Construction of self-repairing polyethersulfone membrane with high density hydrophilic microregions by two dimensional restricted channels for enhanced dyes/salts selective separation.

Based on the dye/salts separation efficiency and membrane injury caused by serious pollution of dye/salts wastewater, this study constructed a 2D tight ultrafiltration membrane that could both solve the membrane injury problem and improve the dye/salts separation efficiency, the compatibility of good self-healing performance and penetration performance by 2D material magnesium-aluminum Layered double hydroxide (MgAl-LDH). The self-repairing of physical injury was achieved through the swelling effect of AMPS-PAN, this property was proved by permeate flux, the retention performance of salts in dye/salts solution, the comparison of scanning electron microscope (SEM), and the mechanical strength after physical injury. The healing of chemical injury occured through the reaction of CC and polyethersulfone chain breakage, which was confirmed by X-ray photoelectron spectroscopy (XPS), permeate flux, the retention performance of salts in dye/salts solution, and mechanical property. The high separation efficiency of dye/salts was achieved through 2D material MgAl-LDH, which was proved by separation selectivity ɑ. The compatibility of good self-healing performance and penetration performance was obtained by 2D material MgAl-LDH, which was proved by the penetration and self-healing performance. Morever, the membrane illustrated excellent both permeability and dye/sals separation efficiency, just like the permeate flux, the retention performance of sodium sulfate in methyl blue/sodium sulfate solution, the retention performance of Na2SO4 in methyl blue/Na2SO4 solution, the retention rate of methyl blue were 99.1 L/m2h, 12.5%, 7.9%, 97.7%, respectively. The results of pollution index and contact angle also proved that the membrane had anti-pollution performance.

Deeply Reconstructed Hierarchical Ni-Co Microwire for Flexible Ni-Zn Microbattery with Excellent Comprehensive Performance.

The rise of flexible electronics calls for efficient microbatteries (MBs) with requirements in energy/power density, stability, and flexibility simultaneously. However, the ever-reported flexible MBs only display progress around certain aspects of energy loading, reaction rate, and electrochemical stability, and it remains challenging to develop a micro-power source with excellent comprehensive performance. Herein, a reconstructed hierarchical Ni-Co alloy microwire is designed to construct flexible Ni-Zn MB. Notably, the interwoven microwires network is directly formed during the synthesis process, and can be utilized as a potential microelectrode which well avoids the toxic additives and the tedious traditional powder process, thus greatly simplifying the manufacture of MB. Meanwhile, the hierarchical alloy microwire is composed of spiny nanostructures and highly active alloy sites, which contributes to deep reconstruction (≈100 nm). Benefiting from the dense self-assembled structure, the fabricated Ni-Zn MB obtained high volumetric/areal energy density (419.7 mWh cm-3 , 1.3 mWh cm-2 ), and ultrahigh rate performance extending the power density to 109.4 W cm-3 (328.3 mW cm-2 ). More surprisingly, the MB assembled by this inherently flexible microwire network is extremely resistant to bending/twisting. Therefore, this novel concept of excellent comprehensive micro-power source will greatly hold great implications for next-generation flexible electronics.

Multi-MXene assisted large-scale manufacturing of electrochemical biosensors based on enzyme-nanoflower enhanced electrodes for the detection of H2O2 secreted from live cancer cells.

In situ monitoring of H2O2 in cellular microenvironments plays a critical role in the early diagnosis and pretreatment of cancer, but is limited by the lack of efficient and low-cost strategies for the large-scale preparation of real-time biosensors. Herein, a universal strategy for MXene-based composite inks combined with a scalable screen-printing process is validated in large-scale manufacturing of electrochemical biosensors for in situ detection of H2O2 secreted from live cells. Compositing biocompatible carboxymethyl cellulose (CMCS) with excellent conductive MXene, a water-based ink electrode (MXene/CMCS) with tunable viscosity is efficiently printed with desirable printing accuracy. Subsequently, the MXene/CMCS@HRP electrochemical biosensor exhibits stable electrochemical performance through HRP nanoflower modification, showing rapid electron transport and high electrocatalytic capacity, and demonstrating a low limit of detection (0.29 µM) with a wide linear detection range (0.5 µM-3 mM), superior sensitivity (56.45 µA mM-1 cm-2), long-term stability and high anti-interference ability. Moreover, this electrochemical biosensor is effectively employed for in situ detection of H2O2 secreted from HeLa cells, revealing good biocompatibility and outstanding biosensing capability. This proposed strategy not only extends the possibility of low-cost biomedical devices, but also provides a promising approach for early diagnosis and treatment of cancer.

Optimization mechanism and applications of ultrafast laser machining towards highly designable 3D micro/nano structuring.

Three-dimensional (3D) micro/nano structures are significant in many applications because of their novel multi-functions and potential in high integration. As is known, the traditional methods for the processing of 3D micro/nano structures exhibit disadvantages in mass production and machining precision. Alternatively, ultrafast laser machining, as a rapid and high-power-density processing method, exhibits advantages in 3D micro/nano structuring due to its characteristics of extremely high peak power and ultra-short pulse. With the development of ultrafast laser processing for fine and complex structures, it is attracting significant interest and showing great potential in the manufacture of 3D micro/nano structures. In this review, we introduce the optimization mechanism of ultrafast laser machining in detail, such as the optimization of the repetition rate and pulse energy of the laser. Furthermore, the specific applications of 3D micro/nano structures by laser processing in the optical, electrochemical and biomedical fields are elaborated, and a valuable summary and perspective of 3D micro/nano manufacturing in these fields are provided.

Low-Cost In Vivo Full-Range Optical Coherence Tomography Using a Voice Coil Motor.

In this work, we demonstrated a novel and low-cost full-range optical coherence tomography (FROCT) method. In comparison with the off-pivot approach, which needs precise control of the deflecting distance and should be adjusted for different situations, our proposed method is more flexible without regulating the system itself. Different from the previous systems reported in the literature, which used a high-cost piezo-driven stage to introduce the phase modulation, our system utilizes a cost-effective voice coil motor for retrieving the complex-valued spectral signal. The complex-valued data, with a twofold increase in the accessible depth range, can be calculated using an algorithm based on the Hilbert transform and Dirac delta function. To confirm the effectivity of our method, both simulation and experiments were performed. In particular, for the in vivo experiment, we presented the FROCT result of a fingernail fold, demonstrating the availability of in vivo imaging. Since the key element of our system is a low-cost voice coil motor, which is flexible and more accessible for most of the clinics, we believe that it has great potential to be a clinical modality in the future.

Progress in Iron Oxides Based Nanostructures for Applications in Energy Storage.

The demand for green and efficient energy storage devices in daily life is constantly rising, which is caused by the global environment and energy problems. Lithium-ion batteries (LIBs), an important kind of energy storage devices, are attracting much attention. Graphite is used as LIBs anode, however, its theoretical capacity is low, so it is necessary to develop LIBs anode with higher capacity. Application strategies and research progresses of novel iron oxides and their composites as LIBs anode in recent years are summarized in this review. Herein we enumerate several typical synthesis methods to obtain a variety of iron oxides based nanostructures, such as gas phase deposition, co-precipitation, electrochemical method, etc. For characterization of the iron oxides based nanostructures, especially the in-situ X-ray diffraction and 57Fe Mössbauer spectroscopy are elaborated. Furthermore, the electrochemical applications of iron oxides based nanostructures and their composites are discussed and summarized.Graphic Abstract.