Stable sensor layers self-assembled onto surfaces using azobenzene-containing polyelectrolytes.
Stable sensor layers self-assembled onto surfaces using azobenzene-containing polyelectrolytes.
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DOI：
10.1039/b105015j
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发表时间：
2001-11
期刊：
影响因子：
--
通讯作者：
O. Mermut;C. Barrett
中科院分区：
文献类型：
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作者：
O. Mermut;C. Barrett
通过从稀水溶液中反复吸附，在带相反电荷的聚合物之间交替，将具有可光致异构的偶氮苯发色团的聚电解质多层化到无机和金属表面上。这些逐层离子自组装薄膜的研究，其适用性作为传感器主机材料相对于标准的控制物理层的性能，多功能性不同的基板和吸附几何形状，和稳定性的形成层的热，溶剂，和超声处理。层厚度被发现是可控的5 A和500 nm之间，通过改变沉积的层的总数，从一个单一的单层到1000层。通过改变吸附溶液的pH来实现对单个层厚度的控制。这种多层自组装被证明是适合于广泛的金属和无机基板，并实现与表面的高曲率（r = 50 nm），和受限的几何形状。沉积的层在有机溶剂、水溶液温度至100 ° C的范围内以及诸如超声处理的清洁方案中表现出良好的解吸稳定性。激光诱导的偶氮苯生色团的几何异构化被证明是强烈依赖于水溶液的性质，展示了在高碱性介质中作为氢氧化物离子传感器的应用。
Polyelectrolytes functionalized with photoisomerizable azobenzene chromophores were multi-layered onto inorganic and metal surfaces, by the repeated adsorption from dilute aqueous solution, alternating between oppositely charged polymers. These layer-by-layer ionically self-assembled thin films were investigated for their suitability as sensor host materials with respect to the criteria of control over physical layer properties, versatility to different substrates and adsorption geometries, and stability of the formed layers to heat, solvent, and sonication. Layer thickness was found to be controllable between 5 A and 500 nm by varying the total number of layers deposited, from a single monolayer to 1000 layers. Control over individual layer thickness was achieved by varying the pH of the adsorption solutions. This multi-layer self-assembly was demonstrated to be suitable for a wide range of metal and inorganic substrates, and achievable with surfaces of high curvature (r = 50 nm), and confined geometry. The deposited layers exhibited good stability to desorption in a range of organic solvents, aqueous temperatures to 100 degrees C, and cleaning protocols such as sonication. The laser-induced geometric isomerization of the azobenzene chromophores was shown to be strongly dependent on aqueous solution properties, demonstrating an application as a hydroxide ion sensor in highly alkaline media.