Multiscale Models And Dynamics Simulation Of Polyurea Aerogels

The molecular dynamics simulation with COMPASS forcefield was successfullyused to simulate the polyurea aerogels of dendrimer Desmodur N3300A molecules atdifferent densities. The radial distribution functions (RDFs) were utilized to study theshort order of the local structures of the simulated polyurea aerogels. All bonds in thesimulated systems were well distributed by analyzing the intra-and inter-molecularcorrelation of bonds formed between homogeneous or heterogeneous atoms.Moreover, the specific bonds correlation analysis revealed the relationship betweenthe intensity of bonds and the density of the structure. The bonds intensity increasedwith the decreasing of the system’s density. The constant strain approach was adoptedto calculate the mechanical properties of all the simulation systems. The simulationresults of Group B were well agreed with the experimental data. Furthermore, theincrease of the molecule mass at same densities can significantly enhance themechanical properties of the represented polyurea aerogel system.DPD simulations were conducted to investigate the structure and kinetics ofpolyurea aerogels formation via thermally induced phase separation on themesoscopic level. PUA molecules can form a framework structure when PUA contentwas from30%to70%using DPD simulation.A method on the mesoscopic level was provided which can be taken as asupplement for the theories and experiments on the microscale and macroscale. DPDis a useful method for creation of random porous nanostrcutures formed byself-assembly of organic nanoparticles.