Novel Nanomaterials and Performance Industrial Products, 2013

 

 

Project Leader

You-Lo Hsieh, professor of fiber and polymer science
Division of Textiles and Clothing, UC Davis

This project is developing strategies to isolate major rice straw components and to generate new nanomaterials for value-added industrial products.

Electron microscopy of cellulose nanofibrils aerogels frozen (a) and freeze dried (b). Inserts are photographs of aerogels.

Several chemical pathways involving minimal chemical input, water use, thermal input, and byproduct generation have been evaluated and optimized to separate the major rice straw components—cellulose, hemicellulose, lignin, and silicon. Two processes have been successfully demonstrated to derive pure cellulose and to isolate hemicellulose, lignin, and silica.

The objectives of 2012 research were to improve the yield of cellulose nanocyrstals and nanofibrils; to design functional nanomaterials and nanocomposites; and to develop functional carbon fibers from hemicellulose, lignin, and silica mixtures.

Cellulose nanocrystals with diameters less than 10 nanometers (nm) and lengths ranging from 200 nm to 400 nm, as well as cellulose nanofibrils 2 nm wide and a micrometer long, have been generated.

Pure silica nanoparticles have been derived from thermal pyrolysis of rice straw followed by chemical extraction. Silica nanodiscs and carbon fibers have been synthesized from rice straw silicon and hemicellulose-lignin, respecitvely.

Successful conversion of these rice straw componenets to cellulose nanocrystals, self-assembled fibrils, as well as silica gel and nanoparticles, sets the foundation for further development of rice straw-based nanomaterials for value-added industrial products.

Potential applications of these materials include a wide range of consumer and industrial membranes for filtration, absorbent technology, liquid-proofing, and other uses. Nanocomposites and high-performance carbon fibers could also find applications in semiconducting, light-emitting, electronic, and heat-resistant materials.