Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
Nanotechnology. 2013 Oct 18;24(41):415502. doi: 10.1088/0957-4484/24/41/415502. Epub 2013 Sep 17.
The present paper reports on the development of new sensing active coating on the basis of nanocontainers containing pH-indicating agent. The coating is able to detect active corrosion processes on different metallic substrates. The corrosion detection functionality based on the local colour change in active cathodic zones results from the interaction of hydroxide ions with phenolphthalein encapsulated in mesoporous nanocontainers which function as sensing nanoreactors. The mesoporous silica nanocontainers are synthesized and loaded with pH indicator phenolphthalein in a one-stage process. The resulting system is mesoporous, which together with bulkiness of the indicator molecules limits their leaching. At the same time, penetration of water molecules and ions inside the container is still possible, allowing encapsulated phenolphthalein to be sensitive to the pH in the surrounding environment and outperforming systems when an indicator is directly dispersed in the coating layer.The performed tests demonstrate the pH sensitivity of the developed nanocontainers being dispersed in aqueous solutions. The corrosion sensing functionality of the protective coatings with nanocontainers are proven for aluminium- and magnesium-based metallic substrates. As a result, the developed nanocontainers show high potential to be used in a new generation of active protective coatings with corrosion-sensing coatings.
本文报道了基于含有 pH 指示剂的纳米容器的新型传感活性涂层的开发。该涂层能够检测不同金属基底上的活性腐蚀过程。基于活性阴极区局部颜色变化的腐蚀检测功能源于氢氧根离子与被封装在介孔纳米容器中的酚酞的相互作用，介孔纳米容器作为传感纳米反应器。介孔硅纳米容器通过一步法合成并负载 pH 指示剂酚酞。所得体系具有介孔性，这与指示剂分子的体积限制了其浸出。同时，水分子和离子仍可以穿透容器内部，使封装的酚酞对周围环境的 pH 敏感，并优于直接将指示剂分散在涂层中的系统。进行的测试证明了分散在水溶液中的开发的纳米容器的 pH 敏感性。纳米容器的防护涂层的腐蚀传感功能已被证明适用于铝和镁基金属基底。结果表明，所开发的纳米容器具有在新一代具有腐蚀感应涂层的主动防护涂层中应用的巨大潜力。
