In this thesis, we investigated several photoelectric material systems consisted of conjugated polymers by means of computer simulation. We combined several theory and simulation methods to meodeling different subjects from atomic to mesoscopic scale. We dealt with the problems such as quantum efficiency, structure characteristic, and the phase behavior in material. We hope to have better understanding of the relationship between structure characteristic and functional property in material. It will help an engineering designer to adjust the variables that optimize characteristics linking the synthesis of advanced materials with desired physical properties. This work can be divided into three parts. Long side chain substituted PPV polymers applied in light-emitting diode material : Molecular dynamics simulations were employed to investigate structure features and segment orientation of four poly(phenylene vinylene) (PPV)-like conjugated polymers with long flexible side chains at room temperature. In the simulations, the main chains of the polymers were found to be semi-rigid and to exhibit a tendency to coil into ellipsoidal helices or form zigzag conformations of only limited regularity. It was shown that continuous segments of a chain which are quasi-coplanar along the backbone are in a range of 2~4 repeat units. This implies that long-range electron transfer along same backbones of these polymers may not happen but may be mediated by interchain interactions. The ordered orientation and coupling distance of interchain aromatic rings are found to correlate with important optical properties of materials. Then we combined molecular dynamics simulation and density matrix methods modeling of amorphous light-emitting polymers. A simplified method combining molecular dynamics (MD) simulation and density matrix (DM) theory was developed for the prediction of optical properties of long side chain substituted poly(phenylene vinylene) (PPV) polymers. This MD+DM method takes account of the complexity of molecular packing of polymer chains. The method has been tested to simulate the absorption spectra of four model systems. The wavelengths of absorption maxima of the calculated spectra of these four conjugated polymers are in reasonable agreement with experimental data. The simulation also demonstrated that the importance of including interchain interactions in the calculation. Ion-conducting polymer sPBI-PS(Li+): To understand the mechanism of ionic migration in the amorphous matrixes of polymer electrolytes is crucial for their applications in modern technologies. Here, molecular dynamics (MD) simulation was carried out to investigate the ionic conduction mechanism of a particular conjugated rigid-rod polymer, sPBI-PS(Li+). The backbone of this polymer is poly[(1, 7- dihydrobenzo[1, 2-d:4,5-d¡¦]diimidazole- 2,6-diyl)-2-(2-sulfo)-p-phenylene]. The polymer has pendants of propane sulfonate Li+ ionomer. The MD simulations showed that the main chains of sPBI-PS(Li+) are in layer-like structure. The further detailed structure analysis suggested that the £k-electron of this polymer is not delocalized among aromatic rings. This agrees with the experimental result that sPBI-PS(Li+) shows no electronic conductivity and the conductivity of this polymer is mainly ionic. The calculated migration channels of lithium ions and electrostatic potential distributions indicated clearly that the polymer matrix is anisotropic for the migrations of ions. The migration of lithium ions along the longitudinal direction is more preferable than that along the transverse direction. The relaxations of the polymer host were found to play important roles in the transfer process of lithium ions. The hopping of lithium ion from one -SO3-1 group to another is correlated strongly with characteristic motions of -SO3-1 group on a time scale of about 10-13 s. Self-assembly functional material. Dissipative particle dynamics (DPD) simulations were carried out to investigate mixed ionic and non-ionic molecules, sodium tetradecyl sulfate (STS) and tetradecyl triethoxylated ether (C14E3) aqueous system. Different types of mixed micelles are formed depending on the concentrations of STS and C14E3. Our results are in good agreement to the early NMR measurements. From the investigation of surfactant aggregation, we understand the self-assembly mechanism and classical phase behavior in general diblock copolymer. Further, we investigated the self-assembly process on a particular mushroom-shaped supramolecular film material from molecular character to phase behavior. The miniaturized rod-coil triblock copolymers (PS-PI-RCBC) HEMME had been found to self-assemble into well-ordered nanostructures and unusual head to tail multilayer structure. The purpose of our study is to obtain fundamental understanding the connection of the inherent morphological characterization of single molecule and the mechanism of phase behavior of this polar self-assembly system. Dissipative particle dynamics simulation was carried out to study the mechanism of phase behavior of the solvent-copolymers system. We found that the solvent-induced polar effect under different temperature is important in the process of self-assembly of block copolymers. In different temperature the solvent induces hybrid structure aggregation. Our results are consistent with experimental observations and give evidence for a special mechanism governing the unusual phase behavior in thin films of modulated phases. The sizes and stabilization energies of mushroom-shaped supramolecular clusters were predicted by molecular modeling method. Clusters of sizes from 16 to 90 molecules were found to be stable. In combination of classical and simple quantum mechanical calculations, the band gaps of HEMME clusters with various sizes were estimated. The band gap was converged at 2.45 eV for cluster contains 90 molecules. Nonlinear optical properties of the material were investigated by the semi-empirical quantum mechanical calculations of molecular dipole moment and hyperpolarizabilities. Significant second-order nonlinear optical properties were shown from these calculated properties.

<p dir="ltr">Solid-polymer electrolytes constitute an attractive alternative to flammable liquid electrolytes, but their low ionic conductivity (σ) and transference number (<i>t</i>₊) are not sufficient to replace current liquid electrolytes. In turn, the rational design of new materials is of ultimate importance to overcome the main limitation to high ionic conductivity: the close relationship between ion transport and polymer segmental relaxation. On one hand, the strategy to overcome such issue is designing new composite polymer electrolytes (CPEs) where ceramic particles can modify the properties of the polymer host by increasing the amorphous fraction, enhance the dissociation of salts, hinder the diffusion of anions, and/or create new Li⁺ conduction pathways at the interface ceramic/polymer. One of the main obstacles to achieving higher performance is the limited understanding of transport mechanism and the effect of ceramic filler on the physical properties, ion transport, and interactions with the CPE constituent materials. The dielectric properties of polymers play a critical role in the ability of the polymer to dissolve salts and mediate the electrostatic interactions between the cations and the polymer chain. To further study the effect of the CPE dielectric constant and its impact on ionic conductivity, in this thesis the effect on incorporating High Entropy Oxides (HEO) that possess colossal permittivity into PEO/LiTFSI matrixes is reported. The results show that particles of 700 nm average diameter yield ionic conductivities > 10^‑4 S cm^‑1. Measurements of the complex dielectric function reveal an increase in the rate of relaxation of the ion-coupled chain dynamics. This is in line with the reduced Tg observed in DSC analysis. DSC also reveals no significant change in the degree of crystallinity and results based on FTIR do not indicate a significant dissociation of Li-salt compared to the PEO-based SPE. Finally, the addition of these high dielectric constant fillers of smaller size produces a radical change in the polymer microstructure because of their integration with the polymer matrix. In summary, these results suggest that the improvement in IC is likely due to the formation of efficient Li-pathways involving fast-moving amorphous polymer. Further studies are needed to determine the effect of the HEO fillers on the bonding interactions between the Li cations and the oxygen groups of the polymer. An additional strategy to overcome limitations in ion-transport of polymer electrolytes was pursued in this work through the design of new polymer structures. Single ion-conducting polymer electrolytes (SICPEs) can restrict the diffusion of anions which is responsible for the development of polarization gradients in rechargeable batteries, under high charge/discharge conditions. The design of poly (Li-FAST-<i>alt</i>-DEG) is intended to regulate other aspects such as Li⁺ concentration and free volume of the polymer. Whereas the synthesis of oligomers was successfully accomplished, challenges in the synthetic process hindered the fabrication of the polymer.</p>