Meischein Michael, Fork Marvin, Ludwig Alfred
Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
Nanomaterials (Basel). 2020 Mar 14;10(3):525. doi: 10.3390/nano10030525.
The synthesis of nanoparticles by combinatorial sputtering in ionic liquids is a versatile approach for discovering new materials. Whereas the influence on nanoparticle formation of different pure ionic liquids has been addressed, the influence of (I) dilution of ionic liquid with solvents and (II) different mixtures of ionic liquids is less known. Therefore, mixtures of the ionic liquid [Bmim][(Tf)N] with the organic solvent anisole and other ionic liquids ([Bmim][(Pf)N], [BmPyr][(Tf)N]) were used as liquid substrates for the sputter synthesis of nanoparticles, in order to investigate the influence of these mixtures on the size of the nanoparticles. First, mixtures of anisole with a suspension of sputtered Ag nanoparticles in [Bmim][(Tf)N] were prepared in different volumetric steps to investigate if the stabilization of the NPs by the ionic liquid could be reduced by the solvent. However, a continuous reduction in nanoparticle size and amount with increasing anisole volume was observed. Second, Ag, Au and Cu were sputtered on ionic liquid mixtures. Ag nanoparticles in [Bmim][(Tf)N]/[Bmim][(Pf)N] mixtures showed a decrease in size with the increasing volumetric fraction of [Bmim][(Tf)N], whereas all nanoparticles obtained from [Bmim][(Tf)N]/[BmPyr][(Tf)N] mixtures showed increasing size and broadening of the size distribution. Maximum sizes of sputtered Ag and Au NPs were reached in mixtures of [Bmim][(Tf)N] with 20 vol.% and 40 vol.% [BmPyr][(Tf)N]. The results indicate that ionic liquid mixtures with different portions of cations and anions have the capability of influencing the ionic liquid stabilization characteristics with respect to, e.g., nanoparticle size and size distribution.
通过在离子液体中进行组合溅射来合成纳米颗粒是发现新材料的一种通用方法。虽然已经研究了不同纯离子液体对纳米颗粒形成的影响，但（I）用溶剂稀释离子液体以及（II）不同离子液体混合物的影响却鲜为人知。因此，将离子液体[Bmim][(Tf)N]与有机溶剂苯甲醚以及其他离子液体（[Bmim][(Pf)N]、[BmPyr][(Tf)N]）的混合物用作溅射合成纳米颗粒的液体基质，以研究这些混合物对纳米颗粒尺寸的影响。首先，以不同的体积比制备苯甲醚与溅射的Ag纳米颗粒在[Bmim][(Tf)N]中的悬浮液的混合物，以研究溶剂是否会降低离子液体对纳米颗粒的稳定作用。然而，随着苯甲醚体积的增加，观察到纳米颗粒尺寸和数量持续减小。其次，将Ag、Au和Cu溅射在离子液体混合物上。[Bmim][(Tf)N]/[Bmim][(Pf)N]混合物中的Ag纳米颗粒尺寸随着[Bmim][(Tf)N]体积分数的增加而减小，而从[Bmim][(Tf)N]/[BmPyr][(Tf)N]混合物中获得的所有纳米颗粒尺寸均增大且尺寸分布变宽。在[Bmim][(Tf)N]与20体积%和40体积%的[BmPyr][(Tf)N]的混合物中，溅射的Ag和Au纳米颗粒达到最大尺寸。结果表明，具有不同阳离子和阴离子比例的离子液体混合物有能力影响离子液体对例如纳米颗粒尺寸和尺寸分布等方面的稳定特性。
