Premium
Surface characterization, microstructure, and wetting of networks from α , ω ‐dihydroxy(polydimethylsiloxane) and 1,1,2,2‐tetrahydrotridecafluoro octyltriethoxysilane
Author(s) -
Uilk Janelle,
Johnston Erika E.,
Bullock Steve,
Wynne Kenneth J.
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(200207)203:10/11<1506::aid-macp1506>3.0.co;2-v
Subject(s) - polydimethylsiloxane , contact angle , siloxane , wetting , chemistry , elastomer , scanning electron microscope , analytical chemistry (journal) , microstructure , polymer chemistry , chemical engineering , materials science , composite material , crystallography , organic chemistry , polymer , engineering
Surface‐modified siloxane networks were prepared using the dibutyltin diacetate catalyzed reaction of α , ω ‐dihydroxy(polydimethylsiloxane), HO(Me 2 SiO) n H, with tridecafluoro‐1,1,2,2‐tetrahydrooctyl triethoxysilane, [CF 3 (CF 2 ) 5 (CH 2 ) 2 Si(OC 2 H 5 ) 3 , FTEOS]. Surface characterization of these elastomers was carried out using electron spectroscopy for chemical analysis (ESCA) and atomic force microscopy (AFM). Surface phase separation occurs as a function of increasing ratio of FTEOS to HO(Me 2 SiO) n H. Dynamic contact angle (DCA) analysis with water as the interrogating fluid showed that water contamination affects DCA data in the compositional range 4 x –8 x , where “ x ” is the ratio of ethoxy groups from FTEOS to OH groups in HO(Me 2 SiO) n H. Diffusion of polydimethylsiloxane oil species from the coatings is blocked in compositions of 10 x or greater. Chemical stability is also enhanced for 10 x and 12 x compositions.(A) Tapping mode AFM images. Image area 30 × 30 × 1 μm. (B) DCA data with arrows showing collapse due to water surface contamination, 4 x ‐0.8 cycle before collapse, 6 x ‐1 cycle, 8 x ‐1.6 cycles, 10 x and 12 x ‐stable. Stage speed 100 μm · s −1 and dwell times between sample immersion and withdrawal 10 s.