Adsorption of the Cationic Dye Methylene Blue on Anodic Porous Alumina in Sodium Dodecyl Sulfate Solutions

Abstract

Dyeing of anodic porous alumina (APA) prepared by aluminum anodization is generally achieved by dipping the positively charged APA surface into a negatively charged dye solution. We have proposed a new method to adsorb dyes and molecules onto APA using negatively charged sodium dodecyl sulfate (SDS). In this study, we found that cationic methylene blue (MB) can be adsorbed onto the positively charged APA surface using SDS aqueous solutions. We investigated two adsorption methods: dipping APA into aqueous solutions containing both MB and SDS (method 1) and successive dipping of APA into SDS and then MB aqueous solutions (method 2). The two methods produced different adsorption characteristics. Method 1 adsorption profile reflected formation of dye-rich induced micelles below the critical micellar concentration (CMC) and electrostatic interaction of micelles with MB above CMC. Method 2 adsorption was explained by electrostatic interaction of preadsorbed SDS with APA and MB.

Lasing from Narrow Bandwidth Light-Emitting One-Dimensional Nanoporous Photonic Crystals

“…A preliminary set of experiments were performed to establish the best conditions of pH, temperature, and exposure time to achieve an effective functionalization of NAA-GIFs (Figure a). In this process, as-produced NAA-GIFs were dipped into an aqueous mixture solution of SDS:RhoB at pH 5 and 50 °C for 1 min . Under such conditions, the surface of NAA is positively charged, while RhoB and SDS form negatively charged micelles that are electrostatically attached to the inner surface of NAA-GIFs.…”

“…In this process, as-produced NAA-GIFs were dipped into an aqueous mixture solution of SDS:RhoB at pH 5 and 50 °C for 1 min. 49 Under such conditions, the surface of NAA is positively charged, while RhoB and SDS form negatively charged micelles that are electrostatically attached to the inner surface of NAA-GIFs. Figure 5b shows the Fourier transform infrared spectroscopy (FTIR) absorption spectra of a representative NAA-GIF before and after SDS:RhoB functionalization.…”

Engineering of Solid-State Random Lasing in Nanoporous Anodic Alumina Photonic Crystals

“…After anodization and aluminum substrate removal, the inner surface of the NAA-RL platforms was selectively functionalized with RhoB fluorophore molecules via micellar solubilization of a SDS surfactant. In this process, the NAA-RL platforms were immersed in an aqueous mixture solution of SDS (20 mM) and RhoB (0.8 mM) at a fixed pH of 5 and 50 °C for 1 min . Next, RhoB-functionalized NAA-RLs (RhoB-NAA-RLs) were thoroughly washed with Milli-Q water, dried in an oven at 50 °C for 1 h, and stored in a dry atmosphere until further use.…”

Nanolayer-Constructed TiO(OH)2 Microstructures for the Efficiently Selective Removal of Cationic Dyes via an Electrostatic Interaction and Adsorption Mechanism

“…In recent decades, various methods have been developed to remove dyes such as methylene blue (MB), methyl orange (MO), rhodamine B (Rh B), basic yellow 1, basic green 4, and crystal violet from polluted water. Numerous reports have demonstrated that photocatalytic decomposition, − chemical oxidation, membrane filtration, and adsorption treatment − have been widely used to remove dyes from polluted water. Among these developed methods, the adsorption method has been widely used to efficiently remove organic dyes from contaminated water due to low cost, easy design and operation, convenience, and insensitivity to venomous dyes.…”