The utilization of low-grade and abundant thermal sources based on thermoelectric (TE) materials is crucial for the development of a sustainable society. However, high-performance thermoelectric materials with biodegradable, mass-productive, and low-cost features are rarely reported. Here, from the perspective of sustainable development, natural polymer (bacterial cellulose, BC), and "green" solvent (ionic liquids, ILs) are combined to achieve a transparent, flexible, and robust ionogel (BCIGs) by using a facile and versatile modified co-solvent evaporation method. The proposed BCIGs with 95 wt% 1-ethyl-3-methylimidazolium dicyanamide ([EMIm][DCA]) can have high tensile strength (3.05 MPa), skin-like mechanical stretchability (40.99%), and obvious adhesivity. The BCIGs are thermally stable up to 250 °C. They also exhibit a high ionic conductivity (2.88 × 10 −2 S cm −1 ), high ionic thermovoltage (18.04 mV K −1 ), and low thermal conductivity (0.21 W m −1 K −1 ), resulting in the great ionic figure of merit (ZT i ) of 1.33 at room temperature. Through the model of mesoscopic confined ion transportation under a thermal gradient, it is attributed the great thermoelectric properties to the synergistic effect between ion-cellulose interaction and ion-ion interaction. Moreover, a flexible ionic thermoelectric capacitor (ITEC) device is also demonstrated, showing the potential of the BCIGs in wearable energy supply.

A carbene-catalyzed chemoselective reaction of unsymmetric enedials is disclosed. The reaction provides a concise access to bicyclic furo[2,3-b]pyrroles derivatives in excellent selectivity. A main challenge in this reaction is chemoselective reaction of the two aldehyde moieties in the enedial substrates. Mechanistic studies via experiments suggest that our chemoselectivity controls are mostly achieved on the reducing properties of different sited Breslow intermediates. Several side reactions processes and the corresponding side adducts are also studied by high resolution mass spectroscopy analysis. Our method allows for efficient assembly of the furo[2,3-b]pyrrole structural moieties and their analogues widely found in natural products and pharmaceuticals.

No abstract

Preparation of magnetic nanoparticles coated with chitosan (CS-coated Fe3O4 NPs) in one step by the solvothermal method in the presence of different amounts of added chitosan is reported here. The magnetic property of the obtained magnetic composite nanoparticles was confirmed by X-ray diffraction (XRD) and magnetic measurements (VSM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allowed the identification of spherical nanoparticles with about 150 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy (FTIR) demonstrated that CS-coated Fe3O4 NPs were obtained. Chitosan content in the obtained nanocomposites was estimated by thermogravimetric analysis (TGA). The adsorption properties of the CS-coated Fe3O4 NPs for bovine serum albumin (BSA) were investigated under different concentrations of BSA. Compared with naked Fe3O4 nanoparticles, the CS-coated Fe3O4 NPs showed a higher BSA adsorption capacity (96.5 mg/g) and a fast adsorption rate (45 min) in aqueous solutions. This work demonstrates that the prepared magnetic nanoparticles have promising applications in enzyme and protein immobilization.