Surface modification of polyethylene with multi-end-functional polyethylene additives.
Surface modification of polyethylene with multi-end-functional polyethylene additives.
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DOI：
10.1021/la205158n
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发表时间：
2012-03
期刊：
影响因子：
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通讯作者：
S. Hardman;L. R. Hutchings;N. Clarke;S. M. Kimani;Laura L. E. Mears;Emily F. Smith;J. Webster;R. Thompson
中科院分区：
文献类型：
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作者：
S. Hardman;L. R. Hutchings;N. Clarke;S. M. Kimani;Laura L. E. Mears;Emily F. Smith;J. Webster;R. Thompson
我们已经制备并表征了一系列多氟碳末端官能化聚乙烯添加剂，当与聚乙烯基质共混时，其增加表面疏水性和疏油性。在本体中含有小于1%的氟碳化合物的旋转流延共混膜表面上观察到>112°的水接触角，而在不存在任何添加剂的情况下为约98°。在这些膜中的结晶度引起的表面粗糙度是一个数量级大于是典型的无定形旋铸膜，但太少，以引起超疏水性。X射线光电子能谱（XPS）证实了富集的多氟烃添加剂在空气表面高达80倍的体积浓度。使用离子束分析来量化添加剂的表面过量作为任一共混物组分的组成、官能度和分子量的函数。在某些情况下，过量的添加剂也被发现在基板界面，表明相分离成自分层层。中子反射计和离子束分析的组合允许的表面过剩被量化以上和以下的共混膜的熔点。在这些膜中，其中添加剂和基质组分的熔融温度相对相似（在15 °C内），表面过量几乎与共混膜是半结晶的还是熔融的无关，这表明当允许共混膜冷却到熔点以下时，添加剂与基质经历共结晶。
We have prepared and characterized a series of multifluorocarbon end-functional polyethylene additives, which when blended with polyethylene matrices increase surface hydrophobicity and lipophobicity. Water contact angles of >112° were observed on spin-cast blended film surfaces containing less than 1% fluorocarbon in the bulk, compared to ~98° in the absence of any additive. Crystallinity in these films gives rise to surface roughness that is an order of magnitude greater than is typical for amorphous spin-cast films but is too little to give rise to superhydrophobicity. X-ray photoelectron spectroscopy (XPS) confirms the enrichment of the multifluorocarbon additives at the air surface by up to 80 times the bulk concentration. Ion beam analysis was used to quantify the surface excess of the additives as a function of composition, functionality, and molecular weight of either blend component. In some cases, an excess of the additives was also found at the substrate interface, indicating phase separation into self-stratified layers. The combination of neutron reflectometry and ion beam analysis allowed the surface excess to be quantified above and below the melting point of the blended films. In these films, where the melting temperatures of the additive and matrix components are relatively similar (within 15 °C), the surface excess is almost independent of whether the blended film is semicrystalline or molten, suggesting that the additive undergoes cocrystallization with the matrix when the blended films are allowed to cool below the melting point.