| 水中C60纳米颗粒的稳定性研究 |
| 摘要点击 3605 全文点击 1878 投稿时间：2013-08-08 修订日期：2013-09-28 |
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| 中文关键词 C60 纳米颗粒 稳定性 凝聚 电解质 腐殖酸 |
| 英文关键词 C60 nanoparticles stability aggregation electrolytes humic acid |
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| 中文摘要 |
| 以两种C60纳米颗粒悬浮液为对象，研究贮存时间、pH、电解质和有机物等因素对其稳定性的影响.结果表明，溶剂替换法制备的C60纳米颗粒（C60/son）稳定性优于延时搅拌法（C60/aq），可长时间保持稳定；pH升高可使C60纳米颗粒稳定性增强；电解质投加可使C60纳米颗粒的|ζ|减小、粒径增大，促进凝聚的发生；水中C60纳米颗粒凝聚过程可分为慢速凝聚和快速凝聚两个阶段，符合经典胶体稳定性（DLVO）理论. C60/son的临界凝聚浓度：NaCl 321mmol·L-1、KCl 316mmol·L-1、MgCl2 9.6mmol·L-1和CaCl2 6.7mmol·L-1，C60/aq的临界凝聚浓度：NaCl 295mmol·L-1、KCl 278mmol·L-1、MgCl2 7.8mmol·L-1和CaCl2 5.9mmol·L-1，均远高于其在天然水体中的浓度；腐殖酸存在可通过空间位阻效应显著增强水中C60纳米颗粒的稳定性，这表明C60纳米颗粒可稳定存在于典型的水环境中. |
| 英文摘要 |
| The influences of storage time, pH, electrolytes and organic matters on the stability of two different suspensions of C60 nanoparticles were investigated. The results showed that the C60 nanoparticles prepared by solvent substitution (C60/son) were more stable than that prepared by prolonged stirring (C60/aq), and kept stable for a period of time. Higher pH enhanced the stability of C60 nanoparticles. The presence of electrolyte made a dramatic decrease in the surface zeta potential and an increase in the particle size. The aggregation process of C60 nanoparticles exhibited slow and rapid regions, which was found to be consistent with the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal stability. The critical coagulation concentration (CCC) values of C60/son, obtained from the intersection of the interpolated lines through the slow and fast regions, were estimated as 321 mmol·L-1 NaCl, 316 mmol·L-1 KCl, 9.6 mmol·L-1 MgCl2 and 6.7 mmol·L-1 CaCl2. The CCC values of C60/aq were estimated as 295 mmol·L-1 NaCl, 278 mmol·L-1 KCl, 7.8 mmol·L-1MgCl2 and 5.9 mmol·L-1CaCl2, which were much higher than their concentrations in natural waters. The presence of humic acid enhanced the stability of C60 nanoparticles, which was attributable to steric repulsion. Therefore, C60 nanoparticles will keep relatively stable in typical aquatic environments. |
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