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Upconverting luminescent poly(methylmethacrylate)(PMMA)/poly(urethane)(PU) interpenetrating polymer network (IPN) nanohybrids were prepared using a sequential polymerisation incorporating different wt.% of cerium phosphate (CePO 4) nanoparticles. The effect of miscibility/compatibility of the different PMMA/PU ratios, the addition and dispersion of rod and semi-spherical nanostructures in as well as the performance of selected IPNs under accelerated aging were studied using morphological, emission, thermal and mechanical studies. Structural studies revealed that there were physical interactions between C=O groups and CePO 4 in PMMA/PU IPNs. The addition of a higher wt.% of nanostructures was found to decrease the transparency of the IPNs. Resulting PMMA/PU/CePO 4 IPN nanohybrids are photoluminescent under UV-light, supporting the prolongate of lifetime while maintaining the mechanical properties after being subjected to accelerated weathering. The addition of semi-spherical particles resulted in a more stable materials after accelerated weathering than nanorods.

Microalgae, including cyanobacteria, represent a valuable source of natural compounds that have remarkable bioactive properties. Each microalga species produces a mixture of antioxidants with different amounts of each compound. Three aspects are important in the production of bioactive compounds: the microalga species, the medium composition including light supplied and the photobioreactor design, and operation characteristics. In this study, the antioxidant content and productivity performance of four microalgae were assessed in batch and continuous cultures. Biomass productivity by the four microalgae was substantially enhanced under continuous cultivation by 5.9 to 6.3 times in comparison with batch cultures. The energetic yield, under the experimental conditions studied, ranged from 0.03 to 0.041 g biomass kJ−1. Phenols, terpenoids, and alkaloids were produced by Spirulinaplatensis, Isochrysisgalbana, and Tetraselmissuecica, whereas tocopherols and carotenoids were produced by the four microalgae, except for phycocyanin and allophycocyanin, which were only produced by S. platensis and Porphyridiumcruentum. The findings demonstrate that the continuous cultivation of microalgae in photobioreactors is a convenient method of efficiently producing antioxidants.