Continuous concentric lamellar block copolymer nanofibers with long range order

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Fibers with ordered internal structures are crucial for applications like optical waveguides and sensors.
• Conventional methods for creating these fibers yield diameters greater than 10 micrometers with features larger than 1 micrometer.

Purpose of the Study:

• To develop a new class of continuous fibers and fibrous membranes with nanoscale ordered structures.
• To achieve fiber diameters and feature sizes significantly smaller than those produced by existing techniques.

Main Methods:

• Utilizing confined self-assembly of block copolymers within core-shell electrospun filaments.
• Employing electrospinning to create core-shell structures that guide copolymer assembly.

Main Results:

• Successfully created continuous fibers with long-range ordered concentric lamellar structures.
• Achieved fiber diameters of approximately 300 nm and radial periods of 50 nm, orders of magnitude smaller than conventional methods.
• Observed quantitative variation of copolymer domains with radial position and a novel dislocation accommodating diameter variations.

Conclusions:

• This novel method enables the fabrication of nanoscale ordered fibers, expanding possibilities for advanced material applications.
• The ability to control nanoscale features opens new avenues for photonic band gap fibers, sensors, and drug delivery systems.