Effects of metal ions with different valences on colloidal aggregation in low-concentration silica colloidal systems characterized by continuous online zeta potential analysis

- The low-concentration colloidal stability is characterized online continuously.
- Effects of different valent ions on transition from sol to gel are investigated.
- Zeta potential variations can indicate the transition from silica sol to gel.
- DLVO theory and zeta potential explain the low-concentration colloidal stability.