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1.
Heterogenous nanofluidic membranes with bi-layer structures and ionic diode effect are shown great potential in efficiently harvesting the energy existing in a salinity gradient (or called the osmotic power conversion). However, exploitation of a heterogenous membrane with superior ion selectivity, excellent conductance, and strong ionic diode characteristics has remained a great challenge. Here, a novel heterogenous subnanochannel membrane with a tri-continuous pore structure of a large geometry gradient ranging from sub-nanoscale to nanoscale to sub-microscale, which is composed of a thin and crack-free layer of zeolitic imidazolate framework-8 (ZIF-8)/polystyrene sulfonate (PSS) membranes and an aligned branch-type alumina nanochannel membrane (BANM) is reported. It is demonstrated that such a tri-continuous pore structure can endow the exploited membrane, ZIF-8/PSS@BANM, with enhanced ion selectivity, strong ion current rectification, and ultrafast ion transport properties, in organic electrolyte solutions. Thus, an amazingly high power of ≈50.5 W m−2 is produced by mixing a 2 m LiCl-methanol and pure methanol solutions, which is over 45-fold higher than the existing membranes. Realizing high ion selectivity and amplified directional ion transport at sub-nanoconfined spaces in organic solvents paves the new way to develop ion-channel-mimetic membranes toward efficient ion separation and high-performance energy harvesters for battery applications. 相似文献
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Liuxuan Cao Feilong Xiao Yaping Feng Weiwei Zhu Wenxiao Geng Jinlei Yang Xiaopeng Zhang Ning Li Wei Guo Lei Jiang 《Advanced functional materials》2017,27(9)
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. 相似文献
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采用阳极氧化法,制备了二维有序多孔氧化铝薄膜.用金相显微镜观察了一次阳极氧化和二次阳极氧化后多孔氧化铝的表面形貌.用X射线衍射仪、扫描电子显微镜和UV-VIS-NIR光谱仪等测试手段对多孔氧化铝薄膜进行了表征.结果表明,多孔氧化铝薄膜是非晶态结构,多孔氧化铝薄膜具有整流特性.多孔氧化铝的光学反射率随入射波长红移呈增加趋势,反射光谱具有明显的干涉现象. 相似文献
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Peng Ge Jianglei Zhang Yongshun Liu Shuli Wang Wendong Liu Nianzuo Yu Yuxin Wu Junhu Zhang Bai Yang 《Advanced functional materials》2018,28(29)
Smart pH‐responsive surfaces that could autonomously induce unidirectional wetting of acid and base with reversed directions are fabricated. The smart surfaces, consisting of chemistry‐asymmetric “Janus” silicon cylinder arrays (Si‐CAs), are prepared by precise modification of functional groups on each cylinder unit. Herein, amino and carboxyl groups are chosen as typical pH‐responsive groups, owing to their protonation/deprotonation effect in response to pH of the contacted aqueous solution. One side of the Si‐CAs is modified by poly(2‐(dimethylamino)ethyl methacrylate), while the other side is modified by mixed self‐assembled monolayers of 1‐dodecanethiol and 11‐mercaptoundecanoic acid. On such surfaces, it is observed that acid and base wet in a unidirectional manner toward corresponding directions that are modified by amino or carboxyl groups, which is caused by asynchronous change of wetting property on two sides of the asymmetric structures. The as‐prepared Janus surfaces could regulate the wetting behavior of acid and base and could direct unidirectional wetting of water with reversed directions when the surfaces are treated by strong acid or base. Due to the excellent response capability, the smart surfaces are potential candidates to be applied in sensors, microfluidics, oil/water separation, and smart interfacial design. 相似文献
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Jinzhao Ji Qian Kang Yi Zhou Yaping Feng Xi Chen Jinying Yuan Wei Guo Yen Wei Lei Jiang 《Advanced functional materials》2017,27(2)
In nature, hierarchically assembled nanoscale ionic conductors, such as ion channels and ion pumps, become the structural and functional basis of bioelectric phenomena. Recently, ion‐channel‐mimetic nanofluidic systems have been built into reconstructed 2D nanomaterials for energy conversion and storage as effective as the electrogenic cells. Here, a 2D‐material‐based nanofluidic reverse electrodialysis system, containing cascading lamellar nanochannels in oppositely charged graphene oxide membrane (GOM) pairs, is reported for efficient osmotic energy conversion. Through preassembly modification, the surface charge polarity of the 2D nanochannels can be efficiently tuned from negative (?123 mC m?2) to positive (+147 mC m?2), yielding strongly cation‐ or anion‐selective GOMs. The complementary two‐way ion diffusion leads to an efficient charge separation process, creating superposed electrochemical potential difference and ionic flux. An output power density of 0.77 W m?2 is achieved by controlled mixing concentrated (0.5 m ) and diluted ionic solutions (0.01 m ), which is about 54% higher than using commercial ion exchange membranes. Tandem alternating GOM pairs produce high voltage up to 2.7 V to power electronic devices. Besides simple salt solutions, various complex electrolyte solutions can be used as energy sources. These findings provide insights to construct cascading nanofluidic circuits for energy, environmental, and healthcare applications. 相似文献
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Yanbing Zhang Fengyu Li Xian Kong Tangyue Xue Dan Liu Pan Jia Lili Wang Liping Ding Huanli Dong Diannan Lu Lei Jiang Wei Guo 《Advanced functional materials》2020,30(4)
2D‐material‐based membranes with densely packed sub‐nanometer‐height fluidic channels show exceptional transport properties, and have attracted broad research interest for energy‐, environment‐, and healthcare‐related applications. Recently, light‐controlled active transport of ionic species in abiotic materials have received renewed attention. However, its dependence on inhomogeneous or site‐specific illumination is a challenge for scalable application. Here, directional proton transport through printed asymmetric graphene oxide superstructures (GOSs) is demonstrated under full‐area illumination. The GOSs are composed of partially stacked graphene oxide multilayers formed by a two‐step direct ink writing process. The direction of the photoinduced proton current is determined by the position of top graphene oxide multilayers, which functions as a photogate to modulate the horizontal ion transport through the beneath lamellar nanochannels. This transport phenomenon unveils a new driving mechanism that, in asymmetric nanofluidic structures, the decay of local light intensity in depth direction breaks the balance of electric potential distribution in horizontal direction, and thus generates a photoelectric driving force for ion transport. Following this mechanism, the GOSs are developed into photonic ion transistors with three different gating modes. The asymmetrically printed photonic‐ionic devices provide fundamental elements for light‐harvesting nanofluidic circuits, and may find applications for artificial photosynthesis and artificial electric organs. 相似文献
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Kang-Ting Huang Wen-Hsin Hung Yu-Chun Su Fu-Cheng Tang Lam Dieu Linh Chun-Jen Huang Li-Hsien Yeh 《Advanced functional materials》2023,33(19):2211316
Developing ion-selective membranes with anti-biofouling property and biocompatibility is highly crucial in harvesting osmotic energy in natural environments and for future biomimetic applications. However, the exploration of membranes with these properties in osmotic energy conversion remain largely unaddressed. Herein, a tough zwitterionic gradient double-network hydrogel membrane (ZGDHM) with excellent biofouling resistance and cytocompatibility for sustainable osmotic energy harvesting is demonstrated. The ZGDHM, composed of negatively charged 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as the first scaffold network and zwitterionic sulfobetaine acrylamide (SBAA) as the second network, is prepared by a two-step photopolymerization, thus creating continuous gradient double-network nanoarchitecture and then remarkably enhanced mechanical properties. As verified by the experiments and simulations, the gradient nanoarchitecture endows the hydrogel membrane with apparent ionic diode effect and space-charge-governed transport property, thus facilitating directional ion transport. Consequently, the ZGDHM can achieve a power density of 5.44 W m−2 by mixing artificial seawater and river water, surpassing the commercial benchmark. Most importantly, the output power can be promoted to an unprecedented value of 49.6 W m−2 at the mixing of salt-lake water and river water, nearly doubling up most of the existing nanofluidic membranes. This study paves a new avenue toward developing ultrahigh-performance osmotic energy harvesters for biomimetic applications. 相似文献
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Di Quan Danyan Ji Qi Wen Linhan Du Lili Wang Pan Jia Dan Liu Liping Ding Huanli Dong Diannan Lu Lei Jiang Wei Guo 《Advanced functional materials》2020,30(34)
Heterogeneous structures in nacre‐mimetic 2D layered materials generate novel transport phenomena in angstrom range, and thus provide new possibilities for innovative applications for sustainable energy, a clean environment, and human healthcare. In the two orthogonal transport directions, either vertical or horizontal, heterostructures in horizontal direction have never been reported before. Here, a 2D‐material‐based laterally heterogeneous membrane is fabricated via an unconventional dual‐flow filtration method. Negatively and positively charged graphene oxide multilayers are laterally patterned and interconnected in a planar configuration. Upon visible light illumination on the bipolar nanofluidic heterojunction, protons are able to move uphill against their concentration gradient, functioning as a light‐harvesting proton pump. A maximum proton concentration gradient of about 5.4 pH units mm?2 membrane area can be established at a transport rate up to 14.8 mol h?1 m?2. The transport mechanism can be understood as a light‐triggered asymmetric polarization in surface potential and the consequent change in proton capacity in separate parts. The implementation of photonic–ionic conversion with abiotic materials provides a full‐solid‐state solution for bionic vision and artificial photosynthesis. There is plenty of room to expect the laterally heterogeneous membranes for new functions and better performance in the abundant family of liquid processable colloidal 2D materials. 相似文献
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Audrey Yoke Yee Ho Han Gao Yee Cheong Lam Isabel Rodríguez 《Advanced functional materials》2008,18(14):2057-2063
We present the fabrication of multitiered branched porous anodic alumina (PAA) substrates consisting of an array of pores branching into smaller pores in succeeding tiers. The tiered three‐dimensional structure is realized by sequentially stepping down the anodization potential while etching of the barrier layer is performed after each step. We establish the key processing parameters that define the tiered porous structure through systematically designed experiments. The characterization of the branched PAA structures reveals that, owing to constriction, the ratio of interpore distance to the anodization potential is smaller than that for pristine films. This ratio varies from 1.8 to 1.3 nm V?1 depending on the size of the preceding pores and the succeeding tier anodization potential. Contact angle measurements show that the multitiered branched PAA structures exhibit a marked increased in hydrophilicity over two‐dimensional PAA films. 相似文献
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Wei Guo Hongwei Xia Liuxuan Cao Fan Xia Shutao Wang Guangzhao Zhang Yanlin Song Yugang Wang Lei Jiang Daoben Zhu 《Advanced functional materials》2010,20(20):3561-3567
A dual‐functional nanofluidic device is demonstrated that integrates the ionic gate and the ionic rectifier within one solid‐state nanopore. The functionalities are realized by fabricating temperature‐ and pH‐responsive poly(N‐isopropyl acrylamide‐co‐acrylic acid) brushes onto the wall of a cone‐shaped nanopore. At ca. 25 °C, the nanopore works on a low ion conducting state. When the temperature is raised to ca. 40 °C, the nanopore switches to a high ion conducting state. The closing/opening of the nanopore results from the temperature‐triggered conformational transition of the attached copolymer brushes. Independently, in neutral and basic solutions, the conical nanopore rectifies the ionic current. While in acid solutions, no ion rectifying properties can be found. The charge properties of the copolymer brushes, combined with the asymmetrical pore geometry, render the nanopore a pH‐tunable ionic rectifier. The chemical modification strategy could be applied to incorporate other stimuli‐responsive materials for designing smart multi‐functional nanofluidic systems resembling the “live” creatures in nature. 相似文献
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Gegu Chen Tian Li Chaoji Chen Chengwei Wang Yang Liu Weiqing Kong Dapeng Liu Bo Jiang Shuaiming He Yudi Kuang Liangbing Hu 《Advanced functional materials》2019,29(44)
Here, a highly conductive cationic membrane is developed directly from natural wood via a two‐step process, involving etherification and densification. Etherification bonds the cationic functional group (? (CH3)3N+Cl?) to the cellulose backbone, converting negatively charged (ξ‐potential of ?27.9 mV) wood into positively charged wood (+37.7 mV). Densification eliminates the large pores of the natural wood, leading to a highly laminated structure with the oriented cellulose nanofiber and a high mechanical tensile strength of ≈350 MPa under dry conditions (20 times higher than the untreated counterpart) and ≈98 MPa under wet conditions (×5.5 increase compared to the untreated counterpart). The nanoscale gaps between the cellulose nanofibers act as narrow nanochannels with diameters smaller than the Debye length, which facilitates rapid ion transport that is 25 times higher than the ion conductance of the natural wood at a low KCl concentration of 10 × 10?3 m . The demonstrated cationic wood membrane exhibits enhanced mechanical strength and excellent nanofluidic ion‐transport properties, representing a promising direction for developing high‐performance nanofluidic material from renewable, and abundant nature‐based materials. 相似文献
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将Al片在较高的电压下进行阳极氧化,制备了氧化铝纳米线。其形成机制主要是多孔氧化铝膜生长的同时,其微结构单元阵列在薄膜应力作用下沿薄壁处破裂,从而生成了氧化铝纳米线。扫描电镜和透射电镜观测表明,所得产物结构外形基本一致,呈凹柱面正三棱柱形,表观直径约30～300nm,长度为几微米至数十微米。采用BET法对产物的比表面积进行测量,实验值为5.8×104m2/kg,接近于理论计算值6.2×104m2/kg。实验表明,这种氧化铝一维纳米结构材料对超小Ag和CdS纳米颗粒具有较强的吸附能力,对很难用传统的过滤和离心沉淀法去除的超小纳米颗粒(直径小于10nm)也能做到有效吸附,有望成为超级吸附与过滤材料。 相似文献
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电化学制备亚微米氧化铝有序多孔膜方法研究 总被引：1，自引：0，他引：1
采用电化学阳极氧化法制备亚微米氧化铝有序多孔膜 ,研究了铝电极预处理过程、扩孔时间、阳极氧化时间和阳极氧化电压对亚微米氧化铝有序多孔膜孔径、孔密度以及孔排列有序性的影响规律 ,并且建立了一个理想模型来探讨亚微米氧化铝多孔膜的生长过程 相似文献
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Addressable Au/dipyrimidinyl–diphenyl/Au molecular junctions are fabricated using elastic polymer stamp-printing method. To study the charge transport, current–voltage measurements are carried out from 95 up to 295 K in vacuum under both dark and light conditions. Reversible diode rectification and negative differential resistance phenomena are observed. The rectification efficiency dramatically decreases upon temperature increase or light illumination. Theoretical calculations based on the non-equilibrium Green’s function method combined with the density functional theory is performed to elucidate the negative differential resistance behaviors. We show that the different rectification efficiency is caused by the interfacial asymmetry and the dipole effects. The negative differential resistance may be attributed to the variation of the coupling degree between the incident states of the Au electrodes and the molecular orbitals, which depends largely on the S–Au contact geometry. The direct tunneling and Fowler–Nordheim tunneling act as the main transport mechanisms for low and high bias regions, respectively. The barrier height depends largely on the light illumination, substrate temperature, and bias polarity. The distinctly different adsorbing nature of the Au/molecule interface may account for the performances. 相似文献
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Georgios Pilatos Eleni C. Vermisoglou Georgios E. Romanos Georgios N. Karanikolos Nikos Boukos Vlassis Likodimos Nick K. Kanellopoulos 《Advanced functional materials》2010,20(15):2500-2510
Although hollow nanostructures, such as nanotubes, represent a major portion of nanoscaled materials with a tremendously large application range, a detailed evaluation of their internal characteristics still remains elusive. Transmission electron microscopy is the most common analytical technique to examine the internal configuration of these structures, yet it can only provide evidence of a minimal portion of the overall material, thus, it cannot be accurately generalized. In the present paper, in addition to electron microscopy and other spot‐size analysis methods (X‐ray diffraction, Raman spectroscopy, etc.), a combination of techniques including adsorption, permeability, and relative permeability are employed in order to provide important insights into various crucial details of the overall internal surface and hollow‐space characteristics of carbon nanotube (CNT) arrays and membranes. The CNT arrays are fabricated using anodized alumina as a template in a flow‐through chemical vapor deposition (CVD) reactor. This is the first systematic approach for investigating the internal configuration of template‐based CNT arrays in detail. Key findings are made for the customized optimization of the resulting nanotube membranes for a variety of applications, including separations, nanofluidics and nanoreactors, biological capturing and purification, and controlled drug delivery and release. 相似文献
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模板合成法制备ZnO纳米线的研究 总被引：1，自引：0，他引：1
在草酸和硫酸电解液中分别制备了孔径为40 nm和20 nm左右的多孔氧化铝模板,用直流电化学沉积的方法,在模板孔洞内电解沉积Zn,对其进行高温下的氧化,可得到高度有序的ZnO纳米线.扫描电子显微镜观察显示,多晶的Zn纳米线均匀地填充到多孔氧化铝六角排布的孔洞里,直径与模板孔径相当.X射线衍射谱测量证实,制备的Zn纳米线和ZnO纳米线均为多晶结构,并且对比了模板孔径对纳米线结构的影响.测量了多孔氧化铝厚膜和Zn/Al2O3组装体的吸收光谱,发现其在红外波段的吸收系数有逐渐降低的趋势. 相似文献
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纳米硅颗粒在多孔氧化铝中的光致荧光特性 总被引：2，自引：2，他引：0
采用阳极氧化方法制备了多孔硅（Ps）,经过超声波充分粉碎PS层得到分散的si纳米颗粒（n-Si）,利用高速离心旋转方法将n-si镶嵌到多孔氧化铝（Al2O3）模板中,得到nSi／Al2O3。复合体系。研究了PS、分散的n-Si和n-Si／Al2O3。的荧光（PL）光谱性质,观察到n-Si极强的蓝紫光发射。结果表明,在Al2O3模板中的n-Si,比起PS和丙酮中的发光峰值波长向短波方向“蓝移”,而且半峰全宽（FWHM）也相对变窄。实验现象表明,量子限制效应（QCE）对样品的PL性质有苇要作用,并用QCE对样品的发光“蓝移”现象进行了解释。 相似文献