Theoretical modeling and experimental characterization of erbium-based hydroxyapatites doped with different elements and quantum chemical study of some basic organic compounds

In this thesis, different hydroxyapatites based on erbium are theoretically and experimentally characterized, and certain basic organic compounds are subjected to quantum chemical analysis. This is the first theoretical and experimental analysis of co-doped hydroxyapatite (HAp) structures including yttrium (Y), cerium (Ce), praseodymium (Pr), and erbium (Er). By altering the concentration of Y, Ce, and Pr amounts of 0.13, 0.26, 0.39, 0.52, 0.65, and 0.78 at.%, while Er was maintained fixed at 0.39 at.%, the materials were created utilizing a wet chemical process. The produced samples underwent spectroscopic, thermal, and in vitro biocompatibility testing. The energy bandgap, density of states, and linear absorption coefficient were calculated theoretically. The research was done on the impacts of Y, Ce, and Pr concentration on thermal, morphological, and structural factors. The creation of the HAp structure in the samples was verified by Raman and Infrared (FTIR) spectroscopies. Theoretical studies showed that except for the sample containing 0.39 at.% of the dopant, which showed a drop in the bandgap, increasing the quantity of Y increased density from 3.1724 g cm-3 to 3.1824 g cm-3 and lowered bandgap energy from 4.196 eV to 4.156 eV. In addition by adding Ce atoms at various amounts, the density increased from 3.1745 to 3.1950 g cm-3 and the bandgap energy decreased gradually from 4.1591 eV to 4.1053 eV, except for 0.26Ce-0.39Er-HAp and 0.52Ce-0.39Er-HAp, where the energy bandgap raised. Also, the theoretical results demonstrated an increase in the density from 3.154 to 3.179 g cm-3, as well as steady decreases in the bandgap from 4.1739 to 4.0618 eV by adding Pr atoms. The values of linear absorption appeared reduced with an increase in photon energy. The cell viability was affected by the co-dopant content, and this value was found higher than 83% for all the samples. Quantum mechanical methods were used to examine the corrosion-inhibiting properties of 10 molecules (Benzene (C1), Phenol (C2), Toluene (C3), Benzoic acid (C4), Acetophenone (C5), Chlorobenzene (C6), Bromobenzene (C7), Benzaldehyde (C8), Naphthalene (C9), and Anthracene (C10). The results demonstrated that the behavior of organic-based corrosion inhibitors is connected to the performance of good corrosion inhibitors.