Cation-inhibited transport of graphene oxide nanomaterials in saturated porous media: the hofmeister effects
Cation-inhibited transport of graphene oxide nanomaterials in saturated porous media: the hofmeister effects
复制标题
饱和多孔介质中氧化石墨烯纳米材料的阳离子抑制传输：霍夫迈斯特效应
DOI：
10.1021/acs.est.6b05007
复制
发表时间：
2017
影响因子：
11.4
通讯作者：
Wiesner Mark R.
中科院分区：
文献类型：
--
作者：
Xia Tianjiao;Qi Yu;Liu Jing;Qi Zhichong;Chen Wei;Wiesner Mark R.
带负电荷的纳米颗粒在多孔介质中的传输很大程度上受阳离子的影响。迄今为止，很少有人知道如何相同的价态的阳离子可能会影响纳米粒子的运输不同。结果表明，阳离子对氧化石墨烯（GO）和硫化物还原GO（RGO）在饱和石英砂中的输运的影响服从Hofmeister级数，即碱金属离子对GO输运的抑制作用顺序为Na+< K+< Cs+，碱土金属离子对GO输运的抑制作用顺序为Mg2+< Ca2+< Ba2+。与批量吸附实验和微观数据，我们验证了具有大离子半径的阳离子（因此被弱水合）与石英砂和GO和RGO更强烈地相互作用比小离子半径的阳离子。特别地，可以形成内球络合物的单价Cs+和二价Ca 2+和Ba 2+经由石英砂与GO和RGO之间的阳离子桥接，并且可能经由增强的应变，导致GO和RGO的非常显著的沉积，这是由于来自阳离子桥接的GO和RGO的增强的聚集。Hofmeister效应的存在进一步证实了有趣的观察，即阳离子桥接对于RGO更显著，其含有更大量的羧基和酚基（即，金属络合部分）。研究结果进一步表明，纳米粒子的传输是由纳米粒子表面功能和溶液化学成分之间的复杂相互作用控制的。
Transport of negatively charged nanoparticles in porous media is largely affected by cations. To date, little is known about how cations of the same valence may affect nanoparticle transport differently. We observed that the effects of cations on the transport of graphene oxide (GO) and sulfide-reduced GO (RGO) in saturated quartz sand obeyed the Hofmeister series; that is, transport-inhibition effects of alkali metal ions followed the order of Na+< K+< Cs+, and those of alkaline earth metal ions followed the order of Mg2+< Ca2+< Ba2+. With batch adsorption experiments and microscopic data, we verified that cations having large ionic radii (and thus being weakly hydrated) interacted with quartz sand and GO and RGO more strongly than did cations of small ionic radii. In particular, the monovalent Cs+and divalent Ca2+and Ba2+, which can form inner-sphere complexes, resulted in very significant deposition of GO and RGO via cation bridging between quartz sand and GO and RGO, and possibly via enhanced straining, due to the enhanced aggregation of GO and RGO from cation bridging. The existence of the Hofmeister effects was further corroborated with the interesting observation that cation bridging was more significant for RGO, which contained greater amounts of carboxyl and phenolic groups (i.e., metal-complexing moieties) than did GO. The findings further demonstrate that transport of nanoparticles is controlled by the complex interplay between nanoparticle surface functionalities and solution chemistry constituents.