Preparation of hydrophobic transparent paper via using polydimethylsiloxane as transparent agent

Transparent paper with good hydrophobicity and flexibility was expected to act as an alternative substrate in fabrication of flexible electronics. However, conventional paper made of cellulose fibers was opaque and hydrophilic without undergoing special processing. Herein, cellulose fiber paper was treated by impregnating with hydrolyzed tetraethyl orthosilicate (TEOS) followed by coating with hydrophobic polydimethylsiloxane (PDMS) to prepare hydrophobic transparent paper. The results showed that silica nanoparticles produced by the TEOS hydrolysis improved the paper transparency to some extent, increased the paper thermal stability, but still remained the hydrophilicity of paper. After the paper was further coated with the PDMS and the PDMS was consolidated, the paper became clearly transparent and hydrophobic. The processed paper had a transmittance of more than 90% at 550 nm. The water contact angle of the paper reached about 110°. This work provided a new approach for the fabrication of hydrophobic transparent paper with conventional cellulose fiber paper.