Method of spontaneously patterning a polymer during frontal polymerization

A method of spontaneously patterning a polymer during frontal polymerization, the method comprising:

• activating an initiation region of a monomer solution to initiate a polymerization reaction by exposing the initiation region to heat, light, or electric current, whereby a polymerization front is generated and propagates through the monomer solution in a radial or longitudinal direction away from the initiation region;
• spontaneously heating the monomer solution downstream of the polymerization front by thermal transport away from the polymerization reaction, a localized region of the monomer solution reaching a temperature sufficient for spontaneous initiation of another polymerization reaction, whereby a new polymerization front is generated and propagates through the monomer solution in a circumferential or transverse direction;
• and
• wherein the spontaneous heating of the monomer solution downstream of the polymerization front and the initiation of another polymerization reaction occurs cyclically, producing multiple new polymerization fronts and spatial variations in reaction temperature across the monomer solution, thereby enabling a spontaneously patterned polymer to be formed.

A method of spontaneously patterning a polymer during frontal polymerization, the method comprising:

• activating an initiation region of a monomer solution to initiate a polymerization reaction, whereby a polymerization front is generated and propagates through the monomer solution in a radial or longitudinal direction away from the initiation region;
• spontaneously heating the monomer solution downstream of the polymerization front by thermal transport away from the polymerization reaction, a localized region of the monomer solution reaching a temperature sufficient for spontaneous initiation of another polymerization reaction, whereby a new polymerization front is generated and propagates through the monomer solution in a circumferential or transverse direction,
• wherein a ratio φ=PR/PT of a reaction power density (PR, J m−3 s−1) and transport power density (PT, J m−3 s−1) is in a range from about 0.3 to about 1.3, and
• wherein the spontaneous heating of the monomer solution downstream of the polymerization front and the initiation of another polymerization reaction occurs cyclically, producing multiple new polymerization fronts and spatial variations in reaction temperature across the monomer solution, thereby enabling a spontaneously patterned polymer to be formed.