Erioglaucine Disodium Salt: Water-Soluble Triphenylmethane Anionic Dye

Erioglaucine disodium salt (CAS 3844-45-9) is a reddish-purple to bluish-purple powder with a metallic luster. It is highly soluble in water and ethanol, and its aqueous solution is bright blue. Its molecular structure is that of a triphenylmethane anionic dye, containing three sulfonic acid groups and two sodium ions, which confer water solubility and stability. It exhibits excellent heat, light, and acid-base resistance and is widely used as a blue food coloring agent, a pigment in pharmaceuticals and cosmetics, a biological staining agent, and an industrial dye.

Erioglaucine disodium salt on carbon steel in hydrochloric acid medium

Carbon steels are widely subjecting material to many applications in industry like heat exchangers, construction materials for reactor, oil and gas transport pipeline. These materials are being used due to its mechanical strength. However, it is corroded during cleaning, pickling and descaling. It is necessary to protect them from the unexpected metal dissolution. As a result, it affects the performance and working ability of the treated parts. The use of dyes is new and economical way to use as a corrosion inhibitor with organic dye. Many authors have been worked on the study of corrosion inhibition study of dyes as inhibitor. Erioglaucine disodium salt molecules are possessing benzene ring and sulphonic acid group. Different types of dyes are manufactured for their application in various industries like textile, leather and cosmetic. In many of the textile and leather factories used large amount of pigment as colouring agent for dying the fabric, give off voluminous wastage and disposed after use which mixed with soil and water causing environmental pollution. The present study is focusing on the corrosion protection effect in the absence and presence of Erioglaucine disodium salt was ascertained using gravimetric and electrochemical techniques. The protection effect of the inhibitor in acid medium is detected from SEM and FTIR studies. The experimental results (weight loss) were compared with electrochemical studies results and discussed.[1]

The corrosion inhibitory action of Erioglaucine disodium salt on carbon steel in acid medium was evaluated by weight loss measurement, impedance and polarization studies. The increased inhibitory action against corrosion in the presence of inhibitor with increased of Erioglaucine disodium salt concentration. The effect of concentration and temperature studies were performed on the inhibition effect. The adsorption efficiency of EDS was corroborated with high capacitive loop of Nyquist plot. The polarization behavior of Erioglaucine disodium salt concentration has been recorded showed it behaved as mixed type nature in acid medium. The enhancement in the inhibition action on the carbon steel has increased with increasing inhibitor concentration. The Langmuir adsorption isotherm gave information about the adsorption mode with carbon steel. Thermodynamic properties (ΔS∗, ΔH∗, ΔG° and Ea) of the Erioglaucine of the adsorption reaction were measured from the temperature effect. The hydrogen gas evolution measurement showed the strong adsorption nature of the inhibitor with the metal surface.

Photo-oxidative Decolorization of Erioglaucine disodium salt

The decolorization of Erioglaucine disodium salt (E133) in aqueous solution by K2S2O8 and NaBH4 with AgNPs as an activator was studied spectrophotometrically under normal laboratory conditions. Batch experiments were performed to investigate the effects of reaction time, initial dye concentration, activator concentration, solution pH, and temperature on the decolorization of Erioglaucine disodium salt. K2S2O8 and NaBH4 did not decolorize the dye E133 in the absence of AgNPs. The optimum dosage of AgNPs was 0.01 g/L, and 98% dye Erioglaucine disodium salt degradation was observed with 3.75 mM K2S2O8 at 30 °C in ca. 60 min of reaction time. In the NaBH4/AgNPs system, only 60% dye degradation was observed for an identical reaction condition. The decolorization rate constant increases with the increase in concentrations of AgNPs, K2S2O8, NaBH4, and reaction temperature. The decolorization degree of the E133 responded linearly with K2S2O8 and NaBH4 concentrations. The existence of sulfate radicals (SO4·–) and hydroxyl radicals (HO·) generated during the decolorization of E133 was identified by using ethanol and tertiary butyl alcohol as scavengers. Based on the Erioglaucine disodium salt solution absorbance changes at 628 nm, the decolorization mechanism was proposed and discussed.[2]

References

[1]Palanisamy, K., Kannan, P., & Sekar, A. (2018). Inhibition study of Erioglaucine disodium salt on carbon steel in hydrochloric acid medium using weight loss, electrochemical and thermodynamic properties. Egyptian Journal of Petroleum, 27(4), 445–454. https://doi.org/10.1016/j.ejpe.2017.07.008

[2]Al-Shehri AS, Zaheer Z, Alsudairi AM, Kosa SA. Photo-oxidative Decolorization of Brilliant Blue with AgNPs as an Activator in the Presence of K2S2O8 and NaBH4. ACS Omega. 2021 Oct 8;6(41):27510-27526. doi: 10.1021/acsomega.1c04501. PMID: 34693172; PMCID: PMC8529662.