This study develops a facile and generic way to fast and effectively produce and separate nanoparticles of water-insoluble inorganics from an aqueous medium, aiming to fulfill massive industrial demands for inorganic nanoparticles. As a model study, herein, PbSO₄ nanosuspension with an average particle diameter of ∼50 nm is produced via the in-situ reactive flash nanoprecipitation (RFNP) with chitosan as a pH-sensitive surface stabilizer, whose hydrophobicity can be tuned by varying its pH. By increasing pH of the suspension, the produced chitosan/PbSO₄ nanoparticles could rapidly aggregate and settle down. After filtration and dry, the particles are able to be fast and effectively separated from water so as the size enlargement due to Ostwald ripening and recrystallization is significantly inhibited. The dried nanoparticles as an excellent active material are then used to fabricate an negative electrode, with which the assembled lead acid battery shows ∼150% of a regular discharge capacity (∼100 mA h g⁻¹ at 120 mA g⁻¹ of current density in this study), a doubled cycle number of charge-discharge (>700 cycles), and thus a much longer durability than a commercial battery does. This success in the battery application well demonstrates feasibility and bright prospects of the in-situ RFNP technique in large-scaled synthesis of nanoparticles.

这项研究开发了一种简便而通用的方法，可以快速有效地从水性介质中生产和分离水不溶性无机物的纳米颗粒，旨在满足对无机纳米颗粒的大规模工业需求。作为模型研究，本文通过使用壳聚糖作为pH敏感表面稳定剂的原位反应快速纳米沉淀（RFNP）制备了平均粒径约为50 nm的PbSO ₄纳米悬浮液，可以通过改变其疏水性来调节其疏水性。 pH值 通过提高悬浮液的pH值，可制得壳聚糖/ PbSO ₄纳米粒子可以迅速聚集并沉淀下来。过滤并干燥后，颗粒能够快速有效地与水分离，从而显着抑制了因奥斯特瓦尔德熟化和重结晶而引起的尺寸增大。将干燥的纳米颗粒作为优良的活性材料，然后用于制造一个负电极，与该组装铅酸电池示出了常规的放电容量（〜100毫安ħ克〜150％^-1在120毫安克^-1（本研究中的电流密度），充放电的循环次数增加一倍（> 700个循环），因此其耐用性要比商用电池长得多。这种在电池应用中的成功很好地证明了原位RFNP技术在纳米颗粒大规模合成中的可行性和光明的前景。