New HYPOSENS article in Israel Journal of Chemistry, a compilation of invited papers by top chemists from around the world on a single topic of current interest.
We demonstrate that the efficiency under ambient conditions of optically active molecules encapsulated in polymer nanocapsules can be significantly improved by depositing an inorganic layer onto the polymeric shell. A triplet‐triplet annihilation upconversion (TTA‐UC) system consisting of a porphyrin derivative and perylene is used as a representative case. Different inorganic materials are deposited on the surface of functionalized polymer nanocapsules synthesized by free‐radical polymerization in miniemulsion. First, a silicate clay with formula [Si8(Mg5.45Li0.4)O20(OH)4]Na0.7 is deposited on the surface of positively charged polystyrene nanocapsules via layer‐by‐layer deposition. Second, controlled in situ mineralization of hydroxyapatite and cerium(IV) oxide are carried out on the surface of negatively charged polystyrene nanocapsules. In both cases the inorganic materials on the nanocapsule surface act as a scavenger and avoid the entry of oxygen from the external environment. By avoiding the entry of oxygen, the photo‐oxidation process of perylene molecules is avoided within the system, and an increase in the TTA‐UC properties occurs.
First published: 28 December 2018
Israel Journal of Chemistry Volume58, Issue12 | Special Issue: Functional Polymeric Particles | Pages 1356-1362