Ditelluride bonds have been reported as dynamic covalent bonds which could undergo reversible formation and cleavage at room-temperature. In this work, a novel self-healing ditelluride-containing polyurethane was synthesized by incorporating ditelluride bond into its main chain. Base on the dynamic nature of ditelluride bonds, this polyurethane could self-heal in darkness at room temperature without external intervention. The study on the exchange mechanism revealed that the reversible exchange of ditelluride bonds and the intermolecular hydrogen bonding were the two main factors that responsible for the self-healing behavior of this polyurethane. The ditelluride content and chain mobility of the polymer have a significant effect on its self-healing property. The unique non-intervention self-healing properties and wild applicability makes this polymers ideal for environment friendly smart systems.
By the fine manipulation of the exceptional long-range germanium-telluride (Ge─Te) bonding through charge transfer engineering, we have achieved exceptional thermoelectric (TE) and mechanical properties in lead-free GeTe. This chemical bonding mechanism along with a semiordered zigzag nanostructure generates a notable increase of the average zT to a record value of ~1.73 in the temperature range of 323 to 773 K with ultrahigh maximum zT ~ 2.7. In addition, we significantly enhanced the Vickers microhardness numbers (Hv) to an extraordinarily high value of 247 Hv and effectively eliminated the thermal expansion fluctuation at the phase transition, which was problematic for application, by the present charge transfer engineering process and concomitant formation of microstructures. We further fabricated a single-leg TE generator and obtained a conversion efficiency of ~13.4% at the temperature difference of 463 K on a commercial instrument, which is located at the pinnacle of TE conversion.
Polymer micelles have attracted much attention in the field of controlled drug release because of their excellent hydrophobic drug solubility and fewer drug side effects. However, insufficient sensitivity, insufficient dilution resistance, and ordinary therapeutic effect severely restrict the further development of current drug-loaded polymer micelles. Here, the ditelluride group was introduced for the first time into fluorinated Gemini amphiphilic polymer (FnH12DiTeFnH12) to fabricate polymeric micelles used for controlled release. Camptothecin (CPT) loaded in the FnH12DiTeFnH12 micelles can be rapidly released in a controlled manner through the cleavage of ditelluride bonds by mild H 2 O 2 and glutathione. Meanwhile, the synergism effect of the superhydrophobicity of the fluorocarbon chain and the special Gemini structure endows the drug-loaded polymer micelles with excellent stability and drug-loading content. Moreover, the in vitro studies revealed that the CPT@FnH12DiTeFnH12 micelles exhibited efficient uptake in Hela cells. Notably, about five times lower dosage of loaded CPT had a higher tumor cells growth inhibition than the free CPT, and cell membrane permeability became better with the increase of the fluorocarbon chain length. The CPT@FnH12DiTeFnH12 micelles exhibit excellent physical and chemical properties and good therapeutic effects, indicating their excellent potential for drug delivery and providing a novel avenue for chemotherapy.
危险品化学品经营许可证（带存储）