. and Manna, Arpan and Sonawane, Pramod D. and Kumar, Anil} } @article {43836, title = {Role of base fluid on the thermal conductivity of oleic acid coated magnetite nanofluids}, journal = {COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS}, volume = {529}, year = {2017}, month = {SEP}, chapter = {922-929}, abstract = {

Thermal conductivity enhancement of nanofluids of oleic acid coated magnetite nanoparticles dispersed in four different base fluids (toluene, xylene, mesitylene, kerosene) is studied to understand the role of the solvent (base fluid). From the correlation of the thermophysical properties of the base fluid with the thermal conductivity of the corresponding nanofluid, it is found that the nanofluid with the base fluid of lower intrinsic thermal conductivity and dielectric constant shows relatively larger enhancement in the thermal conductivity. A linear increase in the thermal conductivity with increasing viscosity is observed for all four nanofluids studied. The concentration dependent thermal conductivity studies showed enhancement only above a particular concentration, within the sensitivity of the measurement, and this critical concentration is different for the different nanofluids. The nanofluid with kerosene showed the lowest critical concentration for thermal conductivity enhancement compared to the other nanofluids. The difference between the experimental thermal conductivity and the calculated value using the Maxwell model is found to depend on the critical concentration. By assuming the critical concentration as the zero concentration, it is found that all the studied nanofluids almost follow the Maxwell model of thermal conductivity. Thus, for the dispersions of the same oleic acid coated magnetite nanoparticles, the base fluid affects the critical concentration for thermal conductivity enhancement, probably due to the interfacial effects arising from the surfactant-solvent interactions.

}, keywords = {Brownian-Motion, Enhancement, Heat-transfer Characteristics, Magnetic nanofluids, Maxwell model, Nanoparticles, Particle Migration, Size, stability, Suspension, Temprature, Thermal conductivity, Thermophysical properties, transport mechanism, viscosity}, issn = {0927-7757}, doi = {10.1016/j.colsurfa.2017.06.084}, author = {Lenin, Ramanujam and Joy, Pattayil Alias} } @article {49249, title = {Viscosity effects on the dynamics of diols and diol-based deep eutectic solvents}, journal = {Photochemistry and Photobiology}, volume = {100}, year = {2024}, month = {JUL}, pages = {946-955}, type = {Article}, abstract = {

Diols, characterized by the presence of two hydroxyl groups, form extended hydrogen-bonded networks. Increasing hydrocarbon chain length is known to elevate the viscosity of diols. Given the established influence of viscosity on solvent dynamics, it becomes imperative to comprehend the impact of viscosity on the fluctuation dynamics within diols and establish connections with hydrogen bond formation and breaking dynamics. In this study, we employ two-dimensional infrared spectroscopy to investigate the viscosity dependence of the structural evolution dynamics in three diols with varying chain lengths. Complementing our experimental approach, molecular dynamics simulations are conducted to extract hydrogen bond lifetimes. Our findings reveal a linear correlation between bulk viscosity, solvent fluctuation timescales, and hydrogen bond lifetimes. Notably, the selected diols exhibit the capability to form deep eutectic solvents upon mixing with choline chloride at specific molar ratios. In contrast to molecular solvents like diols, deep eutectic solvents are characterized by the formation of heterogeneous nanodomains, comprising various intercomponent hydrogen-bonded networks. Interestingly, our observations indicate that while the fluctuation dynamics decelerate with increasing bulk viscosity in diol-based deep eutectic solvents, the relationship between viscosity and dynamics is not linear, in contrast to the observed linearity in diols. This nuanced understanding contributes to the broader comprehension of the interplay between viscosity and dynamics in both molecular and deep eutectic solvents. We investigate the impact of viscosity on structural evolution dynamics in diols with varying chain lengths. Employing two-dimensional infrared spectroscopy and molecular dynamics simulations, we explore the relationship between bulk viscosity, solvent fluctuation timescales, and hydrogen bond lifetimes. We report a linear correlation in diols between viscosity, fluctuation timescales, and hydrogen bond lifetimes. Diols also form deep eutectic solvents, characterized by heterogeneous nanodomains. While fluctuation dynamics slow down with increasing bulk viscosity in diol-based deep eutectic solvents, the relationship between viscosity and dynamics is nonlinear, contrasting with diols{\textquoteright} linearity. This understanding enhances comprehension of viscosity-dynamics interplay in molecular and deep eutectic solvents.image

}, keywords = {Dynamics, Hydrogen bond, solvent, spectroscopy, viscosity}, issn = {0031-8655}, doi = {10.1111/php.13950}, author = {Chatterjee, Srijan and Deshmukh, Samadhan H. and Chowdhury, Tubai and Bagchi, Sayan} }