Electron Spin Resonance (ESR) was used to study, at the molecular level, the plasma polymerization of trimethylsilane (TMS) and methane. Direct ESR analysis of the plasma coated Al substrate required the use of a novel ESR technique. TMS plasma deposit on Al showed a single broad resonance line near g = 2.003. The signal was stable in vacuum and decayed on exposure to air, with a significant fraction persisting for days. Results show that this signal arises from silicon dangling bonds. Identical TMS signals were observed from films prepared by the DC cathodic or the AF glow discharge method but their decay rates were different. In contrast, the deposition of methane produced two distinct types of carbon-based signals depending upon the method of deposition. TMS or CH4 films deposited by the DC cathodic method showed slow signals decay and high refractive indices value. While the use of Al as the substrate showed plasma-coating radicals, only substrate radicals were observed when PE was used as the substrate. The nature of radicals formed depends not only on the deposition method used but also on the substrate type. 相似文献
The atmospheric pressure radiofrequency (RF) plasma polymerization of furan was carried out with the objective of synthesizing polyfuran thin film. The structure, compositions and morphology of the plasma deposited polyfuran film were investigated by Fourier transform infrared (FTIR), atomic force microscopy (AFM), ultraviolet‐visible absorption spectroscopy (UV‐vis) and thermogravimetric analysis (TGA). The formation of polyfuran was confirmed using FTIR and UV‐visible analysis. The properties of plasma‐deposited polyfuran were compared with those of chemically synthesized polyfuran. Although the plasma deposited thin film polyfuran shows lower thermal stability than that of chemically synthesized polyfuran. It has better solubility in CHCl3, also. Thin uniform polyfuran films are obtained in plasma assisted polyfuran deposition, while particles are obtained in chemical polyfuran polymerization. 相似文献
Plasma polymerized hydrocarbons made from ethane and methane were produced under different reactor conditions and probed by solid-state carbon-13 nuclear magnetic resonance (13C-NMR) with cross-polarization and magic-angle sample spinning. NMR experiments provided structural information about the plasma polymers. The conditions of low power, high hydrocarbon gas flow rate, and no added hydrogen gas appeared to give the highest amount of nonprotonated sp3 hybridized carbons in the films for the reactor design used. The use of methane or ethane as reactor gas did not affect plasma polymer structure significantly. 相似文献
New forms of click chemistry present new opportunities in materials science. Sulfur(VI) fluoride exchange (SuFEx) is a recently discovered click reaction between molecules containing SOxF groups and silyl ethers, two functionalities that are orthogonal to all other known click chemistries, that generates sulfate or sulfonate connections upon the addition of certain organobases or fluoride sources. SuFEx also has several important advantages over other click reactions in that it is insensitive to ambient oxygen and water, and its precursor materials, especially SOxF, are chemically, UV, and thermally inert. This Concept article focuses on the unique reactivity of SuFEx and its relation to building high molecular weight polymers and surface coatings, both of which make it a powerful new tool for materials science. 相似文献
Polymerization of acrylic acid with hexamethyldisilazane (HMSZ) was carried out in a mixture by use of pulsed and continuous wave plasmas. The polymer deposition rate and the chemical structures of product films were investigated with regard to the power effects of the plasmas. A copolymer-like structure was formed in general, but the products were not necessarily composed of the simple agglomeration of the polymer components. The power consumed in plasma polymerization influenced the chemical structure, and oxide, in the form of Si—O, was produced more densely in the polymers at higher rather than lower powers. The polymer structure was related to the chemical properties, and the surface wetting was also changed by the power used in the plasma copolymerization. The films were moderately hydrophilic in the polymers produced at lower wattages, but became as hydrophobic as those from HMSZ when prepared at high wattages. 相似文献
Surface of polypropylene (PP) film was modified in plasma of dichloromethane (CH2Cl2). The nature of surface modifications and formation of cross-linked layer due to plasma polymerization was studied by surface energy measurements and solubility test. Surface modification achieved by CH2Cl2 plasma was compared with the reported work on chloroform (CHCl3) and carbontetrachloride (CCl4) plasma modifications. Modified surface characterized by ATR-FTIR technique indicated formation of saturated and unsaturated cross-linked product. On the basis of relative intensity change of the specific bands, the site of attachment of chlorine on PP surface was investigated. Adhesive strength of modified film was measured by T-peel test method. Stability of modified surface was studied by measuring surface energy and peel strength after two months. 相似文献
Tailoring of polymers for multifaceted applications is an increasing field, whereby most often the surface properties must be adjusted. Therefore, the coating of common polymers by plasma polymerization is a promising way to modify the surface and meet the demands. Beside the tuning of the required surface properties, good adhesion and stability of the films is essential. This work investigates the plasma deposition of pp-HMDSO films on PC and PC/ABS to generate stable, hydrophobic surfaces. By examining the plasma conditions—deposition rate, energy range, and surface topography—ultrathin, stable films with advancing contact angles up to 110° and receding angles exceeding 90° can be designed. Storage of the siloxane films for 1 year in air at ambient conditions exhibits almost no aging. Thus, these films are superior to fluorocarbon films deposited for comparison. 相似文献
Plasma-polymerized films of vinyltriethoxysilane were surface characterized using the sessile drop technique. The surface
free energy and its components were evaluated using the Owens-Wendt-Kaelble geometric mean method, Wu harmonic mean method,
and van Oss, Chaudhury, and Good acid-base theory. Influence of deposition conditions on the surface free energy was demonstrated
in the study. Improved wettability of the films was related to the diminished concentration of apolar methyl groups in plasma
polymers. An increased concentration of carbonyl and hydroxyl groups resulted in a very small improvement of the polar component. 相似文献