纳米纤维素气凝胶构建及其过滤聚苯乙烯微塑料性能研究

Construction of Nanocellulose Aerogel and Its Filtration Properties for Polystyrene Microplastics

中文关键词:  微塑料  纳米纤维素  气凝胶  过滤性能

Key Words:microplastics  nanocellulose  aerogel  filtration property

中文摘要:

      以漂白桉木浆为原料，分别通过2，2，6，6-四甲基哌啶氧化物（TEMPO）和2，3-环氧丙基三甲基氯化铵（EPTMAC）对其化学改性，并借助高压均质处理得到改性纤维素纳米纤丝（CNF），最后采用冷冻干燥法制备得到改性CNF气凝胶。研究了聚苯乙烯微塑料（PSMPs）种类和浓度对改性CNF气凝胶过滤性能的影响。结果表明，EPTMAC改性气凝胶（QCNF）对羧基化聚苯乙烯（PS-COOH）的过滤效率为99%；TEMPO氧化改性气凝胶（TCNF）对氨基化聚苯乙烯（PS-NH₂）的过滤效率为75%。改性CNF气凝胶对PSMPs的过滤性能得益于材料本身的超亲水性、独特的三维多孔结构和表面丰富的活性结合位点。此外，QCNF气凝胶经过8次循环过滤后，QCNF气凝胶对PS-COOH的过滤效率始终保持在99%以上，过滤通量稳定且超过20.2 L/（m²·h），具有良好的稳定性和可重复利用性。

Abstract:

      Bleached eucalyptus pulp was chemically modified by 2，2，6，6-tetramethylpiperidine-1-oxyl （TEMPO） and 2，3-epoxypropyltrimethylammonium chloride （EPTMAC）， respectively， to produce modified cellulose nanofibrils （CNF） by high pressure homogenization. Then， modified CNF aerogels were prepared by freeze-drying process. The effects of types and concentrations of polystyrene microplastics （PSMPs） on the filtration properties of modified CNF aerogels were studied. Results showed that the filtration efficiency of EPTMAC modified aerogel （QCNF） for carboxylated polystyrene （PS-COOH） was 99%， while the filtration efficiency of TEMPO-oxidized CNF aerogel （TCNF） for aminated polystyrene （PS-NH₂） was 75%. The excellent filtration performance of modified aerogels mainly relied on the super hydrophilicity， unique three-dimensional porous structure and abundant surface active binding sites of the material. In addition， the filtration efficiency and flux of the modified CNF aerogels were over 99% and 20.2 L/（m²·h） after 8 cycles of filtration， showing good stability and reusability.