Articolele autorului Anca Moanta
Link la profilul stiintific al lui Anca Moanta

Spectral and thermal studies of 4-(phenyldiazenyl)phenyl 2-furoate as corrosion inhibitor for carbon steel

The azo-ester, namely 4-(phenyldiazenyl)phenyl 2-furoate (PPF) by a coupling reaction between 4-(phenyldiazenyl)phenol and 2-furoyl chloride in the presence of pyridine was obtained. For characterization of this compound UV-Vis, FTIR and Thermal analysis were used. PPF was investigated as corrosion inhibitor for carbon steel in saline waters using potentiodynamic polarization. Morphology of the surface before and after corrosion was examined by optical

Read more
Synthesis and characterization of an azo dye: 4-(phenyldiazenyl)phenyl 2-furoate. Electrochemical and XPS study of its adsorption and inhibitive properties on corrosion of carbon steel in saline water

A new azo-derivative, 4-(phenyldiazenyl)phenyl 2-furoate (PPF), was obtained by an esterification reaction between 4-(phenyldiazenyl)phenol and 2-furoyl chloride in pyridine. The dye was characterized using elemental analysis, nuclear magnetic resonance (1H and 13C) and mass spectrometry with electro-spray ionization (ESI) techniques. The inhibitive properties of PPF on the corrosion of carbon steel in saline water (SW) have been investigated using

Read more
Characteristic fragmentation patterns of some 4-(phenylazo)phenols obtained by electron impact mass spectrometry

The mass spectra of fourteen substituted 4-(phenylazo)phenols have been recorded and compared. The most intense peaks have been used to characterize these spectra. The molecular ions are observed as highest intensity peaks. The influence of the substituents on the fragmentation is discussed.

Read more
Discoloration of waters containing azo dye Congo Red by Fenton oxidation process. Estimation of activation parameters

The discoloration of waters containing Congo red using Fenton reagent was studied at different pH values and different temperatures. The results reported a significant discoloration after 5 min, at pH = 3.50 and temperature of 55 oC. In these conditions, it was obtained a color removal (CR) equal to 75.6 ± 5 and a relative discoloration rate of 14.12 % / min. Apparent activation energy was determined using the Arrhenius equation. The value of Ea

Read more
Structural characterization, thermal investigation and liquid crystalline behavior of 4-[(4-chlorobenzyl)oxy]-3,4′-dichloroazobenzene

Using the Williamson method, a new dye 4-[(4-chlorobenzyl)oxy]-3,40-dichloroazobenzene (CODA) with liquid crystalline properties was synthesized. The structure and the thermal behavior of CODA were investigated by means of nuclear magnetic resonance, X-ray diffraction, differential scanning calorimetry, and light polarized optical microscopy techniques. The thermophysical processes were monitored by heating-cooling cycles, but the formation of liquid

Read more
Thermal and electron impact decomposition of 4-hydroxy-4′-cyano-azobenzene

In the present work 4-hydroxy-4'-cyano-azobenzene (HCA) azo dye was investigated by means of differential thermal analyses (DTA) and thermogravimetry (TG) in comparison with electron impact (EI) mass spectral (MS) fragmentation at 70 eV.

Read more
Thermal decomposition kinetics of some aromatic azomonoethers. Part IV.Non-isothermal kinetics of 2-allyl-4-((4-(4-methylbenzyloxy) phenyl)diazenyl) phenol in dynamic air atmosphere

Thermal analysis of 2-allyl-4-((4-(4-methylbenzyloxy)phenyl)diazenyl)phenol dye was performed in dynamic air atmosphere. The compound thermal behavior was investigated using TG, DTG and DSC techniques, under non-isothermal linear regime. Kinetic parameters of the two decomposition steps were obtained by means of multi-heating rates methods. Isoconversioanl methods (KAS and FWO), Invariant Kinetic Parameters method and Perez-Maqueda et al. criterion

Read more
A kinetic study on degradation of Methylorange process in aqueous

The degradation of azo dye Methylorange (MO) in aqueous solution by Fenton oxidation process has been investigated. The effects of different reaction parameters such as initial pH and the temperature on the oxidative degradation of Methylorange have been assessed. The UV-Vis spectral changes of Methylorange in aqueous solution during Fenton treatment process were studied. It was easier to destruct the azo linkage (-N=N-) group of Methylorange by

Read more
Spectral analysis and antimicrobial activity of some 4-phenylazo-phenoxyacetic acids
Novel azoderivatives as liquid crystals

In this paper the authors present novel azoderivatives obtained by the condensation of N-chloroacetylaniline with 4­(phenylazo)phenols or 4-hydroxy-4'-(phenylazo)biphenyls. The compounds have been characterised using UV-visible, IR, 1H RMN, and GC MS methods. The liquid crystals properties of these novel azoderivatives were studied through calorimetric measurements and optical texture observations.

Read more