Luminescent Solar Concentrators Based on Renewable Polyester Matrices

Abstract

This study reports for the first time the use of bio‐based alternatives for PMMA as host matrix for luminescent solar concentrators (LSCs). Notably, two types of renewable polyesters were synthesized in varying molar ratios via a two‐step melt‐polycondensation reaction with dibutyl tin oxide as catalyst. The first is a homopolymer of diethyl 2,3:4,5‐di‐O‐methylene galactarate (GxMe) and isosorbide (IGPn), and the second is a random copolymer of GxMe with 1,3‐propanediol and dimethyl terephthalate (GTPn). The two polyesters were found to be optically transparent, totally amorphous with a Tg higher than 45 °C and temperature resistance comparable to PMMA. Lumogen Red (LR) and an aggregation‐induced emission (AIE) fluorophore, TPETPAFN, were utilized as fluorophores and the derived thin polymer films (25 μm) were found highly homogeneous, especially for those prepared from GTPn, possibly due to the presence of compatibilizing terephthalate units in the matrix composition and the higher molecular weight. The spectroscopic characterization and the optical efficiency determination (ηopt) evidenced LSCs performances similar or superior to those collected from LR/PMMA thin films. Noteworthy, ηopt of 7.7 % and 7.1 % were recorded for the GTPn‐based matrix containing LR and TPETPAFN, respectively, thus definitely supporting the bio‐based polyesters as renewable and highly fluorophore‐compatible matrices for high‐performance LSCs.

Host Matrix Materials for Luminescent Solar Concentrators: Recent Achievements and Forthcoming Challenges

“…Very recently (Geervliet et al, 2018), two different types of renewable polyesters obtained via a catalyzed two-step melt-polycondensation reaction (a homopolymer of diethyl 2,3:4,5-di-O-methylene galactarate (GxMe) and isosorbide and a random copolymer of GxMe with 1,3-propanediol and dimethyl terephthalate) were proposed as host matrix materials in thin film LSCs. The spectroscopic characterization and the η opt of resulting LSCs (embedding LR305 or an aggregation-induced emission molecule as guest luminophores) evidenced a performance similar or superior to that of reference LSC thin films based on PMMA/LR305, thus further indicating the potential of bio-based polymers as valuable renewable matrices for highperformance LSCs.…”

Mechanochromic Fluorescent Polymers with Aggregation-Induced Emission Features

“…Moreover the presence of a twisted propeller-shaped conformation renders intermolecular π-π interactions difficult in the aggregate state. Noteworthy, by allowing light emission in the aggregate and solid state, AIE fluorophores (AIEgens) show a striking impact on energy, optoelectronics, life science and the environment [16,17,18,19,20,21,22,23,24,25,26]. Fluorescent sensors based on the AIE mechanism take advantages from the ordinary fluorescent sensors, thanks to the very brilliant emission in the solid state that allows for the development of an efficient ON-OFF, and more interestingly, an OFF-ON optical response towards several interferences [27,28].…”

Tunable Aggregation‐Induced Emission of Imidazole Hydrazones by pH and Anions

“…This is driven by intramolecular hydrogen bonding between the hydrazone NH, CH, naphthyl CH and the Br − anion. The intramolecular hydrogen bonding between hydrazone proton and the Cl − or Br − anions acts as the guiding factor for their planar E ‐configuration, which leads to restricted intramolecular motions (RIM)‐induced AIE …”

“…The intramolecular hydrogen bondingb etween hydrazone proton and the Cl À or Br À anions acts as the guiding factor for their planar E-configuration, which leads to restricted intramolecular motions( RIM)-induced AIE. [27][28][29][30][31] To evaluate the solvent effect on the emission, the fluorescence emissions of 4 in different ratios of water/methanol solution wered etermined. The emission of 4 was almost quenched in am ethanol/water mixture containing 50 %w ater.W hen the water ratio increased to over 61 %, the emission intensity increased drastically and the emission wavelength redshifted from 438 to 443 nm (Figure 6a), although it is still 66 nm shorter compared to that in the solids tate (509 nm).…”