Research On The Modified Activated Carbon Fiber For Selective Reducing The CO Content Of Cigarette Smoke

The security of cigarette is usually evaluated by the content of tar, nicotine and CO all over the world. The ways of reducing these harmful substances in the cigarette smoke and without negative effect on the taste of cigarette have received extensive interests in tobacco industry at abroad and home. With the reference of abundant other studies, the selection of suitable absorption carrier and optimization of coating processing have been carried on and the new technology of reducing CO selectively has been investigated via analyzing the corresponding cigarette samples.The absorption carriers of different kind of activated carbon fibers (ACF for short) are experimentally compared and selected and the effect of ACF location in the filter tip on the content of CO of smoke is investigated. The process of viscose base ACF as primary carrier and placing 10mm far away from cut tobacco end, which is characterized by better effect of reducing the content of CO of cigarette smoke, is obtained.On the base of this, the surface modification processes of ACF by coating monolithic nano-size TiO₂ or Pd and composite Cu-Pd are performed. The alteration of morphology and microstructures between virgin and modified ACF, as well as the influence of which on the absorption for CO, are examined using SEM and specific area/porosity analyzer. The results show that the coat modification increases the surface roughness of ACF resulting in an enhancement of CO absorption performance of ACF. The BET specific area and average porous capacity of modified ACF decrease and the fraction of micro-pores increases. The pump testing of cigarette samples is performed by smoking machine and the element of smoke is analyzed with XPS, and then the effect of coating modification of ACF on the content of CO and security of cigarette smoke is discussed. The ACF modified with monolithic nanosize TiO₂ shows better absorption performance for CO than monolithic Pd coated. The content of CO of Cu-Pd composite modified cigarette smoke is only 12.0mg per piece, which is improved than virgin ACF and monolithic nanosize TiO₂ modified ACF (13.3 and 12.7mg per piece, respectively). The reaction mechanism of Cu-Pd composite modified ACF is studied preliminarily.The effect of heat treatment processing on the surface morphology and component of composite coated ACF is explored, according to the examination of SEM,XPS and XRD.