Department of Chemistry and Physics of Surfaces and Biointerfaces, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovsky sq. 2, 162 06 Prague, Czech Republic.
Neaspec GmbH, Eglfinger Weg 2, 85540 Haar (Munich), Germany.
Anal Chem. 2020 Apr 7;92(7):4716-4720. doi: 10.1021/acs.analchem.9b05661. Epub 2020 Mar 10.
Polymer brush coatings are effective in preventing blood coagulation or bacterial attachment, but their chain conformation, while vital for this effect, was never characterized in high spatial resolution. Here, we report mid-infrared spectroscopic nanoscopy studies of few-nanometer-thin poly(ethylene oxide) (PEO) films which reveal marked spectral variations along the surface at a length scale smaller than 100 nm and originating only from the physical conformation of the chains. The conformation and average orientation of the polymer chains in the layer is extracted from the spectra with the aid of theoretic modeling, confirming the spontaneous formation of a crystalline phase. This result suggests spectroscopic nanoscopy as a powerful new tool to characterize polymer brush coatings.
聚合物刷涂层在防止血液凝固或细菌附着方面非常有效，但它们的链构象对于这种效果至关重要，但其在高空间分辨率下的特征从未被描述过。在这里，我们报告了对几纳米厚的聚（氧化乙烯）（PEO）薄膜的中红外光谱纳米显微镜研究，这些研究揭示了在小于 100nm 的长度尺度上沿表面的明显光谱变化，并且仅源于链的物理构象。借助理论建模从光谱中提取出薄膜中聚合物链的构象和平均取向，证实了结晶相的自发形成。这一结果表明光谱纳米显微镜是一种强大的新工具，可以用于表征聚合物刷涂层。
