Abstract: Nanoparticles (NPs) are the center of attraction in all branches of science, engineering and technology. Therefore, in corrosion science, it is expected that (NPs) will solve the problem of replacement of chromates through inhibitor modification. Among the electrochemical techniques employed for analyses were electrochemical noise (EN), cyclic potentiodynamic polarization (CPP), electrochemical impedance spectroscopy (EIS), and linear polarization resistance (LPR). Other characterization methods such as structural phase analyses with x-ray diffractometer (XRD), functional group analysis with Fourier Transform Infrared (FTIR) spectroscopy and nanoindentation were employed. The synthesized material was identified as nanoparticles by structural phase and UV-vis absorption analyses. All the electrochemical techniques manifested escalation of inhibition efficiency (Ζ %) at the introduction of the (NPs). Almost all the evaluated synergism constants (SQ) of each composite mixture of PECS and MnO2NPs achieved values which are above the threshold of one used to indicate whether synergism or antagonism took place. Nano-indentation with a scanning probe microscope (SPM) shows that the carbon steel encountered highest protection from degradation in 15 % HCl containing both PECS and MnO2NPs, followed by PECS and suffered the greatest degradation attack in the free acid medium. These results are full of prospects for a binary mixture of MnO2NPs+PECS to be used as non chromate corrosion retardant and indicate that this inhibitor modification approach can serve as a substitute to the use of banned cancer- causing and environmentally damaging chemical inhibitors.
Abstract: Nanoparticles (NPs) are the center of attraction in all branches of science, engineering and technology. Therefore, in corrosion science, it is expected that (NPs) will solve the problem of replacement of chromates through inhibitor modification. Among the electrochemical techniques employed for analyses were electrochemical noise (EN), cyclic pote...Show More
Abstract: Methyl violet/ cyclodextrin doped on ZnO nanocrystals were synthesized and characterized by various spectral and microscopic methods. The effect of different polarity of the solvents, α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) on MV were studied by various spectral methods. The inclusion behaviour of MV on both CDs were determined by PM3 method. Doping effect of MV/CD on ZnO nano investigated by UV-visible, fluorescence, FTIR, DTA, XRD, FE-SEM and TEM methods. MV molecule exhibits dual emission in all the solvents, α-CD and β-CD while three absorption maxima noticed in the ground state. The normal Stokes shifted band was originated from the locally excited state and the large Stokes shifted band was due to the emission from a twisted intramolecular charge transfer (TICT) state. Presence of isosbestic point suggest 1:1 inclusion complex is formed. HOMO-LUMO gap for MV/β-CD inclusion complex was more negative, which support that this complex is more stable than MV/α-CD inclusion complex. A red or blue shifted absorption and fluorescence maximum was seen in β-CD/MV/ZnO nanocrystals than MV/CD. Nanoparticle size was measured by TEM-EDS and X-RD methods. TEM image showed nanocrystals are formed in ZnO/MV/β-CD.
Abstract: Methyl violet/ cyclodextrin doped on ZnO nanocrystals were synthesized and characterized by various spectral and microscopic methods. The effect of different polarity of the solvents, α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) on MV were studied by various spectral methods. The inclusion behaviour of MV on both CDs were determined by PM3 metho...Show More