Preparation And Molecular Dynamics Simulation Study Of Dendrimer/RE Nanocomposites

Dendrimers are mono-distributed and nano-scale novel polymers. Their extraordinary structures make the macromolecules bearing unique qualities and functions and are causing an extensive concern of all over the world. In the last few years, the study and research on dendrimers have attracted the interest of biochemistry, catalysis, nano-material etc. Rare earth (RE) elements have special structure of 4f electron. So they can be provided with outstanding catalysis activity, magnetism, super conductance property, photo electricity transfer, photo magnetism and fire resistance property. It is very interesting to research dendrimer/RE-nanocomposite. Simultaneity, with the development of computer technology, simulation approaches is playing a more and more important role in nanomaterial field. It could study the path, transition state and mechanism of chemistry reaction and replace some material experiments, for instance, chemosynthesis, structure analysis, characterization and so on. It could provide some informations that cannot or hardly gain by experiments. So molecular simulations could shorten study period and cut developed cost in the design of new material.In this paper, on the basis of reviews of the research progress of nanocomposite and molecular simulation. The present work was focused on the synthesis and molecular dynamics simulation of dendrimer/RE nanocomposite. The main contents were as follows.PAMAM/RE nanocomposites were successfully prepared in the presence of PAMAM dendrimer as template. At the same time, we apply molecular dynamics simulation to RE-nanocomposites. The stability and mechanism of the RE/PAMAM nanocomposites system were studied from the view-points of molecular structure and energy's fluctuation in NVT system. The simulation results intercompare experiment and concluded scientific viewpoint.We gradually explored to introduce hyperbranched polymers in RE nanocomposites as new organic-phase. Hyperbranched poly(amine-ester)s (HPAE) based upon pentaerythritol (as a core molecule) were synthesized by preudo-one-step method and characterized by GPC, FT-IR, ~1H NMR and TG-DTA. Then the hyperbranched poly(amine-ester)s were act as templates, HPAE/RE nanocomposites were prepared and simulated research. The simulation results revealed HPAE were appropriate as templates and stabilizer comparatively. This result was consistent with experiment. Eventually, we contrastively analyzed composite effect of PAMAM and HPAE.From the viewpoint of molecular simulation, Molecular dynamics simulations of HO-PAMAM-2.5/La nanocomposite system were performed from the view-points of molecular structure and energy's fluctuation in NVT system, The motivation of this work was to understand the stability and mechanism of the nanocomposite in different proportion. Whereafter, according to the simulation results, HO-PAMAM-2.5/La were prepared and characterized by transmission electron microscopy (TEM). This result was consistent with MD simulation.From the view of molecular dynamics, we researched the tetrad effect of RE in the presence of PAMAM dendrimer and studied the complex effect of dendrimer and inorganic particle from a size on the nanometer scale.To sum up, we systematic studied dendrimer/RE-nanocomposite from the preparation and characterization to mechanism simulation and interpretation, from macroscopical experiment phenomenon to microcosmic image of molecular. We firstly combine molecular dynamics simulations with experiment and gained the scientific conclusion. Accordingly, molecular simulation is a feasible assistant experiment method in material field.