Transparent composites prepared from bacterial cellulose and castor oil based polyurethane as substrates for flexible OLEDs

Flexible and transparent composites were prepared from bacterial cellulose (BC) and castor oil based polyurethane (PU). The new BC/PU composites exhibit excellent transparency (up to 90%) in the visible region and great mechanical properties, with a tensile strength of up to 69 MPa and a Young's Modulus up to 6 GPa. The resulting free-standing thin films possessed low surface roughness (below 1 nm), and whose properties suggest a potential candidate substrate for flexible light emitting devices. Subsequently, the fabrication of flexible organic light emitting diodes (flexible OLEDs) was successfully investigated by using flexible transparent BC/PU membranes rather than standard flat glass substrates.