Zea Cristina, Alcántara Jenifer, Barranco-García Rosa, Morcillo Manuel, de la Fuente Daniel
National Centre for Metallurgical Research (CENIM/CSIC), Avda. Gregorio del Amo 8, 28040 Madrid, Spain.
Institute of Polymer Science and Technology (ICTP/CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain.
Nanomaterials (Basel). 2018 Jun 28;8(7):478. doi: 10.3390/nano8070478.
Different approaches have been considered for the development of smart anticorrosive coatings by the incorporation of nanocontainers loaded with corrosion inhibitors into the protective layer. Nanocontainers are designed to allow a controlled release of the inhibitor in response to an external stimulus, thus, achieving more efficient and more economical use of the active component. In this case, a pH change is a very interesting stimulus to trigger the release because corrosion processes cause local pH changes. To this end, a special focus has been placed on the use of mesoporous silica nanoparticles (MSN) as nanocontainers due to their interesting characteristics, such as larger surface area, versatile functionalisation, stability, etc. However, the use of hollow mesoporous silica nanoparticles (HMSN), with a large central hole combined with an external mesoporous silica shell, offers an additional advantage due to the higher loading capacity. In the present work, HMSN have been efficiently synthesised, loaded with sodium phosphomolybdate, as a non-toxic alternative to the use of chromates, and encapsulated by a layer of an oppositely charged polyelectrolyte, poly(diallyldimethylammonium chloride) (PDDA). The morphology and textural properties of the produced nanocapsules have been studied by different techniques (SEM/EDS, TEM/EDS, Brunauer⁻Emmett⁻Teller (BET) analysis method, ζ-potential). Finally, the releasing capacity and corrosion protection at different pH values have been studied, confirming the smart behaviour of the encapsulated loaded HMSN.
通过将负载缓蚀剂的纳米容器掺入保护层来开发智能防腐涂层，人们已经考虑了不同的方法。纳米容器的设计目的是使其能够响应外部刺激而控制缓蚀剂的释放，从而更高效、更经济地使用活性成分。在这种情况下，pH值变化是触发释放的一个非常有趣的刺激因素，因为腐蚀过程会导致局部pH值变化。为此，由于介孔二氧化硅纳米颗粒（MSN）具有诸如更大的表面积、多功能官能化、稳定性等有趣特性，人们特别关注将其用作纳米容器。然而，具有大中心孔并结合外部介孔二氧化硅壳的中空介孔二氧化硅纳米颗粒（HMSN），由于其更高的负载能力而具有额外的优势。在本工作中，已经高效合成了HMSN，负载了磷钼酸钠，作为使用铬酸盐的无毒替代品，并被一层带相反电荷的聚电解质聚二烯丙基二甲基氯化铵（PDDA）包裹。通过不同技术（扫描电子显微镜/能谱分析（SEM/EDS）、透射电子显微镜/能谱分析（TEM/EDS）、布鲁诺尔-埃米特-泰勒（BET）分析方法、ζ电位）研究了所制备纳米胶囊的形态和结构性质。最后，研究了不同pH值下的释放能力和腐蚀防护性能，证实了包裹负载的HMSN的智能行为。
