Preparation of dual functional mesoporous MCM-41 containing alkaline and transition metalgroups for selectively removing hydrogen cyanide from cigarette smoke
In this study, inorganic mesoporous MCM-4l was synthesised by hydrothermal synthesis and functionalised by both alkaline and transition metal groups. The structures of the obtained dual functional MCM-41 were characterised by XRD, elemental analysis, thermographimetry (TG) and nitrogen adsorption at -196 °C. The results showed that the aminopropyltriethoxysilane (APS) and transition metal ion modified MCM-41 had been successfully synthesised, meanwhile, the modified MCM-41 retained its hexagonal structure and high specific surface area with good thermal stability at 180 °C. A model reactor was used to evaluate the HCN removing ability from cigarette smoke and optimise the preparation conditions of the material. When alkaline functional reagent dosage was 4 mL APS/(g MCM-41) following modification by transition metal ion Zn2+, the corresponding material Zn2+/c-APS/ MCM-41 was found to be the most effective for reducing HCN in cigarette smoke. The material was applied in cigarettes by means of dual filter. Compared with the control cigarette, the HCN delivery of the testing cigarettes was selectively reduced by 31.2%, while the deliveries of tar, nicotine, CO, B[a]P, NNK, NH3, crotonaldehyde and phenol changed little. The hazard index was reduced by 0.4.
The overall sensory quality and aroma style of the test cigarettes were almost similar to those of the control. The results indicated that the dual functional mesoporous MCM-41 containing both alkaline and transition metal groups was a promising filter additive for removing HCN from cigarette smoke.