Ag and Au Nanoparticles as Color Indicators for Monomer/Micelle–Nanoparticle Interactions

Abstract

Ag and Au nanoparticles (NPs) were used as color indicators to determine the monomer/micelle adsorption on the NP surface. A simple methodology based on the color change of Ag/Au NPs upon interacting with surface-active molecules was developed. A contrasting color change occurred when NPs interact with the monomer/micelle. This was demonstrated by monitoring the adsorption behavior of a series of Gemini surfactants. UV–visible measurements showed a large change in the intensity and wavelength of Ag/Au NP absorbance upon the surface adsorption of the monomer/micelle of Gemini surfactants. The mechanism of surface adsorption and molecular orientation on the solid–liquid interface of NPs was determined by performing the FT-IR and XPS measurements. Results demonstrated that sharp color changes from yellow to red for Ag NPs and red to purple for Au NPs happened when the Gemini surfactant monomer/micelle adsorbs on the NP surface. This colorimeter-based methodology highlighted the applicability of Ag/Au NPs in complex media where such NPs frequently encounter surface-active molecules.

Cationic surfactant modified iron nanoparticles for removal of orange II in batch mode: Kinetics, isotherms, mechanistic, and thermodynamic approach

“…6 Surfactants capped zerovalent iron NPs were used as an adsorbent to the extraction of protein stabilized gold NPs from an aqueous bulk. 7,8 Surfactants (cationic, anionic and nonionic) were also employed as a solubilizing media for oily sludge 9 and coal tar 10 to the degradation of aromatic hydrocarbons by thermally activated persulfate. Xue et al 9 and Deng et al 10 suggested that the surfactant could solubilized the oily sludge and coal tar components such as saturated and polyaromatic hydrocarbons into the deep hydrophobic core, and increases the solubility by reducing the surface tension in an aqueous solution.…”

Harnessing the Waste-to-Wealth Potential of Saraca asoca Plant-Derived Nanoparticles for the Sustainable Removal of Cationic Dyes through Regenerative Adsorption

“…13 Metal NPs, such as Ag, Au, and Fe, have been used for dye adsorption due to their unique surface properties. 14 oxide NPs, such as TiO 2 , 15 SnO 2 , 16 and ZnO, 15 have also been studied for dye adsorption due to their photocatalytic activity. However, the usage of green nanoadsorbents promotes the adoption of sustainable methods that will boost the green economy.…”

“…Metal NPs, such as Ag, Au, and Fe, have been used for dye adsorption due to their unique surface properties . Metal oxide NPs, such as TiO 2 , SnO 2 , and ZnO, have also been studied for dye adsorption due to their photocatalytic activity.…”

Effects of cationic and anionic micelles on the redox reaction of Erythrosine B by H2O2 in presence of Cu‐Fe nanoparticles

“…21,22 The nanoparticles have been investigated for the removal of environmental contaminants because they are inert, economical, possess high surface area, and have the ability for its surface modifications. 23,24 Additionally, the small dosage of nanoparticles have high efficiency in the treatment of large quantity of contaminants. However, the nanoparticles have its own some shortcomings like agglomeration into larger particle size, potential exposure and entry into the human body and limited working pH range.…”

“…Recently, iron (II) oxide nanoparticles‐H 2 O 2 has been investigated for its catalytic activity in placed the Fe 2+ ‐H 2 O 2 system for the environmental remediation of various contaminants 21,22 . The nanoparticles have been investigated for the removal of environmental contaminants because they are inert, economical, possess high surface area, and have the ability for its surface modifications 23,24 . Additionally, the small dosage of nanoparticles have high efficiency in the treatment of large quantity of contaminants.…”