LAUSR

In the theoretical/computational section of this work, external electric field effects (EF) on some electronic characteristics (at molecular/atomic scale) of the chitosan-like molecular (as biopolymer) system are studied. These results show that the mechanism of the variation of the HLG gap and consequently the electrical conductivity ( I – V curves and molecular Joule-like effect) and thus local molecular electron transport efficiency ( $$ \Delta N $$ Δ N ) depend on the intensity of the applied external electric field. In addition, using atoms-in-molecules theory, the electronic response (such as atomic electron density, kinetic energy and viral force) of each atomic basin and each intra-molecular section to the EF are studied. Also, based on the molecular DOS diagram, the value of the global chemical softness, and thus the inhibition efficiency, of this molecular system is acceptable. Furthermore, in the experimental section of this work, the chitosan biopolymer was used as corrosion inhibitor in H 2 SO 4 on aluminum (AA1005). The primary corrosion techniques like electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) was used to analyze the corrosion inhibition process. Also, EIS study reveals that corrosion is under kinetically controlled. The PDP proposed that chitosan composite is mixed-type corrosion inhibitor and inhibit corrosion by blocking the active sites presenting over the metal surface.