The diffusion and transport of substances between a hydrogel and its environment have received tremendous research interest, due to the wide range of applications of hydrogel materials in fields related to drug carriers and drug delivery vehicles. To date, much research has been done to tailor the diffusion and transport of substances through hydrogels, where most efforts were focused on tuning the 3D network properties of the hydrogel including loop size, hydrophobicity of building blocks and the stimuli-responsive properties of backbones. These conventional strategies, however, usually suffer from complicated fabrication procedures and result in a homogeneous increase in hydrophobicity of the hydrogel network, leading to low efficiency control over the diffusion of substances through the hydrogel. Herein, a facile strategy that can functionalize the surfaces of hydrogels, while keeping the interior network unchanged, was reported, and is realized by quaternization reaction confined to the hydrogel/oil interface. Owing to the introduction of the photo-responsive molecule IBSP as a modifier, the surface wettability of the resulting hydrogel can be controlled by light both in air and underwater environments. Consequently, the diffusion rate of a substance through this modified hydrogel can be regulated by light, which brings convenience to the controlled release of hydrogels and other hydrogel-related fields.

Chen Lie    Yao Xi    Gu Zhandong    Zheng Kaikai    Zhao Chuang-Qi    Lei Wenwei    Rong Qinfeng    Lin Ling    Wang Jiaobing    江雷     刘明杰   

Chemical Science

2017

Recent advances in materials science and nanotechnology have lead to considerable interest in constructing ion-channel-mimetic nanofluidic systems for energy conversion and storage. The conventional viewpoint suggests that to gain high electrical energy, the longitudinal dimension of the nanochannels (L) should be reduced so as to bring down the resistance for ion transport and provide high ionic flux. Here, counterintuitive channel-length dependence is described in nanofluidic osmotic power generation. For short nanochannels (with length L < 400 nm), the converted electric power persistently decreases with the decreasing channel length, showing an anomalous, non-Ohmic response. The combined thermodynamic analysis and numerical simulation prove that the excessively short channel length impairs the charge selectivity of the nanofluidic channels and induces strong ion concentration polarization. These two factors eventually undermine the osmotic power generation and its energy conversion efficiency. Therefore, the optimal channel length should be between 400 and 1000 nm in order to maximize the electric power, while balancing the efficiency. These findings reveal the importance of a long-overlooked element, the channel length, in nanofluidic energy conversion and provide guidance to the design of high-performance nanofluidic energy devices.

Cao Liuxuan    Xiao Feilong    Feng Yaping    Zhu Weiwei    Geng Wenxiao    Yang Jinlei    Zhang Xiaopeng    Li Ning    Wei Guo    江雷    

Advanced Functional Materials

2017

Here, we describe a simple method to prepare oil-repellent surfaces with inherent reactivity. Liquid-like copolymers with pendant reactive groups are covalently immobilized onto substrates via a sequential layer-by-layer method. The stable and transparent nanocoatings showed oil repellency to a broad range of organic liquids even in the presence of reactive sites. Functional molecules could be covalently immobilized onto the oil-repellent surfaces. Moreover, the liquid repellency can be maintained or finely tailored after post-chemical modification via synergically tailoring the film thickness, selection of capping molecules, and labeling degree of the capping molecules. Oil-repellent surfaces that are capable of post-functionalization would have technical implications in surface coatings, membrane separation, and biomedical and analytical technologies.

Liu Peng    Zhang Hengdi    He Wenqing    Li Hualin    Jiang Jieke    Liu Meijin    Hongyan Sun    何明亮    Jiaxi Cui    江雷     姚希   

ACS Nano

2017

A convenient and controlled organic semiconductor alignment strategy, superhydrophobic micropillar flow-coating (SMFC), is presented. Patterned, large-area (>1 cm) 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) single-crystalline arrays which show hole mobilities up to 6.8 cm V s were obtained via this method. Crucially, the polymorphism of TIPS-pentacene was regulated by tuning the flow rate, solvent and the substrate hydrophobicity. These results indicate that this technique is reliable for creating uniform and homogenous organic single-crystalline arrays with controlled crystal packing, thickness, and position.

Xiao Chengyi    Kan Xiaonan    Liu Chunming    Wei Jiang    Zhao Guangyao    Zhao Qiang    Zhang Lei    Wenping Hu    Wang Zhaohui    江雷    

Journal of Materials Chemistry C

2017

Ionic liquids (ILs) acting as new functional solvents have significant impact in both synthetic and materials chemistry. However, the usage of volatile organic solvents in both synthesis and recycling of ILs usually imposes environmental issues. In this study, according to intrinsic wetting threshold theory, a membrane-based approach assisted by superwettability is developed for efficient, convenient, and economical purification of water-immiscible ILs. By precisely tailoring surface energy, the porous membrane is capable of hydrophobicity and superILphilicity (defined as IL contact angle close to zero), selectively allowing ILs to pass through. This kind of functional membrane can not only separate IL/water mixtures, but also IL/water systems containing inorganic salts, organic compounds, amino acids, and proteins.

Zhang Jiajing    Hongliang Liu    江雷    

Advanced Functional Materials

2017

The efficient recognition and isolation of rare cancer cells holds great promise for cancer diagnosis and prognosis. In nature, pollens exploit spiky structures to realize recognition and adhesion to stigma. Herein, a bioinspired pollen-like hierarchical surface is developed by replicating the assembly of pollen grains, and efficient and specific recognition to target cancer cells is achieved. The pollen-like surface is fabricated by combining filtering-assisted assembly and soft lithography-based replication of pollen grains of wild chrysanthemum. After modification with a capture agent specific to cancer cells, the pollen-like surface enables the capture of target cancer cells with high efficiency and specificity. In addition, the pollen-like surface not only assures high viability of captured cells but also performs well in cell mixture system and at low cell density. This study represents a good example of constructing cell recognition biointerfaces inspired by pollen-stigma adhesion.

Wang Wenshuo    杨高    Cui Haijun    Jingxin Meng    Shutao Wang    江雷    

Advanced Healthcare Materials

2017

Control of stem cell behaviors at solid biointerfaces is critical for stem-cell-based regeneration and generally achieved by engineering chemical composition, topography, and stiffness. However, the influence of dynamic stimuli at the nanoscale from solid biointerfaces on stem cell fate remains unclear. Herein, we show that electrochemical switching of a polypyrrole (Ppy) array between nanotubes and nanotips can alter surface adhesion, which can strongly influence mechanotransduction activation and guide differentiation of mesenchymal stem cells (MSCs). The Ppy array, prepared via template-free electrochemical polymerization, can be reversibly switched between highly adhesive hydrophobic nanotubes and poorly adhesive hydrophilic nanotips through an electrochemical oxidation/reduction process, resulting in dynamic attachment and detachment to MSCs at the nanoscale. Multicyclic attachment/detachment of the Ppy array to MSCs can activate intracellular mechanotransduction and osteogenic differentiation independent of surface stiffness and chemical induction. This smart surface, permitting transduction of nanoscaled dynamic physical inputs into biological outputs, provides an alternative to classical cell culture substrates for regulating stem cell fate commitment. This study represents a general strategy to explore nanoscaled interactions between stem cells and stimuli-responsive surfaces.

Wei Yan    Mo Xiaoju    Pengchao Zhang    Li Yingying    Jingwen Liao    Li Yong-Jun    Zhang    Ning Chengyun    Shutao Wang    Xuliang Deng    江雷    

ACS Nano

2017

Superwettability is a centuries-old concept that has been rediscovered in past decades, largely owing to new understanding of the mechanisms of special wetting phenomena in nature. Combining multiscale structures and surface chemical compositions is crucial to fabricate interfacial materials with superwettability. In this Review, we detail the historical development and summarize the various combined superwetting states in superwettability systems. Nature-inspired design principles of superwettable materials are also briefly introduced. Superwettability systems can be extended from 2D surfaces to 0D nanoparticles, 1D fibres and channels, and 3D integrated materials. We discuss new phenomena and the advantages that superwettability-based systems have for chemical reactions and materials fabrication, including emerging applications that utilize single extreme wetting states or that combine two extreme wetting states. Finally, we provide our perspective for future research directions.

刘明杰    Shutao Wang    江雷    

Nature Reviews Materials

2017

Liu Jing    Wang Li    Wang    Guo Fengyun    Hou Lanlan    Chen Yuee    Liu Jingchong    Yong Zhao    江雷    

Small

2017

Huawei Chen    Zhang Liwen    Zhang Pengfei    Zhang Deyuan    Han Zhiwu    江雷    

Small

2017