不同分子量天然有机质和电解质对碳纳米管稳定性的影响  

Effects of natural organic matter with different molecular weight and electrolytes on the stability of multi-walled carbon nanotubes

作　　者：方华[1,2] 杨嘉惠 章婷婷 于江华 曹惠忠[1] 

机构地区：[1]南京信息工程大学环境科学与工程学院,南京210044 [2]大气环境与装备技术协同创新中心,南京210044

出　　处：《环境化学》2017年第12期2634-2640,共7页Environmental Chemistry

基　　金：国家自然科学基金(41401546);江苏省普通高校研究生实践创新计划项目(SJLX15_0391)资助~~

摘　　要：以多壁碳纳米管(multi-walled carbon nanotubes,MWNTs)为对象,研究不同分子量分布区间天然有机物(natural organic matter,NOM)和电解质对MWNTs在水中凝聚及分散行为的影响.结果表明,低分子量(<1 k Da)有机物是NOM的主要构成部分,随着分子量的增大NOM的芳香性增强.电解质投加可通过压缩双电层作用引起水中的MWNTs的凝聚,凝聚过程符合经典DLVO理论.在低电解质浓度条件下,NOM可通过空间位阻作用抑制MWNTs凝聚;且随分子量增大,NOM抑制作用越强.而在高电解质浓度条件下,高分子量(>100 kDa)NOM可强化凝聚发生.不同分子量区间NOM将通过不同机制影响碳纳米材料在水中的凝聚.Effects of natural organic matter（NOM） with different molecular weight and electrolytes on the aggregation and dispersion of multi-walled carbon nanotubes（MWNTs） were investigated.The results showed that low molecular weight NOM（ 1 kDa） was the major portion of NOM.The aromaticity of NOM was enhanced with increasing molecular weight.Electrolytes induced aggregation of carbon nanomaterials by the mechanism of compressing the electric double layer,which conformed to the classic colloidal stability theory（Derjaguin-Landa-Verwey-Overbeek,DLVO）.At low electrolyte concentration,NOM inhibited the aggregation of nanoparticles by steric repulsion effect.However,high molecular weight NOM（100 kDa） promoted the aggregation of MWNTs with high concentration electrolyte.NOM with different molecular weight could influence the aggregation of carbon nanomaterials through different mechanisms in aquatic systems.

关 键 词：天然有机物 分子量 多臂碳纳米管 电解质 凝聚 

分 类 号：X131.2[环境科学与工程—环境科学]