Molecular Dynamics Simulation Of The Diffusion Of Water Into Polyvinylidene Fluoride And Composites By Inorganic Particles

Polyvinylidene fluoride has the advantages of stable physicochemical properties and high mechanical strength,and has broad application prospect in the field of water treatment.However,the polymer material itself is hydrophobic,and membrane fouling easily occurs during practical application,thereby causing the decrease of membrane separation efficiency and operation cost Increase.The use of hydrophilic inorganic nanoparticles to prepare organic-inorganic composite membranes to improve the hydrophilicity of membranes is becoming one of the hot topics in the field of membrane materials.It combines the excellent properties of nanoparticles and polymers,has been widely used in many fields.Due to the large number of atoms on the surface of nanoparticles,high activity and more broken bonds,it is easy to agglomerate,and its nano-size effect cannot be well played.Many researchers'experimental results show that the modification of nano-particles can effectively improve the composite performance.In the dissertation,the initial polyvinylidene fluoride(PVDF)model was constructed by Material Studio software,and then optimized by molecular dynamics simulation The results show that the calculated model is very close to the experimental one.The results show that the model constructed in this paper and the rationality of the adopted parameters lay the foundation for the next hybrid membrane model.The PVDF model was established to establish the organic-inorganic composite materials represented by PVDF/titanium dioxide particles and PVDF/modified graphene sheets.Then study the filler on polyvinylidene fluoride.Effects of Water Molecules on the Molecular Dynamics and Mechanical Properties of PVDF/Titanium Dioxide Hybrid Membranes.It can be concluded that the addition of inorganic particles in a small size and low concentration environment can improve the diffusion of water molecules in the inorganic/polyvinylidene fluoride hybrid membrane and significantly improve the mechanical properties.Effect of Different Groups in Graphene on Graphene/PVDF Composites.The hydroxyl and carboxyl groups play a major role in the diffusion of water molecules in polyvinylidene fluoride.The result of the dominant effect of carboxyl and carbonyl on the mechanical properties of the composites.The mechanism of microscopic interaction of composite materials can be obtained from the aspects of energy and its interaction.This method enriches and develops the research technology of nanocomposites and expands the application fields of molecular simulation.