Stable zinc oxide nanoparticle dispersions in ionic liquids
Stable zinc oxide nanoparticle dispersions in ionic liquids
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DOI：
10.1007/s11051-014-2341-2
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发表时间：
2014-04
影响因子：
2.5
通讯作者：
A. Wittmar;D. Gautam;Carolin Schilling;U. Dörfler;Wolfgang Mayer-Zaika;M. Winterer;M. Ulbricht
中科院分区：
文献类型：
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作者：
A. Wittmar;D. Gautam;Carolin Schilling;U. Dörfler;Wolfgang Mayer-Zaika;M. Winterer;M. Ulbricht
采用动态光散射和先进流变学方法研究了咪唑类离子液体的亲水性和阳离子烷基链长度对超声分散ZnO纳米粒子的影响。通过化学气相合成法合成的ZnO纳米粉末与一种市售材料平行使用。在制备分散体之前，通过透射电子显微镜、X射线衍射、具有BET分析的氮吸附和FT-IR光谱确定纳米颗粒特性。亲水性离子液体分散所有研究的纳米粉体更好，在亲水性离子液体的系列中，观察到随着阳离子的烷基链长度的增加，分散质量的改善。特别是对于烷基链较短的离子液体，分散液中纳米粒子的浓度和超声处理时间等因素对分散液的质量有显著影响。此外，纳米粉末特性（微晶形状和尺寸以及团聚水平）影响分散质量。结果表明，所研究的离子液体是有前途的候选人的吸收介质在气相合成反应器的末端，允许直接制备非团聚的纳米粒子分散体，而无需补充添加分散剂和稳定剂。
The influence of the hydrophilicity and length of the cation alkyl chain in imidazolium-based ionic liquids on the dispersability of ZnO nanoparticles by ultrasound treatment was studied by dynamic light scattering and advanced rheology. ZnO nanopowder synthesized by chemical vapor synthesis was used in parallel with one commercially available material. Before preparation of the dispersion, the nanoparticles characteristics were determined by transmission electron microscopy, X-ray diffraction, nitrogen adsorption with BET analysis, and FT-IR spectroscopy. Hydrophilic ionic liquids dispersed all studied nanopowders better and in the series of hydrophilic ionic liquids, an improvement of the dispersion quality with increasing length of the alkyl chain of the cation was observed. Especially, for ionic liquids with short alkyl chain, additional factors like nanoparticle concentration in the dispersion and the period of the ultrasonic treatment had significant influence on the dispersion quality. Additionally, nanopowder characteristics (crystallite shape and size as well as the agglomeration level) influenced the dispersion quality. The results indicate that the studied ionic liquids are promising candidates for absorber media at the end of the gas phase synthesis reactor allowing the direct preparation of non-agglomerated nanoparticle dispersions without supplementary addition of dispersants and stabilizers.