Catalog NumberHG54217
CAS Number54-21-7
CategoryAnionic Surfactants
Sodium Salicylate Synergizes the Corrosion Inhibition of Mild Steel in 1 M HCl
Mobin, Mohammad, et al. Materials Chemistry and Physics 191 (2017): 151-167.
The corrosion of mild steel in acidic medium is a serious problem in cleaning and pickling operations. In this work, sodium salicylate (SS) was used as a synergist for improving the corrosion-inhibition action of two biodegradable, low-toxicity, cationic gemini surfactants (m-E2-m, m = 12 or 14) for mild steel (MS) in 1 M HCl solution.
Key Findings
· Synergistic enhancement by SS: Adding 0.01 M SS to solutions of m-E2-m surfactants increased inhibition efficiency relative to either component alone. The effect was judged synergistic: the calculated synergism parameter (Sθ) exceeded unity, indicating that the combined system produces more inhibition than the sum of individual effects.
· Mechanism of action - co-adsorption: Experimental and spectroscopic evidence supports a co-adsorption model on the steel surface. Two co-adsorption modes were discussed: (a) competitive adsorption, in which SS anions and cationic gemini surfactants occupy different surface sites, or (b) cooperative adsorption, where SS chemisorbs to metal sites and cationic surfactants bind to the anion layer via electrostatic attraction-both scenarios help build a more protective interfacial film.
· The gemini surfactants behave as mixed-type inhibitors (affecting anodic and cathodic reactions) and the adsorption of inhibitors on MS follows the Langmuir adsorption isotherm, consistent with monolayer adsorption behavior.
Modulating Surfactant Properties and Aggregation Behavior Through Sodium Salicylate Addition
Zhao, Liuchen, et al. Journal of Molecular Liquids 225 (2017): 897-902.
The functional properties of surfactant systems can be significantly enhanced through strategic formulation with specific additives. This study examined the role of sodium salicylate (NaSal) as a structure-forming agent for optimizing the interfacial behavior and aggregation characteristics of didecyldimethylammonium formate (DDAF), a quaternary ammonium surfactant.
1. Lowered CMC and modified adsorption kinetics: Addition of NaSal decreases the critical micelle concentration (cmc) of DDAF aqueous solutions, indicating promoted micellization. Despite enhanced micellization, NaSal slows the initial diffusion/adsorption of surfactant molecules from the bulk to the subsurface during the first few seconds.
2. Wetting behavior - delayed spreading and higher initial contact angle: For droplets of 0.1 mM DDAF, increasing NaSal concentration (1 mM → 100 mM) caused the initial contact angle to rise and the time to reach equilibrium spreading to increase. A representative change in contact angle at t = 2 min increased from 46° to 95° as NaSal loading increased.
3. Promotion of intermolecular H-bonding and phase transformation: Quantum-chemical results indicate that electrostatic interactions between DDAF and salicylate weaken the intramolecular O-H···O hydrogen bond within salicylate anions, favoring the formation of intermolecular O-H···O hydrogen bonds among salicylate ions. NaSal can induce a transition from wormlike micelles to vesicles when the molar ratio DDAF/NaSal is in the range 7/3 to 8/2.
4. Mechanistic: Electrostatic interactions between DDAF and NaSal weakened the intramolecular hydrogen bonding within NaSal molecules. This promoted the formation of an extended intermolecular hydrogen-bonding network among NaSal anions, which governed the observed changes in surfactant behavior.
Sodium Salicylate as a Highly Effective Antidote for Lethal Paraquat Poisoning
Dinis-Oliveira, R. J., et al. Free Radical Biology and Medicine 42.7 (2007): 1017-1028.
Paraquat dichloride (PQ) poisoning triggers a complex cascade of lung damage involving oxidative stress, inflammation, platelet activation, and nuclear factor kappa B (NF-κB) pathway activation. This study examined the remarkable therapeutic potential of Sodium Salicylate (NaSAL) as a comprehensive treatment for acute PQ poisoning.
Experimental Design: In an experimental model, rats were exposed to a lethal dose of PQ (25 mg/kg). Sodium Salicylate treatment (200 mg/kg) was administered intraperitoneally 2 hours post-PQ exposure, simulating a realistic clinical scenario where patients arrive for treatment after poison ingestion.
Key Results:
· Survival: 100% of PQ-only animals died by Day 6, whereas NaSal-treated, PQ-exposed rats showed full survival extended for more than 30 days.
· Comprehensive Protection: NaSal treatment caused a significant reduction in PQ-induced oxidative stress. The PQ-triggered increases in glutathione peroxidase and catalase expression were absent in NaSal-treated animals. NaSal prevented activation of NF-κB in lung tissue following PQ exposure. PQ-induced platelet activation was significantly reduced by NaSal. Histopathological lung lesions induced by PQ were strongly attenuated in NaSal-treated animals.
· Overall outcome: The combination of biochemical, cellular and histological improvements correlated with the complete rescue from PQ lethality in this model.