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Hybrid ionic fluids (HIFs) are newly emerging and fascinating sustainable solvent media, which are attracting a great deal of scientific interest in protecting the native structure of proteins. For a few decades, there has been a demand to consider ionic liquids (ILs) and deep eutectic solvents (DESs) as biocompatible solvent media for enzymes; however, in some cases, these solvent media also show limitations. Therefore, this work focuses on synthesising novel HIFs to intensify the properties of existing ILs and DESs by mixing them. Herein, HIFs have been synthesised by the amalgamation of a deep eutectic solvent (DES) and an ionic liquid (IL) with a common cation or anion. Later on, the stability and activity of hen's egg white lysozyme (Lyz) in the presence of biocompatible solvent media and HIFs were studied by various techniques such as UV-vis, steady-state fluorescence, circular dichroism (CD), Fourier transform infrared spectroscopy (FT-IR) and dynamic light scattering (DLS) measurements. This work emphasises the effect of a DES (synthesised using 1 : 2 choline chloride and malonic acid) [Maline], ILs (1-butyl-3-methylimidazolium chloride [BMIM]Cl or choline acetate [Chn][Ac]) and their corresponding HIFs on the structure and functionality of Lyz. Moreover, we also studied the secondary structure, thermal stability, enzymatic activity and thermodynamic profile of Lyz at pH = 7 in the presence of varying concentrations (0.1 to 0.5 M) of [BMIM]Cl and [Chn][Ac] ILs, Maline as a DES, and Maline [BMIM]Cl (HIF 1 ) and Maline [Chn][Ac] (HIF 2 ). Spectroscopic results elucidate that ILs affect the activity and structural stability of Lyz. In contrast, the stability and activity are inhibited by DES and are enhanced by HIFs at all the studied concentrations. Overall, the experimental results studied explicitly elucidate that the structure and stability of Lyz are maintained in the presence of HIF 1 while these properties are intensified in HIF 2 . This study shows various applications in biocompatible green solvents, particularly in the stability and functionality of proteins, due to their unique combination where the properties counteract the negative effect of either DESs or ILs in HIFs.

γ-Valerolactone (GVL) is a platform chemical for the synthesis of both biofuels and biochemicals. The LA production from depithed sugarcane bagasse (DSB) resulted in a 55% LA yield, and the resulting LA was used to produce GVL. The effect of process parameters, namely, temperature (25–200 °C), time (2–10 h), and catalyst loading (0.5–5 g) were investigated for the GVL production from LA. Thereafter, the optimized conditions were used to produce GVL from LA derived from depithed sugarcane bagasse (DSB) yielded a GVL of 77.6%. The hydrogen required for the reduction of LA to GVL was formed in situ by formic acid and triethylamine in the presence of methanesulfonic acid (MsOH). Different solvents (including water and alcohols) were also tested to determine their effect on GVL yield, and water yielded the highest GVL of 78.6%. Different types of catalysts, which included mineral acids and ionic liquids, were used to determine their effect on GVL yield, and to provide a benchmark against MsOH. The GVL yield from DSB-derived LA is 1.0% lower than the GVL yield from a commercial sample of LA. LA generated from DSB has the potential to replace fossil fuel-derived LA. [ABSTRACT FROM AUTHOR]

The micellar behavior of a nonionic surfactant, polyoxyethylene (20) sorbitan monolaurate (Tween-20) in different wt% of a hydrophilic ionic liquid, 3-methyl-1-pentylimidazolium tetrafluoroborate ([C 5 mim][BF 4 ]) was investigated using techniques like fluoremetry and dynamic light scattering. Two fluorescence probes viz. pyrene and pyrene-1-carboxaldehyde were utilized. The critical micelle concentration (cmc) of Tween-20 was found to increase with increasing amount of [C 5 mim][BF 4 ]. The significant increase in cmc and decrease in aggregation number ( N agg ) indicates an “unfavorable” micellization within aqueous Tween-20 solution when [C 5 mim][BF 4 ] is present. The increase in dipolarity upon [C 5 mim][BF 4 ] addition suggests increased water penetration due to the presence of [C 5 mim][BF 4 ] in the micellar pseudophase. Dynamic light scattering studies provide the evidence of micelle-like aggregates even in the presence of 2 wt% [C 5 mim][BF 4 ]. [ABSTRACT FROM AUTHOR]

The densities of the ternary systems containing the ionic liquid 1-butyl-3-methylimidazolium methyl sulphate ([BMIM] [MeSO4] ) were determined. The ternary systems studied were ([BMIM] [MeSO4] + nitromethane + methanol or ethanol or 1-propanol) at the temperatures (303.15 and 313.15) K. The ternary excess molar volumes were calculated from the experimental densities at each temperature, being negative for allmole fractions of the ionic liquid. Theminimumternary excess molar volumes increase with an increase in temperature for the systems ([BMIM] [MeSO4] + nitromethane + methanol or ethanol), and decrease for the system ([BMIM] [MeSO4] nitromethane + 1-propanol). The results are interpreted in terms of the alcohol chain length and the intermolecular interactions. [ABSTRACT FROM AUTHOR]

The densities and speeds of sound for binary mixtures containing the solute ionic liquid (IL) methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([MOA][TfN]), solute/solvent methanol, and solvent methyl acetate have been measured at 298.15, 303.15, 308.15 and 313.15 K at atmospheric pressure. The binary mixtures studied are ([MOA][TfN] + methyl acetate or methanol), and (methanol + methyl acetate). The apparent molar volume, V and the apparent molar isentropic compressibility, k, have been evaluated from the experimental density and speed of sound data, respectively. The parameters of a Redlich-Mayer type equation were fitted to the apparent molar volume and apparent molar isentropic compressibility data. The apparent molar volume and apparent molar isentropic compressibility at infinite dilution, $V_{\phi}^{0}$ and $k_{\phi}^{0}$, respectively, of the binary solutions have also been calculated at each temperature. The infinite dilution apparent molar volume indicates that intermolecular interactions for (IL + methyl acetate) mixtures are stronger than for (IL + methanol) mixtures at all temperatures except at 298.15 K, and that $V_{\phi}^{0}$ for the (IL + methyl acetate or methanol) binary systems increases with an increase in temperature. For the (methanol + methyl acetate) system the intermolecular interaction are weaker and $V_{\phi}^{0}$ also increases with an increase in temperature. Values of the infinite dilution apparent molar expansibility, $E_{\phi}^{0}$, indicate that the interaction between (IL + methyl acetate) is greater than for (IL + methanol) and (methanol + methyl acetate). The isentropic compressibilities increase with an increase in temperature for each binary system. At a fixed temperature the isentropic compressibilities also increase with an increase in concentration of the solute for the systems (IL + methyl acetate) and (methanol + methyl acetate), but decrease for the system (IL + methanol). Negative values of $k_{\phi}^{0}$ for ([MOA][TfN] + methyl acetate or methanol) and (methanol + methyl acetate) mixtures can be attributed to the predominance of a penetration effect resulting in greater resistance to compression. [ABSTRACT FROM AUTHOR]

Abstract: The activity coefficient at infinite dilution for 30 solutes: alkanes, alkenes, cycloalkanes, alkynes, ketones, alcohols, and aromatic compounds was determined from gas–liquid chromatography (glc) measurements at three temperatures (303.15, 313.15, and 323.15)K. The ionic liquid: trioctylmethylammonium bis(trifluoromethylsulfonyl)imide, was used as the stationary phase. For each temperature, values were determined using two columns with different mass percent packing of the ionic liquid. The selectivity value was calculated from the to determine the suitability of the solvent as a potential entrainer for extractive distillation in the separation of an hexane/benzene mixture, indicative of a typical industrial separation problem for benchmarking purposes. [Copyright &y& Elsevier]

Excess molar volumes have been evaluated from density measurements over the entire composition range for binary systems of an ionic liquid (IL) and an alcohol at T = (298.15, 303.15 and 313.15) K. The IL is 1-butyl-3-methylimidazolium methylsulphate [BMIM]+[MeSO4]- and the alcohols are methanol, ethanol or 1-propanol. The Redlich-Kister smoothing polynomial equation was used to fit the excess molar volume data and the partial molar volumes were determined from the Redlich-Kister coefficients. For all the systems studied, the excess molar volumes were negative over the entire composition range at all temperatures. The results are interpreted in terms of the alcohol chain length and the intermolecular interactions. [ABSTRACT FROM AUTHOR]

Abstract: Excess molar volumes, have been evaluated from density measurements over the entire composition range for ternary liquid system of ionic liquid (1-ethyl-3-methyl-imidazolium diethylenglycol monomethylether sulphate {[EMIM][CH3(OCH2CH2)2OSO3]) (1)+methanol (2)+water (3)} at T =(298.15, 303.15, and 313.15)K. A vibrating tube densimeter was used for these measurements at atmospheric pressure. The values were found to be negative at T =(298.15 and 303.15)K. For {[EMIM][CH3(OCH2CH2)2OSO3] (1)+methanol (2)+water (3)} at T =313.15K the values become positive at higher mole fraction of ionic liquid and at a corresponding decrease in mole fraction of water. All the experimental data were fitted with the Redlich–Kister equation. The results have also been analysed in term of graph theoretical approach. [Copyright &y& Elsevier]

The liquid–liquid equilibrium data are presented for ternary mixtures {1-methyl-3-octyl-imidazoliumchloride (MeOctImCl) + benzene + an alkane} at T=298.2 K. The alkanes used were heptane, dodecane, and hexadecane. The compositions of the ternary mixtures on the coexistence curve and the conjugate solutions were evaluated using densities and a standard density calibration curve. The solvent MeOctImCl is an ionic liquid, which has a very low vapour pressure and a very high boiling temperature, and is therefore, a potentially environmentally friendly solvent. This ‘neoteric’ solvent is soluble in water and stable in air. There are very few data in the literature on ternary mixtures involving ionic liquids. The NRTL equation was used to correlate the experimental tie-lines. The NRTL equation gave good correlation of the tie-line data. There are no data in the literature for the mixtures discussed in this paper. The effectiveness of the extraction of benzene from an alkane by MeOctImCl is reported as a ratio of solubilities in the two phases. This quantity, known as the ‘selectivity’, was found to increase with increasing carbon number of the alkane. [Copyright &y& Elsevier]

Background: Sugarcane bagasse is an abundant and geographically widespread agro-industrial residue with high carbohydrate content, making it a strong candidate feedstock for the bio-based economy. This study examines the use of the low-cost protic ionic liquid triethylammonium hydrogen sulfate ([TEA][HSO4]) to fractionate a range of South African sugarcane bagasse preparations into a cellulose-rich pulp and lignin. The study seeks to optimize pretreatment conditions and examine the necessity of applying a depithing step on bagasse prior to pretreatment. Results: Pretreatment of five bagasse preparations, namely whole, industrially depithed, laboratory depithed (short and long fiber) and pith bagasse with [TEA][HSO4]:[H2O] (4:1 w/w) solutions produced highly digestible cellulose-rich pulps, as assessed by residual lignin analysis and enzymatic hydrolysis. Pretreatment under the optimized condition of 120 °C for 4 h produced a pretreated cellulose pulp with up to 90% of the lignin removed and enabled the release of up to 69% glucose contained in the bagasse via enzymatic hydrolysis. Glucose yields from whole and depithed bagasse preparations were very similar. Significant differences in lignin recovery were obtained for laboratory depithed bagasse compared with whole and industrially depithed bagasse. The silica-rich ash components of bagasse were seen to partition mainly with the pulp, from where they could be easily recovered in the post-hydrolysis solids. Conclusions: The five bagasse preparations were compared but did not show substantial differences in composition or cellulose digestibility after pretreatment. Evidence was presented that a depithing step appears to be unnecessary prior to ionoSolv fractionation, potentially affording significant cost and energy savings. Instead, lignin re-deposition onto the pulp surface (and, in turn, particle size and shape) appeared to be major factors affecting the conditioning of bagasse with the applied IL. We show that pith bagasse, a common by-product of paper making, can be successfully conditioned for high glucose release while allowing recovery of lignin and silica-rich ash. The glucose yields obtained for bagasse using [TEA][HSO4]-water mixtures were ~ 75% as high as for conventional aprotic ionic liquids such as [Emim][OAc]; this result is highly promising for commercialization of ionoSolv processing given [TEA][HSO4] is 40 times less expensive, thermally stable and recyclable. [ABSTRACT FROM AUTHOR]

• New limiting activity coefficients for 33 solutes in ionic liquid and eutectic solvent. • Intermolecular interactions explained through excess thermodynamic properties. • Influence of diethylene glycol on ionic liquid is discussed. • COSMO-SAC predictions were qualitatively in very good agreement with the experimental data. One of the suitable and convenient techniques in predicting the feasibility of an extracting solvent for liquid mixtures is to compare the selectivity and capacity of the components to be separated at infinite dilution. In this work, the separation parameters (selectivity and capacity) were calculated from the activity coefficients at infinite dilution. The activity coefficients at infinite dilution were computed from the retention data acquired by a gas liquid chromatography operated at different temperatures, T = (313.15 – 373.15) K and at atmospheric pressure. The volatile organic solutes (alkanes, alkenes, alkynes, alcohols, ketones, aromatic hydrocarbons, tetrahydrofuran, thiophene and acetonitrile) were tested in 1-ethyl-3-methylimidazolium tetrachloroaluminate and an eutectic solvent (1-ethyl-3-methylimidazolium tetrachloroaluminate and diethylene glycol). The influence of diethylene glycol on 1-ethyl-3-methylimidazolium tetrachloroaluminate ionic liquid in separation of molecular solutes was discussed. The results were interpreted in terms of molecular interactions occurring between the investigated extracting solvents and volatile organic solvents. These were further elucidated by computing the excess thermodynamic parameters at infinite dilution including (enthalpies, Δ H 1 E , ∞ , Gibbs free energies, Δ G 1 E , ∞ , and entropy term, T ref Δ S 1 E , ∞ ). The values of selectivity and capacity were calculated for the separation problems comprising azeotropic mixtures and the values were compared with other possible extracting solvents found in the literature. Both investigated solvents were suitable for the extraction of cyclohexane/ethanol, acetone/ethanol, or tetrahydrofuran/methanol. For the stated mixtures, the IL gave selectivity values approximately greater than the mixed ionic liquid with diethylene glycol. COSMO-SAC predictions were qualitatively in very good agreement with the experimental data. The model predicted the results in the correct quadrant. The signal for the effect of temperature on the activity coefficients at infinite dilution values were predicted correctly for the solutes in the ionic liquid and eutectic solvent. [ABSTRACT FROM AUTHOR]

Abstract: Experimental densities, speeds of sound, and refractive indices of the binary mixtures {1-butyl-3-methylimidazolium methylsulphate ([BMIM]+[MeSO4]−)+methanol, or 1-propanol, or 2-propanol, or 1-butanol} were measured over the whole range of composition at T =(298.15, 303.15, 308.15, and 313.15)K. From the experimental data, excess molar volumes, excess isentropic compressibilities, deviation in refractive indices and molar refractions were calculated. The excess molar volumes, change in isentropic compressibilities, and deviation in refractive indices were fitted by the Redlich–Kister smoothing polynomial. The Lorentz–Lorenz equation was applied to correlate the volumetric properties and predict the density or the refractive index of the binary mixtures. Results for these quantities have been discussed in terms of intermolecular interactions between the components of the mixtures. For all the systems studied, the excess molar volume and excess isentropic compressibility are negative, while the change in refractive index on mixing is always positive over the entire composition range and at all temperatures. [Copyright &y& Elsevier]

Abstract: Activity coefficients at infinite dilution have been determined for 27 solutes, viz. water and organic compounds (n-alkanes, cycloalkanes, 1-alkenes, 1-alkynes, aromatics, alcohols, and ketones) in the ionic liquid Ammoeng 100, by gas–liquid chromatography at four different temperatures, T =(308.15, 313.15, 323.15, and 333.15)K. Columns with different phase loadings (20 to 24)% of the ionic liquid in the stationary phase were employed to obtain values at each temperature investigated. Partial molar excess enthalpies at infinite dilution () were calculated for the solutes from the temperature dependency relationship of the values for the temperature range in this study. The uncertainties in the determinations of the and values are 6% and 10%, respectively. Selectivity values at infinite dilution (), have been computed from the values to assess the potential candidacy of the Ammoeng 100 ionic liquid for the separation of alkane/alcohol mixtures. The results from this study have been compared to those available for several ionic liquids from previous investigations. [Copyright &y& Elsevier]

Abstract: In this work, activity coefficients at infinite dilution () have been obtained for 19 polar and non-polar organic solutes in the form of n-alkanes, cycloalkanes, 1-alkenes, 1-alkynes, aromatic compounds, and ketones in the ionic liquid methyl(trioctyl)ammonium thiosalicylate by gas–liquid chromatography at three different temperatures, i.e. T =(303.15, 313.15, and 323.15)K. Two columns with different phase loadings of the ionic liquid in the stationary phase (25% and 30%) were employed to obtain values at each temperature investigated. Partial molar excess enthalpies at infinite dilution () were calculated for each of the solutes from the temperature dependency of the values for the temperature range in this study. Selectivity values at infinite dilution () were computed from the values to screen the potential candidacy of the ionic liquid for the separation of n-hexane/benzene mixtures. The results from this study have been compared to those available for several other classes of ionic liquids and commercial solvents employed in solvent-enhanced industrial separation processes. [Copyright &y& Elsevier]

The molecular interactions of amino acids with the different ionic liquids (ILs) are important in order to study the stability and behavior of the amino acids. In this study, we have examined the interactions of glycine in the aqueous solutions with two aprotic ionic liquids based on cholinium cation, namely, cholinium propanoate [Chl][Pro] and cholinium hexanoate [Chl][Hex]. The different interactions were quantified through their partial molar volumes (V ϕ) where it was found that the shorter chained [Chl][Pro] interacts more with the molecules of the glycine, compared to [Chl][Hex]. The derivation of infinite dilution parameter through the application of the Masson equation revealed further insights into the different types of interactions. The calculated limiting partial molar volume of transfer, (Δ V ϕ 0 values for water to aqueous solutions of ILs indicated that hydrophobic-hydrophobic interactions dominates over other attractive interactions in longer chain [Chl][Hex] than in [Chl][Pro]. The calculation of hydration number (n H) revealed that with increasing IL concentrations, lesser number of water molecules remain attached to the glycine, indicating the structure breaking nature of the ILs, which were further confirmed from the Hepler equation. Unlabelled Image • Apparent molar properties of glycine in aqueous solutions of choline based ionic liquids were investigated. • The V ∅ values for glycine in aq. [Chl][Pro] were found to be higher than that of aq. [Chl][Hex]. • Solute–solvent interactions dominate over solute–solute interactions in studied systems [ABSTRACT FROM AUTHOR]

Abstract Thermoresponsive polymers (TRPs) that undergo significant conformation/aggregation changes in response to changes in temperature have extensive range of potential applications in various fields of science and technology. Among different types of TRPs, poly (N -isopropylacrylamide) (PNIPAM) is a suitable amphiphilic polymer for studying the conformational changes due to its biocompatible behavior with various additives. In order to get deeper insights of the TRPs in the presence of additives, we examined the collapse and aggregation of thermoresponsive polymer (PNIPAM) in aqueous solution containing variable amounts of 1-allyl-3-methylimidazolium bromide ([Amim][Br]). The influence of ionic liquid on the lower critical solution temperature (LCST) of PNIPAM aqueous solution were examined with the aid of comprehensive biophysical techniques such as UV–visible absorption spectroscopy, steady-state fluorescence spectroscopy, thermal fluorescence spectroscopy, viscosity (η) and dynamic light scattering (DLS) measurements. With the addition of 5 mg/mL of [Amim][Br] to the PNIPAM aqueous solution the LCST has been decreased towards lower temperatures. Further with the addition of higher concentration (10 and 15 mg/mL) of [Amim][Br] the decrease in the LCST of PNIPAM has been more pronounced towards lower temperatures. Our experimental results explicitly elucidated that the decrease in the LCST of the PNIPAM with increase in the concentration of [Amim][Br] is due to the substantial variations in the interactions among amide group of polymer, ions of ionic liquid and water molecules. The experimental results of the current investigation can be used for the design of smart polymer-based devices, as its LCST is close to body temperature. The results provide an alternative way to tune the phase transition temperature of the broadly accepted model PNIPAM polymer. Graphical abstract Schematic depiction of interactions between PNIPAM aqueous solution and [Amim][Br]. Unlabelled Image Highlights • To explore the interactions between polymer and an ionic liquid • Examined the influence of the [Amim][Br] on the phase transition behavior of PNIPAM • [Amim][Br] decreased the lower critical solution temperature of PNIPAM. • The addition of [Amim][Br] creates disturbance in the hydration shell around PNIPAM polymer. • The results elucidated the hydrated state of the polymer becomes a dehydrated state. [ABSTRACT FROM AUTHOR]

A solution protocol to synthesize CdS quantum dots (QDs) using 1-ethyl-3-methylimidazolium methanesulfonate ionic liquid is described in this work. Various reaction parameters such as temperature and injection protocols were varied to study the optical and structural properties of the obtained particles. X-ray diffraction (XRD) studies confirmed the formation of cubic and hexagonal phases depending on the reaction conditions. Peak broadening in the diffraction patterns revealed the formation of small sized quantum dots and the morphological studies further showed formation of nano-sized particles in the range of 2–15 nm, with close to spherical shaped morphologies. Blue-shifted band gaps further confirmed formation of very small CdS nanoparticles, which dependent on the reaction temperatures. [ABSTRACT FROM AUTHOR]

The influence of different alkylammonium-based ionic liquids (ILs) on the temperature-dependent aqueous poly( N -isopropylacrylamide) (PNIPAM) solution is explored by the comprehensive experimental analysis. The co-solvents investigated in the present study included a series of ILs with a fixed (trifluromethylsulfonyl)imide [NTf 2 ] − anion and variable ammonium cations such as butyltrimethylammonium (IL-1), methyl-trioctylammonium (IL-2), diethylmethyl(2-methoxyethyl)ammonium (IL-3) and ethyldimethylpropylammonium (IL-4). The thermal phase transitions of aqueous solution of thermo-responsive polymer (TRP) in ammonium-based ILs were studied by various experimental techniques such as fluorescence spectroscopy, dynamic light scattering (DLS) and viscosity ( η ). We further employed field emission scanning electron microscope (FESEM) to reveal the distinct morphological changes of various self-assembled morphologies. Our results reveal that the lower critical solution temperature (LCST) of the TRP can be significantly altered by the ILs. The phase transition state of aqueous TRP decreases as the concentration of IL increased. We find that IL-4 lowers the LCST of TRP significantly more as compared to the other ILs. Our experimental results reveal that the hydrophobic interactions are predominant between the monomers of PNIPAM and ions of the ILs. This research work highlights new opportunities for the wide applications in engineering of the bio-responsive smart PNIPAM-based devices and appropriate selection of ILs, which should allow for increasing the usage of thermo-responsive phase behaviour of polymers. [ABSTRACT FROM AUTHOR]

In this study, the solvation behaviour of monosaccharide's in aqueous solutions of newly synthesized ionic liquid: cholinium propanoate [Chl][Pro] has been studied at various temperatures and concentrations. The volumetric properties of two monosaccharides (viz. D (+)glucose and D (+)-xylose) were evaluated from density and speed of sound data. Apparent molar volume, V 2,φ and apparent molar isentropic compressibility, K s,2,φ calculated from experimental data were used to evaluate respective infinite dilution values (X 2 º = V 2 º or K º s,2). The volumetric transfer volumes (Δ t V 2 º or Δ t K º s,2) were also evaluated to analyze the solute-co-solute interactions. The Δ t V 2 º and Δ t K º s,2 values reveal that the interaction between ionic liquid and monosaccharides increases with concentration and temperature. The positive transfer parameter reveals hydrophilic-ionic interactions as evaluated from structural interaction model. Image 1 • Solute-solvent interactions of monosaccharides in aq. ionic liquid have been studied. • Positive Δ t V 2 º and Δ t K º s,2 values for D (+)Glucose in aq. [Chl][Pro] have been observed. • Positive transfer values suggest the dominance of hydrophilic type of interactions. • D (+)-xylose demonstrated both positive and negative Δ t V 2 º values. • Negative transfer values suggest dominance of hydrophobic types of interactions. [ABSTRACT FROM AUTHOR]

Thermoresponsive polymers (TRPs) are known to exhibit changes in conformational states, with a change in the solution temperature. Obviously, temperature is the key factor that responds to the conformational transition behavior of TRPs. Among various TRPs, poly (N -vinylcaprolactam) (PVCL) is a suitable amphiphilic polymer for the study of conformational changes due to its compatible behavior with various additives. In the current study, the effect of 1-allyl-3-methylimidazolium bromide ([Amim][Br]) on phase transition behavior of PVCL aqueous solution was studied. In order to investigate the alterations on phase behavior of PVCL in [Amim][Br], various biophysical techniques such as ultraviolet-visible absorption spectroscopy, steady-state fluorescence spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermal fluorescence spectroscopy, dynamic light scattering (DLS) and differential scanning calorimetry (DSC) were used. Our experimental results explicitly elucidated that [Amim][Br] increases the lower critical solution temperature (LCST) of PVCL with increasing the concentration of ionic liquid (IL). The main rationale observed is attributed to the IL interaction affinity depending on its cationic and anionic part's affinity towards water molecules that are strongly attached to the bonds in pure PVCL and become more attracted to the IL and thus resulted in the facilitation of hydrated form of PVCL. Unlabelled Image [ABSTRACT FROM AUTHOR]