4.6. Wettability alteration with membrane-forming material
Contact angles were measured using water-wet and oil-wet
rock with and without semi-permeable copper hexacyanoferrate
membrane as illustrated in Fig. 9. Contact angles of water were 0°
and close to 0° for water-wet rock and water-wet rock covered
with copper hexacyanoferrate membrane. Contact angles of oil
were 42° and 40° for oil-wet rock and oil-wet rock covered with
copper hexacyanoferrate membrane. The wettability of rocks does
not change with the formation of a semi-permeable membrane of
copper hexacyanoferrate.