The layer-by-layer (LbL) assembly approach has been widely used to fabricate multilayer coatings on substrates with multiple cycles, whereas it is hard to access thick films efficiently. Here, we developed an ion diffusion-directed assembly (IDDA) strategy to rapidly make multilayer thick coatings in one step on arbitrary substrates. To achieve multifunctional coatings, graphene oxide (GO) and metallic ions were selected as the typical building blocks and diffusion director in IDDA, respectively. With diffusion of metallic ions from substrate to negatively charged GO dispersion spontaneously (i.e., from high-concentration region to low-concentration region), GO was assembled onto the substrate sheet-by-sheet via sol–gel transformation. Because metallic ions with size of subnanometers can diffuse directionally and freely in the aqueous dispersion, GO was coated on the substrate efficiently, giving rise to films with desired thickness up to 10 μm per cycle. The IDDA approach shows three main merits: (1) high efficiency with a μm-scale coating rate; (2) controllability over thickness and evenness; and (3) generality for substrates of plastics, metals and ceramics with any shapes and morphologies. With these merits, IDDA strategy was utilized in the efficient fabrication of functional graphene coatings that exhibit outstanding performance as supercapacitors, electromagnetic interference shielding textiles, and anticorrosion coatings. This IDDA approach can be extended to other building blocks including polymers and colloidal nanoparticles, promising for the scalable production and application of multifunctional coatings.

中文翻译：

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离子扩散定向组装方法对氧化石墨烯厚多层膜的超快涂层

逐层（LbL）组装方法已被广泛用于在多个循环上在基板上制造多层涂层，但是很难有效地访问厚膜。在这里，我们开发了一种离子扩散导向组件（IDDA）策略，可以在任意衬底上一步一步地快速制作多层厚涂层。为了获得多功能涂料，分别选择了氧化石墨烯（GO）和金属离子作为IDDA中的典型构建基块和扩散导向器。与金属离子的扩散从基板到带负电荷的GO分散自发（我。ê，从高浓度区域到低浓度区域），GO组装到基板上的片材由片材经由溶胶-凝胶转变。由于亚纳米大小的金属离子可以在水分散液中自由定向扩散，因此GO可以有效地涂覆在基材上，从而形成每个周期的厚度最大为10μm的薄膜。IDDA方法显示出三个主要优点：（1）高效，微米级涂布率；（2）对厚度和均匀度的可控性；（3）具有任何形状和形态的塑料，金属和陶瓷基板的通用性。凭借这些优点，IDDA策略被用于功能性石墨烯涂层的高效制造，这些石墨烯涂层具有出色的超级电容器，电磁干扰屏蔽纺织品和防腐涂层性能。这种IDDA方法可以扩展到其他构建基块，包括聚合物和胶体纳米颗粒，