Rapid evaporation of solvent from spray colloidal droplets induces directed self-assembly among the nanoparticles, eventually interlocking them into correlated granular structures. In this work, it is demonstrated that anisotropy in colloidal interparticle interaction plays a key role in governing the surface topology of spray-dried granules. Colloidal dispersion comprised of spherical nanosilica (NS) and cylindrical carbon nanotubes (CNT) was chosen as a model system in this regard. For identical polarities of the colloidal components, granules with prominent wrinkle-like modulations are obtained, which is in drastic contrast with the case of opposite polarities. The extent of surface modulation depends on the relative concentration of CNT with respective to NS. A plausible mechanism for the formation of surface modulation is elucidated on the basis of the evolving anisotropic interparticle interactions during assembly. Electron microscopy, small-angle scattering, Raman spectroscopic techniques have been used for quantitative characterization of these micro-granules.

喷雾胶体液滴中溶剂的快速蒸发引起纳米颗粒之间定向的自组装，最终将它们互锁成相关的颗粒结构。在这项工作中，证明胶体颗粒间相互作用中的各向异性在控制喷雾干燥颗粒的表面拓扑结构中起着关键作用。在这方面，选择由球形纳米二氧化硅（NS）和圆柱形碳纳米管（CNT）组成的胶体分散体作为模型系统。对于胶体组分的相同极性，获得具有明显皱纹样调制的颗粒，这与相反极性的情况形成鲜明对比。表面调节的程度取决于CNT相对于NS的相对浓度。基于组装过程中各向异性粒子间相互作用的发展，阐明了形成表面调节剂的合理机制。电子显微镜，小角散射，拉曼光谱技术已用于这些微粒的定量表征。