The Preparation Of AuNPs-PDMS Composite Flexible Films And Its Properties Research

With the development of information, materials science, nanotechnology and micro-electronic technology, flexible electronics is rapidly emerging as a new industry.In recent year, lots of new techniques and principles are applied to flexible electronic devices. The advancing of new composite materials promoted the development of flexible electronic devices, which offers electrical, biological and optical properties.In our work, the AuNPs- PDMS composite flexible films were studied primarily. The AuNPs-PDMS composite films were successfully fabricated using the chemical reduction.The factors influencing the structure and performance of composite films were analyzed and discussed, including the degree of crosslinking, thickness, and reducing time. Specific tasks are as follows:1. The thickness and Young’s modulus of PDMS films are tested and analyzed. It is found that they affects the structure and properties of composite membrane. Young’s modulus of different crosslinking degree of PDMS thin film were measured by AFM. The Young’s modulus of PDMS films is determined by the crosslinking degree.The thickness of PDMS were measured by profiler DEKTAKXT. The increase in the spining speed effect with decrease in thickness.2.The AuNPs-PDMS composite films with different crosslinking degree, thickness and incubation time are fabricated using reduction method. The properties were obtained by SEM, TEM and UV visible absorption spectrum.It can be observed that there is gold layer in the composite films and the gold layer have a distance about 3μm from the surface. By changing the thickness, the degree of cross linking and the incubation time, the morphology of gold nanoparticles in the PDMS films can be synthesized, and it is also controllable. The absorption peak intensity have a relationship with the amount of gold particles. The structure and distribution of gold particles in the film is analysised by TEM. The gold nanoparticles have a face-centered cubic(FCC) structure3.In this thesis, the nonlinear phenomenon of the electrical conductivity of Au NPs-PDMS flexible composite films is observed. In addition, the electrical conductivity of the composite films is influenced by the reduction time, ambient temperature and so on. The reduction time affects the amount of nano gold species, the change in the number of gold species in the polymer will change the gap between the gold nanoparticles, which can lead to changes in the electrical properties of the composite films. As the temperature increases, the resistance of the composite films decreases.