O.A. Konovalova^a*, A.R. Khajdarova^a**, R.G. Ibragimov^a***, M.Kh. Salakhov^b,c****

^aKazan National Research Technological University, Kazan, 420015 Russia

^bTatarstan Academy of Sciences, Kazan, 420111 Russia

^cKazan Federal University, Kazan, 420008 Russia

E-mail: *olga.konovalova@bk.ru, **xajdarova.alya@bk.ru, ***equus.meteores@gmail.com,  ****equus.meteores@gmail.com

Received December 1, 2017

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Abstract

Polymeric membranes used in medicine and biotechnology, for example in hemodialysis and gas separation, and their modification have been studied. The object of the study is polysulfone porous membranes characterized by reproducible physical properties and well-controlled porosity. Modification of the membranes has been performed in a high-frequency electric discharge at low-pressure (18.4 Pa) in Ar and CF₄ medium with an operating frequency of 13.56 MHz and a power of 1500 W. The morphology of the surface of porous polysulfone membranes before and after their treatment by low-temperature plasma has been studied by means of atomic-force microscopy. A Solver P47H (NT-MDT) atomic force microscope with NSG20-type cantilevers has been used in contact and semi-contact operating modes. The following differences in the structure and measured and analyzed phenomenological parameters of polysulfone membranes before and after plasma-based modification have been evolved: dependence of the RMS of roughness of the surface, amplitude of the heights, average arithmetic roughness on the scan scale. It has been revealed that the influence of a high-frequency plasma wave on polysulfone membranes smoothes its surface that indicates a decrease of surface porosity of these membranes and explains the decrease of water permeability and the subsequent increase of retention capacity. It has been shown that plasma treatment improves the hydrophilic surface properties of the internal surfaces of hollow fiber polysulfone membranes. Significant changes have been established in adhesion characteristics of a control set surfaces of polysulfone membranes and the modified ones.

Keywords: polysulfone membranes, atomic force microscopy, porous membranes, hollow fibers, high-frequency low-pressure plasma

Figure Captions

Fig. 1. 2D ( a,  b) and 3D ( c,  d) AFM image of the polysulfone membrane surface, scan size 3 * 3  μm²:  a,  c – control sample,  b,  d – modified sample.

References

1. Zhao C., Xue J., Ran F., Sun S. Modification of polyethersulfone membranes – A review of methods. Prog. Mater. Sci., 2013, vol. 58, no. 1, pp. 76–150. doi: 10.1016/j.pmatsci.2012.07.002.

2. Borisov I., Ovcharova A., Bakhtin D., Bazhenov S., Volkov A., Ibragimov R., Gallyamov R., Bondarenko G., Mozhchil R., Bildyukevich A., Volkov V. Development of polysulfone hollow fiber porous supports for high flux composite membranes: Air plasma and piranha etching. Fibers, 2017, vol. 5, no. 1, pp. 2–19. doi: 10.3390/fib5010006.

3. Bryjak M., Gancarz I., Pozniak G., Tylus W. Modification of polysulfone membranes 4. Ammonia plasma treatment. Eur. Polym. J., 2002, vol. 38, no. 4, pp. 717–726. doi: 10.1016/S0014-3057(01)00236-1.

4. Gancarz I., Pozniak G., Bryjak M. Modification of polysulfone membranes 1. CO₂ plasma treatment. Eur. Polym. J., 1995, vol. 35, no. 8, pp. 1419–1428. doi: 10.1016/S0014-3057(98)00240-7.

5. Kim K.S., Lee K.H., Cho K., Park C.E. Surface modification of polysulfone ultrafiltration membrane by oxygen plasma treatment. J. Membr. Sci., 2002, vol. 199, no. 1–2, pp. 135–145. doi: 10.1016/S0376-7388(01)00686-X.

6. Zhang X., Zhang Sh., Wang Yu., Zheng Yi, Han Yu., Lu Yin. Polysulfone membrane treated with NH₃-O₂ plasma and its property. High Perform. Polym., 2017, pp. 1–6. doi: 10.1177/0954008317737358.

7. Mohammad A.W., Hilal N., Pei L.Y., Amin I.N.H.M., Raslan R. Atomic force microscopy as a tool for asymmetric polymeric membrane characterization. Sains Malays., 2011, vol. 40, no. 3, pp. 237–244.

8. Konovalova O.A., Nalimov D.S., Zamaleev A.Z. Salakhov M.Kh. Biocompatibility investigation of polypropylene endoprosthesis using atomic force microscopy. World Appl. Sci. J., 2013. vol. 21, no. 7, pp. 1089–1095. doi: 10.5829/idosi.wasj.2013.21.7.2875.

9. Kasper K., Herrmann K.-H., Dietz P., Hansma P.K., Inacker O., Lehmann H.-D., Rintelen Th. Investigation of dialysis membranes with atomic force microscopy. Ultramicroscopy, 1992, vol. 42–44, pt. 2, pp. 1181–1188. doi: 10.1016/0304-3991(92)90421-F.

10. Barzin J., Feng C., Khulbe K.C., Matsuura T., Madaeni S.S., Mirzadeh H. Characterization of polyethersulfone hemodialysis membrane by ultrafiltration and atomic force microscopy. J. Membr. Sci., 2002, vol. 237, nos. 1–2, pp. 77–85. doi: 10.1016/j.memsci.2004.02.029.

11. Volkov V.V., Ibragimov R.G., Abdullin I.Sh., Gallyamov R.T., Ovcharova A.A., Bildyukevich A.V. Modification of polysulfone porous hollow fiber membranes by air plasma treatment. J. Phys.: Conf. Ser., 2016, vol. 751, no. 1, art. 012028, pp. 1–5. doi: 10.1088/1742-6596/751/1/012028.

For citation: Konovalova O.A., Khajdarova A.R., Ibragimov R.G., Salakhov M.Kh. Studying modified porous medical membranes by atomic force microscopy. Uchenye Zapiski Kazanskogo Universiteta. Seriya Fiziko-Matematicheskie Nauki, 2018, vol. 160, no. 1, pp. 81–88. (In Russian)

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