Визначення ізоелектричної точки поверхнево-модифікованих оксидів металів у водних середовищах

R. S. Petryshyn; I. R. Muts; Z. M. Yaremko

doi:10.15407/hftp16.02.204

Authors

R. S. Petryshyn Ivan Franko National University of Lviv
I. R. Muts Ivan Franko National University of Lviv
Z. M. Yaremko Ivan Franko National University of Lviv

DOI:

https://doi.org/10.15407/hftp16.02.204

Keywords:

surface-modified metal oxides, isoelectric point, electrosurface properties, aqueous suspensions

Abstract

The position of the isoelectric point of aqueous suspensions of metal oxides/hydroxides depends on many factors, in particular, on the parameters of the crystal lattice, its defects, and the presence of impurities. Since the isoelectric point is an integral characteristic of the electrosurface properties of charged surfaces of amphoteric oxides in their aqueous suspensions, studies aimed at its determination are relevant.
A new approach to the determination of the isoelectric point for surface-modified metal oxides, in which ionized surface hydroxyl groups in aqueous medium appear not only as a result of their ionization reactions involving pH-determining Н+ and ОН– ions, but also other reactions, has been proposed. The essence of this approach is to determine experimentally the dependence of the difference in pH of suspensions and the pH of the aqueous solutions on which these suspensions are based on the pH of the initial aqueous solutions. Based on this dependence, four variable parameters characterizing it are estimated by the least squares method, namely: two ionization constants of surface hydroxyl groups, the total concentration of surface hydroxyl groups, and the difference in the fraction of ionized surface hydroxyl groups that are not related to the pH-determining ions Н+ and ОН–.
Based on the results obtained, an equation has been developed that allows to estimate the position of the isoelectric point for surface-modified metal oxides in their aqueous suspensions using the found variable parameters. In the case when the presence of ionized surface hydroxyl groups is associated only with pH-determining Н+ and ОН– ions, the proposed equation is simplified to the classical equation.
The application of the obtained equation is illustrated by the example of determining the isoelectric point of aqueous suspensions of modified titanium dioxide.

References

1. Parks G.A. The isoelectric points of solid oxides, solid hydroxides, and hydroxo complex systems. Chem. Rev. 1965. 65(2): 177. https://doi.org/10.1021/cr60234a002

2. Kosmulski M. Isoelectric points and points of zero charge of metal(hydr)oxides: 50 years after Parks review. Adv. Colloid Interface Sci. 2016. 238: 1. https://doi.org/10.1016/j.cis.2016.10.005

3. Kosmulski M. The pH-dependent surface charging and the points of zero charge. J. Colloid Interface Sci. 2002. 253(1): 77. https://doi.org/10.1006/jcis.2002.8490

4. Sonnefeld J. On the influence of background electrolyte concentration on the position of the isoelectric point and the point of zero charge. Colloids Surf., A. 2001. 190(1-2): 179. https://doi.org/10.1016/S0927-7757(01)00677-X

5. Gulicovski J., Čerović L., Milonjic S. Point of zero charge and isoelectric point of alumina. Mater. Manuf. Processes. 2008. 23(6): 615. https://doi.org/10.1080/10426910802160668

6. French R.A., Jacobson A.R., Kim B., Isley S.L., Penn R.L., Baveye P.C. Influence of ionic strength, pH, and cation valence on aggregation kinetics of titanium dioxide. Environ. Sci. Technol. 2009. 43(5): 1354. https://doi.org/10.1021/es802628n

7. Waseem M., Munsif S., Rashid U., Din I. Physical properties of α-Fe2O3 nanoparticles fabricated by modified hydrolysis technique. Appl. Nanosci. 2013. 2014(4): 643. https://doi.org/10.1007/s13204-013-0240-y

8. Nowacka M., Ambrożewicz D., Jesionowski T. TiO2-SiO2/Ph-POSS functional hybrids: preparation and characterisation. J. Nanomater. 2013. 2013(1): 1. https://doi.org/10.1155/2013/680821

9. Wang X., Sun T., Zhu H., Han T., Wang J., Dai H. Roles of pH, cation valence, and ionic strength in the stability and aggregation behavior of zinc oxide nanoparticles. J. Environ. Manag. 2020. 267: 110656. https://doi.org/10.1016/j.jenvman.2020.110656

10. Suttiponparnit K., Jiang J., Sahu M., Suvachittanont S., Charinpanitkul T., Biswas T. Role of surface area, primary particle size, and crystal phase on titanium dioxide nanoparticle dispersion properties. Nanoscale Res. Lett. 2010. 6: 27. https://doi.org/10.1007/s11671-010-9772-1

11. Khalameida S., Skvarek E., Janusz W., Sydorchuk V., Leboda R., Skubiszewska-Zięba J. Electrokinetic and adsorption properties of different titanium dioxides at the solid/solution interface. Cent. Eur. J. Chem. 2014. 12: 1194. https://doi.org/10.2478/s11532-014-0568-5

12. Szekeres M., Tombácz E. Surface charge characterization of metal oxides by potentiometric acid-base titration, revisited theory and experiment. Colloids Surf., A. 2012. 414: 302. https://doi.org/10.1016/j.colsurfa.2012.08.027

13. Kravchenko A.A., Demianenko E.M., Grebenyuk A.G., Lobanov V.V. Structure of the interface «silica surface - electrolyte solution»: theoretical simulation. Him. Fiz. Tehnol. Poverhni. 2018. 9(3): 212. [in Ukrainian]. https://doi.org/10.15407/hftp09.03.212

14. Brown M.A., Abbas Z., Kleibert A., Green R.G., Goel A., May S., Squires T.V. Determination of Surface Potential and Electrical Double-Layer Structure at the Aqueous Electrolyte-Nanoparticle Interface. Phys. Rev. X. 2016. 6: 011007-1. https://doi.org/10.1103/PhysRevX.6.011007

15. Trefalt G., Behrens S.H., Borkovec M. Charge regulation in the electrical double layer: ion adsorption and surface interactions. Langmuir. 2016. 32(2): 380. https://doi.org/10.1021/acs.langmuir.5b03611

16. Mahlalela L.C., Ngila J.C., Dlamini L.N. Characterization and stability of TiO2 nanoparticles in industrial dye stuff effluent. J. Dispersion Sci. Technol. 2017. 38(4): 584. https://doi.org/10.1080/01932691.2016.1183501

17. Yang C., Yu M., Wang J. Colloidal TiO2 nanoparticles with near-neutral wettability: An efficient Pickering emulsifier. Colloids Surf., A. 2019. 570: 224. https://doi.org/10.1016/j.colsurfa.2019.03.035

18. Bronze-Uhle E.S., Dias L.F.G., Trino L.D., Matos A.A., Lisboa-Filho P.N. Physicochemical characterization of albumin immobilized on different TiO2 surfaces for use in implant materials. Colloids Surf., A. 2019. 564: 39. https://doi.org/10.1016/j.colsurfa.2018.12.028

19. He Y., Zhou B., Liang H., Wang L., Li J., Li B. Silver nanoparticles on flower-like TiO2-coated polyacrylonitrile nanofibers: Catalytic and antibacterial applications. Colloids Surf., A. 2017. 529: 380. https://doi.org/10.1016/j.colsurfa.2017.06.025

20. Murath S., Saringer S., Somosi Z., Szilagyi I. Effect of ionic compounds of different valences on the stability of titanium oxide colloids. Colloids Int. 2018. 2(3): 32. https://doi.org/10.3390/colloids2030032

21. Rouster P., Pavlovic M., Cao T., Katana B., Szilagyi I. Stability of titania nanomaterials dispersed in aqueous solutions of ionic liquids of different alkyl chain lengths. J. Phys. Chem. C. 2019. 123(20): 12966. https://doi.org/10.1021/acs.jpcc.9b03983

22. Yaremko Z.M., Muts I.R. Electrosurface properties of aqueous suspensions of metal oxides and peculiarities of their crystal structure. In: Chemistry, Physics and Technology of Surface: Book of abstracts of Ukrainian Conference with International Participation. (29-30 May, 2024, Kyiv, Ukraine). P. 82.

23. Li C., Farrell S., Gilbert B., Zarzycki P. Deep neural network surrogate for complexation model of metal oxide/electrolyte interface. Comput. Mater. Sci. 2024. 238: 112932. https://doi.org/10.1016/j.commatsci.2024.112932

24. Petryshyn R.S., Yaremko Z.M., Soltys M.M. Determination of the ionization constants for surface hydroxyl groups of modified titanium dioxide in its aqueous suspensions. Him. Fiz. Tehnol. Poverhni. 2013. 4(2): 165. [in Ukrainian].