Research On Several Types Of Porous Material Control-released Fragrance

Owing to more attention being paid on health of human being,the development of low harm、low tar and high aroma of tobacco have became a more and more important direction in cigarette industry.In this work,we studied the adsorption and desorption behaviors of flavors on different types of adsorbent materials and their mechanism for adsorbing and releasing flavors.In this work,we studied the adsorption of three kinds of flavors（geranylacetone、methylphenate and menthol）on various adsorbents,including Hβ-zeolite、AC、aluminum silicate and silica gel.Results showed that the adsorption capacities and the flavor conservation rate are related to the texture properties of adsorbents.The larger the surface area of the adsorbent,the greater the adsorption capacities of flavors.Meanwhile,the more the micropores of the adsorbent,the higher the conservation rate.The desorption kinetics and the diffusion of flavors of the four adsorbents were investigated.The desorption kinetic curves of flavors of adsorbents were measured by thermo-gravimetric technique,and the relationship of De（t）^q（t）were obtained.Results showed that the larger the pore size of an adsorbent was,the higher the diffusion coefficient of flavors within the adsorbent became.The diffusion coefficient of flavors decreased with the decrease of amounts adsorbed.Knudsen diffusion was dominant in flavors desorption from Hβ-zeolite,and its Knudsen diffusion coefficient was nearly constant due to its even pore size of 0.6 nm.The surface diffusion was dominant in flavors desorption from activated carbon due to its rich micropores with the pore size below 0.5 nm.Modification of Hβ zeotiles by H₂ reduction is studied.The effects of surface modification by H₂ reduction on the adsorption and desorption properties of geranylacetone over Hβ zeotiles were investigated.As the treatment time of H₂ reduction increased,the geranylacetone adsorption capacities remained the same at the initial stage and then decreased by further increasing the treatment time.This can be explained by the decreased surface strong acidic groups and the increased weak adsorption sites during H₂ reduction,resulting in even adsorption capacity and increased desorption kinetics of geranylacetone over the modified Hβ.In this study,the Hβ zeotiles were modified by loading starch sugar and then carbonized.Results showed that as starch sugar concentration increased,the geranylacetone adsorption capacities remained the same and then decreased.Meanwhile,the geranylacetone desorption rate increased,which reached 77.53% at the starch sugar concentration of 50g/L.The TPD results showed that the original Hβ zeotiles had two types of adsorption sites for geranylacetone,while after carbonization,the amount of strong adsorption sites decreased,while the weak adsorption sites increased.