Perfluoroalkyl end-functionalized oligoesters: Correlation between wettability and end-group segregation

We report a detailed investigation of the processes of the surface segregation in correlation with the wetting properties of perfluoroalkyl end-functionalized linear aromatic oligoesters. We have compared properties of films containing different fluorine concentration prepared by the spin-coating technique and by melting of polymer grain onto the supported substrate. We demonstrate that both methods can be used for the preparation of highly hydrophobic and oleophobic surfaces. Obtained layers possess high value of n-hexadecane advancing contact angle and low contact angle hysteresis. Moreover, oligoester films with the surface energies as low as 11 mJ/m(2) were prepared with 10.7 wt % of fluorine in the system and possessed higher oleophobicity than Teflon AF. We showed that the advantages of use of melting of polymer grain are higher surface enrichment and closer packing of perfluorinated species and, as a result, a higher hydro/oleophobicity, especially at lower F contents (< 6 wt %). This is a first report about an influence of preparation method onto the surface properties of perfluorinated polymers.