碳气凝胶的制备及其对极性农药的吸附性能

以机械球磨联合TEMPO氧化对木浆纤维进行预处理,并通过高温热解制备碳气凝胶,对其形貌、元素组成、比表面积、孔径结构以及表面官能团进行表征分析,并以阳离子型毗虫啉(IMI)和阴离子型2,4-D为目标物评价其吸附性能.结果 表明:经机械球磨联合TEMPO氧化改性显著增加碳气凝胶的孔和表面C=O官能团含量、比表面积及极性,...

Carbon aerogels: Preparation and adsorption properties to polar pesticides

The wood pulp fibers were pretreated with the mechanical ball-milling combined with TEMPO oxidation technology, and then were applied to prepare the carbon aerogels under the high-temperature pyrolysis. The morphology, element composition, special surface area, pore structure and surface functional groups of carbon aerogels were all analyzed, and their adsorption properties were evaluated by cationic imidacloprid (IMI) and anionic 2,4-D. The results showed that modification with mechanical ball-milling combined with TEMPO oxidation could significantly increase the contents of pores, surface C=O functional groups, and polarity of carbon aerogels, and reduce their layer thickness and aromaticity. Their highest specific surface area was over 2631m²/g. The adsorption isotherms of IMI and 2,4-D on carbon aerogels could be well described by the Freundlich model. The main adsorption mechanism of IMI on carbon aerogels was cation/p/π-π electron donor-acceptor interactions, hydrogen bonding, pore filling, electrostatic attraction, while the adsorption of anionic 2,4-D on prepared carbon aerogels was mainly restrained by the electrostatic repulsion. The maximal adsorption capacity of IMI and 2,4-D of the prepared carbon aerogels were 437mg/g and 286mg/g, respectively. Therefore, carbon aerogels modified with the mechanical ball-milling combined with TEMPO oxidation technology had the great potential in the field of adsorption removal of organic pollutants in water.