【摘要】 随着纳米科技的不断进步,越来越多的金属基纳米颗粒(MNPs)被添加到油漆、除草剂、杀虫剂等产品中.其大量应用使得MNPs在储存、运输、使用以及处理等过程中不可避免地进入到环境中,从而对生物乃至人类健康产生威胁.环境中丰富的溶解性有机质(DOMs)容易通过静电吸引、配体交换、疏水性等作用吸附到纳米颗粒的表面,从而影响MNPs的迁移转化及生态效应.DOMs的吸附可能会降低MNPs表面电势,加速颗粒聚集,或堵塞表面微孔而减小颗粒的有效暴露面积,抑制金属离子的释放;DOMs吸附也可能增加其释放出的金属离子发生络合反应的几率,从而促进MNPs的溶解.以上矛盾结论的产生是因为DOMs在MNPs表面的吸附行为机制还不十分清晰,有待更深入的研究.因此,本文就DOMs在MNPs表面产生吸附的机理,及其对MNPs聚集、分散及溶解等过程产生的影响进行了系统的评述,并重点剖析了如何量化DOMs在MNPs表面的吸附作用,及不同环境因子对DOMs在MNPs表面的吸附行为的影响,提出为了提高MNPs环境行为及生态效应评估的准确性,建立DOMs吸附作用与MNPs聚集、分散和溶解间的相关关系将是今后研究的重点.更多还原

【Abstract】 More and more metal-based nanoparticles(MNPs) have been added to products such as paints, herbicides and pesticides owing to the continuous improvement of nanotechnology. The wide application of MNPs makes them inevitably enter the environment duringstorage, transportation, use and processing, thus threatening the health of environmental organisms and even human beings. Dissolved organic matters(DOMs) are abundant in the environment. They are easily adsorbed on the surface of MNPs by electrostatic attraction, ligand exchange and hydrophobic interactions, which affect the migration, transformation and ecological effects of MNPs in the environment. On the one hand, the adsorption of DOMs onto the surface of MNPs may lead to the decrease of their surface potential, which makes MNPs easy to aggregate. DOMs can also block the micropore on the surface of MNPs and reduce the effective specific surface area of MNPs exposed to the medium, thus inhibiting the release of metal ions from MNPs. On the other hand, the adsorption of DOMs onto the surface of MNPs may increase the possibility of complexing metal ions with DOMs, thereupon promoting the dissolution of MNPs. However, at present, the adsorption mechanism of DOMs onto the surface of MNPs is still unclear, which leads to the contradiction of the above conclusions and needs further investigation. Therefore, this article systematically reviewed the underlying adsorption mechanisms of DOMs onto the surface of MNPs, and their potential effects on the aggregation, dispersion and dissolution of MNPs. It also focused on how to quantitatively determine the adsorption of DOMs onto the surface of MNPs, and how to describe the influence of different environmental factors on DOMs adsorption onto the surface of MNPs. To improve the accuracy for assessing the environmental behaviors and ecological effects of MNPs, the relationship between the adsorption of DOMs and the aggregation, dispersion and dissolution of MNPs should be well understood.更多还原