Hansen Solubility Parameters of Coal Tar-Derived Typical PAHs

Article pubs.acs.org/jced

Hansen Solubility Parameters of Coal Tar-Derived Typical PAHs Using Turbidimetric Titration and an Extended Hansen Approach Xiongchao Lin,† Guangce Jiang,‡ and Yonggang Wang*,† †

School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266101, PR China

‡

S Supporting Information *

ABSTRACT: The advantage of selectivity for coal tar extraction can be obtained by using the solubility parameter of Hansen theory as a guide. However, most of the Hansen solubility parameters (dispersion contributions, δd; polarity contributions, δp; hydrogen bonding contributions, δhb) of coal tar components (e.g., polycyclic aromatic hydrocarbons, PAHs) were inadequate. This study estimated the Hansen solubility parameters of naphthalene, acenaphthene, anthracene, phenanthrene, pyrene, and fluoranthene from coal tar by applying a new approach regulated by turbidimetric titration and a calculating program based on the method of exhaustion. The extended Hansen approach was used to verify the new approach and evaluate the solubility of the six PAH components in different solvents. The results show that the new method can clearly identify the differences in Hansen solubility parameters caused by various combinations of benzene rings among some isomers (e.g., anthracene and phenanthrene). Among the six PAH compounds, high relativity between their Hansen solubility parameters and solubility data was revealed, indicating an excellent reliability of the new method. An extended Hansen approach is appropriate for the estimation of solubility for the six PAHs with acceptable deviations. Moreover, the relationship between the Hansen solubility sphere and the extended Hansen approach was successfully presented by regression analysis.

1. INTRODUCTION The Hansen solubility parameter (HSP) is an important physical indicator for most organic compounds, and it is especially useful for solvent selection.1−5 Since the HSP is a reflection of intermolecular forces, it would also have close relations with some other properties, such as the swelling property,6,7 surface mobility,8 etc. The HSP has also been used in many separation techniques, such as crystallization9 and chromatography,10,11 etc., for the calculation of the phase equilibrium. There are two indispensable factors for applying the HSP to the prediction of the dissolving property: the HSPs of the solute/solvent and the radius of the Hansen solubility sphere. However, for polycyclic aromatic hydrocarbons (PAHs), those data are usually inadequate. In this case, the group-contribution methods might work,12−14 while all existing group-contribution methods cannot clarify the differences among the isomers with various combinations of benzene rings (e.g., anthracene and phenanthrene). The theory of the HSP has been adopted in the field of petroleum and coal chemistry, whose feedstock is abundant in PAHs. An attempt has been made to relate HSPs of solvents to the solubility of coal tar pitch;15 such a concept was also used to guide the process of removing n-alkanes from diesels.16 Subsequently, a bitumen model was proposed, which is a more complete mathematical description of the stability of bitumen in terms of the HSP.17 All studies mentioned above © 2017 American Chemical Society

are typical and available, but the HSPs of solutes are usually ignored. On the other hand, another bitumen solubility model has been established by using the HSP.18 It mainly focused on the investigation of the mixed HSPs and the dissolve radius of Venezuelan bitumen, while the HSPs for individual components within the bitumen, such as PAHs, are still unclear. Naphthalene, acenaphthene, anthracene, phenanthrene, pyrene, and fluoranthene are PAHs which exist widely in coal tar and some other heavy oil system. These compounds and their congeners show great influence on the properties of the coal tar feedstock. However, the HSPs of those compounds (except naphthalene) are less concerned in previous literature. This study aims to investigate the HSPs of the six PAHs and estimate their solubility in different solvents with a new approach for estimating HSPs by turbidimetric titration. This new method can be considered as a supplement of the traditional estimating method, since the turbidimetric titration has a close relation with solubility data. The HSPs of the six PAH compounds have thus been obtained, and the extended Hansen approach was also conducted to verify the new approach and evaluate the solubility of the six PAHs in different solvents. Received: August 19, 2016 Accepted: February 10, 2017 Published: February 17, 2017 954

DOI: 10.1021/acs.jced.6b00740 J. Chem. Eng. Data 2017, 62, 954−960

Journal of Chemical & Engineering Data

Article

CED = δt2 = ΔEv /Vm = (ΔHv − RT )/Vm

2. EXPERIMENTAL SECTION 2.1. Materials. The PAH compounds (as-received without further purification) used in turbidimetric titration are naphthalene, acenaphthene, anthracene, phenanthrene, and pyrene. Detailed information on the adopted materials and solvents is listed in Table 1.

where CED is the cohesive energy density; and δt is the total solubility parameter; ΔEv is the cohesive energy; ΔHv is the standard enthalpy of vaporization at 298 K; and Vm is the molar volume. The total solubility parameters of naphthalene, acenaphthene, anthracene, phenanthrene, pyrene, and fluoranthene at 298 K and 1 atm are calculated by eq 3, as shown in Table 2. The vaporization enthalpies of those compounds were reported by Roux.22

Table 1. Sample Description Tablea Chemicals Naphthalene Acenaphthene Anthracene Phenanthrene Pyrene Fluoranthene Acetone THFc Ethanol NMPd Formamide

Source

Mass Fraction Purity

Analysis Method

0.99 0.99 0.99 0.97 0.97 0.98 0.995 0.998 0.95 0.99 0.995

GCb GC GC GC GC GC

Sigma Sigma Sigma TCI TCI TCI Sinopharm Chemical Reagent Co.

(3)

Table 2. Total Solubility Parameters of the 6 PAH Compounds

All compounds were directly used without further purification. bGas chromatography. cTHF = tetrahydrofuran. dNMP = 1-methyl-2pyrrolidone.

Chemicals

ΔHv (kJ/mol)

Vm

δt

Naphthalene Anthracene Phenanthrene Acenaphthene Pyrene Fluoranthene

55.4 79.9 78.3 66.5 89.4 87.1

125.5377 156.7573 158.9946 141.4780 159.8854 174.6589

20.5 22.2 21.8 21.3 23.3 22.0

a

2.4. Evaluation of Hansen solubility parameters. Hansen solubility sphere. The solubility parameter “distance” (Ra) is defined as eq 4 Ra =

2.2. Turbidimetric titration. The turbidimetric titration process was similar to that in the previous literature.19,20 For a single titration, a certain mass of sample was dissolved in 2 mL of solvent (solvent or mixed solvent which can dissolve the solute effectively). In the titration process, the solution was titrated with an antisolvent, which can hardly dissolve the solute, until precipitation occurred. Ethanol (δd = 15.8, δp = 8.8, δhb = 19.4), acetone (δd = 15.5, δp = 10.4, δhb = 7), THF (δd = 16.8, δp = 5.7, δhb = 8), NMP (δd = 18, δp = 12.3, δhb = 7.2), and their mixture were used as solvents, while H2O (δd = 15.6, δp = 16, δhb = 42.3) and formamide (δd = 17.2, δp = 26.2, δhb = 19) were used as antisolvents. All the solvents are of analytical grade, and all experiments were conducted under 298 K and 1 atm. The molar fraction solubility of solute in the mixed solvent after titration can be approximately calculated by eq 1. X 2 = n2 /(n2 + nsolvent )

(4)

In eq 4, δd1, δp1, and δhb1 refer to HSPs of solvents, whereas δd2, δp2, and δhb2 refer to HSPs of solutes. By taking HSPs of solutes as the center, eq 4 can be regarded as an expression of a series of ellipsoids with changes in the value of Ra on a threedimensional system of coordinates. When Ra equates to a specific value, R0, the dissolving radius of the solute, the ellipsoid is the Hansen solubility sphere of the solute. Solute can be effectively dissolved by the solvent if the HSPs of the solvent are inside the Hansen solubility sphere. Principle of the estimation. The form of the Hansen solubility sphere was adopted in this study. The schematic diagram for estimating HSPs by turbidimetric titration and the computer program is shown in Figure 1. HSPs of solvents and a certain solute can be considered as points on a threedimensional system of coordinates. In Figure 1, blue points correspond to HSPs of solvents with similar solubility (X2) for a certain sample, the coordinate with the red point is the HSP of the sample, and the red area (A) is the area defined by the restricted conditions of HSP of the sample (red point). This study assumes that those blue points are on (or around) the surface of an ellipsoid in the form of eq 4 (surface B in Figure 1), and the center of the ellipsoid (red point) corresponds to HSPs of the sample. Thus, theoretically, if coordinates of more than 4 points on the surface of the ellipsoid could be obtained, then the center of the ellipsoid (HSPs of solute, red point in Figure 1) would be found. The detailed information for the estimation process, including turbidimetric titration, data selection, and calculation procedure (a computer program built in Matlab), can be found the Supporting Information (Part II, Figure s1 and Figure s2).

(1)

where X2 is the molar fraction concentration of solute, and n2 and nsolvent are the molar number of solute and total mixed solvents after titration. When the precipitation occurs in the mixed solvent, its HSP can be calculated by eq 2. δblend = φcomp1δcomp1 + φcomp2δcomp2 + ...

4(δd1 − δd 2)2 + (δp1 − δp2)2 + (δhb1 − δhb2)2

(2)

where δblend is the partial solubility parameter of the mixed solvent, δcomp1, δcomp2, ... are the partial solubility parameters of the individual solvents, and φcomp1, φcomp2, ... are the volume fractions of the individual solvents. X2 and δblend are two key results widely adopted in data processing. A series of titrations for the six PAH compounds have been conducted to estimate their HSPs. The detailed experimental procedure and results (X2 and δblend) are listed in Supporting Information (Tables s1−6). 2.3. Total solubility parameters. The total solubility parameter is defined as follows,21

3. RESULTS AND DISCUSSION 3.1. HSPs of the six PAH components. From the titration and calculating process, HSPs of naphthalene, 955



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if the symmetry of the aromatic structure increases. Such a conclusion can be indirectly proved by the RP-HPLC spectrum (shown in Figure 3). The chromatographic column of the RPHPLC system was Eclipse PAH (Agilent). A gradient elution was conducted in the chromatographic process. The mobile phase was 45% acetonitrile + H2O at the beginning, and from 15 to 60 min, the volume percent of acetonitrile in the mobile phase changes from 40% to 100%. The details of the analysis conditions are listed in Supporting Information (Table s7). It can be found that the retention time of these aromatic hydrocarbons basically increased with δd increasing. For isomers, the peaks of compounds with higher polarity would appear earlier in a reversed phase chromatography process. The retention time of phenanthrene is less than that of anthracene, similar to fluoranthene and pyrene. This phenomenon is consistent with the results obtained in this study. The evaluation of HSPs for the six PAH compounds by group contribution methods was also investigated, and the results are listed in Table 3. The description of the symmetry plane influence in the method mentioned by Hoftyzer and Van Krevelen12 is partly coincident with the results of this study, but the calculation of this method meets some problems because of the insufficient contribution value. The HSPs obtained from the Hoy method13 have dubiously large values of δp and δhb, and the method was unable to identify the differences between the isomers with various combinations of benzene rings. Among the three group contribution methods, the method provided by Stefanis and Panayiotou14 received the most similar HSPs to those obtained in this study. However, only little differences can be found between anthracene and phenanthrene, as well as pyrene and fluoranthene, indicating that an improvement can be made on the prediction of HSP changes caused by various benzene-ring combinations. 3.2. Extended Hansen approach. The extended Hansen approach was thus conducted to estimate the solubility and verify the HSPs obtained from turbidimetric titration23−25 for the six PAHs. According to the theory, the relationship between solubility and HSPs can be described as eq 5.

Figure 1. Schematic diagram of estimating HSPs from turbidimetric titration. (A) The area defined by restricted conditions; (B) The ellipsoid defined by the Hansen solubility parameters of mixed solvents when the precipitation occurred.

acenaphthene, anthracene, phenanthrene, pyrene, and fluoranthene were obtained, as shown in Table 3. Among those Table 3. HSPs of the 6 PAH Compounds group contribution methods Chemicals Naphthalene

Acenaphthene

Anthracene

Phenanthrene

Pyrene

Fluoranthene

δd δp δhb δd δp δhb δd δp δhb δd δp δhb δd δp δhb δd δp δhb

This study

Method Aa

Method Bb

19.4 1.9 5.9 20.4 2.5 3.2 21.8 2.3 3.5 20.8 2.6 5.4 22.5 1.6 4.0 20.8 2.5 6.7

19.5 1.5 5.2 20.7 1.3 5.8 21.1 1.5 5.1 20.7 1.5 5.7 21.6 1.9 7.1 21.2 1.9 7.8

16.24 9.62 6.15 19.64 10.39 8.41 22.02 13.20 9.52 22.02 13.20 9.52 23.16 10.70 13.99 23.16 10.70 13.99

−log X 2 = −log X 2i + A[CI(δd1 − δd 2)2 + CII(δp1 − δp2)2 + CIII(δhb1 − δhb2)2 ] + C0

(5)

Xi2

where X2 and are the molar fraction solubility and molar fraction ideal solubility; CI, CII, CIII, and C0 are model coefficients; δd1, δp1, and δhb1 are HSPs of solute, whereas δd2, δp2, and δhb2 are HSPs of solvent; and A is a term from regular solution theory:

a

Method A: group contribution methods provided by E. Stefanis and C. Panayiotou.14 bMethod B: group contribution methods provided by Hoy.13

A = V2ϕ12 /(2.303RT )

(6)

where V2 is molar volume of the solute, ϕ1 is the volume fraction of solvent, R is the gas constant, and T is the absolute temperature. The ideal solubility of the solute can be evaluated from eq 7:

compounds, HSPs of naphthalene can be found in previous literature (δd = 19.2, δp= 2, δhb = 5.9),1 which are quite similar to the ones obtained in this study. The relationships between HSPs of solute and chosen points (selected by X2) of the 6 PAH compounds are shown in Figure 2. The low RSD % within [Ra] shows a tight connection between the chosen test points and HSPs of the solute. Several distinct tendencies can be found among the HSPs of those PAH compounds. The dispersion force parameters (δd) basically increase with the increasing number of benzene rings, while the parameters of polar force (δp) and hydrogen bonding force (δhb) are strongly affected by the symmetry of the molecular structure; for instance, both of them would decrease

log X 2i =

ΔSmf ΔHmf T T log = log R Tm TmR Tm

(7)

In eq 7, X2i is the ideal solubility of each solute; ΔSfm and ΔHfm are the molar entropy and enthalpy of fusion under the fusion point (Tm, in degrees Kelvin); R is the molar gas constant; and T is the temperature at which the solubility is evaluated (298 K in this study). 956



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Figure 2. Selected test points and HSPs of the six PAHs compounds (selected by molar fraction of solute).

As X2i can be considered as a constant at the same temperature, eq 5 can be turned into:

and the calculation procedure are applicable to describe the dissolving properties of the six PAHs. In order to evaluate the correlating strength of those regression equations, the calculated solubilities of all those compounds are plotted against the experimental data (both obtained from this study and other literature) in Figure 4, and the detailed data including the solubility, calculation values, and absolute deviation for the six PAH compounds are listed in Supporting Information (from Tables s8−s13). This shows that the solubilities of naphthalene and acenaphthene can be evaluated by an extended Hansen approach with high accuracy. While for anthracene, phenanthrene, pyrene, and fluoranthene,

−log X 2 = A[CI(δd1 − δd 2)2 + CII(δp1 − δp2)2 + CIII(δhb1 − δhb2)2 ] + C

(8)

The model constants (CI, CII, CIII, C) of the six PAH compounds in eq 8 were deduced by regression analysis, as shown in Table 4. Solubility data obtained from other literature was also applied in the regression process.26−31 The correlation index for each regression equation presented here is above 0.90, which indicates that HSPs obtained from turbidimetric titration 957



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this study can only be those with a large value of δhb. Although the dispersion of test points has been enhanced by recombining good solvent before the titration process, it still cannot meet the needs of estimating the HSPs by an extended Hansen approach.24 Another possible reason for the poor correlation between solubility data and the HSP is that the hydrogen bond force in the theory of the Hansen solubility parameter is more appropriate to be further divided. The interaction between a solute and solvent molecule is different from that between the solute interacting with itself in its pure state. The acidic or basic (the proton donor or acceptor) character of the hydrogen bonded compound was not discriminated by Hansen’s approach, which would lead to complementarity matching problems.34 Considering of this, a LSER (linear solvation energy relationships) model or PSP (partial solvation parameter) would be a potential way to achieve a more precise estimation of the solubility of PAHs in different solvents.35,36 3.3. Extended Hansen approach and Hansen solubility sphere. The relationship between the extended Hansen approach and the Hansen solubility sphere can also be clarified through regression analysis. A parameter named Ra′ is defined by eq 9,

Figure 3. RP-HPLC spectrum of sample solution containing 16 PAH compounds.

Table 4. Extended Hansen Approach of the 6 PAH Compounds

a

Chemicals

C

CI

CII

CIII

Ra

Naphthalene Acenaphthene Anthracene Phenanthrene Fluoranthene Pyrene

−1.093 −1.809 −3.592 −1.420 −1.477 −0.517

−2.056 −1.222 −2.201 −1.910 −1.456 −2.193

−0.500 −0.260 −0.135 −0.290 −0.330 −0.279

−0.508 −0.330 −0.154 −0.365 −0.370 −0.312

0.9994 0.9967 0.9235 0.9684 0.9791 0.9694

Ra′ = A(4(δd1 − δd 2)2 + (δp1 − δp2)2 + (δhb1 − δhb2)2 ) (9)

It is assumed that the molar fraction of solute (X2) can always be found in a certain relation with Ra′, as shown in eq 10.

Correlation coefficient.

−log X 2 = C1Ra′ + C

(10)

Regression analysis has been done for each of the six PAH compounds in the form of eq 10. The solubility data used in the regression analysis was obtained from turbidimetric titration in this study and/or from other literature. The correlation coefficients for the solubilities of the six PAH compounds in the form of eq 10 are more than 90%, as shown in Table 5. Table 5. Correlation Coefficients between Ra′ and lnX2 of the 6 PAHs Compounds Correlation coefficient Chemicals

Figure 4. Calculated solubility of all the compounds versus the experimental values.

Naphthalene Acenaphthene Anthracene Phenanthrene Fluoranthene Pyrene

relative deviations ranging from 10% and 15% widely exist between calculated values and experimental data. The correlation coefficient of the equation for anthracene (0.9235) was the lowest among the six PAH compounds. This is mainly caused by its low solubility, which makes the precipitate inconspicuous, since only a low initial concentration can be achieved in the initial solution before the titration process. Though the average value of multiple determinations (3 times, absolute deviation less than 0.03 mL) was used to reduce error, uncertainties still exist. Previous attempts made to estimate the HSPs of the six PAH compounds by an extended Hansen approach failed24,25 due to the nonuniform distribution of test points in the 3-dimensional coordinate system. The lower part of the ellipsoidal models usually stays under the plane defined by the x-axis and y-axis, which means points in this area cannot be actually obtained from experiments. As a consequence, the antisolvents used in

Series Aa

Series Bb

26

0.999326 0.981227,28 0.816529 0.934630 0.976631 0.942831

0.9912 0.989727,28 0.871229 0.939030 0.959631 0.931831

a

Series A: solubility data obtained from the literature. bSeries B: solubility data obtained from the literature and this study.

Equation 10, which is a special case of eq 8, can be regarded as an intergradation between the extended Hansen approach and the Hansen solubility sphere. Equation 10 can also be altered into: 4(δd1 − δd 2)2 + (δp1 − δp2)2 + (δhb1 − δhb2)2 = 958

−log X 2 − C C1A

(11) DOI: 10.1021/acs.jced.6b00740 J. Chem. Eng. Data 2017, 62, 954−960


Article

III. Independent cal-culation of the parameter components. J. Paint Technol. 1967, 39, 505−510. (5) Fardi, T.; Stefanis, E.; Panayiotou, C.; Abbott, S.; van Loon, S. Artwork conservation materials and Hansen solubility parameters: A novel methodology towards critical solvent selection. J. Cult. Herit. 2014, 15, 583−594. (6) Nielsen, T. B.; Hansen, C. M. Elastomer swelling and Hansen solubility parameters. Polym. Test. 2005, 24, 1054−1061. (7) Liu, G.; Hoch, M.; Wrana, C.; Kulbaba, K.; Qiu, G. A new way to determine the three-dimensional solubility parameters of hydrogenated nitrile rubber and the predictive power. Polym. Test. 2013, 32, 1128−1134. (8) Hansen, C. M. Aspects of solubility, surfaces and diffusion in polymers. Prog. Org. Coat. 2004, 51, 55−66. (9) Baughman, R. H.; Hall, L. J.; Kozlov, M.; Smith, D. E.; Prusik, T. Crystallized diacetylenic indicator compounds and methods of preparing the compounds. U.S. Patent 8,269,042, September 18, 2012. (10) Hansen, L. C.; Sievers, R. E. Highly permeable open-pore polyurethane columns for liquid chromatography. J. Chromatogr. A 1974, 99, 123−133. (11) Adamska, K.; Voelkel, A. Hansen solubility parameters for polyethylene glycols by inverse gas chromatography. J. Chromatogr. A 2006, 1132, 260−267. (12) Hoftyzer, P.; Van Krevelen, D. Properties of polymers; Elsevier: Amsterdam, 1976; pp 152−155. (13) Hoy, K. The Hoy Tables of Solubility Parameters; Union Carbide Corporation: Charleston, West Virginia, 1985. (14) Stefanis, E.; Panayiotou, C. Prediction of Hansen solubility parameters with a new group-contribution method. Int. J. Thermophys. 2008, 29, 568−585. (15) Blanco, C. G.; Guillen, M. D. Study of relationships between solvent effectiveness in coal tar pitch extractions and solvent solubility parameters. Ind. Eng. Chem. Res. 1991, 30, 1579−1582. (16) Lu, Y.; Shi, J.; Sun, L. Investigation of the selection of extraction solvent for extracting the n-alkane from diesel by means of solubility parameters theory. J. Fuel Chem. Technol. 2008, 36, 297−301. (17) Redelius, P. Solubility parameters and bitumen. Fuel 2000, 79, 27−35. (18) Redelius, P. Bitumen solubility model using Hansen solubility parameter. Energy Fuels 2004, 18, 1087−1092. (19) Suh, K.; Clarke, D. Cohesive energy densities of polymers from turbidimetric titrations. J. Polym. Sci., Part A-1: Polym. Chem. 1967, 5, 1671−1681. (20) Suh, K.; Corbett, J. Solubility parameters of polymers from turbidimetric titrations. J. Appl. Polym. Sci. 1968, 12, 2359−2370. (21) Hildebrand, J. H.; Scott, R. L. Regular solutions; Prentice-Hall: Englewood Cliffs, NJ, 1962. (22) Roux, M. V.; Temprado, M.; Chickos, J. S.; Nagano, Y. Critically evaluated thermochemical properties of polycyclic aromatic hydrocarbons. J. Phys. Chem. Ref. Data 2008, 37, 1855−1996. (23) Martin, A.; Wu, P.; Adjei, A.; Beerbower, A.; Prausnitz, J. Extended Hansen solubility approach: Naphthalene in individual solvents. J. Pharm. Sci. 1981, 70, 1260−1264. (24) Wu, P.; Beerbower, A.; Martin, A. Extended Hansen approach: calculating partial solubility parameters of solid solutes. J. Pharm. Sci. 1982, 71, 1285−1287. (25) Kharwade, M.; Subrahmanyam, C.; Sathesh Babu, P. Total and partial solubility parameters prediction: Lornoxicam in individual solvents. J. Pharm. Res. 2013, 7, 409−413. (26) Chang, W. Solubilities of biphenyl, naphthalene, perfluorobiphenyl, perfluoronaphthalene and hexachloroethane in nonelectrolytes. North Dakota State University, 1969. (27) Wang, Z.; Jiang, P. Solubility of Acenaphthene in Different Solvents from (283.00 to 323.00) K. J. Chem. Eng. Data 2009, 54, 150−151. (28) Acree, W. E., Jr; Abraham, M. H. Solubility predictions for crystalline polycyclic aromatic hydrocarbons (PAHs) dissolved in organic solvents based upon the Abraham general solvation model. Fluid Phase Equilib. 2002, 201, 245−258.

In previous literature, the term A was considered as a constant, as it varied in a narrow range compared with other variations of the independent variables.32,33 Under this condition, when the value of X2 corresponds to the boundary between soluble and insoluble, eq 11 conforms to the definition of the Hansen solubility sphere.

4. CONCLUSIONS Hansen solubility parameters of six PAHs compounds were estimated by applying a new concept; moreover, the relationship between their HSPs and solubility in different solvents was revealed by an extended Hansen approach. The results demonstrate that, among the six PAHs components, the dispersion force parameters (δd) increased with increasing number of benzene rings and were similar among isomers, such as anthracene and phenanthrene, while the polar force and hydrogen bonding force parameters (δp and δhb) declined when the symmetry of the aromatic structure increased. HSPs obtained in this study were consistent with that estimated by the traditional method (naphthalene) and demonstrated a strong correlation with the solubility data in regression analysis, presenting a good applicability in describing dissolving capacity; primarily, the solubility of naphthalene and acenaphthene can be accurately evaluated by the extended Hansen approach.

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jced.6b00740. Additional tables, figures, and experimental results (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*Tel.: +861062339882; fax: +861062331897. E-mail address: [email protected]. ORCID

Xiongchao Lin: 0000-0003-1370-7059 Funding

The authors greatly acknowledge the financial support by the National Key Research and Development Program (Grant No. 2016YFB060030301) and Joint Funds of the National Natural Science Foundation of China (Grant No. U1261213). Notes

The authors declare no competing financial interest.

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ABBREVIATIONS HSP, Hansen solubility parameter; PAHs, polycyclic aromatic hydrocarbons; RP-HPLC, reversed-phase high-performance liquid chromatography

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REFERENCES

(1) Hansen, C. M. Hansen solubility parameters: a user’s handbook; CRC Press: 2012. (2) Hansen, C. M. The Three Dimensional Solubility Parameter and Solvent Diffusion Coefficient; Danish Technical: Copenhagen, 1967; pp 14. (3) Hansen, C. M. 50 Years with solubility parameterspast and future. Prog. Org. Coat. 2004, 51, 77−84. (4) Hansen, C. M. The three-dimensional solubility parameter-key to paint component affinities: solvents, plasticizers, polymers, and resins. II. Dyes, emulsifiers, mutual solubility and compatibility, and pigments. 959



Article

(29) Roy, L. E.; HernÁ ndez, C. E.; Acree, W. E., Jr Solubility of Anthracene in Organic Nonelectrolyte Solvents. Comparison of Observed Versus Predicted Values Based Upon Mobile Order Theory. Polycyclic Aromat. Compd. 1999, 13, 105−116. (30) Hernández, C. E.; De Fina, K. M.; Roy, L. E.; Sharp, T. L.; Acree, W. Solubility of phenanthrene in organic nonelectrolyte solvents. Comparison of observed versus predicted values based upon Mobile Order theory. Can. J. Chem. 1999, 77, 1465−1470. (31) Roy, L. E.; HernÁ andez, C. E.; Acree, W. E., Jr Thermodynamics of mobile order theory. Part 3. Comparison of experimental and predicted solubilities for fluoranthene and pyrene. Polycyclic Aromat. Compd. 1999, 13, 205−219. (32) Bustamante, P.; Escalera, B.; Martin, A.; Selles, E. A modification of the extended Hildebrand approach to predict the solubility of structurally related drugs in solvent mixtures. J. Pharm. Pharmacol. 1993, 45, 253−257. (33) Bustamante, P.; Martin, A.; Gonzalez-Guisandez, M. Partial solubility parameters and solvatochromic parameters for predicting the solubility of single and multiple drugs in individual solvents. J. Pharm. Sci. 1993, 82, 635−640. (34) Panayiotou, C. Partial solvation parameters and LSER molecular descriptors. J. Chem. Thermodyn. 2012, 51, 172−189. (35) Sherry, A. D.; Purcell, K. F. Linear enthalpy-spectral shift correlation for perfluoro-tert-butyl alcohol. J. Am. Chem. Soc. 1972, 94, 1853−1857. (36) Panayiotou, C. Redefining solubility parameters: The partial solvation parameters. Phys. Chem. Chem. Phys. 2012, 14, 3882−908.

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Hansen Solubility Parameters of Coal Tar-Derived Typical PAHs

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