Synthesis and hydrophobic adsorption properties of microporous/mesoporous hybrid materials

Abstract

a b s t r a c tHybrid materials of silicalite-1 (Sil-1)-coated SBA-15 particles (MSs) have been successfully synthesized by crystallization process under hydrothermal conditions. These MSs materials were characterized by X-ray diffraction, nitrogen adsorption/desorption and TEM techniques, which illustrated that the silicalite-1-coated SBA-15 particles were successfully prepared and had large pore volume and hierarchical pore size distribution. Further experimental studies indicated that longer crystallization time under basic condition caused the mesostructure of SBA-15 materials to collapse destructively and higher calcination temperature tended to disrupt the long-range mesoscopic order while they had little influence on the phase of microcrystalline silicalite-1 zeolite. The resultant MSs materials were investigated by estimating dynamic adsorption capacity under dry and wet conditions to evaluate their adsorptive and hydrophobic properties. The hydrophobicity index (HI) value followed the sequence of silicalite-1 > MSs > SBA-15, which revealed that the SBA-15 particles coated with the silicalite-1 seeds enhanced the surface hydrophobicity, and also were consistent with FTIR results. Our studies show that MSs materials combined the advantages of the ordered mesoporous material (high adsorptive capacity, large pore volume) and silicalite-1 zeolite (super-hydrophobic property, high hydrothermal stability), and the presence of micropores directly led to an increase in the dynamic adsorption capacity of benzene under dry and wet conditions.

Multifunctional Silica-Based Nanoparticles with Controlled Release of Organotin Metallodrug for Targeted Theranosis of Breast Cancer

“…Consequently, the MSNs have stood out in different biomedical fields such as molecular imaging (fluorescence and magnetic resonance imaging) and drug delivery [39][40][41][42][43][44][45]. Especially in this last research area, MSN have shown a lots of benefits [46] such as a variable and controllable particle and pore size, a large surface area that can be selectively functionalized for drug delivery or high biocompatibility [47][48][49] or the possibility of combining several functionalities in a single nanosystem [50]. In this sense, one of these possible combinations is represented by the theranosis or the generation of a single nanoentity able to combine therapeutic and diagnostic features at the same time [28,[51][52][53][54][55].…”

Facile preparation of hierarchically porous diatomite/MFI-type zeolite composites and their performance of benzene adsorption: The effects of NaOH etching pretreatment

“…These composites can benefit in their application from both the zeolitic function (e.g., adsorption or catalytic performance) and the function of the supports (e.g., mechanical stability, pressure drop reduction, or mass transport). Various materials including porous stainless steel [24], porous glass [25], solid foam monoliths [26,27], ordered mesoporous silicates [28], and porous minerals [29][30][31] have been used as permanent supports. Among these materials, diatomite is a particularly attractive support [32].…”

Mesoporous silicalite-1 nanospheres and their properties of adsorption and hydrophobicity

“…The high angle XRD data in Fig. 3(b) exhibited distinctive peaks of crystalline silicalite-1 zeolite structure at 7.8°, 8.8°, 23°, 23.6°and 24.4°(2h) for all MSN-x samples, which can be indexed as (101), (200), (501), (303) and (133) reflections [1,3], respectively. Compared to Sil-1 zeolite, the intensities of the related peaks of MSN-x materials were much lower, which indicated that the synthesis method had some inverse influence on the formation of crystalline zeolite pore wall.…”

“…A hydrophobicity index (HI) was used to evaluate the hydrophobic property of MSN-x materials as defined in our previous study [1]. Under the identical experimental conditions, the higher HI value means the more hydrophobic property.…”

“…There are a number of technologies available for VOCs abatement, among which, sorption is a reliable chemical engineering method widely used because of the flexibility of the system, low energy and cheap operation costs. The MFI type silicalite-1 (Sil-1) zeolite without cations and silanols defects exhibits high hydrophobic property during the adsorption of volatile organic compounds (VOCs) under wet conditions [1][2][3]. However, the microporous nature of Sil-1 zeolite (diameter <2 nm) disables the bulky molecules access to the inner pores due to the mass diffusion [4].…”