Fuchong Li,Wei Liu,Yang Gao,Li Tian,Junhong Guo,Jinfeng Cui,Baoping Yang
Organic fluorescent materials are widely applied in different important fields, such as light-emitting display, explosive detection, molecular imprinting, and so on, because of their low cost, easy functionalization, and large-scale fabrication. In this work, we designed and synthesized a new kind of organic fluorescent polysulfate composite material through post-sulfonation sulfur-fluorine exchange polymerization (a new kind of click chemistry) by symmetric molecular. Sulfur-fluorine exchange polymerization: symmetrical structure SO2F−R1−SO2F molecular reacted with symmetrical OH−R2−OH molecular through nucleophilic reaction in the presence of inorganic base. The polysulfate material was further modified by ClSO3H to get PSE−SO3H materials. Tb3+was highly dispersed on PSE−SO3H to afford organic-inorganic hybrid fluorescent materials through the conventional coordination chemistry method. The emission wavelength of the organic-inorganic hybrid fluorescent polymer PSE−SO3H−Tb3+was between 475 and 685 nm, the quantum yield reached 1.18%, and fluorescence lifetime lasted for 730.168 us, with the pure green light emission and long light-emitting lifetime. The fluorescence film was prepared through phase transformation method by the fluorescent polymer material PSE−SO3H−Tb3+. The film has the strong stability property in different pH conditions (pH 1~13). Thus, this kind of organic fluorescent polysulfate composite material may have certain prospects application in terms of detection and luminescence in extreme chemical environments in the future.Keywords:polysulfate material;rare earth matal;Tb3+;fluorescence;polymer;symmetric molecular;stepwise polymerization
Crosslinked structure is proved to be efficient to improve breakdown strength ( E B ), thermal stability and charge-discharge efficiency ( η ) of polymer film capacitors, which is of great interest for their application in electric power systems and electrical automobile industry. However, highly crosslinked molecular networks usually lead to weak polarization ability of polymer, which greatly restrict their energy storage density ( U d ). To improve polymers’ high-field polarization ability while guaranteeing their E B and thermal stability, we propose the asymmetric molecular chain structure in crosslinked network of epoxy resin by attaching ring-like alicyclic amine (ACA) and linear polyether amine (PEA) on phenol via Mannich reaction. The film exhibits high U d up to 9.12 Jcm −3 at 550 MVm −1 and ambient temperature with 90% efficiency, which is a record high value for U d among single-layer polymer under the same condition. At 200 MVm −1 and 120 °C, a future operating condition towards electric-vehicle applications, prepared film still exhibits U d of 1 Jcm −3 with 90% efficiency, which is twice of the state-of-the-art BOPP. The results prove that the asymmetric ACA-PEA structure can greatly improve U d of crosslinked polymer film while maintaining superior energy storage efficiency at high temperature. This work paves a new way for the material design of high-performance polymer film capacitor.
Heterografted molecular brushes (HMBs) bearing two or more types of side chains have attracted tremendous attention because of their asymmetric structures and multiple functionalities. However, the controlled synthesis of HMBs with three types of side chains remains a challenge. The structure–property–application correlations of HMBs with three types of side chains are still not clear. Herein, based on the multivalent monomer strategy, we report the synthesis of well-defined asymmetric HMBs comprising three different side chains by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP), thiol–epoxy coupling reaction, and ring-opening polymerization (ROP). PA-g-PAzo/PEG/PLA with a polyacrylate (PA) backbone, hydrophobic poly(azobenzene-methacrylate) (PAzo) brush, hydrophilic polyethylene glycol (PEG) brush, and hydrophobic polylactide (PLA) brush was synthesized and characterized. The self-assembly behavior of PA-g-PAzo/PEG/PLA with a short backbone and relatively strong intermolecular association in solutions was investigated. Well-defined platelets with tunable morphologies were constructed. Subsequently, PA-g-PFA/PEG/PLA with a fluorophilic poly(pentafluoropropyl acrylate) (PFA) brush, hydrophilic PEG brush, and lipophilic PLA brush was synthesized and further used as an efficient surfactant for the stabilization of different emulsions. Our study offers a platform for exploring the unique properties of asymmetric HMBs.
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