Destabilisation of Pickering emulsions using pH

► Destabilisation of Pickering emulsions stabilised by silica was achieved using pH. ► Silica nanoparticles behaved in accordance with classical DLVO theory. ► Maximum oil loss was (75%) at pH 2.94 (around silica i.e.p.) and at pH 7.1. ► Complete oil recovery was achieved when pH adjusted before emulsification. ► Contact angles of silica nanoparticles were greatly affected by changing the pH.