Theoretical Studies On Mesoscopic Morphology Of Comb-Like Peptoid Copolymers

Along with the development of biomedical research, the study of peptide and protein is increasing. Peptoid is a kind of peptidomimetic, it not only possesses the advantages of peptide but also can overcome certain properties of peptide. So peptoid has obtained the in-depth research and exploitation. At present, the research of peptoid mainly embodies in the aspects of the relation between structure and properties, aggregation behavior, drug delivery and drug release etc. The numerous research has a close relationship with self-assembly. Especially, most studies are about the research of amphiphilic peptoid copolymer. The research of the self-assembly plays an important part in the experiment. Meanwhile, theoretical study is developing. Particularly, advances in the development of computer simulation technology make theoretical study received high attention. Theoretical study not only can be used as an auxiliary means for experiments, but also can have the effect of prediction and guidance for experimental research.Dissipative particle dynamics (DPD) is a molecular dynamics simulation method in mesoscopic scale. Based on the idea of coarse graining, it succeeds in associating the atomic simulation with the mesoscopic simulation. DPD simulation is not only straightforward, and also can overcome the computer simulation limits in time and space. In order to raise the veracity of the DPD simulation, we not only calculate the Flory-Huggins parameter to get the non-bonded interactions of the beads, but also calculate the bonded interactions of the coarse graining molecules through the all atomic dynamics simulation.In this paper, we use dissipative particle dynamics to study the theoretical simulation of self-assembly behavior of the comb-like peptoid copolymer. The comb-like structure make the study more meaningful. We simulate the Nte6-Neh3o, Nte9-Neh27, Nte12-Neh24, Nte18-Neh18, and Nte24-Neh12 at 303K,323K,343K,363K and 373K five different temperatures by Dissipative Particle Dynamics. We obtained a phase diagram based on the results of simulations. There are lamellar phase and disorder phase two kinds of morphologies. We mainly adopt the analysis methods of the radial distribution function (RDF) and order parameter to analyze the results, and we calculate the layer spacing. Meanwhile, we discuss the formation of the lamellar phase process on a phase point. It shows that temperature, block copolymer composition and interaction parameters have an effect on the formation of the morphology.