Chemistry, Physics and Technology of Surface

ISSN 2518-1238 (Online), ISSN 2079-1704 (Print)

In view of the chemical stability and inactivity of the polymer, polyvinylidene fluoride membranes are widely used in the processes of concentration, separation and fractionation of substances of different chemical nature. Because of the hydrophobic nature of the surface, these membranes are highly exposed to contamination, which significantly reduces their useful life. This paper is devoted to the development of a method of modifying the surface of polyvinylidene fluoride membranes with water-soluble polymers containing amino groups such as polyethyleneimine of branched structure and polyallylamine hydrochloride of linear one. The advantage and novelty of this method consist in the simplicity of modification (only one stage) and the usage of cheap non-aggressive reagents. Polymer grafted to the membrane surface was used as a linker for immobilization of magnetite nanoparticles. Magnetic nanoparticles fixed on polymeric linkers create oscillations in the boundary layer and cause additional turbulization when an external magnetic field is applied. Membranes modification with polyethyleneimine and polyallylamine hydrochloride is confirmed by IR spectroscopy. Immobilization of magnetite nanoparticles onto the membrane surface is confirmed by scanning electron microscopy. Surface properties of modified membranes are studied using electrokinetic analysis. It has been shown that grafting of the branched linker increases zeta potential of the membrane surface in two times comparing with the linear one. The transport properties of magnetically active membranes were studied in the process of ultrafiltration of BSA solutions. The dependence of the volume flux through the membranes on the applied pressure at various concentrations of protein has been studied. It is shown that immobilization of magnetite nanoparticles on the membrane and their movement in the boundary layer under the influence of a magnetic field reduces the effect of concentration polarization.

polyvinylidene fluoride membrane; magnetite nanoparticles; ultrafiltration; concentration polarization

1. Gao W., Liang H., Ma J., Han M., Chen Z., Han Z., Li G. Membrane fouling control in ultrafiltration technology for drinking water production: A review. Desalination. 2011. 272(1–3): 1.https://doi.org/10.1016/j.desal.2011.01.051

2. Guo W., Ngo H.H., Li J. A mini-review on membrane fouling. Bioresour. Technol. 2012. 122: 27. https://doi.org/10.1016/j.biortech.2012.04.089

3. Jhaveri J.H., Murthy Z.V.P. Nanocomposite membranes. Desalin. Water Treat. 2016. 57(55): 5. https://doi.org/10.1080/19443994.2015.1120687

4. Madaeni S., Ghaemi N., Alizadeh A., Joshaghani M. Influence of photo-induced superhydrophilicity of titanium dioxide nanoparticles on the anti-fouling performance of ultrafiltration membranes. Appl. Surf. Sci. 2011. 257(14): 6175. https://doi.org/10.1016/j.apsusc.2011.02.026

5. Huang J., Zhang K., Wang K., Xie Z., Ladewig B., Wang H. Fabrication of polyethersulfone-mesoporous silica nanocomposite ultrafiltration membranes with antifouling properties. J. Membr. Sci. 2012. 423–424: 362. https://doi.org/10.1016/j.memsci.2012.08.029

6. Lee K.P., Mattia D. Monolithic nanoporous alumina membranes for ultrafiltration applications: characterization, selectivity-permeability analysis and fouling studies. J. Membr. Sci. 2013. 435: 52. https://doi.org/10.1016/j.memsci.2013.01.051

7. Thuyavan Y.L., Anantharaman N., Arthanareeswaran G., Ismail A. Adsorptive removal of humic acid by zirconia embedded in a poly (ether sulfone) membrane. Ind. Eng. Chem. Res. 2014. 53(28): 11355. https://doi.org/10.1021/ie5015712

8. Li J.H., Shao X.S., Zhou Q., Li M.Z., Zhang Q.Q. The double effects of silver nanoparticles on the PVDF membrane: surface hydrophilicity and antifouling performance. Appl. Surface Sci. 2013. 265: 663. https://doi.org/10.1016/j.apsusc.2012.11.072

9. Mir F.Q., Shukla A. Negative rejection of NaCl in ultrafiltration of aqueous solution of NaCl and KCl using sodalite octahydrate zeolite-clay charged ultrafiltration membrane. Ind. Eng. Chem. Res. 2010. 49(14): 6539. https://doi.org/10.1021/ie901775v

10. Dudchenko A.V., Rolf J., Russell K., Duan W., Jassby D. Organic fouling inhibition on electrically conducting carbon nanotube–polyvinyl alcohol composite ultrafiltration membranes. J. Membr. Sci. 2014. 468: 1. https://doi.org/10.1016/j.memsci.2014.05.041

11. Konovalova V.V., Burban A.F., Ivanenko O.I., Perhun P.I. Ultrafiltration of water-soluble polymers by magneto active membranes. Naukovi zapysky NaUKMA. Chem. Sci. Tech. 2015. 170: 3. [in Ukrainian].

12. Vitola G., Mazzei R., Fontananova E., Giorno L. PVDF membrane biofunctionalization by chemical grafting. J. Membr. Sci. 2015. 476: 483. https://doi.org/10.1016/j.memsci.2014.12.004

13. Kang G., Cao Y. Application and modification of poly(vinylidene fluoride) (PVDF) membranes – A review. J. Membr. Sci. 2014. 463: 145. https://doi.org/10.1016/j.memsci.2014.03.055

14. Ross G.J., Watts J.F., Hill M.P., Morrissey P. Surface modification of poly (vinylidene fluoride) by alkaline treatment: 1. The degradation mechanism. Polymer. 2000. 41(5): 1685. https://doi.org/10.1016/S0032-3861(99)00343-2