Aminopropyl Functionalised MCM-41: Synthesis and Application for Adsorption of Pb(II) and Cd(II)

Abstract

This paper shows a comparison of porous properties of aminopropyl-MCM-41 materials functionalised via the direct and indirect methods. The obtained materials were characterised using X-ray powder diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), adsorption/desorption isotherms of nitrogen, and Fourier-transfer infrared (FT-IR) spectroscopy. The results showed that the direct method provided the aminopropyl-MCM-41 material with well-ordered pores and high surface areas but with a lower quantity of grafted 3-aminopropyltriethoxysilane than the indirect method. To remove the organic template in the indirect method, solvent extraction with HCl/C2H5OH and calcination at 500°C were used, and the former gave a higher quantity of grafted 3-aminopropyltriethoxysilane in the resulting aminopropyl-MCM-41 materials. The experimental data were applied to the isotherm models of adsorption including Langmuir, Freundlich, Redlich–Peterson, and Sips either in the linear or nonlinear form. In order to avoid the bias of the determination coefficient and the error function method, the paired-samples t-test as an alternative method was first proposed to look for the most appropriate adsorption isotherms. The maximum adsorption capacity of Cd(II) and Pb(II) was 14.08 mg·g−1 and 64.21 mg·g−1, respectively. The mechanism of complexation and isoelectric interaction was suggested to explain the adsorption of Pb(II) and Cd(II) from aqueous solutions on aminopropyl functionalised MCM-41 in the range of pH from 2 to 9.

Efficient Activation of Coal Fly Ash for Silica and Alumina Leaches and the Dependence of Pb(II) Removal Capacity on the Crystallization Conditions of Al-MCM-41

“…Upon ligand (MPTMS and APTMS) grafting on AM41E-120-48, as shown in Figure 4 d, three hk0 diffraction peaks were still visible but decreased in intensities, illustrating the successful ligand grafting and still intact mesoporous structure [ 48 ].…”

<p>In vitro and in vivo Evaluation of Succinic Acid-Substituted Mesoporous Silica for Ammonia Adsorption: Potential Application in the Management of Hepatic Encephalopathy</p>

“… 9 In past years, various investigations have been carried out on the adsorption of heavy metals by mesoporous silica. 10 , 11 These studies resulted in the development of a novel application for MS materials in sensors, 12 catalysts, 13 drug delivery carrier, 14 gene delivery, 15 an adsorbent 16 , 17 and also as an antidote agent. 13 In this regard, Farjadian et al reported that EDTA modified MS could be potent antidote agents while assessed in vitro and in vivo in adsorption of iron 18 and copper.…”

Optimization of amine functionalization of MCM-41 for its covalent decoration in nanofiltration membranes for purification of saline- and micropollutant-contaminated feeds

“…In addition, another important peak of the MCM-41 framework was found at 800 cm −1 which showed the presence of Si–O stretching vibration. 31 Similarly, the ISM Zeolite showed all of the peaks that were identified in the FTIR analysis of M Zeolite, but an additional broad peak was found spanning from 3600 cm −1 to 3400 cm −1 which was due to stretching vibration of the N–H bond of TMSPTA. Another characteristic peak of C–N bond stretching was found at around 1300 cm −1 which further confirmed the presence of TMSPTA in ISM Zeolite.…”

“…The synthesis of mesoporous MCM-41 (ref. 31) was carried out by stirring CTAB (0.25 g) in 240 mL of DI water and 3.5 mL of 2 M NaOH solution at 80 °C for 30 min. Subsequently, 4.7 g of TEOS was added that initiated the precipitation.…”

“…NH 2 -MCM-41 derivatives were synthesized using in situ and post-synthetic functionalization procedures. 31 After establishing the structure of NH 2 -MCM-41, the different derivatives of NH 2 -MCM-41 were covalently crosslinked in the active layer of the membranes during interfacial polymerization (IP). The NH 2 -MCM-41 derivative was added to an aqueous phase containing a tetra-amine, N , N ′-bis(3-aminopropyl)ethylenediamine (BAPEDA).…”