Anodized Aluminum Optical Performance Testing Of The Porous Membrane

When been keep in acidic electrolysis bath (such as sulfuric acid, ethane diacid, phosphoric acid, chrome acid ect.), the surface of aluminun sheet will be generated a porous thin film, whose micropores are parallel pore geometry is regular and the diametral of micropore is in the nanometer class. This kind of oxide aluminum with the specific nanometer structure supplied a new path which can develop a late model functional material.For ages, people are always concerned with porous aluminum membrane in the aspect of its purpose and rapid development, whose advantages are: (1) degree of hardness of the barrier layer is higher than diamond spar ;(2) possess good wear-resisting property, excellent corrosion resistance and better chemical stability;(3) with the vary of electrolysis technology, the shape and the dimension of the micropore presented diversity, and the thickness of the membrane can be changed in a large range;(4)the method is simple, and has low request for facility and environmental.Have been researched about existing conditions of porous alumina, we want to know about optical property of itself, so we tests some kinds of porous alumina, which is in different preparation conditions.In order to test the same membrane for several time, we've been placed the porous aluminum membrane between the transparency window with Canada balsam before the test, the transparency window is consists of two BaF2 materials, which possessed good optical property and a rather large transparent extent. In this paper, we studied the character of the transmitted spectrum and the polarization of porous aluminum membrane.In the first section, we mainly introduce the developing process of the porous aluminum membrane and the late model functional material act as host or mother plate. Based on the general situation, it is an important subject to study the optical property of porous aluminum itself.The second section, firstly, the morphology , mechanism and process of formation are discussed in detail; then we have a summary to the generating ruleof the aluminum membrane: fall of current in the beginning, current density rise subsequent and prone to stable value in the end. In this section, we also discussed some physical property, such as absorptive capacity, ion osmotic permeability, frictional behavior and acoustical behavior.The third section is one of the most important parts of this paper. In this part, we studied the character of the transmitted spectrum. The two BaF2 materials which are used for transparency windows are parallel to each other and undergo the optical polishing, then the porous aluminum membrane is fixed between the BaF2 with Canada balsam to test its' optical property. Test instrument contains UV-3101PC spectral photometer and ER-460 spectral photometer. Firstly, experimental result shown the similarity of the transmitted spectrum of each porous alumina with different thickness and same aperture about 20nm : transmission will be bring down with the increase of the thickness. Secondly, if the sample are in the different aperture and same thickness about 20um, the tendency of the transmitted spectrum will be more complexity: when the aperture is less than optimum aperture at, the transmission will be increased gradually; when greater than at, the result will be opposite. If we've qualified the thickness is 20um , the optimum aperture at will be between 40 nm ~ 100nm .The fifth section is discussed the character of the polarization of porous aluminum membrane. In the experiments, we've placed the BaF2 windows with the porous alumina fixed between the two right-angled prism. The testing are two-part: firstly, fixed-point measurement with laser; then, continuously scanning in the UV-3101PC spectral photometer. The results are two-part too: if the sample are in the different thickness and the same aperture about 20nm , the tendency of the transmitted spectrum present wave character: if the wavelength is constant, extinction ratio raised with the increase of the thickness. If the sample are in the differ...