Riccomagno Eva, Shayganpour Amirreza, Salerno Marco
Department of Mathematics, University of Genova, via Dodecaneso 35, I-16146 Genova, Italy.
Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova, Italy.
Materials (Basel). 2017 Apr 15;10(4):417. doi: 10.3390/ma10040417.
Anodic porous alumina is a known material based on an old industry, yet with emerging applications in nanoscience and nanotechnology. This is promising, but the nanostructured alumina should be fabricated from inexpensive raw material. We fabricated porous alumina from commercial aluminum food plate in 0.4 M aqueous phosphoric acid, aiming to design an effective manufacturing protocol for the material used as nanoporous filler in dental restorative composites, an application demonstrated previously by our group. We identified the critical input parameters of anodization voltage, bath temperature and anodization time, and the main output parameters of pore diameter, pore spacing and oxide thickness. Scanning electron microscopy and grain analysis allowed us to assess the nanostructured material, and the statistical design of experiments was used to optimize its fabrication. We analyzed a preliminary dataset, designed a second dataset aimed at clarifying the correlations between input and output parameters, and ran a confirmation dataset. Anodization conditions close to 125 V, 20°C, and 7 h were identified as the best for obtaining, in the shortest possible time, pore diameters and spacing of 100-150 nm and 150-275 nm respectively, and thickness of 6-8 µm, which are desirable for the selected application according to previously published results. Our analysis confirmed the linear dependence of pore size on anodization voltage and of thickness on anodization time. The importance of proper control on the experiment was highlighted, since batch effects emerge when the experimental conditions are not exactly reproduced.
阳极多孔氧化铝是一种基于古老工业的已知材料，但在纳米科学和纳米技术中有着新出现的应用。这很有前景，但纳米结构氧化铝应由廉价的原材料制造。我们使用商用铝制餐盘在0.4M的磷酸水溶液中制备多孔氧化铝，旨在设计一种有效的制造方案，用于制造牙科修复复合材料中的纳米多孔填料，这是我们团队之前已证明的一种应用。我们确定了阳极氧化电压、槽液温度和阳极氧化时间等关键输入参数，以及孔径、孔间距和氧化物厚度等主要输出参数。扫描电子显微镜和粒度分析使我们能够评估纳米结构材料，并使用实验的统计设计来优化其制造。我们分析了一个初步数据集，设计了第二个数据集以阐明输入和输出参数之间的相关性，并运行了一个验证数据集。已确定接近125V、20°C和7小时的阳极氧化条件是最佳的，以便在尽可能短的时间内分别获得100 - 150nm和150 - 275nm的孔径和孔间距，以及6 - 8μm的厚度，根据先前发表的结果，这些对于所选应用是理想的。我们的分析证实了孔径对阳极氧化电压以及厚度对阳极氧化时间的线性依赖性。强调了对实验进行适当控制的重要性，因为当实验条件不能精确重现时会出现批次效应。
