Controllable Synthesis And Adsorption Properties For Pb²⁺ Of Monolith Silica Based Aerogels

Researchers carried out extensive and in-depth research about silica aerogels,especially in the filed about how to use a simple and effective way.On the basis of predecessors' work,this paper has made some improvements under ambient drying,the main research contents are shown below:?1?Wet gels were prepared by sol-gel method,TEOS and APTES were used as silica resources.The monolith silica aerogels were prepared under ambient drying.There were three kinds of diisocyanate have been used to crosslink wet gels,the backbone of silica aerogel became stronger after crosslinking.The amino groups from APTES have double effect during the preparing process.First,to provide reaction sites with diisocyanate in order to form polymer along with the backbone of wet gels.Second,the superfluous amino groups have a positive effect in the field of adsorption of Pb²⁺in waste water.There is no need to have the procedure of redundant solvent exchange and surface modification,and the period of preparation is short than ever before.?2?The monolith silica aerogels were synthesized using SDS and polymer as co-templates,TEOS and APTES were used as co-precursors.It was able to obtain monolithic silica aerogels by using diisocyanate reacted with amino groups from APTES to form a conformal coating over the surface of the silica aerogels network.After removing co-templates of SDS and polymer,silica aerogel still remains the integrity.The prepared sample show well controllable mesoporosity with higher mesopore ratio and significantly higher specific surface area.And the adsorption experiment indicates the silica aerogels have a positive effect for the removal of Pb²⁺.?3?In this part,monolith silica/carbon aerogels were prepared from the pyrolysis of polymer and APTES modified formaldehyde phenol organic aerogels under ambient drying.Different properties have been investigated during the research.And subsequent adsorption experiments proved silica/carbon aerogels are efficient for the removal of Pb²⁺.