Investigations On N,S-doped MWNTs/GO Composites For The Removal Of Cadmium From Mainstream Cigarette Smoke

It is well-known that smoking is harmful to health.Therefore,it is of great importance to reduce the harmful substances in cigarette smoke for protecting human health.In the present work,multiwalled carbon nanotubes(MWNTs)are modified by hyperbranched polyethyleneimine(BPEI)and Na2S respectively,and afterwards combined with graphene oxide(GO)to form N,S-doped MWNTs/GO composites for the modification of cigarette filter.The N,S-doped MWNTs/GO modified cigarette filter can achieve an effective removal of cadmium from mainstream smoke and expand the application of carbon nanomaterials in the field of tobacco harm reduction.Chapter 1 gives a brief introduction to the harm of cigarette smoke and heavy metal,the progress of cigarette additive,the preparation and application of carbon nanomaterials and aerogel.Chapter 2 prepares GO,BPEI or Na2S modified MWNTs.Based on the above materials,N,S-doped MWNTs/GO composites are prepared by lyophilization technique.The obtained composites are characterized by means of FT-IR,SEM,TGA and Zeta potential.Chapter 3 employs the BPEI-MWNTs/GO or S-MWNTs/GO modified cigarette filter for the removal of Cd from mainstream smoke.The cigarette filters before and after modification for the removal effectiveness of Cd from mainstream smoke are compared in detail.In the experiment,the effects of N,S-doped MWNTs/GO dosage in the filter and the length of the modified filter on the removal efficiencies of Cd from mainstream smoke are investigated,respectively.The cigarette filters modified by 10 mg of BPEI-MWNTs/GO or S-MWNTs/GO can achieve the removal efficiencies of 85%and 86%for Cd from mainstream smoke,respectively.When cigarette filters modified by 0.5 mg of BPEI-MWNTs/GO or S-MWNTs/GO at the length of 10 mm are connected to the end of the original cigarette,the removal efficiencies of 87%and 86%for Cd from mainstream smoke are obtained respectively.In addition,N,S-doped MWNTs/GO modified cigarette filter has been applied for other five brands of cigarettes,giving rise to a significant improvement of the removal of Cd from mainstream smoke with respect to the original filters.