Simulation Of Morphology And Dielectric Properties Of Polyethylene/Montmorillonite Nano-composite

PE is a kind of cable insulation material which is widely used in industrialarea. The long term effect of electric field will cause breakdown of insulation ofPE. So it is important to improve the insulation characteristic of PE. As the scaleeffect, interface effects and experimental instrument accuracy problems, onlythrough the experimental phenomena have been unable to meet the study ofmaterial modification and design. Therefore, we used molecular modelingtechniques to study the nature of PE and PE/MMT nano-composites.In this thesis, the defect model of PE, MMT, Octadecyl trimethylammonium chloride, PE/MMT is built based on Material Studio software. Inorder to optimize the model, the molecule method is used. On the basic of thismodel, the trajectory of molecule, the energy, structure and polarization oftrajectory is calculated. The depth of PE trap is calculated using densityfunctional theory theory.By building a model of MMT which has a layer of water molecule, aconclusion that the MMT growth in water due to the hydrogen bond. The usingof intercalator can improve the distance between each layer of MMT. The modifyof MMT can change MMT from dear inorganic to dear organic. Through theanalysis of structure model, energetic characteristic of PE PE/MMT nanomaterial, a conclusion can be gotten. That is the energy of PE/MMT is lower thanPE, the structure is stable than PE, and it can also reach balanced status duringprocess of simulation. The PE and MMT is combined with strong VDW andelectrostatic force by calculating the binding energy. The intensity of polarizationof nano-composite is stronger than PE in same electric field by calculating PEPE/MMT polarization strength. This phenomenon also shows the trend of growth as the temperature increasing. The benzene ring, conjugated double bond andcarbonyl group, aldehyde group factors are the important cause leading to thecharge trap exist. The addition of proper amount of MMT can also increase thedepth of trap. As the existence of trap, the dielectric property of PE will change.