Photocatalytic immobilization of P-25 nanoparticles on low density polyethylene films. UV-A photo-induced hydrophilicity and photocatalytic activity

JULIAN RENGIFO; JOHN JAIRO ALVEAR; LUIS PIZZIO; DANIEL PAIS OSPINA; DIEGO MARIN SILVA; PAULA OSORIO-VARGAS; ADRIANA PINOTTI

Puerto Vallarta

Congreso; XXVII Congreso Iberoamericano de Catálisis; 2020

Immobilization of TiO2-P-25 nanoparticles onto low density polyethylene films (LDPE) was successfully achieved through a simple photocatalytic procedure leading to the functionalization of polymer surface by photo-induced ?OH radicals forming -C=O and -COOH species. A systematic study to find the optimal conditions of irradiation time, pH and P25 amounts was performed by using a response surface methodology (RSM) of type central composite experimental design (DCC) - 23 in 3 blocks. It was found that circumneutral pH (5.0), low amounts of P-25 nanoparticles (0.4 g L-1) and irradiation times of 5h (LDPE-P25-5 films) may be the best immobilization conditions. This was confirmed by SEM-EDS micrographs. LDPE-P25-5 films exhibited the best photocatalytic activity removing malachite green from water and it was also observed an interesting UV-A photo-induced hydrophilicity since angle contact dropped from 118 to 7° after 60 min of irradiation. These findings suggest that this simple photocatalytic procedure may allow the preparation of TiO2-polymeric films with interesting properties to be applied as photoinduced self-cleaning and antimicrobial surfaces.