Surface deposition of silica nanoparticles (SiNPs) is widely used for constructing omniphobic membranes for membrane distillation (MD) with an aim of creating hierarchical and reentrant textures. Herein, we report a comprehensive analysis of the effects of physical properties of SiNPs on membrane performance from the viewpoint of their dimensions and morphologies. An emerging fabrication technology, i.e., the electrospray method, was also investigated and systematically compared to the conventional solution deposition. SiNPs with spherical dimensions of 30 nm aggregated significantly in solution deposition process, forming a surface layer with uncontrollable defects and becoming vulnerable to inorganic fouling. While membranes utilizing SiNPs with a diameter of 200 nm showed severe pore blocking, which resulted in much lower operational fluxes. However, the fluxes could be improved by 20–50% using hollow mesoporous SiNPs, where the intrinsic cavities provided extra channels for vapor transport. More importantly, using a high-voltage electric field in the electrospray procedure resulted in a uniform distribution of SiNPs, thereby endowing an ideal membrane surface layer for a robust MD operation. The proposed study provides new insights into the effects of the physical properties of SiNPs, and shows the advantage of electrospray technology in fabricating defect-free MD membranes for sustainable applications.

二氧化硅纳米粒子 (SiNPs) 的表面沉积被广泛用于构建用于膜蒸馏 (MD) 的全疏水膜，目的是创建分层和可重入的纹理。在此，我们从尺寸和形态的角度综合分析了 SiNPs 的物理性质对膜性能的影响。还研究了一种新兴的制造技术，即电喷雾法，并与传统的溶液沉积进行了系统比较。球形尺寸为 30 nm 的 SiNPs 在溶液沉积过程中显着聚集，形成具有无法控制的缺陷的表面层，并且容易受到无机污染。而使用直径为 200 nm 的 SiNP 的膜表现出严重的孔阻塞，导致操作通量低得多。然而，使用中空介孔 SiNPs 可以将通量提高 20-50%，其中本征腔为蒸汽传输提供了额外的通道。更重要的是，在电喷雾过程中使用高压电场导致 SiNP 的均匀分布，从而为稳健的 MD 操作提供了理想的膜表面层。拟议的研究为 SiNPs 物理性质的影响提供了新的见解，并展示了电喷雾技术在制造可持续应用的无缺陷 MD 膜方面的优势。从而为稳健的 MD 操作提供了理想的膜表面层。拟议的研究为 SiNPs 物理性质的影响提供了新的见解，并展示了电喷雾技术在制造可持续应用的无缺陷 MD 膜方面的优势。从而为稳健的 MD 操作提供了理想的膜表面层。拟议的研究为 SiNPs 物理性质的影响提供了新的见解，并展示了电喷雾技术在制造可持续应用的无缺陷 MD 膜方面的优势。