Volume 10 Issue 1, January 2018

β-ketoenamine-linked covalent organic frameworks and their post-synthetic modification is performed in a continuous-flow of microdroplets in a serial manner.

A N-doped carbon nanotube catalyst containing a high concentration of single Fe atoms was prepared by a simple and scalable atomic isolation method, in which a metal isolation agent was introduced to isolate single Fe atoms and was then evaporated to produce abundant micropores that host single Fe atom active sites. As a result, the catalysts obtained showed excellent ORR performance, even better than that of commercial Pt/C catalysts in an acidic medium.

Superelastic alloys suitable for low-temperature environments are crucially lacking. Here, we report an excellent superelastic (rubber-like) strain of more than 7% at 4.2 K using a Cu–Al–Mn shape-memory alloy. This alloy also possesses a small stress hysteresis of less than 30 MPa down to 4.2 K, resulting in particularly persistent elastocaloric cooling ability in the low-temperature region. The present Cu–Al–Mn alloy will have significant engineering impact, especially in the fields of aerospace engineering, superconducting technologies, and liquefied-gas-storage technologies, as a new class of materials combining superelastic properties and persistent elastocaloric cooling properties even at cryogenic environments.

Chiral magnetic domain-wall (DW) speed variation is investigated. We demonstrate that the symmetric contribution in the DW speed attributes to the chiral DW energy density. Next, by deducing this symmetric contribution, the additional asymmetry was extracted. The extracted additional asymmetry exhibits truly antisymmetric nature and is governed by DW chirality. Moreover, this antisymmetry (additional asymmetry) changes overall DW speed more than a factor of 100 to the extent of dominating the symmetric contribution. These findings not only provide the artifact-free Dyzaloshinskii–Moriya interaction measurement scheme, but also contribute to the investigation of the origin of the additional asymmetry.

Spontaneous nematodynamic standing waves in liquid crystal medium is demonstrated. The standing wave manipulates the molecular orientation to form tunable periodic defect arrays with concentric director profiles, which can serve as optical vortex array inducer or as tunable micro-liquid crystal lens array. In addition, the standing waves hold unique features such as diagonal nodal lines, self-adaption to broad resonance frequencies, and a step-like increase of wavelength with increasing frequency. It also exerts asymmetric mechanical pressure that can relocate small particles. The results lead to new approaches in director manipulation, colloidal assembly, and singular optics.

High mechanical strength hydrogel material was fabricated from egg white proteins. Egg white proteins were condensed at a regular interval with ionic surfactants and gelled by heating. The maximum compressive fracture strength was 34.5 MPa, which is 150-fold higher than that of boiled egg white. The high strength is due to the synergic effects of both covalent and non-covalent networks.

Herein, an idea of creating MoS₂/GO nanocomposites was brought about, which were constructed to integrate the merits for both materials with additional benefits and shield the mutual weaknesses. It turned out that MoS₂/GO nanocomposites manifested beneficial multi-functionalities including favorable lung targeting, enhanced drug loading capacity, increased tumor killing efficacy and improved biosafety as well. This study would open a new path that may lead to desirable use of MoS₂/GO nanocomposites in cancer therapeutics.

Gyroid-structured Au periodic metallic materials were fabricated by an electroless deposition method. By controlling the deposition time, we successfully acquired 3D-distributed hotspots of high density. The as-required plasmonic substrates demonstrate ultra-high SPR enhancement (~10⁹) with superior reproducibility and uniformity. Combined with FDTD simulations, we revealed that the ultrahigh enhancement is originated from the interconnected helices, which not only increase the density of the hotspots but also increase the scattering cross-section of the incidence light. The mechanism deduced here will provide insight into the future design and selection of novel surface plasmonic resonance (SPR) substrates, as many other bicontinuous interconnected systems are available.

A simple and robust single-step in situ synthesis of carbon dots (C-dots) within a porous silicon oxide (PSiO₂) matrix is reported. The resulting new hybrid guest–host material exhibits promising capabilities as a label-free dual-mode optical biosensor via modulation of both the optical reflectance associated with the PSiO₂ matrix, as well as the C-dots’ fluorescence, and these two signals can be observed and collected simultaneously. The resulting sensing platform exhibits enhanced sensitivity, improved linear response, as well as a wider dynamic range in comparison to its single components.