This review comprehensively summarizes the recent progress in surface-grafting polymers, including their formation process and the utilization of surface-grafting polymers as functional materials of insulators, conductors and semiconductors in versatile organic electronic devices.

The instability of organic field-effect transistors (OFETs) is one key obstacle to practical application and is closely related to the unstable aggregate state of organic semiconductors (OSCs). However, the underlying reason for this instability remains unclear, and no effective solution has been developed. Herein, we find that the intrinsic tensile and compressive strains that exist in OSC films are the key origins for aggregate state instability and device degradation. We further report a strain balance strategy to stabilize the aggregate state by regulating film thickness, which is based on the unique transition from tensile strain to compressive strain with increasing film thickness. Consequently, a strain-free and ultrastable OSC film is obtained by regulating the film thickness, with which an ultrastable OFET with a five-year lifetime is realized. This work provides a deeper understanding of and a solution to the instability of OFETs and sheds light on their industrialization.

The processing, morphological structure, and properties of polymeric materials are closely related with each other. Morphological structure of polymeric materials is formed in situ under complex temperature and external force fields during processing, and in turn affects the ultimate performances of products. With the increasingly widespread application and more stringent requirement of polymeric materials, improved processing technologies are needed in order to improve product quality. A new processing methodology, i.e., morphology control, appears to achieve a significant improvement by structuring the morphological structure of polymeric materials. This paper presents a summary of four different types of morphology control technologies, namely, shear controlled orientation in injection molding, vibration-assisted injection molding/extrusion, rotational extrusion, and in situ microfibrillation/formation. Methods of application and their resulting effects on morphological structure and mechanical performances of polymeric materials are presented in a review format.