Multiscale Simulations of Conducting Conjugated Polymers and Nanoparticles

• Main Authors: Cheng-Kuang Lee, 李正光
• Other Authors: none
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/59627714592849100138

博士 === 國立中正大學 === 化學工程所 === 98 === In this dissertation, multiscale simulation schemes are utilized to investigate structural and dynamic properties of conducing conjugated polymers (i.e. MEH-PPV or PANI-EB) from atomistic to mesoscopic scales in solution or quenching state. These polymers can be utilized as a conducing or light-emitting layer of polymer-based light-emitting diodes (PLED) or as an active layer of organic photovoltaic cells. To understand their material properties in these applications, we have modeled realistic polymer chains at different levels of coarse-graining (CG) with varying simulation protocols. In particular, all the potential fields employed in these CG polymer models were constructed by essential statistical trajectories gathered from atomistic molecular dynamics simulations, so as to warrant a self-consistent and parameter-free modeling. Predictions were obtained on fundamental solutions properties using the aforementioned multiscale schemes, including coil size, persistence length, solvent quality and center-of-mass diffusivity of single polymer chains as well as structural and dynamic properties of supramolecular aggregates, that are otherwise difficult or even impossible to evaluate through usual experimental measurements. In addition, the full-atom models back-mapped from the CG models can further be exploited to investigate the effects of anisotropic, localized π-π or hydrogen-bond interactions in the quenching state as well as in subsequent quantum computations to evaluate the conjugation length and electron-hole transport coefficients etc. On the other hand, the multiscale scheme has also been applied to constructing nanoparticle (i.e. silica) pair interactions for particle radii ranging from nanoscale to microscale and arbitrary shapes. In future perspective, complex fluids composed by hybrid polymers and nanoparticles may thus be studied by parameter-free, multiscale simulations.