Please wait.'

Page is loading'


Home  > Raw materials & technologies  > Applications  > Nanocomposites as efficient UV-shielding c...

Saturday, 21 September 2019
pdf
Raw materials & technologies, Applications

Nanocomposites as efficient UV-shielding coatings for packaging applications

Wednesday, 14 October 2015

Spanish researchers developed poly(l-lactide) (PLLA)/ZnO nanocomposites as efficient UV-shielding coatings for packaging applications.

ZnO has been selected as the most suitable UV-shielding material. Source: Stephanie Hofschlaeger/pixelio.de

ZnO has been selected as the most suitable UV-shielding material. Source: Stephanie Hofschlaeger/pixelio.de

ZnO has been selected as the most suitable UV-shielding material over 10 different metallic nanoparticles.

Nucleating effect of ZnO

Results reveal a nucleating effect of ZnO in which PLLA crystallisation half time is reduced from 7.4 to 4.7 min with only 0.05 wt % ZnO. UV–vis spectroscopy confirms the UV-shielding effect in PLLA/ZnO nanocomposites, where the ultraviolet spectrum is blocked by 61.2% for a concentration as low as 0.45 vol %, while the 95.9% of the visible radiation passes through the material. A schematic representation explaining obtained UV-shielding effect is constructed based on the photon mean free path reduction as ZnO concentration increases. Water contact angle increased from 81° up to 91° for the 5 wt % nanocomposite, which would result beneficial in view to develop materials for packaging applications. Dynamic mechanical analysis exhibits a Tg increase with nanoparticle loading arising from the chain confinement caused by the presence of ZnO interacting surfaces.

The study is published in: Journal of Applied Polymer Science, Special Issue: Bio-based Packaging, Volume 133, Issue 2, January 10, 2016

top of page
Comments (0)
Add Comment

Post comment

You are not logged in

register