Synthesis, Corrosion Inhibition Performance and Biodegradability of Novel Alkyl Hydroxyethyl Imidazoline Salts

Self-assembled systems based on novel hydroxyethylated imidazolium-containing amphiphiles: Interaction with DNA decamer, protein and lipid

The study on aggregation capacity of novel imidazolium-containing amphiphiles of 1-(2-hydroxyethyl)alkylimidazolium bromide series and their interaction with bio-objects (DNA decamer, bovine serum albumin, phospholipid) was performed. It was revealed that introduction of hydroxyethyl moiety into the surfactant molecule resulted in 1.5-2-fold decrease of critical micelle concentration. These modified amphiphiles quantitatively bind DNA decamer due to intercalation and hydrophobic interactions with lipoplex formation. The evaluation of membranotropic properties of these surfactants exhibited that initiation of disordering and compression of the model cell wall consisting of dipalmitoyl phosphocholine (regulation of permeability for various compounds) could be achieved by variation of the length of hydrophobic tail of imidazolium-containing amphiphiles. Transition from individual surfactants solutions to their mixtures with protein (bovine serum albumin) is accompanied by 8-fold decrease of aggregation thresholds and characterized by the presence of two critical points. The binding of components of surfactant/BSA binary systems took place through tryptophan amino acid residue of peptide macromolecule.

Effect of operating conditions and interfering substances on photochemical degradation of a cationic surfactant

This work investigates the degradation kinetics of a recalcitrant organic pollutant, cetyltrimethylammonium bromide (CTAB), using direct UV and UV-H₂O₂ advanced oxidation processes. Direct photolysis at 253.7 nm showed only 55% degradation up to fluence dose of 40.65 J/cm² for an initial CTAB concentration of 100 mg/L. The apparent fluence-based pseudo-first-order rate constant and quantum yield were 2.29(±0.325) × 10^-5 cm²/mJ and 0.305(±0.043) mol/Einstein, respectively. In case of UV-H₂O₂, >99% degradation was observed up to a fluence dose of 0.79 J/cm². The rate constant was ∼200 times higher compared to direct photolysis, which was due to hydroxyl radical generation in the UV-H₂O₂ process. The second-order hydroxyl radical rate constant for CTAB was found to be 1.59(±0.18) × 10⁹ M^-1 s^-1. The effects of H₂O₂ dose, initial CTAB concentration and relevant water quality parameters (pH, alkalinity and nitrate concentrations) were studied; all of these influenced the rate constants. CTAB degradation was also examined in the municipal wastewater matrix. It is concluded that UV-H₂O₂ represents an efficient treatment process for CTAB in environmental matrices.