通孔PAA模板的快速制备与纳米电容器的构建

发布时间：2018-03-08 06:44

  本文选题：通孔PAA模板　切入点：快速制备　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：高度有序的多孔阳极氧化铝(Porous Anodic Alumina,PAA)模板被广泛用于各种纳米功能材料的制备中,但通孔PAA模板的快速制备仍是一个挑战。本文为了构建铝纳米柱阵列的电介质电容器,着重研究了大小孔间距(孔径)PAA模板的快速制备方法和通孔工艺,并利用PAA通孔模板,采用真空熔融压注法,通过优化压注工艺参数,成功地制备出大面积高度有序的铝纳米柱阵列,并通过阳极氧化法在纳米柱表面形成一层电介质薄膜,构建了纳米电容器。首先,在不同浓度草酸溶液中不同氧化电压下进行高场恒压阳极氧化,探究影响PAA膜有序度的主要因素,结果表明:提高电解液浓度和氧化电压均能有效地提高PAA膜的有序度(Ordering degree)。其中在62 V、0.75 molL-1草酸电解液中单面阳极氧化所得的PAA膜最为规整,有序度达75.6%,生长速率高达134.54μm-1;对62 V单面氧化的PAA膜和48 V双面氧化的PAA膜分别进行单向腐蚀150 min和40 min后均可得到完全通孔的PAA模板。其次,在磷酸的乙醇溶液、低浓度草酸溶液中可实现在常温下大孔间距PAA模板的制备,但仍存在生长速率偏慢,PAA膜孔道不规整等问题。在单取代磷酸酯溶液中可实现大孔径PAA模板的快速制备,在该电解液体系中,电压可调控范围非常广(200-380 V)、PAA膜的生长速率为磷酸溶液中的30-60倍。对340 V氧化的PAA膜进行单向腐蚀8 h可得到完全通孔的PAA模板。另外,为了构建纳米电容器,先在抛光的铝基体上研究阳极氧化铝电介质膜的形成工艺和性能。结果表明柠檬酸氢二铵和硼酸铵溶液中所得的电介质膜的漏电流较小;在40℃下所得的电介质膜的综合介电性能较好;在同等氧化电压下柠檬酸氢二铵中加入少量磷酸单丁酯可以得到"污染层"更薄的氧化铝膜,因此可以明显降低致密膜的漏电流,并且随着添加剂浓度的增加氧化铝致密膜的漏电流越小。最后,以不同孔径的通孔PAA模板,利用不同的压注工艺制备出不同直径的铝纳米柱阵列,研究不同工艺方法对铝纳米柱阵列的影响。结果表明,所加的压力应以65 MPa为宜,压注温度应低于铝的熔点(660℃),其中在200℃下开始施加压力至65 MPa,其后在保压的同时升温至400℃,保温保压一段时间后再缓慢升温至650℃可以制备大面积较为规整的铝纳米柱阵列,对该工艺条件下制备的铝纳米柱阵列利用阳极氧化法在纳米柱表面形成一层电介质膜,构建了纳米结构的电介质电容器,在测试频率为50 Hz时,与平面结构电介质电容器相比,其比容提高了 20.8倍。
[Abstract]:Porous Anodic aluminum oxide (PAA) templates with highly ordered order have been widely used in the preparation of various nano-functional materials, but the rapid preparation of through pore PAA templates is still a challenge. In this paper, the rapid preparation method and through pore technology of large and small pore spacing (PAA) template are studied. By using PAA through pore template and vacuum melt pressing method, the process parameters of pressure injection are optimized. A large area and highly ordered aluminum nanocolumn array was successfully prepared, and a layer of dielectric film was formed on the surface of the nanocrystalline column by anodizing method to construct the nanocrystalline capacitor. High field constant voltage anodic oxidation was carried out in oxalic acid solution with different concentrations. The main factors affecting the order of PAA films were investigated. The results show that increasing electrolyte concentration and oxidation voltage can effectively improve the ordering degree of PAA film, and the PAA film obtained by anodic oxidation on one side is the most regular in 62 V ~ 0.75 molL-1 oxalic acid electrolyte. The order degree was 75.6 and the growth rate was 134.54 渭 m ~ (-1). After unidirectional corrosion of 62V PAA film and 48V double-sided oxidation PAA film for 150 min and 40 min respectively, the PAA template could be obtained. Secondly, in the ethanol solution of phosphoric acid, the through pore PAA template could be obtained. In low concentration oxalic acid solution, the large pore spacing PAA template can be prepared at room temperature, but there are still some problems such as slow growth rate and irregular pore channel. The rapid preparation of large pore size PAA template can be realized in monosubstituted phosphate solution. In this electrolyte system, the voltage adjustable range is very wide. The growth rate of the film is 30-60 times as high as that in the phosphoric acid solution. The PAA film with 340V oxidation can be corroded in one direction for 8 hours. In addition, a fully porous PAA template can be obtained. In order to construct nanocrystalline capacitors, the formation process and properties of anodic alumina dielectric films were studied on polished aluminum substrates. The results showed that the leakage current of dielectric films obtained in the solution of diammonium citrate and ammonium borate was small. The dielectric film obtained at 40 鈩，

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