Preparation And Thermal Properties Of Polyaniline Based Form-stable Phase Change Materials Doped By Copper Nanowires

Phase change materials (PCMs) is a kind of latent heat storage materials. The phase transition of PCMs occurs at a certain temperature with the absorption or release of a great amount of heat. PCMs can be used to store thermal energy and regulate temperature, and solve the time and spatial mismatch between the supply and utilization of heat energy. In recent years, the research of form-stable PCMs has attracted much attentions. However, their poor thermal conductivity is one of the important issues and need to be addressed in applied research. Nanomaterials are reported to exhibit unique physical and chemical properties, such as small size effect, surface effect, quantum size effect and macroscopic quantum tunnel effect. In particular, metal nanomaterials possess ultra-high thermal conductivity. This thesis is concentrated on the investigation of applying copper nanowires (Cu NWs) to enhance the thermal conductivity of an organic form-stable PCM. The research is main focused in three aspects as follows:1. Preparation of polyaniline (PANI) based form-stable PCMs and research of the maximum content of palmitic caid (PA) wraped by PANI. PA was choosed as PCM, a microemulsion system contain PA and aniline was prepared. From the system, PA/PANI form-stable PCM was obtained by means of emulsion polymerization of aniline. A series of PA/PANI PCMs with different loading of PA were used to research the maximum content of PA in the form-stable PCM. The results show that the maximum loading of PA in the form-stable PCM with good form stability is 80 mass%. The composite PCMs with the loading of PA no more than 80 mass% possess good form stability, excellent thermal energy storage performance and high thermal stability.2. Two different surfactants, sodium dodecyl benzene sulfonate (SDBS) and cetyltrimethyl ammonium bromide (CTAB), were used to prepare PA/PANI/Cu composite form-stable PCMs by means of emulsion polymerization. The structure, morphology, energy storage property and thermal conductivity of the PA/PANI/Cu composite PCMs were investigated. The results show that the figuration performance of the composite PCMs prepared by applying both kinds of surfactants is satisfying. Only alcohol was removed in the process of composite PCMs preparation, Cu NWs can be dispersed in the composite PCMs intactly and not be damaged and oxidated under the protection of PA. The doping of Cu NWs can improve the thermal conductivity of PA/PANI composite PCMs. When 10 mass% Cu NWs were added, the thermal conductivity of the PA/PANI/Cu composite PCM was increased to 0.45 W m-1 K-1,which is 0.15 W m-1 K-1 higher than that of pure PA.3. Tetradecanol (TD)/PANI/Cu composite form-stable PCMs were prepared via emulsion polymerization. TD, PANI and Cu NWs were used as PCM, structure supporting material, and thermal conductivity filler, respectively. When CTAB was used as surfactant, the final product was not successfully yielded. For the composite form-stable PCMs prepared by applying SDBS as surfactant, the figuration performance is become more excellent as the loading of Cu NWs increased. The thermal conductivity of TD/PANI/Cu composite material, in which 4 mass% Cu NWs were added, attains 0.507 W m-1 K-1. It indicates that small amount of Cu NWs can effectively improve the thermal conductivity of the TD/PANI/Cu composite form-stable PCMs.