Gold Nanocomposite Honeycomb Films With Controllable Pore Size And Their Properties

Honeycomb in nature was built smartly. It contains thousands of interlinked chambers. Every chamber is a strict hexagon column. The adjacent chambers arranged in hexagon array. This structure was called honeycomb structure which can be reproduced in chemical lab. Recently, highly ordered structural materials have attracted considerable attention because of their potential applications such as catalytic materials, sensors, micro-reactors, optical devices, tissue engineering scaffolds, and biomedicine. In basic research, many researchers have produced such highly ordered structural materials using template method and self-assembly method. They called them honeycomb films vividly. The conventional templates conclude colloidal particles, block copolymers, surfactants, and even bacteria. However, some disadvantages exist in this template method. The size of the template is fixed and the formation of the films is at the cost of the template. Furthermore, the ordered degree and the removal of the template are problems difficult to resolve. In1994, a breath figure method was first reported by Francois’s group. In this method, condensed water droplets act as templates for self-microfabrication in high humidity atmosphere. After that, honeycomb films formed by Breath Figure became hot research. Breath Figure method is a facile and efficient self-assembly for fabricating honeycomb films. It has been developed for several decades and many porous films system have been set up. However, these researches focused on polymers and aimed at the regularity and their template application. In practice, the synthesis of polymer is complicated and difficult. Therefore, we use nanoparticles with good property as basic material, and mixed with simple polymers, using Breath Figure method to form honeycomb films. Then, the size controllable property and Raman Scattering effect were discussed. The outline and contents of this Master thesis are as follows:In Chapter1, the research status and the recent development of fabrication of honeycomb films by breath figure method, including forming methods, building materials, mechanism, impact factors and application, were reviewed. The purpose and significance of this thesis are also demonstrated.In Chapter2, Au nanoparticles stabilized by three different mercaptans, C14H29SH, C16H33SH, and C18H37SH, were synthesized using an established two-phase method. And Au NPs honeycomb-patterned films on cleaned ITO glass surfaces were prepared. The effect of polymer for honeycomb film structures was discussed by adding polymer or not. The concentration, polymers, stabilizers of nanoparticles were studied for nanoparticles/polymer system. Using these methods, the pore size of honeycomb films can be well controlled. The controllable honeycomb films have potential applications in cell culturing, filtration, and segregation.In Chapter3, some interesting phenomena, including appearance of leaf structure, fracture of pores, formation of elliptical pores, different size distribution of film pores, and aggregates on the cross section, were introduced and the relevant mechanism were proposed. These can provide valid data for opening structure research of honeycomb films.In Chapter4, the Raman spectrum property of honeycomb films was discussed. Assembled nanoparticles have typical Raman Scattering effect; therefore, Au nanoparticle aggregates can act as active substrates for SERS. Functional honeycomb films endowed this property of nanoparticles can be prepared. Experiments show that Raman scattering spectra are closely related to the structure of the honeycomb films. The more regular the honeycomb films were, the stronger the SERS was, and conversely, the weaker the SERS.