超颗粒的结构和质地决定了它们的性能和性能,因此在研究和工业应用中起着至关重要的作用。盐的添加是操纵纳米颗粒的胶体稳定性的众所周知的策略。在这项研究中,这种方法用于调整喷雾干燥的超制品的结构。三种不同的盐(NaCl,将CaCl2和AlCl3)添加到二元二氧化硅(SiO2)纳米颗粒分散体(尺寸为40和400nm)中,以通过降低静电排斥或增强阳离子桥接来改变其胶体稳定性。取决于添加盐的阳离子化合价和纳米颗粒尺寸,临界盐浓度,产生纳米粒子团聚,在不同的盐量下达到。利用这种现象来调整通过喷雾干燥二元分散体获得的超颗粒的最终结构,从核壳到Janus样结构到充分混合的结构。因此,这也调整了纹理属性,如表面粗糙度和所获得的超制品的孔系统。我们的结果为通过操纵二元纳米颗粒分散体的稳定性来控制喷雾干燥的超颗粒的结构提供了见解,他们建立了复合粒子设计的框架。
The structure and texture of
supraparticles determine their properties and performance, thus playing a critical role in research studies as well as industrial applications. The addition of salts is a well-known strategy to manipulate the colloidal stability of nanoparticles. In this study, this approach is used to tune the structure of spray-dried
supraparticles. Three different salts (NaCl, CaCl2, and AlCl3) were added to binary silica (SiO2) nanoparticle dispersions (of 40 and 400 nm in size) to change their colloidal stability by lowering the electrostatic repulsion or enhancing the cation bridging. Dependent on the cation valence of the added salt and the nanoparticle size, the critical salt concentration, which yields nanoparticle agglomeration, is reached at different salt amounts. This phenomenon is exploited to tune the final structure of
supraparticles - obtained by spray-drying binary dispersions - from core-shell to Janus-like to well-mixed structures. This consequently also tunes textural properties, like surface roughness and the pore system of the obtained
supraparticles. Our results provide insights for controlling the structure of spray-dried
supraparticles by manipulating the stability of binary nanoparticle dispersions, and they establish a framework for composite particle design.