Controlling effect of hydroxyl phenyl aminopropyl cationic surfactants on the catalytic and biological performance of AgNPs

Abstract

Three Hydroxy phenyl aminopropyl cationic surfactants with different carbon tail length; 8 (HPAPO), 12 (HPAPD), and 16 (HPAPH) have been synthesized successfully. The hydrophobic tail showed a pivotal impact on the morphological structure of the prepared silver nanoparticles (AgNPs) in terms of particles size, stability and yields as confirmed by TEM, DLS and UV-Vis spectroscopy measurements. The prepared AgNPs by HPAPH surfactant has a uniform structure with smaller particles size, and higher stability compared to that prepared by shorter chain length surfactants HPAPO and HPAPD. The HPAPH surfactant lead to formation AgNPs with size 12.9 ± 3.5 nm with high zeta potential 75.9± 6.4 mV indicating for highest stability. The surface and thermodynamic properties of the HPAPO, HPAPD and HPAPH surfactants are dependent on temperature and the hydrophobic tail length. The adsorption affinity is enhanced as temperature or chain length is increased. Increasing the surfactant hydrophobic tail or the solution temperature lead to decreasing the critical micelle concentration (CMC) of the surfactant solution. The hydrophobic chain exhibited a significant impact on the catalytic activity of the AgNPs toward removal some toxic pollutants such as methylene blue (MB) and p-nitrophenol (p-NP). The synthesized AgNPs using longer surfactant tail (HPAPH/AgNPs) showed highest catalytic activity compared to that prepared via shorter chain, which consider a promising study in terms of surfactant chain influence on the catalytic performance. The prepared cationic surfactants have good biological activity which is enhanced in case of in-cooperation with AgNPs. Both HPAPH Surfactant and HPAPH/AgNPs nano-hybrid system trigger maximum inhibition zone against all inspected microorganism, compared to surfactant with shorter chain.