From the solvothermally treated poly(vinylidenefluoride) colloidal suspension to sticky hydrophobic coating

Abstract

Solvothermally treating an as-prepared poly(vinylidenefluoride) (PVDF) colloidal suspension leads to a significant impact on the surface properties of the resulting topcoat on a pertinent prime coating. The coating, possessing a fibrous porous matrix, exhibits a water contact angle in the range of 115-136°. However, the coating possesses droplets sticking ability that can be attributed to the pseudo-hydrogen bonding effect of the polarized C-H bonds in each repeating unit of PVDF polymer chains. The hydrophobicity of the topcoat is affected by the formulation of colloidal suspension, which is carried out by introducing a solution of PVDF in dimethylforamide into an excess of methanol. The colloidal suspension formed is subjected to solvothermal treatment subsequently. By thermodynamics, the treatment enhances chain packing density and growth of crystallites inside the colloidal particles of PVDF in the methanol-dominant dispersion medium. Furthermore, the realized chain packing states are retained during the drying of coating through chain affixation role of a small number of poly(divinylbenzene) nodules generated in situ. As a result, a fibrous porous matrix composed of the PVDF submicron knots is attained. The coexistence of the polarized CH 2 group and the fibrous porous structure prompts a sticky hydrophobic surface. © 2013 Springer-Verlag Berlin Heidelberg.