Application Foundation Of Two Types Of Modified MOFs/AC Materials For CO Reduction And Flavor Storage And Release In Cigarette

Two cigarette industry’s future development goals: one is through technological innovation producing less harmful tobacco products, in order to reduce the content of CO in mainstream smoke and improve the safety of cigarette; Another is developing flavor-enhancing technology. In this paper, adsorption techniques were basic applied research to reduce the CO content in cigarette smoke and flavor-enhancing.Three types of MOFs was synthesized, and their dynamic adsorption properties of CO is compared by using fixed-bed adsorption technology. We found that, Ni-DOBDC material at after activation at 250 ℃, its dynamic CO adsorption capacity is up to 73.91 mg/g, which is more than the traditional composite adsorbents and other metal-organic framework materials. The adsorption selectivity for both mixed gas CO/N₂ and CO/CO₂ on Ni-DOBDC was calculated by using IAST model. Meanwhile, the isosteric heat of three gases on it was calculated, too. The results showed that, Ni-DOBDC materials for CO/N₂ and CO/CO₂ have good adsorption selectivity. Adsorption selectivity of Ni-DOBDC for mixed gas CO/N₂ is over in 1000. The size relationship of their isosteric heat on Ni-DOBDC: CO> CO₂> N₂. This indicates that the adsorption force between Ni-DOBDC and CO is significantly higher than that Ni-DOBDC with N₂ and CO₂.For Ni-DOBDC is easy to lose activity after absorbing water, this paper applied polydimethylsiloxane（PDMS） vapor deposition to modify Ni-DOBDC materials and material characterization was done. The results showed that, their crystal structure is not damaged, remain intact. EDS results show that their PDMS loading was 1.99%, 2.35%.In this paper, hydrophobic properties and CO adsorption properties on PDMS@Ni-DOBDC were characterized. The results show, PDMS @ Ni-DOBDC of water vapor adsorption ratio to be reduced about 25% of raw materials, modified Ni-DOBDC materials have a certain hydrophobic properties. Meanwhile, in the same pretreatment temperature, CO static adsorption performance on PDMS modified Ni-DOBDC material, is 16.2%-22.2% higher than raw materials.Different concentrations of glucose is used to char YK and SY-1 materials, researching the adsorption and desorption properties of essences. After carbonization the total pore volume of materials decreased, while the proportion of mesoporous actually was rising. Carbonized by glucose solution, surface acidic groups’ content of the materials increases. By calculating material desorption activation energy of ethyl acetate, the desorption activation energy of the carbonized materials is lower than that of the raw material. It shows the method of carbonization can effectively weaken the binding force between fragrance molecules and activated carbon materials, which will help flavor of slow-release.