Initiated Chemical Vapor Deposition of Poly(1H,1H,2H,2H-perfluorodecyl Acrylate) Thin Films
ABSTRACT A solvent-free initiated chemical vapor deposition (iCVD) process was used to create low surface energy poly(1H,1H,2H,2H-perfluorodecyl acrylate) (PPFDA) thin films at deposition rates as high as 375 nm/min. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy showed full retention of the fluorine moieties, and no measurable cross-linking was detected. Additionally, the FTIR studies support the hypothesis that film deposition results from vinyl polymerization. For all iCVD PPFDA films, the static contact angle was found to be 120.8 +/- 1.2 degrees. The roughness of the films was found to be between 14.9 and 19.8 nm RMS, and the refractive index of the films was found to be between 1.36 and 1.37. The deposition rate was studied as a function of the substrate temperature and the partial pressure of the monomer. It was found that the deposition rate increases with decreasing substrate temperature and increasing monomer partial pressure. It was also found that the molecular weight increases with decreasing substrate temperature and increases with increasing monomer partial pressure. The highest molecular weight measured was 177 300 with a polydispersity of 2.27. Quartz crystal microbalance (QCM) measurements showed that these effects correlated with an increased monomer concentration at the surface. The deposition rate data and the QCM data were quantitatively analyzed to find the rate constants of the process using a previously published model for the iCVD process involving nonfluorinated monomers. The determined values of the rate constants of the surface polymerization were found to be similar to the rate constants measured in liquid-phase free radical polymerization. The kinetic data found in this paper can now be used to study iCVD deposition onto substrates with more complex geometries.
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- "In particular, perfluoroacrylates offer fast polymerization due to the unsaturated acrylate group and hydrophobicity for the fluorinated pendant chain. As a result of the –CF 3 terminated side groups and comblike structure, the typical range of surface energies for fluorinated acrylic polymers is very low (5.6 to 7.8 mN/m) (Gupta & Gleason, 2006). "
ABSTRACT: Preferred crystallographic orientation (texture) in thin films frequently has a strong effect on the properties of the materials and it is important for stable surface properties. Organized molecular films of poly-perfluorodecylacrylate p(PFDA) were deposited by initiated Chemical Vapor Deposition (iCVD). The high tendency of p(PFDA) to crystallize has been fully retained in the polymers prepared by iCVD. The degree of crystallinity and the preferred orientation of the perfluoro side chains, either parallel or perpendicular to the surface, were controlled by tuning the CVD process parameters (i.e. initiator to monomer flow rate ratio, filament temperature, and substrate temperature). Super- hydrophobicity (advancing water contact angle, WCA, of 160°, low hysteresis of 5°), and oleophobicity (advancing CA with mineral oil of 120°) were achieved. Low hysteresis was associated with high crystallinity, particularly when the orientation of the crystallites resulted in the perfluoro side groups being oriented parallel to the surface. The latter texture resulted in smoother film (RMS roughness < 30 nm) than the texture with the chains oriented perpendicularly to the surface. This can be very advantageous for applications that require smooth but still crystalline films.Physics Procedia 12/2013; 46:56-61. DOI:10.1016/j.phpro.2013.07.045
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ABSTRACT: Initiated chemical vapor deposition of polymers (iCVD) is a process similar to hot-wire CVD (HWCVD) in which a free-radical initiating species is employed to greatly increase the growth rate while decreasing the required energy input. In general, iCVD allows for the deposition of linear polymer, copolymer and/or crosslinked films with a wide range of functions. Surveyed examples include antimicrobial, superhydrophobic, superhydrophilic, and other functional thin polymer films and coatings.Surface and Coatings Technology 09/2007; 201(22-201):9400-9405. DOI:10.1016/j.surfcoat.2007.05.003 · 2.00 Impact Factor
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ABSTRACT: Furan ring-functionalized solid surfaces are achieved by the initiated chemical vapor deposition (iCVD) method, a solvent-free process to form films under mild conditions. The polymerization of furfuryl methacrylate monomer is initiated by a resistively heated filament wire. The functionality of the furan group in the iCVD film enabled Diels-Alder chemistry with 4-phenyl-1,2,3-triazolin-3,5-dione (N-PTD).Macromolecular Rapid Communications 12/2007; 28(23):2205 - 2209. DOI:10.1002/marc.200700466 · 4.94 Impact Factor