Ionic-liquid-functionalized zeolitic imidazolate frameworks (ZIF) were synthesized using the co-ligands of 2-methylimidazole and amine-functionalized ionic liquid during the formation process of frameworks. The resulting ionic-liquid-modified ZIF had a specific surface area of 1707 m2·g−1 with an average pore size of about 1.53 nm. Benefiting from the large surface area and the high solubility of carbon dioxide in ionic-liquid moieties, the synthesized materials exhibited a carbon dioxide adsorption capacity of about 24.9 cm3·g−1, whereas it was 16.3 cm3·g−1 for pristine ZIF at 25 °C under 800 mmHg. The results demonstrate that the modification of porous materials with ionic liquids could be an effective way to fabricate solid sorbents for carbon dioxide adsorption.
The design of appropriate thermally responsive fragrance carrier systems is of significant importance for the application of fragrance in the food and tobacco industries. In this study, we investigate the potential of sorbitan monostearate and guar gum for the stabilization of menthol under ambient conditions and the thermally-induced release of menthol. Our results show that the sorbitan monostearate carrier could well stabilize the menthol for at least up to 15 days with neglectable menthol loss due to the favorable binding of menthol on the sorbitan monostearate carrier. In addition, rapid and controlled release of menthol could take place at a temperature of 80 °C in the sorbitan monostearate carrier system. As a comparison, guar gum could not stabilize menthol as a result of its poor compatibility. Our results suggest that sorbitan monostearate can be an ideal carrier material for the support of fragrance. In addition, our results also provide a useful guide for the tailored design of thermally responsive fragrance carriers.
Alkaloids, typical nitrogen compounds, were found to be abundant in tobacco waste. The recovery of alkaloids from tobacco waste for biological pesticides could reduce the use of traditional chemical pesticides and avoid the pollution of farmland by the leaching of alkaloids from tobacco waste. Considering the fact that alkaloids can easily volatilize, thermal treatment is expected to be a potential technology to achieve the release and recovery of alkaloids from tobacco waste. For better understanding of conversion behavior of nitrogen-containing compounds in tobacco waste during thermal treatment, purge/trap-GC/MS (gas chromatography mass spectrometry), PY-GC/MS (pyrolysis-gas chromatography mass spectrometry), and fixed-bed/ATD-GC/MS (auto-thermal desorption gas chromatography mass spectrometry) were adopted to detect the ingredients and concentration of nitrogen-containing compounds in tobacco waste and/or volatiles. The results of purge/trap-GC/MS showed that nitrogen-containing compounds in tobacco waste could be effectively evaporated at 180 °C in the forms of N-benzyl-N-ethyl-P-isopropyl benzamide, 2-Amino-4-methylphenol, or N-butyl-tert-butylamine. Specifically, N-benzyl-N-ethyl-P-isopropyl benzamide was the main nitrogenous compound in the volatiles of tobacco wastes accordingly. (S)-3-(1-Methyl-2-pyrrolidinyl) pyridine was dominant in N-compounds in pyrolysis condition according to the results of Py-GC/MS. In air atmosphere, with the heating temperature increasing, the concentration of main (S)-3-(1-Methyl-2-pyrrolidinyl) pyridine was firstly increased and then decreased. Besides, the interactions between the released volatiles could be accelerated at a high temperature. Accordingly, these findings suggested that pyrolysis under proper conditions could effectively promote the extraction of alkaloids from tobacco waste.
Fragrance is a commonly used substance in a number of commercial products, and fine control over the release behavior of the fragrance is essential for its successful application. Understanding the release behavior of the fragrance is the key to realizing the control of its release. Herein, we use tobacco leaf as the model substrate and investigate the mechanism of eugenol release from tobacco leaf. Our results show that interaction between eugenol and tobacco leaf is weak physical adsorption, and the eugenol release from tobacco leaf substrate is a temperature-dependent process. Further analysis on the release behavior reveals that eugenol release is closely associated with the morphology change of tobacco leaves under heating conditions. Our results provide insight into the release mechanism of fragrance from polymer substrate and may be useful for the future design of fragrance release systems.
Efficient capture of particulate matter in the smoke mainstream using low-cost filter pads is important for cost-effective analysis of mainstream smoke. The Cambridge filter pad (CFP) is the standard material for the collection of particulate matter in the mainstream. In this work, we report a low-cost alternative to CFP, which is composed of a cellulose acetate fiber (CAF) interlayer and two cotton fiber (CF) layers on both sides. The CF/CAF/CF filter exhibited high affinity toward typical tobacco additives such as glycerol and glycerol triacetate. In addition, the CF/CAF/CF filter had a favorable porous structure for the trapping of particulate matter. Due to these beneficial features, the CF/CAF/CF filter exhibited improved particulate matter trapping performance. These results suggest that the as-developed CF/CAF/CF filter could be a low-cost alternative to CFP.