Forouzangohar Mohsen, Kookana Rai S
Commonwealth Scientific and Industrial Research Organisation, Advanced Materials Transformational Capability Platform, PMB 2, Glen Osmond, 5064, Australia.
J Environ Monit. 2011 May;13(5):1190-4. doi: 10.1039/c0em00689k. Epub 2011 Mar 11.
We studied the sorption behaviour of fullerene nano-C(60) particles (nC(60)) in soil from binary solvent mixtures of ethanol-water in order to critically evaluate the previous reports in the literature that the partitioning mechanism explains the soil sorption of fullerene C(60) as hydrophobic molecules. The sorption of nC(60) particles was studied in a range of solvent mixtures by changing volume fractions of ethanol from 20 to 100 percent. Sorption and particle characteristics were found to be very different in ethanol : water mixtures above and below 60% ethanol. In the range of 20-60% ethanol, sorption increased from 1.2 to 14.6 L kg(-1) accompanied by a change in zeta (ζ) potential from -32.4 to -7.2 mV. This observation can be attributed to hydrophilic interactions that negatively charged nC(60) particles undergo with soil colloids and water molecules. From 60% to 100% ethanol volume fractions, hydrophobic interactions of weakly charged nanoparticles may control the overall extent of soil sorption. The findings of this study indicate the importance of hydrophilic forces in controlling the sorption behaviour of nC(60) particles which are stabilized in water dominated solvent mixtures. The validity of the partitioning mechanism and K(OC) modelling approach in describing and estimating the sorption of nC(60) particles in soil (previously suggested in the literature) are, therefore, questioned.
我们研究了富勒烯纳米C(60)颗粒（nC(60)）在乙醇 - 水二元溶剂混合物中的土壤吸附行为，以便严格评估文献中先前的报道，即分配机制将富勒烯C(60)作为疏水分子的土壤吸附解释清楚。通过将乙醇的体积分数从20% 改变到100%，在一系列溶剂混合物中研究了nC(60)颗粒的吸附。发现在乙醇含量高于和低于60%的乙醇 - 水混合物中，吸附和颗粒特性有很大差异。在20% - 60%乙醇范围内，吸附量从1.2增加到14.6 L kg(-1)，同时ζ电位从 - 32.4 mV变为 - 7.2 mV。这一观察结果可归因于带负电荷的nC(60)颗粒与土壤胶体和水分子之间发生的亲水相互作用。从60%到100%乙醇体积分数，弱带电纳米颗粒的疏水相互作用可能控制土壤吸附的总体程度。本研究结果表明亲水力在控制nC(60)颗粒吸附行为中的重要性，这些颗粒在以水为主的溶剂混合物中是稳定的。因此，对文献中先前提出的分配机制和K(OC)建模方法在描述和估算土壤中nC(60)颗粒吸附方面的有效性提出了质疑。
