Aggregation and dissolution of ZnO nanoparticles synthesized by different methods: Influence of ionic strength and humic acid

- Synthesis procedure can substantially influence surface properties of ZnO-NPs.
- Ionic strength enhances ZnO-NPs aggregation regardless of synthesis methods.
- Humic acid largely reduces ZnO-NPs aggregation regardless of ionic strength.
- Humic acid increases ZnO-NPs dissolution regardless of pH and synthesis methods.
- Physicochemical property of ZnO-NPs plays important roles in ZnO-NPs dissolution.