Preparation Of Porous Aromatic Frameworks And Cellulose Composite Aerogel For Contaminant Adsorption

With the increasing environmental pollution,the preparation of adsorbent materials with high adsorption capacity,environmental friendliness,economy and easy recycling has become one of the most concerned scientific issues for chemical researchers.Porous aromatic material PAF-1 is expected to be particularly useful for removal of organic compounds in water due to its high specific surface area and high chemical and thermal stability.However,the powder form of PAF-1 still limits its applicability in purification of water.This work chooses cellulose nanofibers as skeleton to build monolithic composite aerogel.Herein our research work is presented as follows:1.PAF-1@cellulose nanofibril?CNF?composite aerogel are prepared through double-cross-linked?physical and chemical cross-linked?method and applied as adsorbents to remove BPA from water.With combination of the high surface area(2203 m² g^-1)of PAF-1 and the bulk skeleton of CNF,as well as strong interactions between BPA molecules and the networks,the resulted composite aerogels can remove 77.7%of BPA,within 10seconds at the adsorption rate of 532.2 mg g^-1 min^-1.And their removal efficiency reaches97%after 1 hour adsorption.The adsorption capacity of PAF-1@CNF composite aerogels towards BPA is estimated to be as high as 1000 mg g^-1 according to Langmuir adsorption model.Moreover,the PAF-1@CNF composite aerogel also has remarkable reusability.After twelve consecutive BPA adsorption/desorption cycles,the composite aerogel still maintains a good adsorption performance which could remove up to 95.7%of BPA and PAF-1 still firmly attached to CNFs.2.Ammonia adsorption functional PAF via postsynthetic modification of PAF-1 is obtained using-SO₃H,named PAF-1-SO₃H.Then,PAF-1-SO₃H@CNF composite aerogel are prepared which using trimethoxymethylsilan?MTMS?as cross-linker.The characterization of N₂ absorption demonstrate the BET surface area is 557 m² g^-1.In addition,the ammonia adsorption capacity of PAF-1-SO₃H@CNF composite aerogel is 7.2mmol g^-1 by ammonia adsorption test.