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Developing easy and green strategy to prepare functional materials with outstanding properties based on naturally abundant and environmentally friendly raw materials is highly desirable for sustainable development. Herein, an easy and green strategy was reported to in situ synthesize and disperse citrate-based fluorophores (CFs) in polyvinyl alcohol (PVA) matrix. By a simple heating treatment of the mixture aqueous solution of citric acid/cysteine/PVA, CF-PVA blends were obtained in the form of homogeneous transparent films or coatings. Due to the effective UV absorption of CFs, CF-PVA film and coating exhibited full-band blocking of UV irradiation while still allowing high transmission of visible light. Protection by CF-PVA film and coating effectively reduced UV-induced rhodamine B degradation and cell death. Furthermore, the down-conversion property of CF-PVA coating enables conversion of invisible UV irradiation into visible blue light emission, and we further demonstrated the application of CF-PVA coating for fabricating emissive transparent display. Given the abundant and environmentally friendly raw materials, easy and green preparation, excellent UV-blocking, and converting properties, we believe that the CF-PVA blends are promising for applications in UV shielding, transparent display, and energy harvesting. [ABSTRACT FROM AUTHOR]

Inspired by the chromogenic reaction of itaconic anhydride and tertiary amine, fluorescent poly(amino ester) polyols are designed and synthesized by melt polycondensation of itaconic anhydride and triethanolamine. The obtained polymers contain no conventional conjugated fluorophores and still display bright fluorescence and good water solubility. The unconventional fluorescence is speculated to be due to the clusters of oxidized tertiary amines and carbonyl groups. Interestingly, the fluorescent polymers exhibit selective sensitivity to specific metal ions, which quench the fluorescence of the polymers. When various metal ions including Na+, Mg2+, Al3+, K+, Ca2+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Ba2+ and Pb2+ are added to the aqueous polymer solution, only Fe3+ ions decrease dramatically the fluorescence intensity of the polymer solution. Meanwhile, the quenched fluorescence can be recovered by adding L-cysteine. Therefore, the fluorescent polymers can be applied as new sensing platform for label-free detection of Fe3+ ions and L-cysteine. [ABSTRACT FROM AUTHOR]

In order to better understand the interrelation between liquid crystal fillers and functional polymers, a series of liquid crystalline shape memory polyurethane composites (LC-SMPUCs), named shape memory polyurethane (SMPU)-4-hexadecyloxybenzoic acid (HOBA) composites, are prepared by incorporating HOBA into SMPU based on a polyethylene glycol (PEG) soft segment. The results demonstrate that the dimerization structure of HOBA is maintained in the as-prepared SMPU-HOBA composites, facilitating liquid crystalline properties. Characterization results display smectic C phase upon heating, while the isotropic temperature shifts to a higher temperature, broadening the temperature range of the liquid crystalline phase. The SMPU-HOBA composites form a two-phase separated structure containing a SMPU phase and a HOBA phase; the incorporated HOBA can promote crystallizability of both soft and hard segments of SMPU, while crystalline hard phases are maintained within the high temperature range. Thus, SMPU-HOBA composites demonstrate a two-step modulus change upon heating that releases a triple-shape memory effect. The final shape fixing ratio is higher than 99%, and the final shape recovery ratio reaches 90%. Therefore, the SMPU-HOBA composites successfully provide a desirable combination of liquid crystalline properties and triple-shape memory properties, making them ideal candidates for smart sensor, smart labels, etc. [ABSTRACT FROM AUTHOR]