Mesoscopic Simulation Study On Supramolecular Materials Based On Reversible Bond Algorithm

After decades of vigorous development,supramolecular materials have developed numerous different new types with great application potential.At present,the main problem hindering the further development and application of supramolecular materials is the multiple interactions and couplings of this complex system,which makes it difficult to predict the properties of materials and achieve rational design of materials.For this complex system,the theoretical methods are few and are often limited.Based on the above research background,we propose models and algorithms to study on vitrimer,supramolecular block copolymers and supramolecular liquid crystals.The main research contents of this paper are as follows: 1.Dynamics and Reaction Kinetics of Coarse-Grained Bulk VitrimersDue to the complex composition of vitrimer and the dynamic bond exchange reactions(BERs),the mechanism behind its unique dynamic behavior is not fully understood.We used the hybrid molecular dynamics-Monte Carlo(MD-MC)algorithm to establish a molecular dynamics model that can faithfully reflect BERs,and reveal the intrinsic mechanism of the dynamic behavior of the vitrimer system.The simulation results show that BERs change the diffusion mode of the vitrimer's constituent molecules,which in turn affects the BER and other relaxation dynamics.2.Simulation Study of Process-Controlled Supramolecular Block Copolymer Phase Separation with Reversible Reaction AlgorithmWe propose a novel method to describe supramolecular reactions in dissipative particle dynamics,which includes a reversible reaction to accurately reproduce the strength,saturation,and dynamic properties of the reversible bonds in the simulations.The thermodynamic properties and dynamic processes of the supramolecular diblock copolymer melts in both equilibrium and non-equilibrium states were studied using this method.The simulation results show that the method can faithfully characterize phase behaviors and dynamic properties of supramolecular diblock copolymer melts,especially in a non-equilibrium state,which provides a novel tool to unveil self-assembly mechanism.3.Simulation study on the self-assembly of supramolecular liquid crystal polymers containing dendritic side chainsWe proposed a coarse grained model of dendritic liquid crystal molecules,and studied the effect of rigid rod and tail chain length on the liquid crystal polymer phase structure by DPD,and verified the feasibility of the model.Introducing a main chain that can associate with the active end of a rigid rod,combined with the reversible bond algorithm,the hydrogen-bonded supramolecular liquid crystal polymer was successfully simulated.The influence of hydrogen bond strength on its phase structure was explored,and the effect of the ratio of two liquid crystal molecules with different rigid rod lengths on the size of the phase region of the supramolecular liquid crystal was studied.