The acoustical and viscometric properties of L-Alanine (neutral, nonpolar) and L-Arginine (basic, charged) in 10% aqueous glycerol have been investigated over a concentration range of 0.01 to 0.1 mol·kg⁻¹ at temperatures T = 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K under atmospheric pressure. Experimental measurements of ultrasonic velocity (µ), density (ρ), and viscosity (η) have been used to derive adiabatic compressibility (), apparent molar volume (Φv), partial molar volume (Φ°v), relative viscosity (η/η₀), and solvation number (n_s), Transfer partial molar volume (ΔΦ°v) and transfer partial molar compressibility (ΔΦ°k) from pure water to 10% aqueous glycerol have also been determined for both amino acids at each temperature. L-Arginine exhibited higher ultrasonic velocity values and greater decrease in adiabatic compressibility compared to L-Alanine, reflecting the stronger molecular interactions arising from its positively charged guanidinium side chain. The relative viscosity (η/η₀) values greater than unity for both amino acids confirm strong solute-solvent interactions in 10% aqueous glycerol, with L-Arginine exhibiting higher relative viscosity values than L-Alanine throughout the investigated concentration and temperature range, attributed to the stronger interactions arising from its positively charged guanidinium side chain. The solvation numbers obtained from adiabatic compressibility data indicate a larger solvation sphere around L-Arginine molecules, reflecting stronger solvophilic hydration due to electrostatic interactions of the guanidinium group with surrounding solvent molecules. The transfer partial molar compressibility () values were found to be negative for L-Arginine and positive for L-Alanine across the entire temperature range investigated. This contrasting behavior clearly demonstrates the differential effect of glycerol on the two amino acids — glycerol strengthens and rigidifies the hydration shell of L-Arginine through strong hydrogen bonding interactions with its charged guanidinium group, while it weakens and disrupts the hydration shell of L-Alanine due to the weaker affinity of glycerol for its nonpolar methyl side chain. The results provide clear evidence for the dominant role of side chain polarity and charge in governing the solvation behavior and molecular interactions of amino acids in aqueous glycerol medium, with implications for understanding protein stabilization mechanisms in polyol-containing biological and pharmaceutical systems.

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1. Millero FJ. Molal volumes of electrolytes. Chem Rev. 1971;71(2):147-176.
2. Friedman HL, Krishnan CV. Studies of hydrophobic bonding in aqueous alcohols: enthalpy measurements and model calculations. J Solution Chem. 1973;2(2):119-140.
3. Ali A, Hyder S, Sabir S, Chand D, Nain AK. Volumetric, viscometric, and refractive index behaviour of α-amino acids and their groups' contribution in aqueous D-glucose solution at different temperatures. 2005.
4. Palani R, Geetha A. Acoustical and excess thermodynamic studies of molecular interaction in aqueous mixed solvent systems at 303, 308 and 313 K. Phys Chem Liq. 2009;47(5):542-552.
5. Millero FJ, Lo Surdo A, Shin C. The apparent molal volumes and adiabatic compressibilities of aqueous amino acids at 25 °C. J Phys Chem. 1978;82(7):784-792.
6. Jacobson B, Halonen E, Faurholt C. Intermolecular free lengths in the liquid state. I. Adiabatic and isothermal compressibilities. Acta Chem Scand. 1952;6:1485-1498.
7. Ali A, Khan S, Nabi F. Volumetric, viscometric and refractive index behavior of amino acids in aqueous glycerol at different temperatures. J Serb Chem Soc. 2007;72(5):495-512.
8. Jones G, Dole M. The viscosity of aqueous solutions of strong electrolytes with special reference to barium chloride. J Am Chem Soc. 1929;51(10):2950-2964.
9. Feakins D, Freemantle DJ, Lawrence KG. Transition state treatment of the relative viscosity of electrolytic solutions. Applications to aqueous, non-aqueous and methanol-water systems. J Chem Soc Faraday Trans 1. 1974;70:795-806.
10. Perron G, Desnoyers JE. Volumes and heat capacities of benzene derivatives in water at 25 °C: group additivity of the standard partial molal quantities. Fluid Phase Equilib. 1979;2(4):239-262.
11. Banipal TS, Kaur D, Banipal PK. Effect of magnesium acetate on the volumetric and transport behavior of some amino acids in aqueous solutions at 298.15 K. J Chem Thermodyn. 2006;38(10):1214-1226.
12. Chauhan S, Pathania L, Sharma K, Kumar G. Volumetric, acoustical and viscometric behavior of glycine and DL-alanine in aqueous furosemide solutions at different temperatures. J Mol Liq. 2015;212:656-664.
13. Kumar D, Lomesh SK, Nathan V. Molecular interaction studies of L-alanine and L-phenylalanine in water and in aqueous citric acid at different temperatures using volumetric, viscosity and ultrasonic methods. J Mol Liq. 2017;247:75-83.
14. Naz S, Jamal MA, Khosa MK, Naseem B, Muneer M. Effect of temperature on thermo-acoustical parameters of arginine in colloidal solutions. J Mol Liq. 2018;269:476-484.
15. Sawhney N, Kumar M, Sandarve, Sharma P, Sharma AK, Sharma M. Structure-making behaviour of L-arginine in aqueous solution of drug ketorolac tromethamine: volumetric, compressibility and viscometric studies. Phys Chem Liq. 2019;57(2):184-203.
16. Kumar A, Bamezai RK. Interactions of L-arginine with maltose monohydrate in aqueous solutions at 298.15 K: a volumetric study. J Biosphere. 2014;3:11-19.
17. Gupta J, Chand D, Nain AK. Study to reconnoiter solvation consequences of L-arginine/L-histidine and sodium salicylate in aqueous environment probed by physicochemical approach in the temperature range (293.15-318.15) K. J Mol Liq. 2020;305:112848.
18. Kaulgud MV, Patil KJ. Volumetric and isentropic compressibility behavior of aqueous amine solutions. I. J Phys Chem. 1974;78(7):714-717.
19. Banipal TS, Singh G, Lark BS. Partial molar volumes of transfer of some amino acids from water to aqueous glycerol solutions at 25 °C. J Solution Chem. 2001;30(7):657-670.
20. Gekko K, Timasheff SN. Mechanism of protein stabilization by glycerol: preferential hydration in glycerol-water mixtures. Biochemistry. 1981;20(16):4667-4676.
21. Back JF, Oakenfull D, Smith MB. Increased thermal stability of proteins in the presence of sugars and polyols. Biochemistry. 1979;18:5191-5196.
22. Wolf AV, Brown MG, Prentiss PG. Concentrative properties of aqueous solutions. In: CRC Handbook of Chemistry and Physics. Boca Raton (FL): CRC Press.
23. Kaur K, Juglan KC, Kumar H. Acoustical and volumetric investigation of polyethylene glycol 400 and polyethylene glycol 4000 in aqueous solutions of glycerol at different temperatures. J Chem Thermodyn. 2018;127:8-16.
24. Nain AK, Lather M, Sharma RK. Volumetric, ultrasonic and viscometric behavior of L-methionine in aqueous-glucose solutions at different temperatures. J Mol Liq. 2011;159(3):180-188.
25. Savaroglu G, İldaser AC. Volumetric and acoustic studies of L-tyrosine + L-glutamic acid + water at different temperatures. Thermochim Acta. 2014;582:86-93.
26. Palani R, Geetha A, Saravanan S, Shanbhag V. Intermolecular interactions of some amino acids in aqueous 1,4-dioxane solutions at 298.15 K. Rasayan J Chem. 2008;1(3):495-502.
27. Atkins PW, De Paula J, Keeler J. Atkins' Physical Chemistry. 12th ed. Oxford: Oxford University Press; 2023.
28. Segur JB, Oberstar HE. Viscosity of glycerol and its aqueous solutions. Ind Eng Chem. 1951;43(9):2117-2120.
29. Bagchi S, Nema SK, Singh RP. Ultrasonic and viscometric investigation of ISRO polyol in various solvents and its compatibility with polypropylene glycol. Eur Polym J. 1986;22(10):851-857.
30. Kant S, Kumar S. Effects of alkaline earth metal ions on thermodynamic and ultrasonic properties of ascorbic acid. J Chem Eng Data. 2013;58(5):1294-1300.
31. Kaur H, Thakur RC, Pathania VS, Sharma S. Effect of choline-based ionic liquid (cholinium ethanoate) on volumetric and acoustic properties of aliphatic amino acids (glycine and L-alanine) at T = (288.15, 298.15, 308.15 and 318.15) K. J Mol Liq. 2022;346:118247.
32. Kumar D, Lomesh SK, Nathan V. Molecular interaction studies of L-alanine and L-phenylalanine in water and in aqueous citric acid at different temperatures using volumetric, viscosity and ultrasonic methods. J Mol Liq. 2017;247:75-83.
33. Azhagiri S, Jayakumar S, Padmanaban R, Gunasekaran S, Srinivasan S. Acoustic and thermodynamic properties of binary liquid mixtures of benzaldehyde in hexane and cyclohexane. J Solution Chem. 2009;38(4):441-448.
34. Akhtar Y, Ibrahim SF. Ultrasonic and thermodynamic studies of glycine in aqueous electrolyte solutions at 303 K. Arab J Chem. 2011;4(4):487-490.
35. Riyazuddeen, Altamash T. Ultrasonic velocities and densities of L-histidine or L-glutamic acid or L-tryptophan or glycylglycine + 2 mol L−1 aqueous KCl or KNO3 solutions from (298.15 to 323.15) K. J Chem Eng Data. 2009;54(11):3133-3139.
36. Ali A, Nain AK, Chand D, Lal B. Molecular interactions in binary mixtures of anisole with benzyl chloride, chlorobenzene and nitrobenzene at 303.15 K: an ultrasonic, volumetric, viscometric and refractive index study. Indian J Chem A. 2005;44:511-515.
37. Millero FJ, Lo Surdo A, Shin C. The apparent molal volumes and adiabatic compressibilities of aqueous amino acids at 25 °C. J Phys Chem. 1978;82(7):784-792.
38. Vazdar M, Vymětal J, Heyda J, Vondrášek J, Jungwirth P. Like-charge guanidinium pairing from molecular dynamics and ab initio J Phys Chem A. 2011;115(41):11193-11201.
39. Masson DO. Solute molecular volumes in relation to solvation and ionization. Philos Mag. 1929;8(49):218-235.
40. Kadam UB, Hiray AP, Sawant AB, Hasan M. Densities, viscosities, and ultrasonic velocity studies of binary mixtures of trichloromethane with methanol, ethanol, propan-1-ol, and butan-1-ol at T = (298.15 and 308.15) K. J Chem Thermodyn. 2006;38(12):1675-1683.
41. Rajagopal K, Jayabalakrishnan SS. Volumetric, ultrasonic speed, and viscometric studies of salbutamol sulphate in aqueous methanol solution at different temperatures. J Chem Thermodyn. 2010;42(8):984-993.
42. Bahadur I, Deenadayalu N, Ramjugernath D. Effects of temperature and concentration on interactions in methanol + ethyl acetate and ethanol + methyl acetate or ethyl acetate systems: insights from apparent molar volume and apparent molar isentropic compressibility study. Thermochim Acta. 2014;577:87-94.
43. Eyring H, Hirschfelder J. The theory of the liquid state. J Phys Chem. 1937;41(2):249-257.
44. Eyring H. The activated complex in chemical reactions. J Chem Phys. 1935;3(2):107-115.
45. Hepler LG. Thermal expansion and structure in water and aqueous solutions. Can J Chem. 1969;47(24):4613-4617.
46. Robinson RA, Stokes RH. Electrolyte Solutions. Mineola (NY): Dover Publications; 2002.
47. Chalikian TV, Sarvazyan AP, Breslauer KJ. Partial molar volumes, expansibilities, and compressibilities of α,ω-aminocarboxylic acids in aqueous solutions between 18 and 55 °C. J Phys Chem. 1993;97(49):13017-13026.
48. Hepler LG. Thermodynamic analysis of the Hammett equation, the temperature dependence of ρ, and the isoequilibrium (isokinetic) relationship. Can J Chem. 1971;49(17):2803-2807.
49. Sinibaldi R, Ortore MG, Spinozzi F, Carsughi F, Frielinghaus H, Cinelli S, Onori G, Mariani P. Preferential hydration of lysozyme in water/glycerol mixtures: a small-angle neutron scattering study. J Chem Phys. 2007;126(23):235101.
50. Chalikian TV. Volumetric properties of proteins. Annu Rev Biophys Biomol Struct. 2003;32:207-235.
51. Dashnau JL, Nucci NV, Sharp KA, Vanderkooi JM. Hydrogen bonding and the cryoprotective properties of glycerol/water mixtures. J Phys Chem B. 2006;110(27):13670-13677.

The acoustical and viscometric properties of L-Alanine (neutral, nonpolar) and L-Arginine (basic, charged) in 10% aqueous glycerol have been investigated over a concentration range of 0.01 to 0.1 mol·kg⁻¹ at temperatures T = 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K under atmospheric pressure. Experimental measurements of ultrasonic velocity (µ), density (ρ), and viscosity (η) have been used to derive adiabatic compressibility (), apparent molar volume (Φv), partial molar volume (Φ°v), relative viscosity (η/η₀), and solvation number (n_s), Transfer partial molar volume (ΔΦ°v) and transfer partial molar compressibility (ΔΦ°k) from pure water to 10% aqueous glycerol have also been determined for both amino acids at each temperature. L-Arginine exhibited higher ultrasonic velocity values and greater decrease in adiabatic compressibility compared to L-Alanine, reflecting the stronger molecular interactions arising from its positively charged guanidinium side chain. The relative viscosity (η/η₀) values greater than unity for both amino acids confirm strong solute-solvent interactions in 10% aqueous glycerol, with L-Arginine exhibiting higher relative viscosity values than L-Alanine throughout the investigated concentration and temperature range, attributed to the stronger interactions arising from its positively charged guanidinium side chain. The solvation numbers obtained from adiabatic compressibility data indicate a larger solvation sphere around L-Arginine molecules, reflecting stronger solvophilic hydration due to electrostatic interactions of the guanidinium group with surrounding solvent molecules. The transfer partial molar compressibility () values were found to be negative for L-Arginine and positive for L-Alanine across the entire temperature range investigated. This contrasting behavior clearly demonstrates the differential effect of glycerol on the two amino acids — glycerol strengthens and rigidifies the hydration shell of L-Arginine through strong hydrogen bonding interactions with its charged guanidinium group, while it weakens and disrupts the hydration shell of L-Alanine due to the weaker affinity of glycerol for its nonpolar methyl side chain. The results provide clear evidence for the dominant role of side chain polarity and charge in governing the solvation behavior and molecular interactions of amino acids in aqueous glycerol medium, with implications for understanding protein stabilization mechanisms in polyol-containing biological and pharmaceutical systems.

🔒 This is a subscription article

Full text is available to subscribers and institutional members. Please choose an option below to access it.

1. Millero FJ. Molal volumes of electrolytes. Chem Rev. 1971;71(2):147-176.
2. Friedman HL, Krishnan CV. Studies of hydrophobic bonding in aqueous alcohols: enthalpy measurements and model calculations. J Solution Chem. 1973;2(2):119-140.
3. Ali A, Hyder S, Sabir S, Chand D, Nain AK. Volumetric, viscometric, and refractive index behaviour of α-amino acids and their groups' contribution in aqueous D-glucose solution at different temperatures. 2005.
4. Palani R, Geetha A. Acoustical and excess thermodynamic studies of molecular interaction in aqueous mixed solvent systems at 303, 308 and 313 K. Phys Chem Liq. 2009;47(5):542-552.
5. Millero FJ, Lo Surdo A, Shin C. The apparent molal volumes and adiabatic compressibilities of aqueous amino acids at 25 °C. J Phys Chem. 1978;82(7):784-792.
6. Jacobson B, Halonen E, Faurholt C. Intermolecular free lengths in the liquid state. I. Adiabatic and isothermal compressibilities. Acta Chem Scand. 1952;6:1485-1498.
7. Ali A, Khan S, Nabi F. Volumetric, viscometric and refractive index behavior of amino acids in aqueous glycerol at different temperatures. J Serb Chem Soc. 2007;72(5):495-512.
8. Jones G, Dole M. The viscosity of aqueous solutions of strong electrolytes with special reference to barium chloride. J Am Chem Soc. 1929;51(10):2950-2964.
9. Feakins D, Freemantle DJ, Lawrence KG. Transition state treatment of the relative viscosity of electrolytic solutions. Applications to aqueous, non-aqueous and methanol-water systems. J Chem Soc Faraday Trans 1. 1974;70:795-806.
10. Perron G, Desnoyers JE. Volumes and heat capacities of benzene derivatives in water at 25 °C: group additivity of the standard partial molal quantities. Fluid Phase Equilib. 1979;2(4):239-262.
11. Banipal TS, Kaur D, Banipal PK. Effect of magnesium acetate on the volumetric and transport behavior of some amino acids in aqueous solutions at 298.15 K. J Chem Thermodyn. 2006;38(10):1214-1226.
12. Chauhan S, Pathania L, Sharma K, Kumar G. Volumetric, acoustical and viscometric behavior of glycine and DL-alanine in aqueous furosemide solutions at different temperatures. J Mol Liq. 2015;212:656-664.
13. Kumar D, Lomesh SK, Nathan V. Molecular interaction studies of L-alanine and L-phenylalanine in water and in aqueous citric acid at different temperatures using volumetric, viscosity and ultrasonic methods. J Mol Liq. 2017;247:75-83.
14. Naz S, Jamal MA, Khosa MK, Naseem B, Muneer M. Effect of temperature on thermo-acoustical parameters of arginine in colloidal solutions. J Mol Liq. 2018;269:476-484.
15. Sawhney N, Kumar M, Sandarve, Sharma P, Sharma AK, Sharma M. Structure-making behaviour of L-arginine in aqueous solution of drug ketorolac tromethamine: volumetric, compressibility and viscometric studies. Phys Chem Liq. 2019;57(2):184-203.
16. Kumar A, Bamezai RK. Interactions of L-arginine with maltose monohydrate in aqueous solutions at 298.15 K: a volumetric study. J Biosphere. 2014;3:11-19.
17. Gupta J, Chand D, Nain AK. Study to reconnoiter solvation consequences of L-arginine/L-histidine and sodium salicylate in aqueous environment probed by physicochemical approach in the temperature range (293.15-318.15) K. J Mol Liq. 2020;305:112848.
18. Kaulgud MV, Patil KJ. Volumetric and isentropic compressibility behavior of aqueous amine solutions. I. J Phys Chem. 1974;78(7):714-717.
19. Banipal TS, Singh G, Lark BS. Partial molar volumes of transfer of some amino acids from water to aqueous glycerol solutions at 25 °C. J Solution Chem. 2001;30(7):657-670.
20. Gekko K, Timasheff SN. Mechanism of protein stabilization by glycerol: preferential hydration in glycerol-water mixtures. Biochemistry. 1981;20(16):4667-4676.
21. Back JF, Oakenfull D, Smith MB. Increased thermal stability of proteins in the presence of sugars and polyols. Biochemistry. 1979;18:5191-5196.
22. Wolf AV, Brown MG, Prentiss PG. Concentrative properties of aqueous solutions. In: CRC Handbook of Chemistry and Physics. Boca Raton (FL): CRC Press.
23. Kaur K, Juglan KC, Kumar H. Acoustical and volumetric investigation of polyethylene glycol 400 and polyethylene glycol 4000 in aqueous solutions of glycerol at different temperatures. J Chem Thermodyn. 2018;127:8-16.
24. Nain AK, Lather M, Sharma RK. Volumetric, ultrasonic and viscometric behavior of L-methionine in aqueous-glucose solutions at different temperatures. J Mol Liq. 2011;159(3):180-188.
25. Savaroglu G, İldaser AC. Volumetric and acoustic studies of L-tyrosine + L-glutamic acid + water at different temperatures. Thermochim Acta. 2014;582:86-93.
26. Palani R, Geetha A, Saravanan S, Shanbhag V. Intermolecular interactions of some amino acids in aqueous 1,4-dioxane solutions at 298.15 K. Rasayan J Chem. 2008;1(3):495-502.
27. Atkins PW, De Paula J, Keeler J. Atkins' Physical Chemistry. 12th ed. Oxford: Oxford University Press; 2023.
28. Segur JB, Oberstar HE. Viscosity of glycerol and its aqueous solutions. Ind Eng Chem. 1951;43(9):2117-2120.
29. Bagchi S, Nema SK, Singh RP. Ultrasonic and viscometric investigation of ISRO polyol in various solvents and its compatibility with polypropylene glycol. Eur Polym J. 1986;22(10):851-857.
30. Kant S, Kumar S. Effects of alkaline earth metal ions on thermodynamic and ultrasonic properties of ascorbic acid. J Chem Eng Data. 2013;58(5):1294-1300.
31. Kaur H, Thakur RC, Pathania VS, Sharma S. Effect of choline-based ionic liquid (cholinium ethanoate) on volumetric and acoustic properties of aliphatic amino acids (glycine and L-alanine) at T = (288.15, 298.15, 308.15 and 318.15) K. J Mol Liq. 2022;346:118247.
32. Kumar D, Lomesh SK, Nathan V. Molecular interaction studies of L-alanine and L-phenylalanine in water and in aqueous citric acid at different temperatures using volumetric, viscosity and ultrasonic methods. J Mol Liq. 2017;247:75-83.
33. Azhagiri S, Jayakumar S, Padmanaban R, Gunasekaran S, Srinivasan S. Acoustic and thermodynamic properties of binary liquid mixtures of benzaldehyde in hexane and cyclohexane. J Solution Chem. 2009;38(4):441-448.
34. Akhtar Y, Ibrahim SF. Ultrasonic and thermodynamic studies of glycine in aqueous electrolyte solutions at 303 K. Arab J Chem. 2011;4(4):487-490.
35. Riyazuddeen, Altamash T. Ultrasonic velocities and densities of L-histidine or L-glutamic acid or L-tryptophan or glycylglycine + 2 mol L−1 aqueous KCl or KNO3 solutions from (298.15 to 323.15) K. J Chem Eng Data. 2009;54(11):3133-3139.
36. Ali A, Nain AK, Chand D, Lal B. Molecular interactions in binary mixtures of anisole with benzyl chloride, chlorobenzene and nitrobenzene at 303.15 K: an ultrasonic, volumetric, viscometric and refractive index study. Indian J Chem A. 2005;44:511-515.
37. Millero FJ, Lo Surdo A, Shin C. The apparent molal volumes and adiabatic compressibilities of aqueous amino acids at 25 °C. J Phys Chem. 1978;82(7):784-792.
38. Vazdar M, Vymětal J, Heyda J, Vondrášek J, Jungwirth P. Like-charge guanidinium pairing from molecular dynamics and ab initio J Phys Chem A. 2011;115(41):11193-11201.
39. Masson DO. Solute molecular volumes in relation to solvation and ionization. Philos Mag. 1929;8(49):218-235.
40. Kadam UB, Hiray AP, Sawant AB, Hasan M. Densities, viscosities, and ultrasonic velocity studies of binary mixtures of trichloromethane with methanol, ethanol, propan-1-ol, and butan-1-ol at T = (298.15 and 308.15) K. J Chem Thermodyn. 2006;38(12):1675-1683.
41. Rajagopal K, Jayabalakrishnan SS. Volumetric, ultrasonic speed, and viscometric studies of salbutamol sulphate in aqueous methanol solution at different temperatures. J Chem Thermodyn. 2010;42(8):984-993.
42. Bahadur I, Deenadayalu N, Ramjugernath D. Effects of temperature and concentration on interactions in methanol + ethyl acetate and ethanol + methyl acetate or ethyl acetate systems: insights from apparent molar volume and apparent molar isentropic compressibility study. Thermochim Acta. 2014;577:87-94.
43. Eyring H, Hirschfelder J. The theory of the liquid state. J Phys Chem. 1937;41(2):249-257.
44. Eyring H. The activated complex in chemical reactions. J Chem Phys. 1935;3(2):107-115.
45. Hepler LG. Thermal expansion and structure in water and aqueous solutions. Can J Chem. 1969;47(24):4613-4617.
46. Robinson RA, Stokes RH. Electrolyte Solutions. Mineola (NY): Dover Publications; 2002.
47. Chalikian TV, Sarvazyan AP, Breslauer KJ. Partial molar volumes, expansibilities, and compressibilities of α,ω-aminocarboxylic acids in aqueous solutions between 18 and 55 °C. J Phys Chem. 1993;97(49):13017-13026.
48. Hepler LG. Thermodynamic analysis of the Hammett equation, the temperature dependence of ρ, and the isoequilibrium (isokinetic) relationship. Can J Chem. 1971;49(17):2803-2807.
49. Sinibaldi R, Ortore MG, Spinozzi F, Carsughi F, Frielinghaus H, Cinelli S, Onori G, Mariani P. Preferential hydration of lysozyme in water/glycerol mixtures: a small-angle neutron scattering study. J Chem Phys. 2007;126(23):235101.
50. Chalikian TV. Volumetric properties of proteins. Annu Rev Biophys Biomol Struct. 2003;32:207-235.
51. Dashnau JL, Nucci NV, Sharp KA, Vanderkooi JM. Hydrogen bonding and the cryoprotective properties of glycerol/water mixtures. J Phys Chem B. 2006;110(27):13670-13677.