Three-dimensional (3D) LiFePO 4 @MWCNTs composite has been prepared using phytic acid as the phosphorus source by a simple solvothermal method combined with freeze drying under vacuum. The relationships between the phase structures, the morphologies and electrochemical performance characteristics of the as-prepared samples are studied using a series of characterization methods. It is found that the MWCNTs wrap around the LiFePO 4 particles to form a 3D network because of the reactions between the special functional groups of the phytic acid with Fe 2+ and –C O or –COOH on the surface of the functionalized MWCNTs, resulting in the improvement of conductivity and the electron and ion transport. Due to these merits of MWCNTs and phytic acid, the LiFePO 4 @MWCNTs exhibits good electrochemical performance with high initial discharge capacities of 152.7, 149.6 and 138.8 mAh g −1 at 1, 2 and 5C, respectively. Even at 10C, it still delivers a capacity of 117.5 mAh g −1 .
With an ultrahigh aspect ratio and a similar chemical composition to the biomineral in bone and tooth, ultralong hydroxyapatite nanowires (UHAPNWs) exhibit a meritorious combination of high flexibility, excellent mechanical performance, high biocompatibility, and bioactivity. Despite these exciting merits, the rapid and green synthesis of UHAPNWs remains challenging. In this work, we have developed an environment-friendly, rapid, and highly efficient synthesis of ultrathin UHAPNWs by the microwave-assisted calcium oleate precursor hydrothermal method using biogenic creatine phosphate as the bio-phosphorus source. Owing to the controllable hydrolysis of bio-phosphorus-containing creatine phosphate and the highly efficient heating of microwave irradiation, ultrathin UHAPNWs with a homogeneous morphology of several nanometers in diameter (single nanowire), several hundred micrometers in length, and ultrahigh aspect ratios (>10,000) can be rapidly synthesized within 60 min. This effectively shortens the synthesis time by about two orders of magnitude compared with the traditional hydrothermal method. Furthermore, ultrathin UHAPNWs are decorated in situ with bioactive creatine and self-assembled into nanowire bundles along their longitudinal direction at the nanoscale. In addition, ultrathin UHAPNWs exhibit a relatively high specific surface area of 84.30 m2g–1and high ibuprofen drug loading capacity. The flexible bio-paper constructed from interwoven ibuprofen-loaded ultrathin UHAPNWs can sustainably deliver ibuprofen in phosphate-buffered saline, which is promising for various biomedical applications such as tissue regeneration with anti-inflammatory and analgesic functions.
Owing to the high interface thermal resistance and aggregation in polymer-based materials, the thermal conductivity of multi-walled carbon nanotubes (MWCNTs) has been severely decreased in practical applications. In this work, an amino-functionalized black phosphorene (BP–NH 2 ) fabricated by ball milling has been employed to react with carboxylated multi-wall carbon nanotubes (MWCNTs–COOH) via covalent bonds to prepare a nanofiller (BP–MWCNTs) with high thermal conductivity and excellent flame retardancy. When incorporating 20.0 wt% BP–MWCNTs into cellulose nanofiber (CNF), the CNF/BP–MWCNTs 20.0 shows an in-plane thermal conductivity of 22.38 ± 0.39 W m −1 K −1 and a cross-plane thermal conductivity of 0.36 ± 0.03 W m −1 K −1 , resulting in an anisotropy index of 62.17. The effective medium theory (EMT) calculation demonstrates the interface thermal resistance is reduced to 1/39 that of pure MWCNTs, which is ascribed to the covalent bond between BP–NH 2 and MWCNTs–COOH. Simultaneously, the CNF/BP–MWCNTs 20.0 can pass the testing of UL-94 V-0 grade and the limiting oxygen index (LOI) value can be increased from 18.1% to 29.9%. Its peak of heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), total smoke production (TSP), CO generated per second (COP) and CO 2 generated per second (CO 2 P) are decreased by 37.47%, 43.51%, 50.00%, 35.29%, 50.00% and 19.70%, respectively, which is due to the formation of an intumescent flame-retardant system rich in carbon source (MWCNTs), acid source (BP) and gas source (amino groups). This covalent linkage strategy offers a new thought for the preparation of flexible materials to enhance the thermal conductivity and fire resistance .
危险品化学品经营许可证（带存储）