阳极氧化法制备铝基超疏水涂层及其稳定性和耐蚀性的研究

铝由于在潮湿的环境中很容易受到污染和损坏,从而严重影响了其美观性和用途。为了改善铝基材料的耐腐蚀性能,采用电化学阳极氧化法与十四酸修饰相结合的方式在铝基底上制备了超疏水涂层。通过场发射扫描电镜(FESEM)和X射线能量色散光谱(EDS)对涂层表面形貌和化学组成进行了表征。同时利用接触角测量仪、喷砂实验和电化学测试分别对涂层表面的润湿性、机械稳定性以及耐腐蚀性能进行了研究。结果表明:当阳极氧化电压为20V时,所制备的涂层为最佳铝基超疏水涂层,此时涂层的接触角为(155.2±0.5)°,滚动角为(3.5±1.3)°。其对应的腐蚀电流密度较铝基底降低了2个数量级,腐蚀电位从-0.629V正移到-0.570V,呈现出优异的耐腐蚀性能。此外,该涂层还具有良好的机械稳定性。     

降低二次氧化温度制备高度有序阳极氧化铝模板

传统的两步阳极氧化方法在制备多孔阳极氧化铝(AAO)模板时需要两次反应都在低温条件(0~5℃)下进行以保证膜的稳定生长,然而该制备工艺在温度控制方面通常比较复杂。尝试对制备工艺进行改进,在一次高温(20℃)二次低温(5℃)条件下成功制备出了高度有序的AAO模板。随着第二次反应温度的降低,孔的排列趋于整齐,其孔径、孔隙率和孔的深度都有较显著的变小趋势,而孔间距无明显变化。此外,实验中还发现在高温下容易出现套孔现象,这可能是反应时释放出的焦耳热消散不充分所致,当第二次反应温度降到5℃时被完全消除。     

Electrochemical Surface Modification of Aluminium Sheets for Application to Nano-electronic Devices: Anodization Aluminium and Electrodeposition of Cobalt-Copper

A nano-porous anodized aluminium oxide layer was synthesized on the surface of bulk aluminium at a wide range of anodization voltages. The barrier layer at the pore bottom of anodized aluminium oxide layer was chemically etched to make good electrical contact for nanowires electrodeposited in the pores thus formed on metallic aluminium substrates. Cathodic polarization was examined at a wide range of cathode potentials to investigate the electrodeposition behaviour of Cu and Co into the pores. Co₈₁Cu₁₉/Cu multilayered nanowires were fabricated using a pulse-plating technique into the templates. Co-alloy layer and Cu layer thicknesses were adjusted to 10 nm, by controlling the deposition times. The temperature dependence of the resistance of Co₈₁Cu₁₉/Cu multilayered nanowires grown on the template presented clean metallic characteristics and a giant magnetoresistance (GMR) of 23% was reached at 4 K.     

Catalytic graphitization of Mo-B-doped polyacrylonitrile （PAN）-based carbon fibers

A novel carbon fiber pretreatment was proposed. Polyacrylonitrile (PAN)-based carbon fibers were first anodized in H₃PO₄ electrolyte to achieve an active surface, and then coated with Mo-B catalysts by immersed the carbon fibers in a uniformly dispersed Mo-B sol. The as-treated carbon fibers were then graphitized at 2 400 °C for 2 h. The structural changes were characterized by X-ray diffractometry (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and high-resolution transmission electronic microscopy (HRTEM). The results show that much better graphitization can be achieved in the presence of Mo-B, with an interlayer spacing (d ₀₀₂) of 0.335 8 nm and a crystalline size (L _c) of 28 nm.     

二氧化钛纳米管制备方法及其应用研究进展

讨论了水热合成法和阳极氧化法2种二氧化钛纳米管制备方法,并比较了该2种方法制备的纳米管的区别。针对纳米管特点,对其在光催化、储能、氢敏材料、太阳能染料电池等领域的研究及潜在应用进行了综述,最后对二氧化钛纳米管研究方向提出了建议。     

The Influence of Ti-6AI-4V Chromic Acid Anodization Conditions Upon Anodic Oxide Thickness and Topography

Chromic acid (CA) anodization of Ti-6A1-4V (6% Al, 4% V by weight) produced an anodic oxide on the alloy surface. The influence of specific CA anodization conditions upon anodic oxide thickness was determined. Each CA anodization condition tested was defined by setting five variables: (1) solution composition; (2) anodization time; (3) solution temperature; (4) initial current density; and, (5) anodization potential.

The results confirmed observations by previous workers about oxide thickness and structure. Data indicated an inverse relationship between film thickness and temperature, and that film growth rate decreases with time.     

N掺杂TiO2纳米管阵列膜光催化剂制备及其处理造纸废水的研究

本研究通过阳极氧化技术制备了N掺杂TiO_2纳米管阵列膜光催化剂,用于光催化处理造纸废水中的有机物。采用场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)和紫外可见分光光度计(UV-Vis)对光催化剂表面形貌和化学组成等特征进行了表征。结果表明,当阳极氧化电压为40 V时,TiO_2纳米管阵列膜具有高度有序的形貌,其孔径和纳米管长度达到一个最佳状态;该TiO_2光催化剂的晶型为锐钛矿型,且从UV-Vis的结果来看,其吸收带边发生了明显的红移,对光有很强的吸收能力。将制备的光催化剂用于光催化造纸废水,当光催化剂用量为2.5 g/L,光照时间为60 min时,COD_(Cr)去除率达到80.1%,色度去除率达到90.2%。     

F含量对ZrO2纳米管形貌和相组成的影响

采用阳极氧化法在丙三醇+NH₄F+5vol% H₂O的电解液中制备了高度有序的ZrO₂纳米管阵列, 详细考察了溶液中F含量(0.1~1.1 mol/L)对纳米管形貌﹑相结构和化学组成的影响. 利用扫描电子显微镜(SEM), X射线衍射仪(XRD)和X射线光电子能谱仪(XPS)对不同条件下制备的管径约90~130 nm, 管长约4.8~9.1 μm的纳米管形貌和结构进行了表征. 结果显示, 在含有0.7 mol/L NH₄F的电解液中获得了高度有序且垂直导向的四方相ZrO₂纳米管阵列, 而在较低浓度的电解液中制备的纳米管阵列为无定形结构, 较高浓度下纳米管阵列出现坍塌. 此外, 纳米管近表层处F/O原子比也随F^-浓度的变化而变化.     

制备纳米材料的多孔型氧化铝膜板的阳极氧化工艺研究

多孔型阳极氧化铝膜是制备纳米材料的理想模板。以草酸为电解液研究了高纯铝的阳极氧化工艺,采用扫描电镜对多孔型阳极氧化铝膜的表面及断面形貌进行表征。讨论了阳极氧化电压和电解液温度对多孔阳极氧化铝膜的孔径及孔密度的影响。对氧化膜厚度的测定结果表明,当氧化时间为7 h时,氧化膜厚度达到最大值36μm。     

二氧化钛纳米管染料敏化电池的制备和性能

利用两步阳极氧化法,在钛片上成功制备了高质量的二氧化钛纳米管阵列薄膜。利用场发射扫描电子显微镜,对二氧化钛纳米管阵列薄膜进行了形貌表征。之后,将不同厚度的薄膜组装成背光式染料敏化太阳电池,并测量了它们的光电转化性能。发现,随着薄膜层厚度的增加太阳电池的转化效率也逐渐提高。当薄膜厚度为15μm时,电池的转化效率达到3.04%。