Dynamic adsorption of toluene on pore-size tuned supermicroporous silicas

Abstract

a b s t r a c tThe dynamic adsorption of toluene was investigated using supermicroporous silicas (SMPSs) synthesized through a solvent-free route by using tetraethoxysilane and conventional alkyltrimethylammonium halides as a structure-directing agent. The adsorption capacity of SMPSs depended on their pore diameters, which were precisely tuned in a range from 0.7 to 2.0 nm at single-angstrom intervals. The micropore filling of the molecule that is highly enhanced with micropores smaller than 1 nm improves the dynamic adsorption performance.

Significant Increase in Band Gap and Emission Efficiency of In2O3 Quantum Dots by Size-Tuning around 1 nm in Supermicroporous Silicas

“…SMPSs were synthesized by a solvent-free method which was developed in our previous study. − The pore sizes of SMPSs were controlled by changing the carbon number ( n ) of the alkyl chain of alkyltrimethylammonium chloride (bromide) C n TAC­(B) ( n = 6–18) which was used as a porogen (see Scheme S1 and Table S1 for experimental procedures, adsorption isotherms, and textual properties for SMPSs).…”

“…We synthesized semiconductor QDs using supermicroporous silicas (SMPSs) as templates. − The size of the QDs was strictly tuned below 2 nm by changing the pore size of the SMPSs. The remarkable expansion of the band gap of QDs was observed owing to strong quantum size effects.…”

High Toluene Dynamic Adsorption/Desorption Characteristics for Super-Microporous Silica Synthesized by Using Collagen Fibril as a Template

“…9) Therefore, novel adsorbents superior to the heat resistance and regeneration characteristics as compared with activated carbon have been desired. As representative candidates for the novel adsorbents, zeolite, 2,3,1012) silica gel, 13,14) mesoporous silica, 1527) and super-microporous silica (SMPS) 28) have been studied. Zeolite has micropores and indicates relatively high VOC dynamic adsorption properties, however, it is necessary to treat it at high temperatures for regeneration because the aromatic hydrogens of toluene interact with the zeolite framework oxygen atoms that are Lewis basic sites.…”

“…29) Watanabe et al have reported that super-microporous silica prepared by a solvent-free synthesis method using a surfactant exhibited high toluene dynamic adsorption properties. 28) However, desorption properties of toluene for SMPS have not been clarified.…”

Supermicroporous Silica Nanograins: Synthesis and Application

“…Finally, supermicroporous silicas (SMPSs) with size-controlled pores in the range of 0.7–2.0 nm were successfully obtained using this novel method. SMPSs were found to work as excellent adsorbents for a major organic air pollutant because their pore sizes are similar to the molecular sizes . The pores of SMPSs were utilized as templates of 1 nm scale quantum dots (QDs) of transition metal oxides. − We produced WO 3 as a model semiconducting material to demonstrate the precise tuning of band gap energy with a strong quantum-size effect .…”