Papan Jelena, Hribar Boštjančič Patricija, Mertelj Alenka, Lisjak Darja
Department of Complex Matter, Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia.
Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, P.O. Box 522, 11001 Belgrade, Serbia.
Nanomaterials (Basel). 2021 Oct 22;11(11):2797. doi: 10.3390/nano11112797.
Janus particles, which have two surfaces exhibiting different properties, are promising candidates for various applications. For example, magneto-optic Janus particles could be used for in-vivo cancer imaging, drug delivery, and photothermal therapy. The preparation of such materials on a relatively large scale is challenging, especially if the Janus structure consists of a hard magnetic material like barium hexaferrite nanoplatelets. The focus of this study was to adopt the known Pickering emulsion, i.e., Granick's method, for the preparation of barium-hexaferrite/gold Janus nanoplatelets. The wax-in-water Pickering emulsions were stabilized with a combination of cetyltrimethyl ammonium bromide and barium hexaferrite nanoplatelets at 80 °C. Colloidosomes of solidified wax covered with the barium hexaferrite nanoplatelets formed after cooling the Pickering emulsions to room temperature. The formation and microstructure of the colloidosomes were thoroughly studied by optical and scanning electron microscopy. The process was optimized by various processing parameters, such as the composition of the emulsion system and the speed and time of emulsification. The colloidosomes with the highest surface coverage were used to prepare the Janus nanoplatelets by decorating the exposed surfaces of the barium hexaferrite nanoplatelets with gold nanospheres using mercaptan chemistry. Transmission electron microscopy was used to inspect the barium-hexaferrite/gold Janus nanoplatelets that were prepared for the first time.
具有两个呈现不同性质表面的Janus粒子是各种应用的有前景的候选材料。例如，磁光Janus粒子可用于体内癌症成像、药物递送和光热疗法。在相对大规模上制备此类材料具有挑战性，特别是如果Janus结构由像六方铁酸钡纳米片这样的硬磁材料组成。本研究的重点是采用已知的Pickering乳液法，即Granick方法，来制备六方铁酸钡/金Janus纳米片。水包蜡Pickering乳液在80℃下用十六烷基三甲基溴化铵和六方铁酸钡纳米片的组合进行稳定化处理。将Pickering乳液冷却至室温后，形成了覆盖有六方铁酸钡纳米片的固化蜡的胶体囊泡。通过光学和扫描电子显微镜对胶体囊泡的形成和微观结构进行了深入研究。通过各种工艺参数对该过程进行了优化，例如乳液体系的组成以及乳化的速度和时间。使用具有最高表面覆盖率的胶体囊泡通过利用硫醇化学用金纳米球修饰六方铁酸钡纳米片的暴露表面来制备Janus纳米片。使用透射电子显微镜检查首次制备的六方铁酸钡/金Janus纳米片。
