Various methodologies are practically used to control corrosion. Coatings are the most widely used to protect metals against corrosion. However, due to the weak resistance of polymer coating against the penetration of corrosive solution to the metal/coating interface, the long-term corrosion resistance of the polymer coating is reduced gradually. Recently, nanoparticles have been added to coatings to improve their chemical, mechanical and optical properties. Nanocoatings either have constituents in the nanoscale or are made out of layers that are under 100 nm. Nanocoatings are used effectively to lessen the impact of a corrosive environment due to its various preferences, such as surface hardness, adhesive quality, long haul and, additionally, high-temperature corrosion opposition, and to improve its tribological properties, and so forth. Moreover, nanocoatings can be utilized in more slender and smoother thickness, which permits adaptability in equipment design and lower upkeep and working expenses. This review covers applications related to the management of metal corrosion, including the use of nanomaterials to produce high-performance corrosion inhibitors and corrosion-resistant coatings.

This study reported the doping of polyaniline (PANI) with graphene (G) and multi-walled carbon nanotubes (MWCNTs) by in situ polymerization. The molecular structure of PANI and its composites was observed by FTIR, which shows that the intensity of composites peaks are higher than pure PANI due to charge transfer between the PANI and graphitic allotropes. The structural information and crystallinity of PANI and its composites can be deduced from X-ray diffraction. The morphological characterization was observed by transmission electron microscope, which elucidated that aniline molecules were physically adsorbed and polymerized on the surface of graphene and MWCNTs due to π–π* electron interaction. PANI represents as an external layer of composites with several diameters depending on the PANI deposition degree, where the cores are G and MWCNTs. The conductivity measurement clarified the conductivity value of 0.1 wt% G in PANI matrix is higher 17 times than PANI without it.

The structure effect on corrosion inhibition of two amines and their derivatives is the main object of this article. The first amine was 1,8-diaminooctane and its ethoxylated (50e.o.) 1,8-diaminooctane and propoxylated (50p.o.) 1,8-diaminooctane. The second amine is the tetraethylenepentamine and its ethoxylated (50e.o.) and propoxylated (50p.o.) derivatives. The investigations were carried out by open circuit potential, potentiodynamic polarization, electrochemical impedance, quantum calculations and SEM measurements. The data obtained for the first amine showed the minimum inhibition efficiency (65.5%), meanwhile the maximum inhibition efficiency was 78.9% for its propoxylated derivative. On the other hand the maximium inhibition efficiency was 91% for the second propoxylated amine. The electronic properties; HOMO and LUMO energy levels, energy gap, dipole moment, polarizability, log P, total energy, charge densities, area/molecule and hydration energy have been calculated. The inhibition efficiency was calculated theoretically using the electronic parameters. From the obtained results, there is a significant difference between the inhibition efficiency of the electronic and the inhibition efficiency experimentally. The results were discussed on the light of the chemical structure of the used inhibitors. In general, the inhibition efficiency is affected by the shape and structure of the molecule