Transparent cellulose/polyhedral oligomeric silsesquioxane nanocomposites with enhanced UV-shielding properties

• The dispersion of eight kinds of POSS derivatives in ionic liquid is probed.
• Transparent cellulose/POSS-AN nanocomposites are prepared.
• POSS-AN nanoparticles are uniformly dispersed in cellulose at nanoscale.
• The nanocomposites exhibit excellent anti-UV aging and UV shielding properties.

The solubility of eight types of polyhedral oligomeric silsesquioxane (POSS) derivatives in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) and the dispersion of POSS in cellulose matrix were examined. Only a special POSS containing both aminophenyl and nitrophenyl groups (POSS-AN, NH2:NO2 = 2:6) was selected to prepare nanocomposites, because of its good solubility in AmimCl and high stability during the preparation process. POSS-AN nanoparticles were uniformly dispersed in a cellulose matrix with a size of 30–40 nm, and so the resultant cellulose/POSS-AN nanocomposite films were transparent. The mechanical properties of the films achieved a maximum tensile strength of 190 MPa after addition of 2 wt% POSS-AN. Interestingly, all of the cellulose/POSS-AN films exhibited high UV-absorbing capability. For the 15 wt% cellulose/POSS-AN film, the transmittance of UVA (315–400 nm) and UVB (280–315 nm) was only 9.1% and nearly 0, respectively. The UV aging and shielding experiments showed that the transparent cellulose/POSS-AN nanocomposite films possessed anti-UV aging and UV shielding properties.