Mezour M A, Oweis Y, El-Hadad A A, Algizani S, Tamimi F, Cerruti M
Department of Mining and Materials Engineering, McGill University Montreal Quebec H3A 2B2 Canada.
Faculty of Dentistry, McGill University, 3640, Strathcona Anatomy and Dentistry Building, Rue University Montreal Quebec H3A 0C7 Canada
RSC Adv. 2018 Jul 2;8(41):23191-23198. doi: 10.1039/c8ra02634c. eCollection 2018 Jun 21.
Tailoring the surface chemistry of CoCr alloys is of tremendous interest in many biomedical applications. In this work, we show that CoCr can be modified by diazonium electrografting provided the surface is not homogeneously covered with an oxide layer. Cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) show the electrografting of a poly(aminophenylene) (PAP) layer on CoCr when treated at a reductive potential (CoCr), whereas no PAP film was formed on CoCr and CoCr, treated at open circuit and anodic potentials respectively. Based on XPS results, we attributed the electrografting to the formation of carbide bonds between PAP and the inhomogeneous thin oxide layer of CoCr. We then show an example of application of PAP coatings on CoCr and prove that the presence of a PAP coating on CoCr results in a 5-fold increase of the adherence of poly methyl methacrylate (PMMA) to PAP-coated CoCr compared to uncoated samples; this is of prime significance to improving the long-term stability of dental prostheses. These findings support the importance of reducing the oxide layer for effective functionalization of metal oxides with aryl diazonium salts and suggest a promising surface modification approach for biomedical applications.
在许多生物医学应用中，调整钴铬合金的表面化学性质备受关注。在这项工作中，我们表明，只要钴铬合金表面没有被均匀覆盖一层氧化层，就可以通过重氮盐电接枝对其进行改性。循环伏安法（CV）和X射线光电子能谱（XPS）表明，在还原电位下处理的钴铬合金（CoCr）上会电接枝一层聚（亚苯基）（PAP），而分别在开路和阳极电位下处理的CoCr和CoCr上则没有形成PAP膜。基于XPS结果，我们将电接枝归因于PAP与钴铬合金不均匀薄氧化层之间形成的碳化物键。然后，我们展示了PAP涂层在钴铬合金上的一个应用实例，并证明与未涂层样品相比，钴铬合金上存在PAP涂层会使聚甲基丙烯酸甲酯（PMMA）对PAP涂层钴铬合金的附着力增加5倍；这对于提高牙科假体的长期稳定性至关重要。这些发现支持了减少氧化层对于用芳基重氮盐有效功能化金属氧化物的重要性，并为生物医学应用提出了一种有前景的表面改性方法。
