Recently, composite materials based on chitosan (Chit) and sodium dodecyl sulfate or lauryl sulfate (Ls) have been developed, which have good adsorption properties with respect to lead ions Pb2+. However, their detailed IR spectroscopic analysis has not been carried out. To obtain the Chit–Ls composite, a Chit solution (200 kDa, deacetylation degree 83 %) containing acetic acid was used, so the amino group of Chit will be protonated (NH3+). The ionized state of the Chit amino group in the Chit–Ls composite is indicated by the low-frequency shift of the absorption bands of the bending vibrations of NH bonds. In this case, the most intense absorption band of individual Chit at 1590 cm-1 and the less intense Amide II bands are shifted in the spectrum of the composite to 1524 cm-1. Thus, the IR spectroscopy data indicate ionic interactions between Chit and Ls during the formation of their composite. The formation of Pb2+ complex with the Chit–Ls composite results in multiple low-frequency shifts of the absorption bands of SO bonds. The most significant shift was observed for the absorption band of asymmetric stretching vibrations of SO bonds. It shifts from 1215 cm-1 to 1176 cm-1. A shift of the absorption band of bending vibrations of S=O bonds at 625 cm-1 by -10 cm-1 is also observed. The band at 581 cm-1 shifts to 573 cm-1. These facts indicate the participation of SO bonds in the Chit–Ls composite in the interaction with lead cations. Complexation with Pb2+ ions causes virtually no shift in the absorption bands of stretching vibrations of C–O bonds in the C–O–C and C–OH groups of Chit, which is part of the composite with Ls. It is obvious that the OH groups of Chit are not involved in the formation of the complex. SEM showed that the Chit–Ls composite has plate-like particles with uneven edges and a small rough surface. The surface morphology of the microparticles of the Chit–Ls–Pb(II) composite complex has changed. They have become thicker, have a diverse topological shape, a porous surface, and different sizes.
chitosan, sodium dodecyl sulfate, lead, complex, IR-Fourier spectroscopy, scanning electron microscopy.
1. Zargar V. A review on chitin and chitosan polymers: structure, chemistry, solubility,derivatives, and applications / V. Zargar, M. Asghari, A. Dashti// ChemBioEng Reviews.– 2015. – Vol. 2, № 3– P. 204–226.
2. Kusmono. Water sorption, antimicrobial activity, and thermal and mechanical properties of chitosan/clay/glycerol nanocomposite films / Kusmono, I. Abdurrahim // Heliyon. – 2019. – Vol. 5, № 8. – e02342.
3. Buzinova D. A. Sorbcionnye i baktericidnye svoystva plenok hitozana / D. A. Buzinova, A. B. Shipovskaya // Izvestiya Saratovskogo universiteta. Ser. Himiya. Biologiya. Ekologiya. – 2008.
4. Shi L. E. Chitosan nanoparticles as drug delivery carriers for biomedical engineering / L. E. Shi, X. J. Fang, L. Y. Xing [et al.] // J. Chem. Soc. Pakistan. – 2011. – Vol. 33, № 6. – 929–934.
5. Yakovishin L. Development and IR spectroscopic analysis of composite materials based on poly(methyl methacrylate) and chitosan / L. Yakovishin, E. Tkachenko, Y. Tolstenko [et al.] // Materials Science
6. Yakovishin L. A. Composite materials based on dental acrylic plastic and chitosan / L. A. Yakovishin, E. V. Tkachenko // Chimica Techno Acta. – 2021. – Vol. 8, № 4. – 20218413.
7. Rinodo M. PAV-polielektrolitnye kompleksy na osnove proizvodnyh hitina / M. Rinodo, N. R. Kil'deeva, V. G. Babak // Rossiyskiy himicheskiy zhurnal. – 2008. – T. 52, № 1. – S. 84–91.
8. da Silva Alves D. C. Recent developments in chitosan-based adsorbents for the removal of pollutants from aqueous environments / D. C. da Silva Alves, B. Healy, L. A. d. A. Pinto [et al.] // Molecules.– 2021.– Vol. 26,
9. Vihoreva G. A. Kompleksoobrazovanie v sisteme dodecilsul'fat natriya hitozan / G. A. Vihoreva, V. G. Babak, E. F. Galich [i dr.] // Vysokomolekulyarnye soedineniya. – 1997. – T. 39, № 6.
10. Tkachenko E. V. Izuchenie sorbcionnoy sposobnosti kompleksa hitozan-dodecilsul'fat natriya na primere sorbcii ionov svinca / E. V. Tkachenko, S. V. Rusyaev // Uchenye zapiski Krymskogo
