Stage 2020

Comparative study of hybrid composites to quantify performance and possible applications

Activities

Preparation, characterization and evaluation of new hybrid coatings containing in situ generated nanoparticles

Perspectives for the application of nanocomposites in the field of specialized coatings, dental materials, photocatalysts, etc.

Results

In this stage of the project, hybrid composites containing both modified ZnO nanoparticles and Pd nanoparticles photogenerated in situ in the acrylic matrix simultaneously with the photopolymerization process were prepared. The formation of metallic nanoparticles was evaluated by specific analyzes (UV spectroscopy, TEM, energy dispersive X-ray spectroscopy (EDX) and the spatial distribution of Pd and Zn elements in the photopolymerized matrix).

The photocatalytic abilities of the hybrid coatings incorporating functionalized metal oxide nanoparticles (TiO2, ZnO) as well as noble metal nanoparticles (Ag, Au or Pd) were tested under visible light irradiation in the mineralization of various pollutants (namely phenol, Congo Red, methyl orange, metronidazole). In addition, for the systems that led to the best results, the reuse and regeneration of the hybrid coatings was experimentally tested, the encouraging results recommending their use in water purification under sunlight irradiation.

Evolution of the UV-vis absorption spectrum of an aqueous methyl orange solution by irradiation with visible light in the presence of hybrid film containing ZnO and Au nanoparticles and the photocatalytic efficiency of the film after several reusing cycles.

Hybrid polymeric coatings containing a mixture of noble metal nanoparticles (gold and silver) photogenerated in situ were used as photocatalysts in model organic reactions, namely the obtaining of aromatic amines from the corresponding nitroderivatives. Thus, the achieving of p-phenylenediamine by the reduction reaction of 4-nitroaniline was tested, as well as the obtaining of 2,6-diaminophenol and 2,4,6-triaminophenol from 2,6-dinitrophenol and picric acid, respectively, in the presence of these types of hybrid materials.

For the hybrid coatings with TiO2 or ZrO2 nanoparticles, the variation of mechanical properties after storage at pH 7 and temperature of 37 oC for a period of 30 days was monitored, together with the preliminary evaluation of the adhesion of sealing materials to the dental substrate.

Modification of the mechanical properties of composite materials containing TiO2 or ZrO2 nanoparticles after storage in water at 37 oC for 30 days.

Violeta Melinte, Lenuta Stroea, Andreea L. Chibac, Polymer Nanocomposites for Photocatalytic Applications, Catalysts 2019, 9, 986 (pag. 1-30). doi: https://doi.org/10.3390/catal9120986 (IF = 3.444).

Andreea L. Chibac-Scutaru, Viorica Podasca, Daniel Timpu, Violeta Melinte, Comparative Study on the Influence of Noble Metal Nanoparticles (Ag, Au, Pd) on the Photocatalytic Activity of ZnO NPs Embedded in Renewable Castor Oil Polymer Matrices, Materials 2020, 13, 3468 (pag 1-18). doi: https://doi.org/10.3390/ma13163468 (IF = 3.057)