Polyfluorene-poly(ethylene oxide) diblock copolymers: synthesis and electron transport behavior

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Electronics

Background:

• Poly(9,9-dioctylfluorene) (PFO) is a conjugated polymer with promising optical and electronic properties.
• Block copolymers offer tunable properties by combining different polymer segments.
• End-capping PFO with poly(ethylene oxide) (PEO) can modify its morphology and performance.

Purpose of the Study:

• To synthesize PFO-b-PEO diblock copolymers via end-capping.
• To investigate the impact of PEO chain length on the properties of PFO-b-PEO.
• To evaluate the electron transport performance of the synthesized copolymers.

Main Methods:

• Synthesis of PFO-b-PEO diblock copolymers under mild conditions.
• Characterization of thermal, optical, electrochemical, and crystalline properties.
• Measurement of electron transport performance and mobility.

Main Results:

• PFO-b-PEO diblock copolymers were successfully synthesized.
• Copolymers with shorter PEO chains (Mn = 1000 and 2000 g mol-1) showed higher electron mobilities.
• Electron mobility was superior to both the PFO homopolymer and copolymers with longer PEO chains (Mn = 4000 g mol-1).

Conclusions:

• Short PEO chain end-capping enhances electron mobility in PFO-b-PEO copolymers.
• Increased crystallinity induced by shorter PEO chains is responsible for the improved electron transport.
• These findings suggest potential for tailored block copolymer design in organic electronic applications.