硅表面接枝含氟聚合物刷的动力学与表面性能

Reaction Kinetics and Surface Properties of Fluorinated Copolymer Brushes on the Silicon Wafer

利用表面原子转移自由基聚合(SI-ATRP)法,在硅基体表面接枝了以甲基丙烯酸甲酯(MMA)和甲基丙烯酸十二氟庚酯(DFHM)为单体的嵌段聚合物刷(Si-g-PMMA-b-PDFHM)。通过衰减全反射傅里叶变换红外光谱和X射线光电子能谱分析了聚合物刷的化学结构,采用气相色谱研究了2种聚合路线的反应动力学。进而通过扫描电子显微镜、原子力显微镜和接触角测量仪表征了聚合物刷的表面形貌及润湿性。结果表明,硅片表面引发SI-ATRP的反应动力学为典型的可控聚合反应,A、B方法的反应速率常数分别为0.04916/h和0.03731/h,转化率分别为55%和45%,聚合物刷的厚度分别为4.2μm和4.8μm。硅片表面生长聚合物刷后,粗糙度增加,疏水性能明显提高。

The fluorinated polymer brushes from silicon wafer were synthesized via surface initiated atom transfer radical polymerization （SI-ATRP） using methyl methacrylate （MMA） and dodecafluoroheptyl methacrylate （DFHM） as monomers. The chemical structure of obtained Si-g-PMMA-b-PDFHM was characterized by attenuated total reflectance Fourier transform infrared spectroscopy （ATR-FT-IR） and X-ray photoelectron spectroscopy （XPS）. The reaction kinetic by two Si-Br initiators was evaluated by gas chromatography （GC）. The morphology and wettability of brush modified wafer surface were investigated through scanning electron micrographs （SEM）, atomic force microscope （AFM） and contact angles meter （SCA）. The results indicate that, the kinetic of SI-ATRP initiated by Si-Br is a typical controlled ATRP with the rate constant of 0.04916/h and 0.03731/h, and the conversion rate of 45% and 55 %. When the thickness of copolymer brushes is controlled in 4.2-4.8 μm, the modified surface has high surface roughness and improved hydrophobic property.