离子束与湿度联合暴露诱导的选定聚合物薄膜起皱现象
Wrinkling in Selected Polymer Thin Films Induced by Combined Ion Beam and Humidity Exposure
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中文总结 AI 辅助
本研究探究离子束溅射（IBS）与湿度联合暴露对三种不同亲疏水性聚合物薄膜起皱的影响，结合XPS、FTIR分析揭示起皱源于水吸收溶胀受基底与石墨化层约束，明确pV4D4不起皱因吸水率低。
中文摘要 AI 辅助
本研究探究了离子束溅射（IBS）诱导的三种亲疏水性不同的聚合物表面起皱现象，这三种聚合物分别为聚甲基丙烯酸羟乙酯（pHEMA）、聚4-乙烯基吡啶（p4VP）和聚2,4,6,8-四甲基-2,4,6,8-四乙烯基环四硅氧烷（pV4D4）。研究发现，pHEMA和p4VP薄膜仅在经受离子轰击并随后暴露于水蒸气时才会起皱，而在相同条件下，pV4D4未观察到起皱现象。在IBS前、IBS后以及湿度暴露后，分别进行了X射线光电子能谱（XPS）和傅里叶变换红外光谱（FTIR）测试。XPS结果显示，IBS会在表面层内引发化学变化，在表面形成石墨化薄膜。对于表现出起皱现象的pHEMA和p4VP薄膜，XPS和FTIR表明水会被吸收到薄膜的表面和本体中，导致薄膜发生溶胀。研究人员推测，起皱的形成源于这种溶胀受到刚性底层硅基底和坚硬石墨化表面层的机械约束；相比之下，pV4D4在相同实验条件下未形成褶皱，可归因于其吸水率相对较低，对应的溶胀反应有限。
英文摘要
This study investigates ion beam sputtering (IBS)-induced surface wrinkling phenomena in three polymers with varying hydrophilicity: poly-hydroxy-ethyl-methacrylate (pHEMA), poly-4-vinyl pyridine (p4VP), and poly-2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (pV4D4). It is observed that pHEMA and p4VP films wrinkle only when exposed to ion bombardment and subsequent water vapor exposure. No wrinkling is observed in pV4D4 under these same conditions. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) are performed before IBS, after IBS, and after exposure to humidity. XPS shows that IBS drives chemical changes within the surface layer, creating a graphitized film at the surface. For the polymer films that exhibit wrinkling (pHEMA and p4VP), XPS and FTIR indicate water absorption in both the surface and the bulk of the films, resulting in swelling. We conjecture that the formation of wrinkles arises from this swelling being mechanically constrained by the rigid underlying silicon substrate and the stiff graphitized surface layer. In contrast, the absence of wrinkle formation in pV4D4 under the same experimental conditions can be attributed to its comparatively low water absorption and the correspondingly limited swelling response.
