含有序孔洞的多孔氧化铝薄膜的弹性模量测量

Elastic Modulus Investigation of Nanoporous Alumina Membrane

高纯铝箔在特定的溶液下经过电化学阳极氧化腐蚀,可在其表面生成一层多孔的非晶氧化铝层,孔大致呈六方密排,孔径分布均匀。此类薄膜具有规则的纳米级孔径,大的比表面积,可用在微纳滤方面和纳米材料组装方面。然而,对于此类薄膜力学性能的研究较少,在一定程度上限制其功能的开发和应用。为了获得此类多孔膜的弹性常数,本文用鼓膜法结合散斑干涉实验方法、单轴拉伸结合双光束干涉法和多普勒测振仪三种方法测量氧化铝多孔膜的弹性模量,得到的宏观弹性模量基本相同,并对三种方法的优缺点进行了比较,分析了多孔氧化铝膜与块状氧化铝材料或致密氧化铝膜力学性能的差异。

Nanoporous alumina membranes containing parallel regular pores of uniform size and normal to substrate surface were fabricated by anodically oxidizing high purity aluminum foils in acid solutions. Their fine structure and physical-chemical stability make them very useful as separator in filtering and as template in nanomaterial fabration. However, the significant macro-mechanical properties of this membrane are reported scarcely. In this work, three methods including bulge testing, uniaxial tension testing and resonant method are used to investigate the elastic modulus of this nanoporous membrane. The similarity and discrepancy of the results from these different methods are compared and analyzed. The results indicate unusual mechanical behavior of these nanoporous anodic alumina membranes compared with bulk alumina materials or dense alumina films, which provides improved understanding of the relationship of the micro-meso structure and the mechanical properties.