A Facile And Efficient Way To Speed Up Layer-by-Layer Assembly:Dipping In Agitated Solutions

Layer-by-layer assembly has been widely used as a versatile method for fabricating multilayer thin film with well-tailored structure and composition, due to its advantages, such as:simplicity, low-cost, variety of assembly materials, no limit to the shape and size of the substrates. Because of the structure of nano-porous membranes, it has a wide application prospect in sensors, catalysis and many other aspects. However, as is well-known, the fabrication of thick films through conventional LBL method is quite time-consuming. It greatly impedes the further exploration and development of thick LBL films.In this study, we develop a facile and efficient way to speed up LBL assembly, by which the assembly time of each layer can be shorten to the lowest time without remarkable cost of the film quality. The major alteration of this new method to conventional LBL is vigorously agitated solutions that the substrates are dipped into, instead of a still solution or slow solution flow. Under the help of agitation, the deposition and rinsing time can be shortened to5and30(10each and three times)seconds respectively and the resulting LBL films maintain the morphology as smooth and homogenous as the conventional LBL. In order to differential it from conventional LBL and spray and spin method, this method was named agitated-dipping(AD)LBL in this article. Compared with the conventional one, AD LBL can raise efficiency by more than15times, and moreover, it preserves most of the futures of conventional LBL, such as, simplicity, no limitation the surface planarity of the substrate, recycling of solutions, and so on. AD LBL would be promising as an alternation to rapidly fabrication of LBL films.