Indra Bahadur and Nirmala Deenadayalu*

Size: px

Start display at page:

Download "Indra Bahadur and Nirmala Deenadayalu*"

Esmond Bennett
5 years ago
Views:

1 RESEARCH ARTICLE I. Bahadur and N. Deenadayalu, 200 Densities and Excess Molar Volue for the Ternary Systes (1-Butyl-3-ethyliidazoliu ethyl sulphate + Nitroethane + Methanol or Ethanol or 1-Propanol) at T = ( and ) K Indra Bahadur and Nirala Deenadayalu* Departent of Cheistry, Durban University of Technology, Steve Biko Capus, P.O. Bo334, Durban 4000, South Africa. Received 10 Septeber 2012, revised 16 May 2013, accepted 7 June ABSTRACT The densities of the ternary systes containing the ionic liquid 1-butyl-3-ethyliidazoliu ethyl sulphate ( ] ) were deterined. The ternary systes studied were ( ] + nitroethane + ethanol or ethanol or 1-propanol) at the teperatures ( and ) K. The ternary excess olar volues were calculated fro the experiental densities at each teperature, being negative for all ole fractions of the ionic liquid. The iniu ternary excess olar volues increase with an increase in teperature for the systes ( ] + nitroethane + ethanol or ethanol), and decrease for the syste ( ] + nitroethane + 1-propanol). The results are interpreted in ters of the alcohol chain length and the interolecular interactions. KEYWORDS Density, excess olar volue, ionic liquid, alcohol, nitroethane. 1. Introduction Ionic liquids (ILs) are low-elting olten salts which are coposed of organic cations, and inorganic anions and their properties depend on the type of cation and anion. 1 ILs are studied as green solvents for organic reactions, cobined with a catalyst to extend its life span, and as reagents for nanoaterials. 2,3 The physical properties of ILs such as density, viscosity, elting point, polarity and iscibility with water or olecular solvents, can be finely tuned by changing either the anion or the cation. 2 6 ILs have other properties such as very low vapour pressure, wide electrocheical window, high recyclability, good ionic conductivities, theral stability and nonflaability 7,8 aking the useful solvents for a wide range of applications. 9,10 The applications of ILs are rapidly increasing in all odern scientific fields such as, separations, 11 organic synthesis, 12 hoogeneous two-phase catalysis, 13 extractions, 14 electrocheistry, 15 and polyerization processes. 16 Therophysical properties of ixtures of ILs with different solvents are useful for the design of cheical separation processes. 17,18 Ternary excess olar volues, V E, for IL systes have been reported by various researchers In this paper the densities were easured for the ternary systes ( ] + nitroethane + ethanol or ethanol or 1-propanol) over the entire coposition range at T = ( and ) K and at atospheric pressure. V E data were calculated at T = ( and ) K and at atospheric pressure for IL systes by using the experiental density values. The results are interpreted in ters of interolecular interactions and the alcohol chain length. This work is a continuation of our research group s work on therodynaic properties of 21 26, ILs. * To who correspondence should be addressed. E-ail: niralad@dut.ac.za 2. Experiental 2.1. Materials The cheicals were purchased fro Aldrich or Merck or Fluka and used without further purification. The cheicals, supplier, purity and the literature and experiental density (r) are given in Table 1. The density of the pure cheicals was deterined at T = ( and ) K and at atospheric pressure. The water content in the IL was deterined by using a Karl-Fischer couloeter (Metroh797, Herisau, Switzerland) and the ass percent water content was found to be < The purity of the pure cheicals was assessed by a coparison of the experiental density values with the literature density values where available. 31,36 The structure of the IL used in this work is given in Fig. 1. Figure 1 Structure of 1-butyl-3-ethyliidazoliu ethyl sulphate ] Apparatus and Procedure The ternary ixtures were prepared by transferring the pure liquids into stoppered bottles to prevent evaporation. The IL was first filled into the air-tight glass stoppered 5 c 3 glass vial and weighed. An OHAUS (Pine Brook, NJ, USA) ass balance was used to deterine the ass of each coponent of the ixture. The ass balance has a precision of g. The uncertainty in the ole fraction was estiated to be The ternary ixtures were prepared fro a spreadsheet calculation to obtain a constant z ratio (z = x 2 ) where and x 2 are the ole fractions of the ionic liquid and nitroethane, respectively, with varying ole fractions of ethanol or ethanol or 1-propanol ( ). The densities were easured with an Anton Paar (Graz, Austria)

2 RESEARCH ARTICLE I. Bahadur and N. Deenadayalu, 201 Table 1 Pure copound specifications: supplier, purity, literature and experiental density at T = ( and ) K. Cheical Supplier Purity/ole fraction r/g c 3 Literature Experiental T = K T = KT T= K Methanol Siga-Aldrich a Ethanol Siga-Aldrich a Propanol Merck a Nitroethane Siga-Aldrich b ] Siga-Aldrich b a Reference 31. b Reference 36. DMA 38 vibrating U-tube densieter. Ultra-pure water supplied by SH Calibration Service GbH Graz, Austria and dried air were used for the calibration of the densieter at T = K. 29 The teperature aintenance and control were regulated by a built-in therostat controller with a teperature uncertainty of ±0.02 K. The repeatability and accuracy in experiental easureents was (± and ±0.001) g c 3 for density. The uncertainty in density for the ternary syste was ±0.001 g c 3. The ternary excess olar volues V E were calculated fro the experiental density. The experiental uncertainty in V E was ±0.2 c 3 ol 1. The experiental technique was validated by easuring the density for the test syste (octane + toluene) at T = K and coparing it with the literature density. 37 The difference between experiental and literature density for the test syste was within the experiental error. 3. Results and Discussion Densities, r, and ternary excess olar volues, V E, for the (IL + nitroethane + ethanol or ethanol or 1-propanol) systes as a function of coposition at T = ( and ) K are given in Tables 2 4. TheV E was calculated by using Equation (1): E xm x2m2 + xm 3 3 xm 1 1 x2m2 xm 3 3 V = (1) r r1 r2 r3 where M 1, M 2 and M 3 are the olecular asses, r 1, r 2, and r 3 are the densities of pure coponents 1, 2, or 3, respectively, where 1 refers to the IL, 2 to nitroethane and 3 to ethanol or ethanol or 1-propanol and r is the density of the ixture. The binary V E data for (IL + ethanol) 31, (IL + ethanol) 31, (IL + 1-propanol) 31, (IL + nitroethane) 36, (ethanol + nitroethane) 38, (ethanol + nitroethane) 38 and (1-propanol + nitroethane) 38 were published in the literature. For each ternary syste there are three sets of binary data: (i) (IL + an alcohol) (ii) (IL + nitroethane) and (iii) (an alcohol + nitroethane). (i) (IL + nitroethane + ethanol) The binary V E data for (IL + ethanol) at the teperatures ( and ) K are negative for all ole fractions of the IL due to the ore efficient packing and/or attractive interaction between the IL and the ethanol olecules. 31 The V E values at the teperatures ( and ) K are c 3 ol 1 at = and c 3 ol 1 at = , respectively. 31 For the syste (IL + nitroethane) V E are negative at the teperatures ( and ) K, and at all ole fractions of the IL. 25 The V E,in values at the teperatures ( and ) K are c 3 ol 1 and c 3 ol 1, respectively, both occurring at = For the binary syste (ethanol + nitroethane) V E is negative at the teperature K, and both positive and negative at the teperature K due to the hydrogen bond rupture and dispersive interactions between unlike olecules (positive contributions) and dipole dipole interactions and geoetrical fitting of the nitroethane into the ethanol structure (negative contributions). 38 The V E,invalues at the teperatures ( and ) K are c 3 ol 1 at = and c 3 ol 1 at = , respectively. 38 Figures 2 and 3 are the plots of V E vs. ole fraction of ethanol for the ternary syste (IL + nitroethane + ethanol).v E values are negative for the ternary coposition curves, as can be Figure 2 Graph of excess olar volues, V E,for the ternary ixture ] - ( ) + nitroethane (x 2 ) + ethanol ( ) against ole fraction of ethanol at T = K at constant z = x 2. The sybols represent experiental results:d, ;, ;, ;, ;,. Figure 3 Graph of excess olar volues, V E, for the ternary ixture ] ( ) + nitroethane (x 2 ) + ethanol ( ) against ole fraction of ethanol at T = K at constant z = x 2. The sybols represent experiental results: D, ;, ;, ;, ;,.

3 RESEARCH ARTICLE I. Bahadur and N. Deenadayalu, 202 Table 2 Densities and excess olar volue for ionic liquid ( ) + nitroethane (x 2 ) + ethanol ( ) at T = ( and ) K. r/g c 3 V E 3 1 /c ol ] ( ) + nitroethane (x 2 )+ ethanol ( ) T = K T = K r/g c 3 V E 3 1 /c ol expected, since the three binary V E,in values are all negative. The negative values of V E for (IL + nitroethane + ethanol) show that the (ion-dipole) interactions and packing effect between ethanol, nitroethane and the IL are doinating over the dissociation of any interolecular hydrogen bonds in ethanol and nitroethane. 27 Fro Table 2, it can be seen that for the syste ([BMIM] + [MeSO 4 ] + nitroethane + ethanol) V E,indecreases with a decreasing z values (increasing ole fractions of IL) except at at the teperatures ( and ) K and also at for the teperature K. Fro Table 2, it can also be seen that the V E,in increases with an increase in teperature for the syste ( ] + nitroethane + ethanol). The V E,invalues of ( 2.0 and 1.9) c 3 ol 1 at each teperature are siilar in agnitude to the V E values for the ( ] + ethanol) binary syste. 31 (ii) (IL + nitroethane + ethanol) The binary V E data for (IL + ethanol) at the teperatures ( and ) K are negative for all ole fractions of the IL due to the sae effects that occur in the binary syste (IL + ethanol). The V E,invalues at the teperatures ( and ) K both occur at = and are c 3 ol 1 and c 3 ol 1, respectively. 31 The binary excess olar volues of (IL + ethanol) are greater than for the (IL + ethanol) systes. 31 For the binary syste (ethanol + nitroethane) V E are both positive and negative at the teperatures ( and ) K due to the sae effects that occur in the binary syste (ethanol + nitroethane). 38 The V E,invalues at the teperatures ( and ) K are c 3 ol 1 at = and c 3 ol 1 at = , respectively. 38 The binary excess olar volues of (ethanol + nitroethane) are greater

4 RESEARCH ARTICLE I. Bahadur and N. Deenadayalu, 203 Table 3 Densities and excess olar volue for ionic liquid ( ) + nitroethane (x 2 ) + ethanol ( ) at T = ( and ) K. r/g c 3 V E 3 1 /c ol ] ( ) + nitroethane (x 2 ) + ethanol ( ) T = K T = K r/g c 3 V E 3 1 /c ol than those for the binary syste (ethanol + nitroethane). Figures 4 and 5 are the plots of V E versus ole fraction of ethanol for the ternary syste (IL + nitroethane + ethanol). V E values are negative for the ternary coposition curves. The negative values of V E for the ternary syste (IL + nitroethane + ethanol) are due to the sae effects that occur in the ternary (IL + nitroethane + ethanol) syste. Fro Table 2, it is evident that for the syste ([BMIM] + [MeSO 4 ] + nitroethane + ethanol) V E,indecreases with a decreasing z value except at and 0.04 for both the teperatures ( and ) K. Also, V E,in increases with an increase in teperature for the syste ( ] + E nitroethane + ethanol). TheV,in values of ( 1.8 and 1.7) c3 ol 1 E at each teperature are siilar in agnitude to the V values for the ( ] + ethanol) binary syste. 31 The V E,inof (IL + nitroethane + ethanol) is greater than (IL+ nitroethane + ethanol) for each teperature Figure 4 Graph of excess olar volues, V E, for the ternary ixture ] ( ) + nitroethane (x 2 ) + ethanol ( ) against ole fraction of ethanol at T = K at constant z = x 2. The sybols represent experiental results: D, ;, ;, ;, z = 0.23;,.

5 RESEARCH ARTICLE I. Bahadur and N. Deenadayalu, 204 Table 4 Densities and excess olar volue for ionic liquid ( ) + nitroethane (x 2 ) + 1 propanol ( ) at T = ( and ) K. r/g c 3 V E 3 1 /c ol ] ( ) + nitroethane (x 2 ) + 1-propanol ( ) T=303.15K T = K r/g c 3 V E 3 1 /c ol (iii) (IL + nitroethane + 1-propanol) The binary V E data for (IL + 1-propanol) at the teperatures ( and ) K are negative for all ole fractions of the IL due to the sae effects that occur in the binary systes (IL + ethanol or ethanol). The V E,in values at the teperatures ( and ) K both occur at = are c 3 ol 1 and c 3 ol 1, respectively. 31 The binary excess olar volues of (IL + 1-propanol) are greater than (IL + ethanol) that are greater than the (IL + ethanol) syste due to the increase in the alcohol chain length. 31 Figure 5 Graph of excess olar volues, V E, for the ternary ixture ] ( ) + nitroethane (x 2 ) + ethanol ( ) against ole fraction of ethanol at T = K at constant z = x 2. The sybols represent experiental results: D, ;, ;, ;, ;,.

6 RESEARCH ARTICLE I. Bahadur and N. Deenadayalu, ethanol) is greater than (IL + nitroethane + ethanol) systes due to a decrease in interolecular interactions aong the three coponents and a less copact structure (a decrease in the packing effect) possibly due to the larger 1-propanol olecules. The V E,in increases in the order (IL + nitroethane + 1-propanol) > (IL + nitroethane + ethanol) > (IL + nitroethane + ethanol) at each teperature. Figure 6 Graph of excess olar volues, V E, for the ternary ixture [BMIM] + [MeSO4] - ( ) + nitroethane (x 2 ) + 1-propanol ( ) against ole fraction of 1-propanol at T = K at constant z = x 2. The sybols represent experiental results: D, ;, ;, ;, ;,. 4. Conclusions In this paper, the densities and V E have been reported for the ternary systes (IL + nitroethane + ethanol or ethanol or 1-propanol) at the teperatures ( and ) K. The V E values are negative for all copositions of the IL and V E,in increases with an increase in teperature for the systes (IL + nitroethane + ethanol or ethanol) and decreases for the syste (IL + nitroethane + 1-propanol). The negative V E values are due to strong interolecular interactions, as well as, a ore efficient packing effect aong the alcohol, nitroethane and the IL. The IL, an alcohol and/or the nitroethane are engaged in specific interactions, and the ability of the alcohol to for hydrogen bonds with the IL is increased by the presence of the nitroethane olecules. V E,invalues increase in the order (IL + nitroethane + 1-propanol) > (IL+ nitroethane + ethanol) > (IL+ nitroethane + ethanol) at each teperature. Acknowledgeents The authors acknowledge the National Research Foundation, South Africa, and Durban University of Technology for a postdoctoral scholarship for Dr I. Bahadur. Figure 7 Graph of excess olar volues,, for the ternary ixture ] - ( ) + nitroethane (x 2 ) + 1-propanol ( ) against ole fraction of 1-propanol at T = K at constant z = x 2. The sybols represent experiental results: D, ;, ;, ;, ;,. For the binary syste (1-propanol + nitroethane) V E is positive at the teperatures ( and ) K due to a decrease in the interolecular interactions. The V E,in values at the teperatures ( and ) K both occur at = and are c 3 ol 1 and c 3 ol 1, respectively. 38 The excess olar volues of (1-propanol + nitroethane) are greater than (ethanol + nitroethane) are greater than (ethanol + nitroethane) syste due to the increase in the alcohol chain length. 38 Figures 6 7 are the plots of V E versus ole fraction of 1-propanol for the ternary syste (IL + nitroethane + 1-propanol). V E values are negative for all ternary coposition curves. The negative values of V E for (IL + nitroethane + 1-propanol) are due to siilar effects that occur in the ternary (IL + nitroethane + ethanol or ethanol) systes. Fro Table 4 it can be seen that for the ternary syste ( ] + nitroethane + 1-propanol) V E,in increases with decreasing z values for both teperatures and decreases with an increase in teperature. The V E,in of (IL + nitroethane + 1-propanol) is greater than (IL + nitroethane References 1 T. Welton, Che. Rev.,1999, 99, S. Baj, A. Chrobok and S. Derfla, Green Che.,2006, 8, K.R. Seddon, J. Che. Technol. Biotechnol., 1997, 68, P. Wasserscheid and W. Kei, Angew. Che., Int. Ed.,2000, 39, E.R. Cooper, C.D. Andrews, P.S. Wheatley, P.B. Webb, P. Worald and R.E. Morris, Nature, 2004, 430, H.T. Kariata and N. Sugioto, Angew. Che. Int. Ed., 2012, 51, T. Sato, G. Masuda and K. Takagi, Electrochi. Act., 2004, 49, M.J. Earle, P. McCorac and K.R. Seddon, Green Che., 1999, 1, D. Kerle, R. Ludwig, A. Geiger and D. Paschek, J. Phys. Che. B., 2009, 113, M. Gali ski, A. Lewandowski and I. St pniak, Electrochi. Act., 2006, 51, J.G. Huddleston, H.D. Willias, R.P. Swatloski, A.E. Visser and R.D. Rogers, Che. Coun.,1998, 16, R. Sheldon, Che. Coun., 2001, 23, S. Zhang, Q. Zhang and Z.C. Zhang, Ind. Eng. Che. Res., 2004, 43, J. Esser, P. Wasserscheid and A. Jess, Green Che., 2004, 6, M.V.B. Zanoni, E.I. Rogers, C. Hardacre and R.G. Copton, Anal. Chi. Acta, 2010, 659, P. Kubisa, Prog.Poly. Sci., 2009, 34, M. Freeantle, An Introduction to Ionic Liquids,RSC Publishing, Cabridge, UK, M.T Zafarani Mottar and H. Shekaari, J. Che. Therodyn., 2005, 37, E. Góez, B. Gonzàlez, N. Calvar and Á. Doínguez, J. Che. Therodyn., 2008, 40, B. Gonzàlez, N. Calvar, E. Góez and Á. Doínguez, J. Che. Therodyn., 2008, 40, N. Deenadayalu, S. Kuar and P. Bhujrajh, J. Che. Therodyn., 2007, 39,

7 RESEARCH ARTICLE I. Bahadur and N. Deenadayalu, N. Deenadayalu and P. Bhujrajh, J. Che. Eng. Data, 2008, 53, N. Deenadayalu, I. Bahadur and T. Hofan, J. Che. Eng. Data, 2010, 55, N. Deenadayalu, I. Bahadur and T. Hofan, J. Che. Therodyn., 2010, 42, N. Deenadayalu, I. Bahadur and T. Hofan, J. Che. Eng. Data, 2011, 56, I. Bahadur, N. Deenadayalu, Z. Tywabi, S. Sen and T. Hofan, J. Che. Therodyn., 2012, 49, A.E. Andreatta, A. Arce, E. Rodil and A. Soto, J. Che. Therodyn., 2009, 41, A.E. Andreatta, A. Arce, E. Rodil and A.Soto, J. Solution Che.,2010, 39, P.N. Sibiya and N. Deenadayalu, J. Che. Therodyn., 2008, 40, N. Deenadayalu, S. Sen and P.N. Sibiya, J. Che. Therodyn.,2009, 41, P.N. Sibiya and N. Deenadayalu, S. Afr. J. Che., 2009, 62, P. Bhujrajh and N. Deenadayalu, J. Solution Che., 2007, 36, MMM 33 N. Deenadayalu, K.C. Ngcongo, T.M. Letcher and D. Rajugernath, J. Che. Eng. Data, 2006, 51, N. Deenadayalu, S.H. Thango, T.M. Letcher and D. Rajugernath, J. Che. Therodyn., 2006, 38, I. Bahadurand and N. Deenadayalu, J. Solution Che., 2011, 40, M.A. Iglesias-Otero, J. Troncoso, E. Carballo and L. Roani, J. Che. Eng. Data, 2008, 53, L. Moràvkovà and J. Linek, J. Che. Therodyn., 2008, 40, C-H. Tu, S-L. Lee and I-H. Peng, J. Che. Eng. Data,2001, 46,

Study of Excess Properties of Binary and Ternary Mixtures of Trichloroethene, Ethanoic Acid, and N,N-Dimethylformamide at Different Temperatures

Study of Excess Properties of Binary and Ternary Mixtures of Trichloroethene, Ethanoic Acid, and N,N-Dimethylformamide at Different Temperatures Regular Article PHYSICAL CHMISTRY RSARCH Published by the Iranian Cheical Society www.physcheres.org info@physcheres.org Phys. Che. Res., Vol. 7, No. 2, 347-363, June 2019 OI: 10.22036/pcr.2019.166303.1583