One-Pot Synthesis of Amine-Functionalized Nano-Silica via Sol-Gel Assisted by Reverse Micelle Microemulsion for Environmental Application

Abstract

Amine modified nano-silica was prepared via a one-pot route and under very mild conditions in water in oil microemulsion with a non-ionic surfactant to study the effect of changing the amount of N-[3-(Trimethoxysilyl)propyl]ethylenediamine (DA) added to the synthesis mixture on the characteristics of the obtained nanocomposite such as morphology, crystallinity, surface charge, particle size, surface area, and accordingly the effect of all of these factors on the efficiency of the nanocomposite for the removal of heavy metal ions, namely zinc, from aqueous solutions. XRD, SEM, TGA, BET, DLS, FTIR, and pH0 analysis were performed for samples and the results showed a strong effect for the amount of DA added to the synthesis mixture on the characteristics of the obtained nanocomposites. It was found that increasing the amount of DA added to the synthesis mixture increased the pH0, hydrodynamic particle size obtained by dynamic light scattering analysis, and the particle size obtained by SEM. Sample prepared without the addition of DA (SNP) and the samples prepared with 1.5 mL of DA (SNP-1.5DA) showed a better adsorption performance compared to the samples prepared with 0.5 and 1.0 mL of DA (SNP-0.5DA and SNP-1.0DA, respectively). The main factor affecting the adsorption efficiency was found to be the available surface area for each nanocomposite, which was directly related to the degree of crystallinity as obtained by XRD analysis.

Nano-Silica Modified with Diamine for Capturing Azo Dye from Aqueous Solutions

“…Lu et al (2018) reported a decrease in the adsorption capacity of MO on the surface of biochar at a pH higher than 7 due to the deprotonation of the surface and, thus, repulsive force with the anionic dye [ 22 ]. Da’na et al (2022) applied the amine-modified silica with a pH ZPC around 7 to adsorb Zn 2+ by controlling the solution pH at 7.5, which makes the adsorbent surface negatively charged, and they reported 100% removal of this cation [ 32 ]. Khalaf et al (2019) applied ZnO nanoparticles to adsorb anionicbytionic dyes by controlling the surface charge of the adsorbent [ 13 ].…”

“…Accordingly, slower diffusion is expected to take place at pH = 3.5 with lower removal efficiency. To confirm the rule of amine in improving the surface charge of the adsorbent, other experiments were performed with silica nanoparticles (S), which have a pH ZPC of 2.0 as shown in Figure 1 f [ 32 ]. Thus, at both pH values, the surface will be negatively charged as proposed in Scheme 1 and a repulsive force is expected to prevent the reach of the MO molecules to the adsorption sites on the surface.…”

“…A specific amount of S-DA was sonicated in a specific amount of deionized double-distilled water for 30 min with power sonic 405. The pH ZPC was measured by the equilibrium technique as reported elsewhere [ 32 ]. Kjeldahl analytical titration method was used to estimate the nitrogen content of the S-DA sample [ 33 ].…”

Effect of boron-doping and annealing on the structure, morphological and optical properties of ZnO films prepared by spray pyrolysis method

“…The length of dislocation lines per unit volume is defined by the dislocation density (δ). It represents the number of defects in the film and is estimated as [38]:…”

Synthesis of mesoporous SiO2–CeO2 hybrid nanostructures with high catalytic activity for transamidation reaction

“…[23][24][25] Silica (SiO 2 ) is also an extensively studied porous material having outstanding properties like high-temperature stability, larger surface area, and excessive absorption capacity, all of which are important factors for catalysis. [26][27][28] Silica is naturally transparent, and ceria's lattice parameter (0.541 nm) closely resembles that of silica. Due to these properties, ceria was chosen for making composite with SiO 2 nanoparticles.…”