Functional Mesoporous Material Derived from 3D Net‐Linked SBA‐15

Abstract

A novel, versatile functional mesoporous material with the structure of SBA-15 but a specific 3D net-linked morphology has been prepared by using a facile method. This material has been assessed for its ability to reduce the level of nitrosamines in tobacco smoke so that the actual effect of this material in the reduction of carcinogenic environmental pollutants in a complex chemical system can be verified. By adjusting the force field during the hydrolysis and condensation processes of tetramethyl orthosilicate (TMOS) in an aqueous reaction system, the SBA-15 silica, which has a special morphology in that it is long and fiberlike from a microscopic view but large and block-like from a macroscopic angle, has been successfully synthesized. Moreover, the synthetic product is no longer a powder but a block because of its specific 3D net-linked morphology, which enables the material not only to trap particles in smoke but also to potentially be applied as a device. To strengthen the adsorptive capability of this porous material, a dry-impregnation procedure was applied in which zirconia was coated on the silica wall without changing the morphology. As expected, this functional material shows a high activity in the adsorption of N'-nitrosonornicotine (NNN), a bulky tobacco-specific nitrosamine, in solution and of N-nitrosopyrrolidine (NPYR), a volatile nitrosamine, in the gas stream. Furthermore, this 3D net-linked SBA-15 material can efficiently decrease the amount of nitrosamines and total number of particles in mainstream smoke when it is tested as an additive in the filter of a cigarette, thus providing powerful protection for the environment and public health.

Hierarchical Composites to Reduce N-Nitrosamines in Cigarette Smoke

“…Unlike the simple adsorption of volatile nitrosamines in the gaseous phase, where the carrier gas passes through, while the target carcinogen is trapped by the porous adsorbent, capturing TSNA in cigarette smoke by the filter additive involves several steps. The first, the adsorbent should be able to intercept the particle [ 15 , 38 , 39 , 40 ], and then contact with the target so that the TSNA adhered on the surface of the smoke particle can be captured by the adsorbent. After the adsorption, the purified smoke particle should leave in order to empty the adsorptive site for the successive adsorption procedure [ 41 ].…”

“…The filter holder was wiped twice with a quarter of a filter and added to the centrifuge tube as well. Finally, 30 mL of methanol and 100 μL of an internal standard solution were added [ 15 , 40 ]. The centrifuge tube was shaken for 30 min at 200 rpm on an orbital shaker.…”

Capturing nitrosamines in tobacco-extract solution by hydrophobic mesoporous silica

“…The micropore area and micropore volume were calculated by the t-plot method, according to statistical film thickness (t) in the range 0.35-0.50 nm. The thickness equation used here was developed by Harkins and Jura: t = [13.99/(0.034 − log(P/P o ))] 0.5 [18]. The pore size distribution curves were evaluated from desorption branches of the isotherms using the BJH method [9].…”

Effect of Reaction Time and Hydrothermal Treatment Time on the Textural Properties of SBA-15 Synthesized Using Sodium Silicate as a Silica Source and Its Efficiency for Reducing Tobacco Smoke Toxicity

“…Great research efforts have been focused on the addition of various materials on tobacco with the aim of reducing the number of toxic compounds in smoke. In this sense, some mesoporous materials have been studied as elements capable of retaining some of these compounds [28][29][30][31][32][33][34].…”