Synthesis of Hierarchical CF@Fe3O4 Fibers Decorated with MoS2 Layers Forming Core-Sheath Microstructure toward Tunable and Efficient Electromagnetic Wave Absorption.

Hierarchical structural design has been verified as a feasible strategy to fabricate effective electromagnetic wave (EMW) absorbers, so we designed hierarchical core-sheath composites with magnetic particles and dielectric layers. In this work, a hierarchical structure of carbon fiber (CF)@Fe3O4@MoS2 (CPDF7-M) was prepared by introducing Fe3O4 and depositing MoS2 layers on the surface of fibers. Due to the synergistic effects from the CF@Fe3O4 increasing the conductive and magnetic loss and the outer MoS2 layers improving the impedance matching, the optimal reflection loss (RL) value was -63.1 dB at 2.7 mm and the effective absorption bandwidth (EAB) was 9.1 GHz covering the X and Ku band. Moreover, the EAB values were adjusted with a specific MoS2 loading at different thicknesses, which provided the necessary reference for the construction of efficient and flexible absorbers in the EMW absorption fields.

Core@Double-Shell Engineering of Zn Particles toward Elevated Dielectric Properties: Multiple Polarization Mechanisms in Zn@Znch@PS/PVDF Composites.

Flexible dielectrics with large dielectric constant (ε') coupled with low loss are highly pursued in many applications. To bolster the ε' of raw Zn (zinc)/poly(vinylidene fluoride, PVDF) while maintaining pimping dielectric loss, in this study, the core@double-shell structured Zn@zinc carbonate (ZnCH)@polystyrene (PS) particles are first synthesized through a suspension polymerization of styrene, and then composited with PVDF to elevate the ε' and keep low loss of the composites. By optimizing the PS shells' thickness and tailoring the electrical resistivity of Zn@ZnCH@PS particles, both the slow inter-particle polarization and fast intra-particle polarization in the composites can be decoupled and synergistically tuned, thus, the Zn@ZnCH@PS/PVDF achieves a much higher ε' and lower dielectric loss, simultaneously, which far exceed the unmodified Zn/PVDF. Both experiment and theoretic calculation reveal that the double-shell ZnCH@PS not only induces and promotes multiple polarizations enhancing the composites' ε', especially at the optimized PS's thickness, but also maintains suppressed loss and conductivity thanks to their obvious barrier effect on long-range charge migration. The core@double-shell filler design strategy facilitates the development of polymer composites with desirable dielectric properties for applications in electronic and electrical power systems.

Enhanced thermal transportation across an electrostatic self-assembly of black phosphorene and boron nitride nanosheets in flexible composite films.

For effective heat dissipation in portable electronics, there is a great demand for lightweight and flexible films with superior thermal transport properties. Despite extensive efforts, enhancing the intrinsic low thermal conductivity of polymers while simultaneously maintaining their flexibility is difficult to achieve due to the dilemma of quarrying appropriate filler loading. Herein, a cellulose nanofiber-based film with high in-plane thermal conductivity up to 72.53 W m-1 K-1 was obtained by harnessing the advantage of functionalized boron nitride nanosheets (f-BNNS) and black phosphorene (BP) via the vacuum filtration process. Besides, our unique design based on the electrostatic coupling of black phosphorene and functionalized boron nitride nanosheets significantly reduced the interfacial thermal resistance of the composite films. This work offers new insights into establishing a facile, yet efficient approach to preparing high thermal conductive heat spreaders.

Synthesis of ficin-protected AuNCs in a droplet-based microreactor for sensing serum ferric ions.

A droplet-based microfluidic synthesis approach for preparation of ficin capped gold nano clusters (AuNCs) was developed. Well dispersed AuNCs could be procured within 8 min. Upon excitation wavelength at 340 nm, the resultant AuNCs exhibited a strong blue fluorescence with the maximum emission at 450 nm. Due to the aggregation-induced "turn-off" fluorescence mechanism, the synthesized AuNCs as a fluorescent probe displayed high sensitivity and good selectivity for sensing ferric ions. The relative fluorescence intensity versus ferric ions concentration yielded a good linear calibration in the range of 10.0-1000.0 µM (R2 = 0.998) and the limit of detection was 4.1 µM. Moreover, the possible mechanism for abated fluorescence intensity of AuNCs by adding ferric ions was discussed briefly. Further, the as-prepared fluorescent AuNCs was successfully applied for the detection of serum ferric ions. The results indicated that the droplet-based microfluidic synthesis system could provide a new way for the rapid preparation of AuNCs with good polydispersity and have potential as the sensing probes for the analysis of ferric ions in real biological samples.

Non-enzymatic detection of serum glucose using a fluorescent nanopolymer probe.

A fluorescent probe is described for the determination of serum glucose after hepatotoxin-induced liver injury. The probe is based on the use of a water-soluble polymer and has been prepared from a multi-functional azlactone polymer as the linker, amino boronic acid, and Alizarin Red as the signalling moiety. The excitation/emission peaks of the polymeric fluorescent probe are at 468/567 nm. Fluorescence is reduced on addition of glucose. Intensity drops linearly in the 0.1 mM to 14 mM glucose concentration range. The probe was applied to non-enzymatic detection of glucose in rat serum after CCl4-induced liver damage. Graphical abstract A polymer based fluorescent probe has been constructed and applied for non-enzymatic monitoring of serum glucose following hepatotoxin induced liver injury.