Absorber materials based on polymer nanocomposites containing silver nanoparticles for solar thermal collectors

VALLO, CLAUDIA I.; ASMUSSEN, SILVANA V.

SOLAR ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2018 vol. 174 p. 640 - 647

0038-092X

This study describes the synthesis and characterization of polymer-based nanocomposites to fabricate absorbermaterials for solar thermal collectors. Heat generation by nanosized silver particles (NSP) under irradiation withlight of appropriate wavelength is exploited for an efficient harvesting of solar energy. NSP were synthesized byreduction of silver nitrate (AgNO3) in a methacrylate resin. The photothermal conversion of solar energy intoheat is optimized by increasing the overlap between the plasmonic band of the NSP and the spectral emission ofthe sun. Thus, the synthesis conditions were adjusted in order to broaden the plasmon absorption band of theresultant NSP. The UV?vis spectra of suspensions containing 300 ppm NSP exhibited a broad absorption band inthe range between 360 and 1100 nm with three absorption peaks at 335, 440, and 700 nm. These absorptionbands are associated to the presence of triangular NSP, which was confirmed by TEM microscopy. The resinscontaining NSP were activated with benzoyl peroxide and polymerized after 20 min at 80 °C. The photothermalconversion effect of the nanocomposites was assessed by monitoring the temperature increase with fine thermocouplesembedded in 2-mm thick specimens during irradiation with light of different wavelength. Thetemperature reached during irradiation of nanocomposites showing a very broad absorption band was 115 °Cwhile that of the nanocomposites exhibiting a single peak was 102 °C.