I'm doing some AFM experiments with oil drop (dodecane + surfactant) in water medium using a V-shape, tipless cantilever. The silicon nitride cantilever is applied without any treatment and should be hydrophobic, as I can see the oil drop at the substrate 'jumps' onto the cantilever when approaching. However, I cannot see the drop afterwards as reported in numerous literature, and I suspect that the drop somehow spread on the cantilever instead of maintaining a spherical shape. Is this possible and how can I prevent this without changing the content in the oil phase?
You could try silanising the tip. If you plasma-treat the tips in an oxygen plasma first to clean them and to generate a silicon oxide surface and then expose them to the vapour of e.g. octyldimethylchlorosilane or hexamethydisilazane you will make them more hydrophobic.
Dear Colin,
Thanks for your answer and it's a pleasure to hear from you again. Actually I did read from literature that hydrophobidized tips are occasionally applied for similar systems and I was planning to have a go, however it still puzzles me that, since the problem potentially arises from the hydrophobicity of the cantilever, how come to make it more hydrophobic would solve the problem?
what about using it after the oxygen plasma treatment without hydrophobization.
- Badges
- Science topic
- Similar topics
- Force