Adsorption of L-proline on carbon nanotubes at different temperatures

Abstract

Carbon nanotubes are relatively new hollow cylindrical structures consisting of carbon atoms. The
study of their physicochemical properties is important due to their unique sorption and electronic properties and mechanical strength. Amino acids (AA) are one of the main representatives of biologically active substances involved in many human processes. Therefore, the study of interactions between amino acids and nanotubes is of a priority for biomedical applications. The purpose of the work was to build isotherms of L-proline adsorption on carbon nanotubes at different temperatures and to interpret them. The subject of the research was a study of the influence of temperature on L-proline adsorption on carbon nanotubes. The object of our research was L-proline aqueous solutions and carbon nanotubes MK Nano S1 (Canada). Among the research methods were dispersion, photometry, and volumetric method of building adsorption isotherms combined with the method of variable concentrations, and methods of quantum chemistry. The following results were obtained: isotherms of L-proline amino acid ad Т=25, 45, 65°С. It was established that with an increase in temperature there is an increase in L-proline adsorption.
The cluster adsorption model was used to establish that L-proline is adsorbed in the form of monomers
and clusters with dimensions of 19 and 23.
Isotherms of L-proline amino acid adsorption on carbon nanotubes MK Nano S1 (Canada) were built
from aqueous solution at temperatures of Т=25, 45, 65°С.Isotherms are S-shaped. Adsorption of L-proline on carbon nanotubes increases with an increase in temperature. This can be explained by an increase in the area of the sorbent with an increase of temperature due to carbon nanotubes agglomerate separation. Cluster adsorption model was used to establish that L-proline is adsorbed in the form of monomers at Т=25°С and clusters with the dimension of 19 (Т=65°С) and 23 (Т=45°С).