Study of the Adsorption Properties of MCM-41 Molecular Sieves Prepared at Different Synthesis Times

Abstract

The variation of surface properties of SiMCM-41 and AlMCM-41 nanoporous materials as function of synthesis time was examined. The main properties studied were: surface area, pore diameter, pore volume, mesoporous parameter, and wall thickness. Siliceous MCM-41 molecular sieves were synthesized starting from hydrogels with the following molar compositions: 4.58SiO 2 :0.435Na 2 O:1 CTMABr:200 H 2 O for SiMCM-41, and 4.58SiO 2 :0.485 Na 2 O:1 CTMABr:0.038 Al 2 O 3 :200 H 2 O, for AlMCM-41. Cetyltrimethylammonium bromide (CTMABr) was used as the structural template. The crystallographic parameters were obtained from XRD data and by nitrogen adsorption using the BET and BJH methods. The results obtained showed a significant variation of the surface properties of the MCM-41 materials as a function of the synthesis time reaching silica wall thickness of ca. 2 nm on the fourth day.

Effect of synthesis time and treatment on porosity of mesoporous silica materials

“…Total pore volume of the samples listed in Table 1 follows the same trend. Calcined sample with 24 h synthesis time has a surface area of 739 m 2 /g which is consistent with the previously reported data (Araujo et al 2005).…”

Mesoporous carbon nitride as a metal-free catalyst for the removal of aniline

“…In this study, MCM-41 was synthesized by hydrothermal method. 7,9,19,20 The molar composition of tetraethylorthosilicate, sodium hydroxide, cetyltrimethylammonium bromide, ammonium hydroxide and distilled water was thereby xed to 6, 3, 1, 0.3, and 250, respectively. The sodium silicate solution was prepared by mixing tetraethylorthosilicate and sodium hydroxide in water.…”

Enhanced adsorption of acetylsalicylic acid over hydrothermally synthesized iron oxide-mesoporous silica MCM-41 composites

“…Several methods to treat pharmaceutical pollutants have been reported, such as via electrochemical advanced oxidation processes (AOPs) [6] , photocatalysis [7] , membranes [8,9] , and also adsorption process [10][11][12][13][14][15] . Particular attention has been paid to developing the adsorption technology since it has become one of the superior approaches to eliminate micro organic pollutants in wastewater due to its ease of operation and low cost.…”

“…Particular attention has been paid to developing the adsorption technology since it has become one of the superior approaches to eliminate micro organic pollutants in wastewater due to its ease of operation and low cost. In addition to carbon-based materials [10][11][12] , studies have been continuously carried out to design the adsorbents with high adsorption capacity based on mesoporous silica [13][14][15][16][17] . Among the mesoporous silica, the MCM-41 as one of the M41S mesoporous silica is potentially used as an adsorbent to remove organic pollutants [13][14][15][16] .…”