Zhi-Long Yu

Scalable Template Synthesis of Resorcinol–Formaldehyde/Graphene Oxide Composite Aerogels with Tunable Densities and Mechanical Properties

Resorcinol-formaldehyde (RF) and graphene oxide (GO) aerogels have found a variety of applications owing to their excellent properties and remarkable flexibility. However, the macroscopic and controllable synthesis of their composite gels is still a great challenge. By using GO sheets as template skeletons and metal ions (Co(2+), Ni(2+), or Ca(2+)) as catalysts and linkers, the first low-temperature scalable strategy for the synthesis of a new kind of RF-GO composite gel with tunable densities and mechanical properties was developed. The aerogels can tolerate a strain as high as 80% and quickly recover their original morphology after the compression has been released. Owing to their high compressibility, the gels might find applications in various areas, for example, as adsorbents for the removal of dye pollutants and in oil-spill cleanup.

Polymerization under Hypersaline Conditions: A Robust Route to Phenolic Polymer‐Derived Carbon Aerogels

Polymer-derived carbon aerogels can be obtained by direct polymerization of monomers under hypersaline conditions using inorganic salts. This allows for significantly increased mechanical robustness and avoiding special drying processes. This concept was realized by conducting the polymerization of phenol-formaldehyde (PF) in the presence of ZnCl2 salt. Afterwards, the simultaneous carbonization and foaming process conveniently converts the PF monolith into a foam-like carbon aerogel. ZnCl2 plays a key role, serving as dehydration agent, foaming agent, and porogen. The carbon aerogels thus obtained are of very low density (25 mg cm-3 ), high specific surface area (1340 m2  g-1 ), and have a large micro- and mesopore volume (0.75 cm3  g-1 ). The carbon aerogels show very promising potential in the separation/extraction of organic pollutants and for energy storage.

Selective Detection of Ferric Ions by Blue-Green Photoluminescent Nitrogen-Doped Phenol Formaldehyde Resin Polymer

The smaller, the more fluorescent: The hydrothermal reaction of phenol with hexamethylenetetramine (HMT) leads to two morphologies of phenol formaldehyde resin (PFR), namely, bigger nanoparticles with feeble green fluorescence and smaller amorphous polymers with strong blue-green fluorescence. It reveals that both of them are doped with nitrogen, and the blue-green photoluminescent polymer is confirmed to sense ferric ion (Fe(3+) ) with high selectivity.

Large-Scale Syntheses of Zinc Sulfide⋅(Diethylenetriamine)0.5 Hybrids as Precursors for Sulfur Nanocomposite Cathodes

Nanostructured metal sulfide-amine hybrid materials have attracted attention because of their unique properties and versatility as precursors for functional inorganic nanomaterials. However, large-scale synthesis of metal sulfide-amine hybrid nanomaterials is limited by hydrothermal and solvothermal preparative reaction conditions; consequently, incorporation of such materials into functional nanomaterials is hindered. An amine molecule-assisted refluxing method was used to synthesize highly uniform zinc sulfide⋅(diethylenetriamine)0.5 (ZnS⋅(DETA)0.5 ) hybrid nanosheets and nanobelts in a large scale. The obtained ZnS⋅(DETA)0.5 hybrid nanomaterials can be used as efficient precursors to fabricate functional ZnS nanomaterials and carbon encapsulated sulfur (S@C) nanocomposite cathodes for Li-S batteries.

Highly Stimuli-Responsive Au Nanorods/Poly(N-isopropylacrylamide) (PNIPAM) Composite Hydrogel for Smart Switch

To achieve both fast response and structural integrity during the repeating volume changes are the most significant challenges for thermoresponsive hydrogels. In this work, AuNRs/PNIPAM composite hydrogel with fast thermal/optical response and structural integrity is facilely prepared by electrospinning and following a curing treatment. By combining the photothermal property of AuNRs and thermal-responsive effect of PNIPAM, the composite hydrogel shows fast thermal/photoresponse, high heating rate, and high structural integrity with fierce size change. When laser irradiation begins, the temperature of the film increases from room temperature to 34.5 °C in 1 s and will further increase even to 60 °C in 5 s. Both the porous structure of the hydrogel and the assemble effect of AuNRs within the PNIPAM fibers facilitate the fast responsibility. Furthermore, to take advantage of this fibrous hydrogel adequately, one novel kind of thermal/photocontrolled switch based on the composite hydrogel is prepared, which exhibits fast responsivity and high stability even under acidic or basic conditions.

SiOx Encapsulated in Graphene Bubble Film: An Ultrastable Li‐Ion Battery Anode

SiOx is proposed as one of the most promising anodes for Li-ion batteries (LIBs) for its advantageous capacity and stable Li uptake/release electrochemistry, yet its practical application is still a big challenge. Here encapsulation of SiOx nanoparticles into conductive graphene bubble film via a facile and scalable self-assembly in solution is shown. The SiOx nanoparticles are closely wrapped in multilayered graphene to reconstruct a flake-graphite-like macrostructure, which promises uniform and agglomeration-free distribution of SiOx in the carbon while ensures a high mechanical strength and a high tap density of the composite. The composites present unprecedented cycling stability and excellent rate capabilities upon Li storage, rendering an opportunity for its anode use in the next-generation high-energy LIBs.

Bioinspired polymeric woods

Bioinspired polymeric woods with excellent overall performance can be fabricated by a self-assembly and curing process of resins. Woods provide bioinspiration for engineering materials due to their superior mechanical performance. We demonstrate a novel strategy for large-scale fabrication of a family of bioinspired polymeric woods with similar polyphenol matrix materials, wood-like cellular microstructures, and outstanding comprehensive performance by a self-assembly and thermocuring process of traditional resins. In contrast to natural woods, polymeric woods demonstrate comparable mechanical properties (a compressive yield strength of up to 45 MPa), preferable corrosion resistance to acid with no decrease in mechanical properties, and much better thermal insulation (as low as ~21 mW m−1 K−1) and fire retardancy. These bioinspired polymeric woods even stand out from other engineering materials such as cellular ceramic materials and aerogel-like materials in terms of specific strength and thermal insulation properties. The present strategy provides a new possibility for mass production of a series of high-performance biomimetic engineering materials with hierarchical cellular microstructures and remarkable multifunctionality.

Hierarchically structured Co3O4@carbon porous fibers derived from electrospun ZIF-67/PAN nanofibers as anodes for lithium ion batteries

Continuous porous carbon fibers with uniformly distributed Co3O4 hollow nanoparticles (NPs) have been prepared by direct electrospinning of ZIF-67 NPs followed by a thermal treatment. Benefiting from the unique structural and compositional advantages, ES-CNCo3O4 with hierarchical porous structure shows excellent electrochemical performance as an anode material for lithium ion batteries.