Leland Stanford Junior University

Xiaolin Li

Hongjie Dai

Xiaoming Sun

Zhuang Liu

Disclosed are dispersed graphene sheets, ribbons, graphene molecules and the like which are pristine in the plane, i.e., free of significant defects and chemical modifications such as oxidation. The materials could be functionalized at the edges. These materials are dispersed in solutions rather than in aggregated or insoluble forms as their parent starting materials. Also disclosed is a method comprising the steps of intercalating an insoluble graphitic material. The method may comprise exfoliating graphite and re-intercalating the resultant material with an acid composition, such as oleum, and a strong organic base such as tetrabutylammonium hydroxide in a solvent solution to form a homogenous suspension, which is then agitated to form dispersed graphene materials. The materials may be solubilized with a hydrophilic polymer and can be further manipulated by transfer into different solvents, formation of films, application to optical and electronic devices, and other applications. The materials are solubilized by functional groups mostly at the edges.

Pristine and functionalized graphene materials

Disclosed are nanoparticles, such as carbon nanotubes or other graphitic sheet materials having extended aromatic surfaces, which are used to deliver active agents such as drugs, labels or dyes (termed for convenience a 'drug') to the interior of cells. The nanoparticles are functionalized by a hydrophilic polymer or adsorption of an amphiphilic molecule to render them stable in suspension. The drug is therefore capable of release in the cell exterior. The drug is more rapidly released at lower pH, as found e.g., in tumor cells. The drug may also be linked to a branched chain hydrophilic polymer, so that each polymer molecule carries more than one drug bound by a cleavable linker.

Growing community of inventors

Menlo Park, CA, United States of America

Xiaolin Li