Université de Lyon, Institut des Nanotechnologies de Lyon, site Ecole Centrale de Lyon et site INSA de Lyon, France UMR 5270 CNRS, INSA de Lyon, ECL, UCBL, CPE, France. Laboratoire Nanotechnologies & Nanosystèmes, UMR 3463 CNRS, INSA de Lyon, ECL, UJF, Université de Sherbrooke, Pavillon P2-3IT, 3000 Boulevard de l'Université, Sherbrooke J1K 0A5, Québec, Canada.
Nanotechnology. 2016 Jul 22;27(29):295602. doi: 10.1088/0957-4484/27/29/295602. Epub 2016 Jun 8.
pH was used as the main driving parameter for specifically immobilizing silicon nanowires onto Si3N4 microsquares at the surface of a SiO2 substrate. Different pH values of the coating aqueous solution enabled to experimentally distribute nanowires between silicon nitride and silicon dioxide: at pH 3 nanowires were mainly anchored on Si3N4; they were evenly distributed between SiO2 and Si3N4 at pH 2.8; and they were mainly anchored on SiO2 at pH 2. A theoretical model based on DLVO theory and surface protonation/deprotonation equilibria was used to study how, in adequate pH conditions, Si nanowires could be anchored onto specific regions of a patterned Si3N4/SiO2 surface. Instead of using capillary forces, or hydrophilic/hydrophobic contrast between the two types of materials, the specificity of immobilization could rely on surface electric charge contrasts between Si3N4 and SiO2. This simple and generic method could be used for addressing a large diversity of nano-objects onto patterned substrates.
pH 值被用作主要的驱动参数，将硅纳米线特异性地固定在 SiO2 基底表面的 Si3N4 微方块上。不同 pH 值的涂层水溶液能够在实验中在氮化硅和二氧化硅之间分配纳米线：在 pH 值为 3 时，纳米线主要锚定在 Si3N4 上；在 pH 值为 2.8 时，纳米线均匀分布在 SiO2 和 Si3N4 之间；在 pH 值为 2 时，纳米线主要锚定在 SiO2 上。一个基于 DLVO 理论和表面质子化/去质子化平衡的理论模型被用来研究在适当的 pH 条件下，硅纳米线如何可以被锚定在图案化的 Si3N4/SiO2 表面的特定区域上。这种固定的特异性不是依赖于两种材料之间的毛细作用力或亲水/疏水对比，而是可以依赖于 Si3N4 和 SiO2 之间的表面电荷对比。这种简单而通用的方法可以用于将各种纳米物体寻址到图案化的基底上。
