Dispensable polyimide aerogel prepolymer, method of making the same, method of using the same, and substrate comprising patterned polyimide aerogel

A method for manufacturing a patterned polyimide aerogel film on a substrate, the method comprising:

• forming a soluble polyimide prepolymer sol;
• loading the polyimide prepolymer sol to a sealed dispensing apparatus, the polyimide prepolymer sol having a viscosity of 1,000 to 20,000 centipoise over a time period of 168 hours or more and a gel time of 3 months or more;
• selectively dispensing the polyimide prepolymer sol in a pattern onto a first portion of a surface of a substrate, a second portion of the surface of the substrate not contacted and wetted by the dispensed polyimide prepolymer sol being substantially free of the polyimide prepolymer sol;
• forming a patterned film of a polyimide prepolymer gel on the substrate from the polyimide prepolymer sol, the polyimide prepolymer gel being self-supporting without further imidization and additively patterned by selectively dispensing the polyimide prepolymer sol in the pattern without predefined molds or photoresist;
• drying the polyimide prepolymer gel to form a patterned film of a polyimide prepolymer aerogel on the substrate;
• and
• curing the polyimide prepolymer aerogel on the substrate to complete imidization to form the patterned polyimide aerogel film on the first portion of the surface of the substrate, the second portion of the surface of the substrate not contacted and wetted by the dispensed polyimide prepolymer sol being substantially free of the patterned polyimide aerogel film.