Khan Majharul Haque    Jamali Sina S.    Lyalin Andrey    Molino Paul J.    江雷     Liu Hua Kun    Tetsuya Taketsugu    Zhenguo Huang   

Advanced Materials

2017

PrBaCoCuO (PBCoCu), a layered perovskite oxide with Ba-deficiency at A-site and Cu doping at B-site was synthesized and characterized as cathode material of intermediate-temperature solid oxide fuel cell (IT-SOFC) in comparison with performance of the parent oxide of PrBaCoO (PBCoO). PBCoCu had the same phase structure as that of PBCoO but showed a slight lattice expansion. Results of iodometric titration and thermogravimetry (TG) measurements demonstrated that PBCoCu had a higher concentration of oxygen vacancy than PBCoO did. Electrical conductivities of PBCoCu ranged from 255 S cm at 400 °C to 134 S cm at 800 °C in air, meeting the requirement for the cathode of SOFCs. Thermal expansion coefficient (TEC) of PBCoCu was about one quarter decreased compared with TEC of PBCoO. PBCoCu showed improved electrochemical performance than PBCoO characterized by low area specific resistances (ASRs) ranging from 0.12 Ω cm at 600 °C to 0.017 Ω cm at 750 °C. High peak power densities, 1541 mW cm at 800 °C, 1228 mW cm at 750 °C and 930 mW cm at 700 °C were achieved in a single cell using the PBCoCu cathode. This single cell also showed an operational stability using hydrogen fuel at 650 °C without any decay for 100 h. These results have demonstrated that PBCoCu is a promising cathode material of IT-SOFCs.

Xuening Jiang    Wang Jiao    Jia Guoqiang    Qie Zijian    Shi Yuchao    Idrees Asim    Zhang Qingyu    江雷    

International Journal of Hydrogen Energy

2017

Developing an effective system to clean up large-scale oil spills is of great significance due to their contribution to severe environmental pollution and destruction. Superwetting membranes have been widely studied for oil/water separation. The separation, however, adopts a gravity-driven approach that is inefficient and discontinuous due to quick fouling of the membrane by oil. Herein, inspired by the crossflow filtration behavior in fish gills, we propose a crossflow approach via a hydrophilic, tilted gradient membrane for spilled oil collection. In crossflow collection, as the oil/water flows parallel to the hydrophilic membrane surface, water is gradually filtered through the pores, while oil is repelled, transported, and finally collected for storage. Owing to the selective gating behavior of the water-sealed gradient membrane, the large pores at the bottom with high water flux favor fast water filtration, while the small pores at the top with strong oil repellency allow easy oil transportation. In addition, the gradient membrane exhibits excellent antifouling properties due to the protection of the water layer. Therefore, this bioinspired crossflow approach enables highly efficient and continuous spilled oil collection, which is very promising for the cleanup of large-scale oil spills.

Yuhai Dou    Dongliang Tian    Ziqi Sun    Liu Qiannan    Zhang Na    Kim Jung Ho    江雷     窦士学   

ACS Nano

2017

Many biological ion channels controlled by biochemical reactions have autonomous and periodic gating functions, which play important roles in continuous mass transport and signal transmission in living systems. Inspired by these functional biological ion channel systems, here we report an artificial self-oscillating nanochannel system that can autonomously and periodically control its gating process under constant conditions. The system is constructed by integrating a chemical oscillator, consisting of BrO, Fe(CN), H, and SO, into a synthetic proton-sensitive nanochannel modified with C-quadruplex (C4) DNA motors. The chemical oscillator, containing H-producing and H-consuming reactions, can cyclically drive conformational changes of the C4-DNA motors on the channel wall between random coil and folded i-motif structures, thus leading to autonomous gating of the nanochannel between open and closed states. The autonomous gating processes are confirmed by periodic high-low ionic current oscillations of the channel monitored under constant reaction conditions. The utilization of a chemical oscillator integrated with DNA molecules represents a method to directly convert chemical energy of oscillating reactions to kinetic energy of conformational changes of the artificial nanochannels and even to achieve diverse autonomous gating functions in artificial nanofluidic devices.

Wang Jian    Fang Ruochen    Jue Hou    Zhang Huacheng    Tian Ye    Huanting Wang    江雷    

ACS Nano

2017

Uni-directional liquid spreading without energy input has gained much attention due to its potential application in various areas such as microfluidic devices and energy fields. Recently, continuous uni-directional liquid spreading with fast speed was discovered on the peristome of Nepenthes alata, which possesses superhydrophilic hierarchical microgrooves and duck-billed microcavities with arc-shaped edges and gradient wedge corners. Inspired by the surface structure of the peristome, a novel bio-inspired uni-directional liquid spreading surface with various arc curvatures and wedge angles was built via two-step inclined UV exposure photolithography. The effects of the surface wettability and structural features, i.e. the arc-shaped outlines and wedge corners of microcavities, on the anisotropy of liquid spreading were investigated. The underlying mechanisms were made clear by comparing the effects of surface wettability and structural features of microcavities on both liquid spreading ability and liquid pinning ability. Finally, the controlling of anisotropic liquid spreading and thorough uni-directional liquid spreading were realized. This study provides inspiration to design novel uni-directional liquid spreading surfaces without energy input, and can further expand their application in areas such as non-powered delivery systems, microfluidic devices and self-lubrication in mechanical engineering.

Huawei Chen    Zhang Liwen    Zhang Yi    Zhang Pengfei    Zhang Deyuan    江雷    

Journal of Materials Chemistry A

2017

Directional solution coating by the Chinese brush provides a facile approach to fabricate highly oriented polymer thin films by finely controlling the wetting and dewetting processes under directional stress. The biggest advantage of the Chinese brush over the normal western brush is the freshly emergent hairs used, whose unique tapered structure renders a dynamic balance of the liquid within the brush by multiple forces when interacting with the liquid. Consequently, the liquid is steadily held within the brush without any unexpected leakage, making the liquid transfer proceed in a well-controllable manner. It is demonstrated that the Chinese brush coating enables the crystallization of the polymer and the self-assembly of conjugated backbones to proceed in a quasi-steady state via a certain direction, which is attributed to the controllable receding of the three-phase contact line during the dewetting process by the multiple parallel freshly emergent hairs. The as-prepared polymer thin films exhibit over six times higher charge-carrier mobility compared to the spin-coated films, which therefore provides a general approach for high-performance organic thin-film transistors.

Lin Fang-Ju    Guo Cheng    Chuang Wei-Tsung    Chienlung Wang    Wang Qianbin    Liu Huan    Chainshu Hsu    江雷    

Advanced Materials

2017

Recently, self-healing superhydrophobic surfaces have become a new research focus due to their recoverable wetting performances and wide applications. However, until now, on almost all reported surfaces, only one factor (surface chemistry or microstructure) can be restored. In this paper, a new superhydrophobic surface with self-healing ability in both crushed microstructure and damaged surface chemistry is prepared by creating lotus-leaves-like microstructure on the epoxy shape memory polymer (SMP). Through a simple heating process, the crushed surface microstructure, the damaged surface chemistry, and the surface superhydrophobicity that are destroyed under the external pressure and/or O plasma action can be recovered, demonstrating that the obtained superhydrophobic surface has a good self-healing ability in both of the two factors that govern the surface wettability. The special self-healing ability is ascribed to the good shape memory effect of the polymer and the reorganization effect of surface molecules. This paper reports the first use of SMP material to demonstrate the self-healing ability of surface superhydrophobicity, which opens up some new perspectives in designing self-healing superhydrophobic surfaces. Given the properties of this surface, it could be used in many applications, such as self-cleaning coatings, microfluidic devices, and biodetection.

Lv Tong    Zhongjun Cheng    Zhang Enshuang    Kang Hong Jun    Liu Yuyan    江雷    

Small

2017

Nowadays, oily wastewater and spilled oil have caused great threats on both ecosystem and human life. To address these severe problems, considerable efforts have been possessed on developing novel oil/water separation materials. The porous oil-absorbent materials, especially the porous polydimethylsiloxane (PDMS) with excellent properties of easy fabrication and inherent hydrophobicity, have attracted tremendous attentions from worldwide. The conventional methods using salt or sugar as sacrificial template and water as solvent have been widely adopted to fabricate the porous PDMS sponge. Due to the inherent hydrophobicity of PDMS, the solvent of water hardly penetrates into the inside of PDMS, which results in the difficult and incomplete remove of the hard template. In this contribution, the 3D interconnected porous PDMS sponge is facilely prepared by utilizing a modified technique with the citric acid monohydrate as hard template and ethanol as solvent. The proposed approach is capable of removing the hard template efficiently and thoroughly, which demonstrates promising utilizations in practical applications.

Yu Cunlong    Yu Cunming    Cui Liying    Song Zhiyang    Zhao Xin-Yu    Ma Ying    江雷    

Advanced Materials Interfaces

2017

This paper presents a unique morphological evolution of metal-organic inverse opals (Pb(NO)-poly(St-MMA-AA)) subjected to an electrowetting process. The morphology of the building blocks changes from interconnected pores to separated hollow spheres during the electrowetting process, accompanied by an unusual blue-shift of the stopband position and the decreased wettability of the film. This morphology evolution is attributed to the simultaneous collapse/reconstruction of the metal-organic frame owing to the partial dissolution of the metal salt and the interfacial assembly of the metal-organic coordination around the skeleton. The adjustable morphology can be developed as a novel and simple water-lithography approach for the creation of the photonic crystal pattern.

Liu Junchao    Wan Lun    Zhang Man-Bo    Jiang Kejian    Kai Song    Jingxia Wang    Ikeda Tomiki    江雷    

Advanced Functional Materials

2017

Engineering the wettability of zero-dimensional (0D) materials (particles, powders and agglomerates) is a key issue in applications such as dissolution, dispersion, granulation, coating, drying and so on. In the past, the superwettability of 3-dimensional (3D), 2-dimensional (2D) and 1-dimensional (1D) materials has been intensively studied. However, the superwettability of 0D materials has received limited attention. It is often investigated as a “collective effect” contributed by many closely packed particles, rather than individual ones. This perspective article reviews the current state of understanding in this area. The definition of superwettable 0D materials is first discussed. Some fundamental rules for understanding 0D superwettability are proposed. Then, methods for investigating the superwettable state of 0D materials are briefly introduced, and the potential applications of superwettable 0D materials are described. Finally, the future development of superwettable 0D materials is discussed.

Bin Su    江雷     Xuchuan Jiang    余艾冰   

Powder Technology

2017