Dependance of Poly(acrylic acid) Interfacial Adhesion on the Nanostructure of Electrodeposited ZnO Films
Dependance of Poly(acrylic acid) Interfacial Adhesion on the Nanostructure of Electrodeposited ZnO Films
复制标题
DOI：
10.1021/acsanm.8b02091
复制
发表时间：
2019-02-01
影响因子：
5.9
通讯作者：
Grundmeier, Guido
中科院分区：
文献类型：
--
作者：
Meinderink, Dennis;Orive, Alejandro Gonzalez;Grundmeier, Guido
了解ZnO纳米棒阵列复杂的形貌和表面化学对其与聚电解质聚合物相互作用的影响，对于开发新型ZnO基促粘材料至关重要。采用基于原子力显微镜的单分子力谱分析了pH为7的水溶液中氧化锌（ZnO）膜覆盖不锈钢底物对聚丙烯酸（PAA）的吸附。基于电沉积过程，氧化锌膜的形态可以从片状晶体到纳米棒不等。该方法允许对复杂ZnO纳米结构上的大分子吸附过程进行形态依赖分析，该结构在促进粘附的薄膜领域具有多种应用。由X射线光电子能谱测定的表面化学成分可能与原子力显微镜解吸有关。仅在镜面抛光、预处理的不锈钢上观察到以42 pN为中心的平衡解吸事件（高原）。然而，对于片状ZnO薄膜，聚丙烯酸脱附表现为破裂事件（平均破裂力约为350 pN）和平衡脱附的混合，而ZnO纳米棒结构仅表现为破裂事件，平均破裂力约为1300 pN。这些结果表明，由于聚丙烯酸与ZnO纳米棒的大分子配位，羧酸-锌键同时发生多重断裂。脱附过程的停留时间依赖性进一步支持了界面粘附过程的分析。
Understanding the impact of the intricate morphology and surface chemistry of ZnO nanorod arrays on their interactions with polyelectrolyte polymers is crucial for the development of nascent ZnO-based adhesion-promoting materials. AFM-based single molecule force spectroscopy was applied for the analysis of the adsorption of poly(acrylic acid) (PAA) on zinc oxide (ZnO) film covered stainless steel substrates in aqueous electrolytes at pH 7. Based on the electrodeposition process, the morphology of zinc oxide films could be varied ranging from platelet-like crystals to nanorods. This approach allowed for the morphology dependent analysis of macromolecular adsorption processes on complex ZnO nanostructures which have diverse applications in the field of adhesion-promoting thin films. The surface chemical composition, as determined by X- ray photoelectron spectroscopy, could be correlated to the AFM-based desorption studies. Only equilibrium desorption events (plateaus), centered at 42 pN, were observed on mirror polished, preconditioned stainless steel. However, for platelet-like ZnO films, the poly(acrylic acid) desorption showed a mixture of rupture events (mean rupture forces of about 350 pN) and equilibrium desorption, while ZnO nanorod structures showed solely rupture events with mean rupture forces of about 1300 pN. These results indicate that simultaneous multiple ruptures of carboxylate-zinc bonds occur due to the macromolecular coordination of poly(acrylic acid) to the ZnO nanorods. The analysis of the interfacial adhesion processes is further supported by the dwell time dependence of desorption processes.