Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria, Australia.
J Phys Chem B. 2011 May 26;115(20):6495-502. doi: 10.1021/jp200864k. Epub 2011 May 4.
We describe a new method to characterize the underside (substrate interface) of plasma polymer (PP) thin films via their simple delamination from a sodium chloride single crystal substrate. By depositing the PP film onto an ionic bonded surface such as a sodium chloride crystal, the PP films investigated were easily delaminated from the substrate. Two plasma polymer films deposited from 1-bromopropane (BrPP) and allylamine (AAPP) were used to exemplify this new technique. The top- and underside (substrate-plasma polymer interface) of the films were examined by X-ray photoelectron spectroscopy (XPS) and synchrotron-based near edge X-ray adsorption fine structure (NEXAFS) spectroscopy. The results demonstrate that both films exhibit heterogeneous film structures with their chemical composition and levels of unsaturated species. The underside of both the BrPP and the AAPP films exhibited higher concentrations of oxygen, while their topsides contained higher levels of unsaturated species. These results provide useful insights into the BrPP and AAPP film formation and the chemistry. The delamination technique provides a simple method to analyze the early stages of film chemistry for plasma polymer thin films. Furthermore, this approach opens new opportunities for additional studies on the mechanisms and fundamentals of plasma polymer thin film formation with various monomers.
我们描述了一种新的方法，通过简单地将等离子体聚合物 (PP) 薄膜从氯化钠单晶基底上剥离，来对其底面（基底界面）进行特征描述。通过将 PP 薄膜沉积在离子键合的表面上，如氯化钠晶体，所研究的 PP 薄膜可以很容易地从基底上剥离。我们使用两种由 1-溴丙烷 (BrPP) 和丙烯胺 (AAPP) 沉积的等离子体聚合物薄膜来说明这种新技术。通过 X 射线光电子能谱 (XPS) 和基于同步加速器的近边 X 射线吸收精细结构 (NEXAFS) 光谱对薄膜的顶侧（基底-等离子体聚合物界面）和底面进行了检测。结果表明，两种薄膜均表现出具有不同化学组成和不饱和物种水平的非均相薄膜结构。BrPP 和 AAPP 薄膜的底面都显示出更高浓度的氧，而它们的顶面则含有更高水平的不饱和物种。这些结果为 BrPP 和 AAPP 薄膜的形成和化学性质提供了有用的见解。剥离技术为分析等离子体聚合物薄膜的早期成膜化学提供了一种简单的方法。此外，这种方法为使用各种单体对等离子体聚合物薄膜形成的机制和基础进行进一步研究开辟了新的机会。
