Effect and Mechanism of Solvent Properties on Solution Behavior and Films Condensed State Structure for the Semi-rigid Conjugated Polymers

Solvents have an essential association with polymer solution behavior. However, few researches have been deeply done on this respect. In recent years, our research group focus on the study on effect of solvent properties on solution behavior and film condensed state structure for semi-rigid conjugated polymer up till to apply for optoelectronic device. Herein, influence of solvent properties including solubility of solvent, aromaticity, polarity and hydrogen bonds on semi-rigid polymer chain solution behavior, i.e., single chain conformation, chain shape,size and chains aggregated density were studied by means of static/dynamic laser light scattering(DLS/SLS) and exponential law etc. Effect of solvent properties on condensed state structure of the semi-rigid conjugated polymer film was studied by UV absorption spectroscopy, PL spectroscopy and electron microscopy etc. The essential reasons for the influence were discovered and the mechanism was revealed. It was found that solution behavior with different solvent properties had an essential physical relationship with chains condensed state structure of the semi-rigid conjugated polymers. More importantly, there was a quantitative structure-activity relationship between solution and film. The key to this relationship depended on the interaction between solvent molecules and the semi-rigid conjugated polymer chains. This interaction could also affect optoelectronic devices performance. This study is of great significance to effectively control the condensed state structure of the semirigid conjugated polymers in the process of dynamic evolution from solutions to films. It not only enriches the knowledge and understanding of both semi-rigid conjugated polymer solution behaviors and film condensed state physics based on polymer physics, but also is meaningful to practical application for conjugated polymer and other traditional polymer systems.