Abstract
This study was aimed to prepare material with high porosity and photocatalytic activity by immobilization of TiO2 nanoparticles (NPs) onto poly(lactic acid) (PLA) aerogels. PLA aerogels were prepared in three steps: (1) dissolution of polymer in chloroform at 22 °C, (2) chloroform replacement with ethanol, and (3) supercritical CO2-drying at pressure 19 MPa and temperature 39 ºC. Immobilization of TiO2 NPs was performed by in situ and ex situ methods. Obtained samples were characterized using SEM, EDX, and FTIR analysis. Photocatalytic activity of developed material was tested by following decolorization of dye C.I. Acid Orange 7 in water solution. It was shown that the morphology of PLA aerogels was slightly affected by TiO2 NPs immobilization. PLA aerogels with TiO2 NPs immobilized by ex situ method sustained floatability during test period and provided a complete decolorization of dye solution after 330 minutes of illumination. High photocatalytic activity of the sample was preserved within three repeated cycles of dye decolorization.
Highlights
In the last years, poly(lactic acid) (PLA) gained significant attention as a biodegradable and biocompatible material, produced from renewable resources, which could be used in medicine and food packaging industry [1, 2]
We showed that the scCO2drying method enabled preparation of porous material and that the method of TiO2 NPs immobilization determines material photocatalytic activity
PLA beads were transformed into disc shape alcogels (Figure 1a), which were dried using supercritical CO2 (scCO2) at 19 MPa and 39°C enabling preparation of disc-shape aerogels (Figure 1b)
Summary
Poly(lactic acid) (PLA) gained significant attention as a biodegradable and biocompatible material, produced from renewable resources, which could be used in medicine and food packaging industry [1, 2]. This study tested functionalization of PLA aerogels by immobilization of TiO2 nanoparticles (NPs) for application in treatment of colored wastewaters. PLA aerogels were prepared in three steps: (1) dissolution of PLA in appropriate solvent, (2) so-. Lvent replacement with ethanol, and (3) supercritical CO2 (scCO2) drying. These steps allow formation of highly porous polymer materials [13, 14]. ScCO2 is the most appropriate medium for polymer gel drying and aerogel preparation since it has mild critical conditions, liquid like density, gas like diffusivity, GRAS status (Generally Recognized as Safe), and near zero surface tension [13]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call