Patent ID: 10144786

Abstract:
The method of making nanocrystalline cellulose is a flash lyophilized-acidic hydrolysis method for converting cellulosic fibers into nanocrystalline cellulose. Cellulosic fibers are initially ground in a high-speed, rotary grinder to produce ground cellulose fiber. The ground cellulose fiber is then dried to produce dried, ground cellulose, which is then freeze-dried to yield lyophilized cellulose. Pure concentrated sulfuric acid is then added to the lyophilized cellulose at a liquid/solid ratio of 1:1 (vol/wt) to form a cellulosic paste. The cellulosic paste is diluted in either water or absolute ethanol at a liquid/solid ratio of 1:1 (vol/wt) to form a cellulosic solution, which is then filtered under cooling by liquid nitrogen-vapor. The nanocrystalline cellulose precipitate is then washed until neutralization and dried to yield nanocrystalline cellulose.