Co-reporter:Changchang Zou, Qianqian Li, Yinying Hua, Bihang Zhou, Jingui Duan, and Wanqin Jin
ACS Applied Materials & Interfaces August 30, 2017 Volume 9(Issue 34) pp:29093-29093
Publication Date(Web):August 9, 2017
DOI:10.1021/acsami.7b08032
Covalent organic framework (COF) membranes used for selective removal of CO2 were believed as an efficient and low-cost solution to energy and environmental sustainability. In this study, the amide modified COF nanosheet cluster with a 2D structure was facilely prepared through solid reaction, exhibiting good adsorption-based CO2 selectivity (223 at 273 K and 90 at 298 K) toward N2. Remarkably, the mixed matrix membrane (MMM) that consists of a lesser amount of COF filler (1 wt %) shows promising CO2/N2 gas selectivity (∼64). In addition, the competitive adsorption prompts the selectivity to ∼72 under an equimolar CO2/N2 mixture, which surpasses the values of all reported COF membranes. It is worth to note that the binary gas separation is stable during 120 h.Keywords: CO2/N2 gas separation; covalent organic framework; mixed matrix membrane; morphology transformation; solid reaction;
Co-reporter:Yasin Orooji, Maryam Faghih, Amir Razmjou, Jingwei Hou, Parisa Moazzam, Nahid Emami, Marzieh Aghababaie, Fatemeh Nourisfa, Vicki Chen, Wanqin Jin
Carbon 2017 Volume 111() pp:689-704
Publication Date(Web):January 2017
DOI:10.1016/j.carbon.2016.10.055
A novel polyethersulfone (PES) ultrafiltration membrane containing 0.05–2.00 wt% of synthesized mesoporous carbon nanoparticles (MCNs) was prepared via the phase inversion technique. The structures and properties of MCNs were characterized using a variety of analytic techniques. The MCNs showed the surface area of 1396.8 m2/g and the highest pore size of around 1 nm. The effect of incorporation of MCNs on the composite membrane morphology and performance was investigated through pure water flux, protein adsorption, and bacterial adhesion resistance tests. The membrane's anti-fouling performances were determined under constant-pressure operation at 100 kPa in a dead-end module. The as-prepared nanocomposite membranes were also studied in terms of morphology, structure and surface chemistry. Generally, the incorporation of MCNs into the polymeric membrane improved the pure water flux. The composite membrane containing 0.20 wt% MCNs exhibited the highest antifouling, protein adsorption resistance, and bacterial attachment inhibition property. The incorporation of the MCNs into the membranes introduces a different strategy of inhibiting biomolecule adsorption and bacterial attachment to the membrane surface, instead of killing the bacteria which may lead to more severe membrane fouling by the intracellular substances.
Co-reporter:Haoli Zhou, Jinqiang Zhang, Yinhua Wan, Wanqin Jin
Journal of Membrane Science 2017 Volume 524() pp:1-11
Publication Date(Web):15 February 2017
DOI:10.1016/j.memsci.2016.11.029
•A new method of using a platinum agent to pre-polymerize PDMS polymer is employed.•A thin silicalite-1-PDMS hybrid membrane with a selective layer of 5 µm is developed.•As much as 67 wt% silicalite-1 is incorporated in the thin composite membrane.•The thin composite membrane exhibits a PSI of 80.04 for PV of an ethanol–water mixture.•The composite membrane shows a strong interfacial binding force.Sedimentation of silicalite-1 occurs in the fabrication of thin silicalite-1 filled polydimethylsiloxane (PDMS) hybrid composite membranes if the viscosity of membrane solution is low, which makes this preparation challenging. In this work, a new method that use a platinum catalytic agent to assist the pre-polymerization of PDMS polymer to increase the viscosity of the membrane solution was studied. With this method, supported silicalite-1 filled PDMS hybrid composite membranes were fabricated and applied in the pervaporative separation of a 5 wt% dilute ethanol aqueous solution. The effect of the concentration of platinum catalytic agent on the membrane properties was first investigated using CRM, DSC and extraction experiment. Optimum of viscosity of the composite membrane solution was then conducted and a selective layer of as thin as 5 µm thickness was obtained with a flux of 5.52 kg/m2h in combination with a separation factor of 15.5 at 50 °C. After that the separation performances of different thick membranes, interfacial adhesion properties of hybrid membranes, comparisons with other reported results and membrane stability were investigated. Results showed homemade silicalite-1-PDMS hybrid composite membrane offers relatively high separation performance, indicating a potential industrial application for the separation of ethanol from aqueous solutions.
Co-reporter:Kecheng Guan, Jie Shen, Gongping Liu, Jing Zhao, Haoli Zhou, Wanqin Jin
Separation and Purification Technology 2017 Volume 174() pp:126-135
Publication Date(Web):1 March 2017
DOI:10.1016/j.seppur.2016.10.012
•Novel spray-evaporation method to fabricate GO membrane is developed.•Spraying times and evaporation rate are crucial for GO membrane formation.•GO membrane shows fast and selective hydrogen transporting over carbon dioxide.For gas separation through laminar-structured graphene oxide (GO) membranes, precise nanostructure manipulation is of critical significance for the acquirement of high performance. In this study, facile engineering of GO membranes is realized by combining spraying and solvent evaporation-induced assembly technique. Disordered-to-ordered and porous-to-compact GO membrane structures can be finely and conveniently manipulated via controlling the spraying times and evaporation rate during GO assembly. The as-fabricated GO membranes possess the optimal gas separation performance with H2/CO2 selectivity of 20.9 and H2 permeance of 2.7 × 10−8 mol Pa−1 m−2 s−1, which exceeds the upper bound of polymeric membranes. A probable transport mechanism for different gas molecules is applied to clarify the relationships between membrane structure and gas permeation. This study may explore an efficient and facile approach to fabricate defect-free GO membranes with high controllability and practicability.
Co-reporter:Yu Yin;Lei Shi;Zhenyu Chu
RSC Advances (2011-Present) 2017 vol. 7(Issue 71) pp:45053-45060
Publication Date(Web):2017/09/15
DOI:10.1039/C7RA07817J
In this work, we have developed a new electrochemical aptasensor for IFN-γ assay, based on a hierarchical graphene/AuNPs modified electrode coupled with a dual enzyme-assisted signal amplification strategy. The graphene/AuNPs modified electrode with a large specific area, high conductivity, excellent stability and biocompatibility was used for the immobilization of plentiful duplex DNA strands of capture probes and IFN-γ aptamers. In the presence of IFN-γ, hybridized aptamers were released from the electrode surface due to the formation of aptamer/IFN-γ complexes. Meanwhile, aptamers were digested with RecJf exonuclease and IFN-γ was available for target recycling, creating numerous free capture probes on the electrode surface. Then the hybridization chain reaction was initiated with the help of linker probes and biotin-labeled reporter probes. Thus cascade duplex DNA polymers were produced on the electrode surface, providing lots of binding sites for streptavidin–alkaline phosphatase to generate robust enzyme-catalyzed signals. Due to this dual enzyme-assisted amplification strategy, the prepared aptasensor exhibited a wide linear range from 5 pM–5 nM with an ultralow detection limit of 2 pM (S/N = 3). Besides, the aptasensor showed an excellent selectivity, satisfactory reproducibility and stability, and a great potential in serum analysis. Importantly, the versatility of the designed sensing strategy makes it easily extended for analyzing other biomolecules.
Co-reporter:Changchang Zou;Qianqian Li;Fujun Cheng;Haijun Wang;Jingui Duan
CrystEngComm (1999-Present) 2017 vol. 19(Issue 20) pp:2718-2722
Publication Date(Web):2017/05/22
DOI:10.1039/C7CE00522A
A pair of enantiopure chiral porous coordination polymers (PCPs) with a rare utk topology were prepared using derivatives of L-/D-alanine and Zn(CH3COO)2·2H2O. The framework integrated two types of parallel and uniform 1D channels that were constructed by self-stranding of three equal helical chains and a single helical chain. Among them, the right-handed PCP D-NTU-18 showed enhanced enantioseparation towards racemic 1-phenyl-1-propanol.
Co-reporter:Jiawei Zhu;Guangru Zhang;Gongping Liu;Zhengkun Liu;Nanping Xu
Advanced Materials 2017 Volume 29(Issue 18) pp:
Publication Date(Web):2017/05/01
DOI:10.1002/adma.201606377
The practical applications of perovskite hollow fibers (HFs) are limited by challenges in producing these easily, cheaply, and reliably. Here, a one-step thermal processing approach is reported for the efficient production of high performance perovskite HFs, with precise control over their cation stoichiometry. In contrast to traditional production methods, this approach directly uses earth-abundant raw chemicals in a single thermal process. This approach can control cation stoichiometry by avoiding interactions between the perovskites and polar solvents/nonsolvents, optimizes sintering, and results in high performance HFs. Furthermore, this method saves much time and energy (≈ 50%), therefore pollutant emissions are greatly reduced. One successful example is Ba0.5Sr0.5Co0.8Fe0.2O3-δ HFs, which are used in an oxygen-permeable membrane. This exhibits high oxygen permeation flux values that exceed desired commercial targets and compares favorably with previously reported oxygen-permeable membranes. Studies on other perovskites have produced similarly successful results. Overall, this approach could lead to energy efficient, solid-state devices for industrial application in energy and environmental fields.
Co-reporter:Assoc. Haoli Zhou;Fei Tao;Quan Liu;Chunxin Zong;Wenchao Yang;Assoc. Xingzhong Cao; Wanqin Jin; Nanping Xu
Angewandte Chemie 2017 Volume 129(Issue 21) pp:5849-5853
Publication Date(Web):2017/05/15
DOI:10.1002/ange.201700176
AbstractMicroporous polymer membranes continue to receive tremendous attention for energy-efficient gas separation processes owing to their high separation performances. A new network microporous polyamide membrane with good molecular-sieving performance for the separation of N2 from a volatile organic compound (VOC) mixture is described. Triple-substituted triptycene was used as the main monomer to form a fisherman's net-shaped polymer, which readily forms a composite membrane by solution casting. This membrane exhibited outstanding separation performance and good stability for the molecular-sieving separation of N2 over VOCs such as cyclohexane. The rejection rate of the membrane reached 99.2 % with 2098 Barrer N2 permeability at 24 °C under 4 kPa. This approach promotes development of microporous membranes for separation of condensable gases.
Co-reporter:Assoc. Haoli Zhou;Fei Tao;Quan Liu;Chunxin Zong;Wenchao Yang;Assoc. Xingzhong Cao; Wanqin Jin; Nanping Xu
Angewandte Chemie International Edition 2017 Volume 56(Issue 21) pp:5755-5759
Publication Date(Web):2017/05/15
DOI:10.1002/anie.201700176
AbstractMicroporous polymer membranes continue to receive tremendous attention for energy-efficient gas separation processes owing to their high separation performances. A new network microporous polyamide membrane with good molecular-sieving performance for the separation of N2 from a volatile organic compound (VOC) mixture is described. Triple-substituted triptycene was used as the main monomer to form a fisherman's net-shaped polymer, which readily forms a composite membrane by solution casting. This membrane exhibited outstanding separation performance and good stability for the molecular-sieving separation of N2 over VOCs such as cyclohexane. The rejection rate of the membrane reached 99.2 % with 2098 Barrer N2 permeability at 24 °C under 4 kPa. This approach promotes development of microporous membranes for separation of condensable gases.
Co-reporter:Zhe Song, Zhicheng Zhang, Guangru Zhang, Zhengkun Liu, Jiawei Zhu, Wanqin Jin
Separation and Purification Technology 2017 Volume 187(Volume 187) pp:
Publication Date(Web):31 October 2017
DOI:10.1016/j.seppur.2017.06.063
•The effects of different polymer binders on membrane properties were investigated.•Sulfur poisoning was confirmed taking place during sintering and operation stage.•Sulfate impurities were distributed on the surfaces and in the bulk of membrane.•Sulfate has a negative effect on oxygen permeation flux and long-term stability.Most perovskite oxides are commonly recognized as less tolerance to sulfur and sulfur-containing species. In a hollow fiber fabrication, polymer binders (sulfur-containing polyether sulphone (PES) and sulfur-free polyetherimide (PEI)) are expected to have different impacts on the membrane performance in terms of both permeability and stability. In this study, BaCo0.7Fe0.22Nb0.08O3-δ (BCFN) 4-bore hollow fibers using PES and PEI as binders were prepared by a phase inversion and sintering technique. The sintering behavior, mechanical strength, crystal structure, morphology, composition, oxygen permeation and long-term stability were investigated systematically. Formation of sulfate was identified on the surface and in the bulk of the membrane fabricated via the PES route. The sulfur poisoning was confirmed taking place during not only the sintering stage but also the operation stage. The sulfur-containing PES contributed to a lower oxygen permeation flux than the sulfur-free PEI and also a severe degradation of permeation flux that there was more than 65% decrease over the original value within the first 100 h at 650 °C. Membrane fabricated via the PEI route can operate for more than 300 h without obvious degradation.Download high-res image (99KB)Download full-size image
Co-reporter:Qianqian Li, Long Cheng, Jie Shen, Jiayan Shi, Guining Chen, Jing Zhao, Jingui Duan, Gongping Liu, Wanqin Jin
Separation and Purification Technology 2017 Volume 178(Volume 178) pp:
Publication Date(Web):7 May 2017
DOI:10.1016/j.seppur.2017.01.024
•MAF-6 based MMMs were designed and fabricated for PV separation of ethanol.•The incorporation of MAF-6 overcame the trade-off phenomenon.•The developed MMMs showed significantly improved and stable separation performance.Increasing the hydrophobicity of membrane was believed as an effective approach to enhance the performance of organophilic pervaporation (PV) membrane. In this work, the superhydrophobic alkyl group modificated metal organic framework (MOF) of RHO-[Zn(eim)2] (MAF-6) was incorporated into polydimethylsiloxane (PDMS) polymer to fabricate mixed matrix membranes (MMMs). The morphologies, physical and chemical properties of as-prepared MAF-6 nanocrystals and membranes were characterized with XRD, FESEM, EDX, QCM, contact angle and nano-scratch tests. The pervaporation experiments of ethanol/water mixture show the simultaneously enhanced flux and separation factor of MMMs compared with PDMS pristine membrane (with the optimal flux of 1200 g/m2 h1, and separation factor of 14.9), which stems from the hydrophilicity and high porosity of MAF-6, successfully overcoming the trade-off effect.
Co-reporter:Qianqian Li, Quan Liu, Jing Zhao, Yinying Hua, Jiajia Sun, Jingui Duan, Wanqin Jin
Journal of Membrane Science 2017 Volume 544(Volume 544) pp:
Publication Date(Web):15 December 2017
DOI:10.1016/j.memsci.2017.09.021
•MMMs containing hydrophilic MOF-801 were prepared for pervaporation dehydration.•MOF-801 based MMMs show extraordinary high water/ethanol separation performance.•Molecular simulation was conducted to study the separation mechanism of MOF-801.In order to promote the selective water permeation through porous filler, hydrophilic MOF-801 crystals with superior water adsorption ability were incorporated into chitosan (CS) matrix to fabricate MOF-801/CS mixed matrix membranes (MMMs) for pervaporation dehydration of ethanol. Both the experimental and molecular simulation results confirm the selective adsorption of water molecules in MOF-801 crystals, while the free volume and the lowest energy sorption sites analyses demonstrate the subdued diffusion of ethanol molecules through MOF-801. As a result, the porous structure in MOF-801 provides additional transport pathways for water molecules, and meanwhile makes the transport pathways of ethanol molecules more tortuous, thus achieving simultaneously enhanced flux and separation factor. The optimized membrane with MOF-801 loading of 4.8 wt% exhibits the total flux of 1937 g/m2 h and separation factor of 2156.Download high-res image (261KB)Download full-size image
Co-reporter:Yu Liu, Jingmeng Peng, Danfeng Jiang, Zhenyu Chu, Wanqin Jin
Progress in Natural Science: Materials International 2017 Volume 27, Issue 3(Volume 27, Issue 3) pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.pnsc.2017.04.005
A regular nanostructure has been widely confirmed to result ina marked improvement in material performance in biosensing applications. In the present study, a regular nanostructured Prussian blue (PB) film with two heterogeneous crystal layers was synthesized in-situ using a secondary growth method. A PB seed layer was first controlled to form uniform cube-like crystal nuclei through an ultrasonic reaction with a single reactant. Then, well-defined 100 nm PB nanocubes were further crystallized on this seed layer using a self-assembly approach. In order to accelerate the electron transfer rate during the enzyme reaction for glucose detection, the graphene was used as the main cross-linker to immobilize glucose oxidase on the PB film. The as-prepared biosensor exhibited high electrocatalysis and electron conductivity for the detection of trace glucose with a sensitivity of 141.5 μA mM−1 cm−2, as well as excellent anti-interference ability in the presence of ascorbic acid and uric acid under a low operation potential of −0.05 V.
Co-reporter:Zhenyu Chu, Yu Liu, Wanqin Jin
Biosensors and Bioelectronics 2017 Volume 96(Volume 96) pp:
Publication Date(Web):15 October 2017
DOI:10.1016/j.bios.2017.04.036
•Prussian blue has aroused numerous biosensing research interests due to its charming properties in the last decade.•Control of PB nanostructure is always a challenge for biosensing performance.•Traditional and novel preparation nanotechnologies of PB regular nanostructures are summarized.•Mechanism and key factor of PB regular crystallization are well discussed and concluded.•This review can provide an inspiration to the methodology development of nanostructure control for more materials.In the last decade, Prussian blue (PB) has attracted increased scientific interest in various research fields, such as fuel cells, gas separation and pollution treatment. Due to its advanced catalysis, biocompatibility, selectivity and stability, PB has been widely used in biosensor construction. However, the formation of regular PB nanostructures is challenging due to its fast crystallization rate. Recently, developments in this research area have increased due to emerging novel synthesis methods in nanoscale technology. Various regular nanostructures of PB films that show superior biosensing performance have been prepared. In this review, recent research progress in PB nanostructures is summarized, with special emphasis on the methodology of nanostructure control. The mechanism and key factors in regular PB crystallization are also discussed for each synthesis method. The performance of PB nanostructure-based biosensors is compared with others to show the advantages of nanostructure control. The methodology discussed in this review not only include the regular growth of PB films, but also provides information on the nanostructure control of more crystalline materials, including PB analogues, noble metals, metal oxides and coordination compounds. In addition to biosensing applications and the development of more advanced nanostructures, PB has also shown increased advanced properties in other scientific areas.
Co-reporter:Lei Shi;Yan Wang;Zhenyu Chu;Yu Yin;Danfeng Jiang;Jingyi Luo;Shiming Ding
Journal of Materials Chemistry B 2017 vol. 5(Issue 5) pp:1073-1080
Publication Date(Web):2017/02/01
DOI:10.1039/C6TB02658C
In this work, a novel electrochemical Hg2+ biosensor with high sensitivity and excellent reusability was presented. The sensor was based on tunable vertical single-walled carbon nanotubes (v-SWCNTs) and a target recycling strategy. A facile and scalable approach involving the conformational regulation of self-assembled monolayers was established for the fabrication of v-SWCNTs with tailored orientation and homogeneity. The obtained v-SWCNTs exhibited superior properties including a large specific area, high electrical conductivity, and excellent substrate binding strength, opening up a wide horizon for advanced electrochemical applications. Meanwhile, an efficient Hg2+ recycling strategy was designed using exonuclease III. In this strategy, a trace amount of Hg2+ triggered consecutive nicking reactions, and numerous report probes were released to bind with v-SWCNTs through π–π interactions. Based on the innovative design, an ultralow detection limit of 3 fM (S/N = 3), a wide linear range from 10 fM to 1 μM, high selectivity, and good reliability were achieved for a Hg2+ assay in water and serum samples using the prepared biosensor. Besides, due to the reversibility of π–π interactions, the stable v-SWCNT interface was regenerated for 50 consecutive measurements without obvious signal loss, making it a promising candidate for routine and efficient Hg2+ monitoring.
Co-reporter:Fujun Cheng;Qianqian Li;Jingui Duan;Nobuhiko Hosono;Shin-ichiro Noro;Rajamani Krishna;Hongliang Lyu;Shinpei Kusaka;Susumu Kitagawa
Journal of Materials Chemistry A 2017 vol. 5(Issue 34) pp:17874-17880
Publication Date(Web):2017/08/29
DOI:10.1039/C7TA02760E
Nano-porous coordination polymers (nano-PCPs), as a new class of crystalline material, have become a lucrative topic in coordination chemistry due to the facile tunability of their functional pore environments. However, elucidating the pathways for the rational design and preparation of nano-PCPs with various integrated properties for feasible gas separation remains a great challenge. Here, we demonstrate a new route to achieve nano-PCPs with an integrated pore system and physical properties using a reticular chemistry strategy. By optimizing the position and length of the shortest two alkyl groups in the channels, unprecedented phenomena of improved surface area, gas uptake, gas selectivity, thermal stability and chemical stability were observed in the PCPs, especially in NTU-14, the structure with a pendant ethyl group. Furthermore, the high performance of adsorption- and membrane-based separation makes NTU-14 a promising medium for CH4 purification from a mixture at room temperature.
Co-reporter:Kecheng Guan, Di Zhao, Mengchen Zhang, Jie Shen, Guanyu Zhou, Gongping Liu, Wanqin Jin
Journal of Membrane Science 2017 Volume 542(Volume 542) pp:
Publication Date(Web):15 November 2017
DOI:10.1016/j.memsci.2017.07.055
•Porous nanocrystals embedded graphene membrane was fabricated.•The porous structure of nanocrystals further contributes to the water transport.•Dye retention performance is adjustable according to the embedding amount.Two-dimensional (2D) materials have been received increasing attention in various fields such as physics, material science, chemistry and engineering. In particular, the graphene-based membrane is an emerging subject mainly due to the atomic thickness, simple processing and the compatibility with other materials. In the case of water treatment, stable graphene-based laminar structures as well as high separation performance are pursued. In this work, nanoporous crystals embedded graphene laminate membranes was reported for water purification. Reduced graphene oxide (rGO) nanosheets obtained from a solution chemical process act as building blocks to construct the 2D channels through a pressure-driven filtration process. By incorporating three-dimensional (3D) nanoporous crystals with sub-nano sized aperture size into the 2D graphene laminates, both the inter-layer spacing and numbers of nanofluidic channels are increased, leading to greatly-enhanced water separation performance. The optimized 3D/2D membranes exhibit 15 times higher water permeability than that of the rGO membrane with similar high dye retention rate. The significance of such 3D nanoporous structure and transport mechanism through the 3D/2D membranes is systematically studied. This general approach of enhancing the molecular transport through 2D nanofluidic channels proposed here may also find application in gas separation and battery membranes.Download high-res image (257KB)Download full-size image
Co-reporter:Jiawei Zhu;Gongping Liu;Zhengkun Liu;Zhenyu Chu;Nanping Xu
Advanced Materials 2016 Volume 28( Issue 18) pp:3511-3515
Publication Date(Web):
DOI:10.1002/adma.201505959
Co-reporter:Linlin Li, Jingmeng Peng, Zhenyu Chu, Danfeng Jiang, Wanqin Jin
Electrochimica Acta 2016 Volume 217() pp:210-217
Publication Date(Web):1 November 2016
DOI:10.1016/j.electacta.2016.09.081
A single-layer nanogrid of thiol graphene/Prussian blue (tG/PB) composite film was constructed to realize the high electrocatalytic biosensing of various physiological substances under the low potential. In order to achieve this architecture, a single layer of deformed polystyrene (PS) beads was first prepared as the template for the PB deposition. The structure of PB film can be well controlled to build a nanogrid with uniform 500 nm cavities by the self-assembly approach. This film can capture the thiol graphene into its nanogrid cavities to form the composite nanostructure via a strong ionic bond between thiol group from the graphene and Au from the substrate. Both electrocatalysis and conductivity of the as-prepared tG/PB film can harvest the remarkable enhancements due to the synergic effects of PB and graphene. As demonstrated, biosensors constructed by this film exhibited the high sensitivities and accuracies in the electrocatalytic oxidation of glucose, lactate and glutamate under the very low potential −0.05 V.
Co-reporter:Tian-Yu Chen, Lei Shi, Hao Yang, Xiao-Ming Ren, Chen Xiao, and Wanqin Jin
Inorganic Chemistry 2016 Volume 55(Issue 3) pp:1230-1235
Publication Date(Web):January 15, 2016
DOI:10.1021/acs.inorgchem.5b02439
The organic–inorganic hybrid crystal Ni(en)3Ag2I4 (where en represents 1,2-ethylenediamine) crystallizes in hexagonal space group P63, in which the AgI43– tetrahedra connect into a diamondlike inorganic framework via sharing of the vertex and the Ni(en)32+ octahedra fill in the pores of the framework. UV–vis–near-IR (NIR) spectroscopy disclosed that this hybrid shows intense NIR absorbance centered at ca. 870 nm, and the variable-temperature conductivity measurement revealed that the hybrid is a semiconductor with Ea = 0.46 eV. The electronic band structure of Ni(en)3Ag2I4 was calculated using the density functional theory method, indicating that the NIR absorbance arises from d-d transition within the Ni2+ cation of Ni(en)32+. The homogeneous, compact, and transparent crystalline film of Ni(en)3Ag2I4 was fabricated via a secondary seed growth strategy, which has promising application in NIR devices.
Co-reporter:Haijun Wang, Fujun Cheng, Changchang Zou, Qianqian Li, Yinying Hua, Jingui Duan and Wanqin Jin
CrystEngComm 2016 vol. 18(Issue 30) pp:5639-5646
Publication Date(Web):03 Jun 2016
DOI:10.1039/C6CE00960C
We design and prepare a family of luminescent porous coordination polymers (PCPs) constructed from three C2v symmetry ligands with increased conjugation moieties. Single crystal X-ray analyses revealed that their pore types/sizes and volumes were systematically tuned. Eu-based NTU-5 and NTU-8 emit red light. However, in contrast to the typical green emission of Tb-based PCPs, the increased conjugation moieties in NTU-6 and NTU-9 with a Tb center resulted in a very unusual blue emission. These unique emissions from these iso-structures demonstrated varied pathways of electronic transfer, which were further confirmed by lifetime experiments. Encouraged by these observations, the chromaticity modulation from pink to blue has been well realized by a facile method of self-assembly of the Te-H3L ligand and varied molar ratios of Eu3+/Tb3+ ions. Additionally, NTU-6 and NTU-9 showed high potential for nitrobenzene sensing (quenching effect coefficients: 589.5 and 445.6 M−1) and encapsulation of I2 molecules.
Co-reporter:Hua-Yu Tang, Zhenyu Chu, Cui-Ping Li, Xiao-Ming Ren, Chen Xue and Wanqin Jin
Dalton Transactions 2016 vol. 45(Issue 25) pp:10249-10255
Publication Date(Web):17 May 2016
DOI:10.1039/C6DT01612J
Films of Prussian blue analogue (PBA) Co3[Co(CN)6]2 were fabricated on porous α-alumina, ITO glass, silicon wafer and non-woven fabric substrates via a facile self-assembly method, and were characterized using infrared spectroscopy, X-ray powder diffraction and scanning electron microscope techniques. The films composed of truncated cube-shaped PBA particles are highly oriented with a preferred (100) plane on the glossy and smooth surfaces of ITO glass and silicon wafer, but crystallographically isotropic on the rough surface of porous α-alumina and non-woven fabric substrates. Compact films were achieved on porous α-alumina and surface-functionalized ITO glass. Reversible solvatochromism/vapochromism was discovered and investigated for the powdered and thin-film PBA samples. Such peculiar solvatochromism/vapochromism is related to the process of the adsorbed solvent molecules replacing the coordinated water molecules in octahedral Co2+–(N)4(H2O)2. The change of the Co2+ ion’s coordination atmosphere leads to the variation of crystal field strength, as a result, the d–d transitions within the Co2+ ions are altered to give rise to a color change.
Co-reporter:Shaobin Guo, Zhengkun Liu, Jiawei Zhu, Xin Jiang, Zhe Song, Wanqin Jin
Fuel Processing Technology 2016 Volume 154() pp:19-26
Publication Date(Web):15 December 2016
DOI:10.1016/j.fuproc.2016.07.009
•Novel dual-phase material was proposed to improve the CO2-tolerance of oxygen permeation membrane.•60SDC-40SCN dual phase membrane exhibits a high oxygen permeation flux of 1.54 mL min− 1 cm− 2 under the gradient of air/He.•Oxygen flux of dual-phase 60SDC-40SCN membrane was more than twice that of SCN membrane swept by pure CO2.Dual-phase composite oxide 60 wt% Ce0.8Sm0.2O2 − δ-40 wt% SrCo0.9Nb0.1O3 − δ (60SDC-40SCN) which exhibits high oxygen permeability and good CO2 tolerance was developed. X-ray diffraction (XRD) patterns and dense surface topography observed by scanning electron microscopy (SEM) revealed a good compatibility of the two oxides. A high oxygen permeation flux of 1.54 mL min− 1 cm− 2 through the as-prepared dual-phase membrane (0.8 mm in thickness) was obtained under the gradient of air/He at 1223 K. In situ high-temperature X-ray diffraction demonstrated that SDC and SCN in 60SDC-40SCN membrane could retain their original phase structure from room temperature to 1223 K in CO2-containing atmosphere. The oxygen permeation fluxes of 60SDC-40SCN membrane showed a good reversibility when switching the sweep gas between CO2 and He. Comparing with single-phase SCN membrane, oxygen permeation flux of dual-phase 60SDC-40SCN membrane was more than twice when pure CO2 acted as the sweep gas, and the oxygen permeation flux could remain stable for 120 h. All the experimental results imply that dual-phase 60SDC-40SCN membrane has a great potential in oxy-fuel combustion process.
Co-reporter:Jie Shen, Mengchen Zhang, Gongping Liu and Wanqin Jin
RSC Advances 2016 vol. 6(Issue 59) pp:54281-54285
Publication Date(Web):19 May 2016
DOI:10.1039/C6RA08441A
This work demonstrates a facile method of finely tailoring the graphene oxide (GO) nanochannels by controlling their surface oxygenated functionalities. The as-prepared membrane with subnanometer interlayer nanochannels (0.36 nm) and CO2-philic properties showed excellent preferential CO2 permeation performance, which offers promising potential for CO2 capture.
Co-reporter:Xin Jiang, Jiawei Zhu, Zhengkun Liu, Shaobin Guo, and Wanqin Jin
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 12) pp:3300
Publication Date(Web):September 11, 2015
DOI:10.1021/acs.iecr.5b03036
Ceramic–carbonate dual-phase membranes have attracted a lot of attention because of the emission of CO2 and environmental problems. In this study, a dense SrFe0.8Nb0.2O3−δ–carbonate dual-phase multichannel hollow fiber membrane has been successfully prepared via a phase inversion–sintering technique and impregnation. The morphology, crystal structure, phase stability, breaking load, and CO2 permeation flux of the as-prepared membranes were systematically investigated. The membrane not only had a higher CO2 permeation flux but also was of good thermomechanical stability in thermal recycles. Meanwhile, the membrane can be operated stably at 973 K over 200 h without any degradation of CO2 permeation flux. Our work demonstrates that the ceramic–carbonate dual-phase mixed-conducting multichannel hollow fiber membrane is a promising candidate for postcombustion CO2 capture.
Co-reporter:Danfeng Jiang, Zhenyu Chu, Jingmeng Peng, Wanqin Jin
Sensors and Actuators B: Chemical 2016 Volume 228() pp:679-687
Publication Date(Web):2 June 2016
DOI:10.1016/j.snb.2016.01.076
A Prussian blue (PB) biosensor chip with the nanocubic crystals was fabricated in batch by a screen printing technique for the general detection of various physiological substances. Through a low-speed chemical synthesis approach, the nanostructure of PB slurry was well controlled to be a 100 nm nanocube by the synthesis temperature and reactant concentration. Then, PB slurry was screen-printed as the working electrode to construct a microchip by the integration of the printed reference and counter electrodes. Due to the high electrocatalytic activity attributed by the regular nanostructure of PB electrode, the as-prepared chips exhibited the generally high sensitivities of 83.404, 31.642 and 6.379 μA mM−1 cm−2 for the respective detections of glucose, glutamate and lactate, as well as the excellent selectivity, reproducibility and stability under the low work potential of −0.05 V.
Co-reporter:Jie Shen, Gongping Liu, Kang Huang, Zhenyu Chu, Wanqin Jin, and Nanping Xu
ACS Nano 2016 Volume 10(Issue 3) pp:3398
Publication Date(Web):February 11, 2016
DOI:10.1021/acsnano.5b07304
Two-dimensional (2D) materials with atomic thickness and extraordinary physicochemical properties exhibit unique mass transport behaviors, enabling them as emerging nanobuilding blocks for separation membranes. Engineering 2D materials into membrane with subnanometer apertures for precise molecular sieving remains a great challenge. Here, we report rational-designing external forces to precisely manipulate nanoarchitecture of graphene oxide (GO)-assembled 2D channels with interlayer height of ∼0.4 nm for fast transporting and selective sieving gases. The external forces are synergistic to direct the GO nanosheets stacking so as to realize delicate size-tailoring of in-plane slit-like pores and plane-to-plane interlayer-galleries. The 2D channels endow GO membrane with excellent molecular-sieving characteristics that offer 2–3 orders of magnitude higher H2 permeability and 3-fold enhancement in H2/CO2 selectivity compared with commercial membranes. Formation mechanism of 2D channels is proposed on the basis of the driving forces, nanostructures, and transport behaviors.Keywords: external forces; gas separation; graphene oxide; membranes; molecular sieving; subnanometer channels; two-dimensional
Co-reporter:Gongping Liu, Wanqin Jin and Nanping Xu
Chemical Society Reviews 2015 vol. 44(Issue 15) pp:5016-5030
Publication Date(Web):18 May 2015
DOI:10.1039/C4CS00423J
Graphene is a well-known two-dimensional material that exhibits preeminent electrical, mechanical and thermal properties owing to its unique one-atom-thick structure. Graphene and its derivatives (e.g., graphene oxide) have become emerging nano-building blocks for separation membranes featuring distinct laminar structures and tunable physicochemical properties. Extraordinary molecular separation properties for purifying water and gases have been demonstrated by graphene-based membranes, which have attracted a huge surge of interest during the past few years. This tutorial review aims to present the latest groundbreaking advances in both the theoretical and experimental chemical science and engineering of graphene-based membranes, including their design, fabrication and application. Special attention will be given to the progresses in processing graphene and its derivatives into separation membranes with three distinct forms: a porous graphene layer, assembled graphene laminates and graphene-based composites. Moreover, critical views on separation mechanisms within graphene-based membranes will be provided based on discussing the effect of inter-layer nanochannels, defects/pores and functional groups on molecular transport. Furthermore, the separation performance of graphene-based membranes applied in pressure filtration, pervaporation and gas separation will be summarized. This article is expected to provide a compact source of relevant and timely information and will be of great interest to all chemists, physicists, materials scientists, engineers and students entering or already working in the field of graphene-based membranes and functional films.
Co-reporter:Kang Huang;Gongping Liu;Jie Shen;Zhenyu Chu;Haoli Zhou;Xuehong Gu;Nanping Xu
Advanced Functional Materials 2015 Volume 25( Issue 36) pp:5809-5815
Publication Date(Web):
DOI:10.1002/adfm.201502205
Graphene oxide (GO) laminates possess unprecedented fast water-transport channels. However, how to fully utilize these unique channels in order to maximize the separation properties of GO laminates remains a challenge. Here, a bio-inspired membrane that couples an ultrathin surface water-capturing polymeric layer (<10 nm) and GO laminates is designed. The proposed synergistic effect of highly enhanced water sorption from the polymeric layer and molecular channels from the GO laminates realizes fast and selective water transport through the integrated membrane. The prepared membrane exhibits highly selective water permeation with an excellent water flux of over 10 000 g m−2 h−1, which exceeds the performance upper bound of state-of-the-art membranes for butanol dehydration. This bio-inspired strategy demonstrated here opens the door to explore fast and selective channels derived from 2D or 3D materials for highly efficient molecular separation.
Co-reporter:Jiawei Zhu, Shaobin Guo, Zhenyu Chu and Wanqin Jin
Journal of Materials Chemistry A 2015 vol. 3(Issue 45) pp:22564-22573
Publication Date(Web):11 Aug 2015
DOI:10.1039/C5TA04598C
There is a desire for CO2-tolerant oxygen-permeable membranes for CO2 capture based on the oxyfuel process. Here we report a general doping strategy for developing CO2-tolerant SrFeO3−δ-based oxygen-permeable membranes. To combine excellent CO2 tolerance and high permeability, two novel CO2-tolerant oxygen-permeable membranes of SrFe0.9Ta0.1O3−δ (SFT) and SrFe0.8Sb0.2O3−δ (SFS) have been developed based on this doping strategy. Both SFT and SFS oxides possessed high phase stability especially in a pure CO2 atmosphere for 96 h at 1173 K. The high CO2-tolerant properties were mainly associated with high acidity, high valence and appropriate ionic radius of the Ta or Sb cation and high average metal bond energy of SFT or SFS oxide. Both SFT and SFS disk membranes (1 mm-thick) with low oxygen permeation activation energies exhibited high oxygen permeation fluxes of 0.3 and 0.22 ml min−1 cm−2, respectively, which were unchanged during the long-term operation (130 h) under air/CO2 gradient at 1173 K. Furthermore, the highest oxygen permeation flux of 1.15 ml min−1 cm−2 through the SFT multichannel hollow fiber (MHF) membrane at 1173 K under air/CO2 gradient can meet the requirement of commercial application in the oxyfuel process. The present results would give guidance for the design of CO2-tolerant SF-based membranes.
Co-reporter:Gongping Liu, Wei-Song Hung, Jie Shen, Qianqian Li, Yun-Hsuan Huang, Wanqin Jin, Kueir-Rarn Lee and Juin-Yih Lai
Journal of Materials Chemistry A 2015 vol. 3(Issue 8) pp:4510-4521
Publication Date(Web):06 Jan 2015
DOI:10.1039/C4TA05881J
Mixed matrix membranes (MMMs), consisting of inorganic fillers dispersed in a polymer matrix, are regarded as one of the most promising futuristic membranes. This work reports the utilization of molecular interactions to finely control the conformation and topology of polymer chains to fabricate high-performance polyhedral oligomeric silsesquioxanes (POSS)/polydimethylsiloxane (PDMS) MMMs. The influence of the incorporation of POSS on the polymer structure was systematically studied by molecular dynamics simulations combined with DSC, XRD and IR measurements. The surface and interfacial morphologies of the MMMs were observed through SEM, TEM and AFM characterizations. In particular, positron annihilation spectroscopy was employed to analyze the evolution of free volumes in the MMMs. Results indicated that facilely incorporating POSS into PDMS by molecular interactions could manipulate favorable interfacial morphology and tunable free volumes in MMMs. In the PDMS MMMs, the small free volumes were reduced and the large free volumes increased; these changes were beneficial for the preferential permeation of large-sized molecules through the polymeric membrane. As applied to the bio-butanol recovery from aqueous solutions, the prepared POSS/PDMS MMMs exhibited a simultaneous increase in permeability and selectivity, breaking the permeability-selectivity trade-off limitation, moreover transcending the upper bound of the state-of-the-art organophilic pervaporation membranes. Therefore, our work demonstrates that the proposed approach based on rationally creating molecular interactions can be expected to have broad applicability in fabricating high-quality MMMs for molecular separations.
Co-reporter:Lei Shi, Zhenyu Chu, Yu Liu and Wanqin Jin
Journal of Materials Chemistry A 2015 vol. 3(Issue 16) pp:3134-3140
Publication Date(Web):11 Mar 2015
DOI:10.1039/C5TB00266D
Great challenges remain in the template-assisted fabrication of metal nanowire arrays on substrates, because enormous effort is required to address the adhesion issues between substrates and adopted templates, e.g. anodic aluminum oxide (AAO). Therefore, novel and promising templates are highly desired for the construction of proposed structures. Here, vertical 1,5-diaminoanthraquinone (DAAQ) nanowires were prepared in situ on substrates by a facile method, and these were proven to be a reliable and alternative template for the preparation of a metal nanowire array. As an example, with the wet chemical reduction of HAuCl4, a three-dimensional gold nanowire array (3D GNA) was successfully obtained with a DAAQ template. The proposed 3D GNA has an extremely large roughness factor of ca. 15, as well as high stability and a favorable surface structure for the diffusion of analytes, making it a suitable candidate for the construction of high-performance electrochemical biosensors. As a result, an ultrasensitive aptasensor was constructed for the detection of thrombin, with a general sensing scheme. The fabricated aptasensor displays an impressively ultralow detection limit of 3 fM (S/N = 3) with a wide linear response from 10 fM to 1 nM, as well as excellent selectivity, good reproducibility and acceptable stability. Further, the biosensor exhibits potential for application in the analysis of real serum samples. The developed DAAQ nanowires are envisaged to become a general template for the fabrication of more nanowire arrays and the as-synthesized 3D GNA could open up a wide range of possibilities for potential applications in biological sensing.
Co-reporter:Chen Xiao, Zhengyu Chu, Xiao-Ming Ren, Tian-Yu Chen and Wanqin Jin
Chemical Communications 2015 vol. 51(Issue 37) pp:7947-7949
Publication Date(Web):02 Apr 2015
DOI:10.1039/C5CC02392K
The integrated, highly crystalline and water stable Prussian blue analogue films were successfully fabricated on the porous α-Al2O3, the conducting ITO and the flexible non-woven fabric substrates, respectively, using the self-assembly approach. The proton conduction was investigated for both powdered pellets and the film on the porous α-Al2O3 substrate. This study promotes the practical applications of MOF-based proton conductors in various devices.
Co-reporter:Jiawei Zhu, Shaobin Guo, Zhicheng Zhang, Xin Jiang, Zhengkun Liu, Wanqin Jin
Journal of Membrane Science 2015 Volume 485() pp:79-86
Publication Date(Web):1 July 2015
DOI:10.1016/j.memsci.2015.02.034
•A CO2-tolerant multichannel mixed-conducting hollow fiber membrane was prepared.•The membrane with superb mechanical strength has ultra-high oxygen permeation flux.•The membrane has greatly stable oxygen flux under CO2 atmosphere.A mixed-conducting multichannel hollow fiber membrane (MCMHF) based on CO2-tolerant SrFe0.8Nb0.2O3–δ (SFN) oxide has been successfully prepared by phase inversion and sintering technique. The morphology, breaking load, oxygen permeability under CO2 atmosphere, thermal cycling performance and the long-term stability of the membrane were investigated in detail. The prepared membrane has a significantly high oxygen permeation flux, which is the highest value among the membranes using pure CO2 as sweep gas. The as-prepared MCMHF membrane has good thermal–mechanical stability in the repeated heating and cooling process. Furthermore, by using pure CO2 as sweep gas, the MCMHF membrane is operated stably for more than 500 h without any degradation of oxygen permeation flux. Our work demonstrates that the MCMHF membrane has a great potential for the practical application in the oxyfuel process for CO2 capture technology.
Co-reporter:Shaobin Guo, Jiawei Zhu, Zhengkun Liu, Xin Jiang, Zhicheng Zhang, and Wanqin Jin
Industrial & Engineering Chemistry Research 2015 Volume 54(Issue 27) pp:6985-6992
Publication Date(Web):June 22, 2015
DOI:10.1021/acs.iecr.5b01009
The oxygen permeation performance of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) mixed-conducting multichannel hollow fiber (MCMHF) membranes was improved by surface modification via spin-spraying of a La0.6Sr0.4CoO3−δ (LSC) porous layer. At 1173 K, the oxygen permeation flux of the modified membranes was clearly enhanced and reached 9.68 mL·cm–2·min–1, which is a remarkable high value in the field of mixed-conducting oxygen permeation membrane processes. Theoretical calculations demonstrated that the oxygen transport resistance, especially the surface exchange resistance, obviously decreased as a result of the modified LSC porous layer. Moreover, the process of oxygen permeation through the modified membrane was controlled by both bulk diffusion and the surface oxygen exchange reaction, whereas the oxygen permeation of the unmodified membrane was dominantly controlled by the surface oxygen exchange reaction. The modified MCMHF membranes showed generally stable oxygen permeation fluxes over 100 h at 1173 K.
Co-reporter:Jie Shen;Dr. Gongping Liu;Kang Huang; Wanqin Jin; Kueir-Rarn Lee; Nanping Xu
Angewandte Chemie 2015 Volume 127( Issue 2) pp:588-592
Publication Date(Web):
DOI:10.1002/ange.201409563
Abstract
Graphene oxide (GO) nanosheets were engineered to be assembled into laminar structures having fast and selective transport channels for gas separation. With molecular-sieving interlayer spaces and straight diffusion pathways, the GO laminates endowed as-prepared membranes with excellent preferential CO2 permeation performance (CO2 permeability: 100 Barrer, CO2/N2 selectivity: 91) and extraordinary operational stability (>6000 min), which are attractive for implementation of practical CO2 capture.
Co-reporter:Jie Shen;Dr. Gongping Liu;Kang Huang; Wanqin Jin; Kueir-Rarn Lee; Nanping Xu
Angewandte Chemie 2015 Volume 127( Issue 2) pp:
Publication Date(Web):
DOI:10.1002/ange.201411016
Co-reporter:Jie Shen;Dr. Gongping Liu;Kang Huang; Wanqin Jin; Kueir-Rarn Lee; Nanping Xu
Angewandte Chemie International Edition 2015 Volume 54( Issue 2) pp:
Publication Date(Web):
DOI:10.1002/anie.201411016
Co-reporter:Jie Shen;Dr. Gongping Liu;Kang Huang; Wanqin Jin; Kueir-Rarn Lee; Nanping Xu
Angewandte Chemie International Edition 2015 Volume 54( Issue 2) pp:578-582
Publication Date(Web):
DOI:10.1002/anie.201409563
Abstract
Graphene oxide (GO) nanosheets were engineered to be assembled into laminar structures having fast and selective transport channels for gas separation. With molecular-sieving interlayer spaces and straight diffusion pathways, the GO laminates endowed as-prepared membranes with excellent preferential CO2 permeation performance (CO2 permeability: 100 Barrer, CO2/N2 selectivity: 91) and extraordinary operational stability (>6000 min), which are attractive for implementation of practical CO2 capture.
Co-reporter:Lei Shi;Zhenyu Chu;Yu Liu;Nanping Xu
Advanced Functional Materials 2014 Volume 24( Issue 44) pp:7032-7041
Publication Date(Web):
DOI:10.1002/adfm.201402095
In this work, novel three-dimensional graphene films (3D GFs) with controllable pore structures are directly fabricated on gold substrates through the hydrothermal reduction. An interfacial technique of the self-assembled monolayer is successfully introduced to address the binding issue between the graphene film and substrate. Adscititious silica spheres, serving as new connection centers, effectively regulate the dimensions of framework in graphene films, and secondary pore structures are produced once removing the spheres. Based on hierarchically porous 3D GFs with large surface area, excellent binding strength, high conductivity, and distinct interfacial micro-environments, selected examples of electrochemical aptasensors are constructed for the assay of adenosine triphosphate (ATP) and thrombin (Tob) respectively. Sensitive ATP and Tob aptasensors, with high selectivity, excellent stability, and promising potential in real serum sample analysis, are established on 3D GFs with different structures. The results demonstrate that the surface area, as well as interfacial micro-environments, plays a critical role in the molecular recognition. The developed reliable and scalable protocol is envisaged to become a general path for in situ fabrication of more graphene films and the as-synthesized 3D GFs would open up a wide horizon for potential applications in electronic and energy-related systems.
Co-reporter:Kai Zhang, Guangru Zhang, Zhengkun Liu, Jiawei Zhu, Na Zhu, Wanqin Jin
Journal of Membrane Science 2014 Volume 471() pp:9-15
Publication Date(Web):1 December 2014
DOI:10.1016/j.memsci.2014.06.060
•A porous-dense-porous triple-layer composite membrane structure was proposed.•The composite membrane showed good stability against the reactive atmosphere.•The CO2 conversion reached about 20.58% at the temperature of 900 °C.•The triple-layer structure effectively combined the high O2 permeation and stability.A triple-layer composite membrane with porous-dense-porous structure was proposed to develop a high performance membrane reactor. The triple-layer composite membrane consists of a porous Sr0.7Ba0.3Fe0.9Mo0.1O3−δ (SBFM) layer, a dense 0.5 wt% Nb2O5-doped SrCo0.8Fe0.2O3−δ (SCFNb) layer and a porous La0.8Sr0.2MnO3−δ–yttria stabilized zirconia (LSM/YSZ) layer. The porous layers can effectively reduce the corrosion of the reactive atmosphere to the membrane, while the dense layer permeated oxygen effectively. Compared with single layer dense SCFNb membrane reactor, the triple-layer composite membrane reactor can be operated for more than 500 h. At the temperature of 900 °C, the CO2 conversion can reach 20.58% with the CH4 conversion, CO selectivity and O2 flux being about 84%, 97% and 2.13 mL (STP) cm−2 min−1, respectively. The porous-dense-porous structure can successfully combine the high oxygen permeation and stability of the membrane reactor.
Co-reporter:Haoli Zhou, Lei Lv, Gongping Liu, Wanqin Jin, Weihong Xing
Journal of Membrane Science 2014 Volume 471() pp:47-55
Publication Date(Web):1 December 2014
DOI:10.1016/j.memsci.2014.07.068
•A thin PDMS/PVDF composite membrane with a thickness of 6 μm is developed.•The thin composite membrane shows high performance for PV of a DMC–methanol mixture.•The more permeable DMC can increase the permeability of the less permeable methanol.In this paper, polydimethylsiloxane (PDMS) composite membranes that were supported using polyvinylidene fluoride (PVDF) microfiltration membrane were developed for the pervaporation (PV) of dimethyl carbonate (DMC) from a methanol solution. Experimental studies on the solubility and the diffusivity of pure DMC and methanol in the membrane were first measured. Higher DMC uptake indicates that the sorption step is the rate-limiting step in the selective transport through the membrane. By controlling the fabricating parameters such as the concentration of the casting membrane solution, composite membranes with different thicknesses from 3 to 160 μm were fabricated. When the composite membrane is defect-free, the separation factor is independent of its thickness. The composite membrane with a thickness of 6 μm exhibited a separation factor of 3.95 and a normalized total flux of 0.4872 kg/m2 h in the pervaporation of 28 wt% DMC–methanol mixture at 40 °C. In addition, the membrane swelling effects, pervaporation performance, and stability were investigated. The results of the PDMS composite membrane exhibited higher and more stable performance in separating DMC from the methanol solution. The PDMS composite membrane can be a suitable PV membrane to separate DMC from a methanol solution.
Co-reporter:Gongping Liu, Lin Gan, Sainan Liu, Haoli Zhou, Wang Wei, Wanqin Jin
Chemical Engineering and Processing: Process Intensification (December 2014) Volume 86() pp:162-172
Publication Date(Web):1 December 2014
DOI:10.1016/j.cep.2014.06.013
•PDMS/ceramic composite membrane for PV of ABE aqueous solutions.•Coupling effect in multicomponent systems affected ABE molecular transport.•PV-integrated ABE fermentation for process intensification to improve productivity.Pervaporation (PV) has attracted increasing attention because of its potential application in bio-butanol recovery from fermentation process. In this work, PDMS/ceramic composite membrane was employed for PV separation of acetone–butanol–ethanol (ABE) aqueous solutions. The influence of coupling effect on the molecular transport during the PV process was systematically investigated. The separation performance and transport phenomena of ABE molecules were discussed based on the analysis and calculation of physicochemical properties such as solubility parameter, polarity parameter, interaction parameter, activity coefficient. The results suggested that the ABE separation factor was mainly determined by the intrinsic solubility parameter and driving force. Coupling effect in the ABE multicomponent system was closely related to the interaction parameters between components themselves and between component and membrane. Also, the PDMS membrane was integrated with ABE fermentation to construct an efficient intensification process. It was found that the rate matching of fermentation and in situ removal could improve the ABE productivity by 2 times.
Co-reporter:Gaixue Song, Zhenyu Chu, Wanqin Jin, Hongqi Sun
Chinese Journal of Chemical Engineering (August 2015) Volume 23(Issue 8) pp:1326-1334
Publication Date(Web):1 August 2015
DOI:10.1016/j.cjche.2015.05.003
Photocatalytic degradation is one of the most promising remediation technologies in terms of advanced oxidation processes (AOPs) for water treatment. In this study, novel graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) composites were synthesized by a facile sonication method. The physicochemical properties of the photocatalyst with different mass ratios of g-C3N4 to TiO2 were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 sorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and UV–vis DRS. The photocatalytic performances were evaluated by degradation of methylene blue. It was found that g-C3N4/TiO2 with a mass ratio of 1.5:1 exhibited the best degradation performance. Under UV, the degradation rate of g-C3N4/TiO2 was 6.92 and 2.65 times higher than g-C3N4 and TiO2, respectively. While under visible light, the enhancement factors became 9.27 (to g-C3N4) and 7.03 (to TiO2). The improved photocatalytic activity was ascribed to the interfacial charge transfer between g-C3N4 and TiO2. This work suggests that hybridization can produce promising solar materials for environmental remediation.The mechanism of electron–hole separation and transfer at the interfaces of g-C3N4/TiO2 hybrid photocatalyst is shown in the figure. g-C3N4 can be activated under visible light, the photogenerated electrons would be excited from VB to CB of g-C3N4. The photoinduced electrons in CB of g-C3N4 could transfer to the CB of TiO2 easily via intense interfacial connections since the CB edge potential of g-C3N4 is negative than that of TiO2. Hence, the electron–hole separation efficiency would be improved and the recombination rate is reduced.Download full-size image
Co-reporter:Pengqi Yang, Jingmeng Peng, Zhenyu Chu, Danfeng Jiang, Wanqin Jin
Biosensors and Bioelectronics (15 June 2017) Volume 92() pp:
Publication Date(Web):15 June 2017
DOI:10.1016/j.bios.2016.10.013
•A three-dimensional PB nanocubes/Ag nanowires network was in-situ synthetized in the water.•The network can be served as a water-based ink for the screen-printed flexible biosensor chip.•The chips possess high sensitivity, selectivity and reproducibility under a very low potential.The large-scale fabrication of nanocomposite based biosensors is always a challenge in the technology commercialization from laboratory to industry. In order to address this issue, we have designed a facile chemical method of fabricated nanocomposite ink applied to the screen-printed biosensor chip. This ink can be derived in the water through the in-situ growth of Prussian blue nanocubes (PBNCs) on the silver nanowires (AgNWs) to construct a composite nanostructure by a facile chemical method. Then a miniature flexible biosensor chip was screen-printed by using the prepared nanocomposite ink. Due to the synergic effects of the large specific surface area, high conductivity and electrocatalytic activity from AgNWs and PBNCs, the as-prepared biosensor chip exhibited a fast response (<3 s)， a wider linear response from 0.01 to 1.3 mM with an ultralow LOD=5 µm, and the ultrahigh sensitivities of 131.31 and 481.20 µA mM−1 cm−2 for the detections of glucose and hydrogen peroxide (H2O2), respectively. Furthermore, the biosensor chip exhibited excellent stability, good reproducibility and high anti-interference ability towards physiological substances under a very low working potential of −0.05. Hence, the proposed biosensor chip also showed a promising potential for the application in practical analysis.
Co-reporter:Jiawei Zhu, Shaobin Guo, Zhenyu Chu and Wanqin Jin
Journal of Materials Chemistry A 2015 - vol. 3(Issue 45) pp:NaN22573-22573
Publication Date(Web):2015/08/11
DOI:10.1039/C5TA04598C
There is a desire for CO2-tolerant oxygen-permeable membranes for CO2 capture based on the oxyfuel process. Here we report a general doping strategy for developing CO2-tolerant SrFeO3−δ-based oxygen-permeable membranes. To combine excellent CO2 tolerance and high permeability, two novel CO2-tolerant oxygen-permeable membranes of SrFe0.9Ta0.1O3−δ (SFT) and SrFe0.8Sb0.2O3−δ (SFS) have been developed based on this doping strategy. Both SFT and SFS oxides possessed high phase stability especially in a pure CO2 atmosphere for 96 h at 1173 K. The high CO2-tolerant properties were mainly associated with high acidity, high valence and appropriate ionic radius of the Ta or Sb cation and high average metal bond energy of SFT or SFS oxide. Both SFT and SFS disk membranes (1 mm-thick) with low oxygen permeation activation energies exhibited high oxygen permeation fluxes of 0.3 and 0.22 ml min−1 cm−2, respectively, which were unchanged during the long-term operation (130 h) under air/CO2 gradient at 1173 K. Furthermore, the highest oxygen permeation flux of 1.15 ml min−1 cm−2 through the SFT multichannel hollow fiber (MHF) membrane at 1173 K under air/CO2 gradient can meet the requirement of commercial application in the oxyfuel process. The present results would give guidance for the design of CO2-tolerant SF-based membranes.
Co-reporter:Lei Shi, Zhenyu Chu, Yu Liu and Wanqin Jin
Journal of Materials Chemistry A 2015 - vol. 3(Issue 16) pp:NaN3140-3140
Publication Date(Web):2015/03/11
DOI:10.1039/C5TB00266D
Great challenges remain in the template-assisted fabrication of metal nanowire arrays on substrates, because enormous effort is required to address the adhesion issues between substrates and adopted templates, e.g. anodic aluminum oxide (AAO). Therefore, novel and promising templates are highly desired for the construction of proposed structures. Here, vertical 1,5-diaminoanthraquinone (DAAQ) nanowires were prepared in situ on substrates by a facile method, and these were proven to be a reliable and alternative template for the preparation of a metal nanowire array. As an example, with the wet chemical reduction of HAuCl4, a three-dimensional gold nanowire array (3D GNA) was successfully obtained with a DAAQ template. The proposed 3D GNA has an extremely large roughness factor of ca. 15, as well as high stability and a favorable surface structure for the diffusion of analytes, making it a suitable candidate for the construction of high-performance electrochemical biosensors. As a result, an ultrasensitive aptasensor was constructed for the detection of thrombin, with a general sensing scheme. The fabricated aptasensor displays an impressively ultralow detection limit of 3 fM (S/N = 3) with a wide linear response from 10 fM to 1 nM, as well as excellent selectivity, good reproducibility and acceptable stability. Further, the biosensor exhibits potential for application in the analysis of real serum samples. The developed DAAQ nanowires are envisaged to become a general template for the fabrication of more nanowire arrays and the as-synthesized 3D GNA could open up a wide range of possibilities for potential applications in biological sensing.
Co-reporter:Hua-Yu Tang, Zhenyu Chu, Cui-Ping Li, Xiao-Ming Ren, Chen Xue and Wanqin Jin
Dalton Transactions 2016 - vol. 45(Issue 25) pp:NaN10255-10255
Publication Date(Web):2016/05/17
DOI:10.1039/C6DT01612J
Films of Prussian blue analogue (PBA) Co3[Co(CN)6]2 were fabricated on porous α-alumina, ITO glass, silicon wafer and non-woven fabric substrates via a facile self-assembly method, and were characterized using infrared spectroscopy, X-ray powder diffraction and scanning electron microscope techniques. The films composed of truncated cube-shaped PBA particles are highly oriented with a preferred (100) plane on the glossy and smooth surfaces of ITO glass and silicon wafer, but crystallographically isotropic on the rough surface of porous α-alumina and non-woven fabric substrates. Compact films were achieved on porous α-alumina and surface-functionalized ITO glass. Reversible solvatochromism/vapochromism was discovered and investigated for the powdered and thin-film PBA samples. Such peculiar solvatochromism/vapochromism is related to the process of the adsorbed solvent molecules replacing the coordinated water molecules in octahedral Co2+–(N)4(H2O)2. The change of the Co2+ ion’s coordination atmosphere leads to the variation of crystal field strength, as a result, the d–d transitions within the Co2+ ions are altered to give rise to a color change.
Co-reporter:Gongping Liu, Wei-Song Hung, Jie Shen, Qianqian Li, Yun-Hsuan Huang, Wanqin Jin, Kueir-Rarn Lee and Juin-Yih Lai
Journal of Materials Chemistry A 2015 - vol. 3(Issue 8) pp:NaN4521-4521
Publication Date(Web):2015/01/06
DOI:10.1039/C4TA05881J
Mixed matrix membranes (MMMs), consisting of inorganic fillers dispersed in a polymer matrix, are regarded as one of the most promising futuristic membranes. This work reports the utilization of molecular interactions to finely control the conformation and topology of polymer chains to fabricate high-performance polyhedral oligomeric silsesquioxanes (POSS)/polydimethylsiloxane (PDMS) MMMs. The influence of the incorporation of POSS on the polymer structure was systematically studied by molecular dynamics simulations combined with DSC, XRD and IR measurements. The surface and interfacial morphologies of the MMMs were observed through SEM, TEM and AFM characterizations. In particular, positron annihilation spectroscopy was employed to analyze the evolution of free volumes in the MMMs. Results indicated that facilely incorporating POSS into PDMS by molecular interactions could manipulate favorable interfacial morphology and tunable free volumes in MMMs. In the PDMS MMMs, the small free volumes were reduced and the large free volumes increased; these changes were beneficial for the preferential permeation of large-sized molecules through the polymeric membrane. As applied to the bio-butanol recovery from aqueous solutions, the prepared POSS/PDMS MMMs exhibited a simultaneous increase in permeability and selectivity, breaking the permeability-selectivity trade-off limitation, moreover transcending the upper bound of the state-of-the-art organophilic pervaporation membranes. Therefore, our work demonstrates that the proposed approach based on rationally creating molecular interactions can be expected to have broad applicability in fabricating high-quality MMMs for molecular separations.
Co-reporter:Lei Shi, Yan Wang, Zhenyu Chu, Yu Yin, Danfeng Jiang, Jingyi Luo, Shiming Ding and Wanqin Jin
Journal of Materials Chemistry A 2017 - vol. 5(Issue 5) pp:NaN1080-1080
Publication Date(Web):2016/12/23
DOI:10.1039/C6TB02658C
In this work, a novel electrochemical Hg2+ biosensor with high sensitivity and excellent reusability was presented. The sensor was based on tunable vertical single-walled carbon nanotubes (v-SWCNTs) and a target recycling strategy. A facile and scalable approach involving the conformational regulation of self-assembled monolayers was established for the fabrication of v-SWCNTs with tailored orientation and homogeneity. The obtained v-SWCNTs exhibited superior properties including a large specific area, high electrical conductivity, and excellent substrate binding strength, opening up a wide horizon for advanced electrochemical applications. Meanwhile, an efficient Hg2+ recycling strategy was designed using exonuclease III. In this strategy, a trace amount of Hg2+ triggered consecutive nicking reactions, and numerous report probes were released to bind with v-SWCNTs through π–π interactions. Based on the innovative design, an ultralow detection limit of 3 fM (S/N = 3), a wide linear range from 10 fM to 1 μM, high selectivity, and good reliability were achieved for a Hg2+ assay in water and serum samples using the prepared biosensor. Besides, due to the reversibility of π–π interactions, the stable v-SWCNT interface was regenerated for 50 consecutive measurements without obvious signal loss, making it a promising candidate for routine and efficient Hg2+ monitoring.
Co-reporter:Zhenyu Chu, Linlin Li, Gongping Liu and Wanqin Jin
Chemical Communications 2016 - vol. 52(Issue 86) pp:NaN12709-12709
Publication Date(Web):2016/09/09
DOI:10.1039/C6CC05334C
A novel membrane with heterogeneously functionalized nanocrystal layers was designed to synchronously perform in situ blood separation and sensing for the extraction of pure serum without any blood cells and fibrinogen by size sieving, and simultaneously realizing the electrochemical analysis of various physiological indexes.
Co-reporter:Chen Xiao, Zhengyu Chu, Xiao-Ming Ren, Tian-Yu Chen and Wanqin Jin
Chemical Communications 2015 - vol. 51(Issue 37) pp:NaN7949-7949
Publication Date(Web):2015/04/02
DOI:10.1039/C5CC02392K
The integrated, highly crystalline and water stable Prussian blue analogue films were successfully fabricated on the porous α-Al2O3, the conducting ITO and the flexible non-woven fabric substrates, respectively, using the self-assembly approach. The proton conduction was investigated for both powdered pellets and the film on the porous α-Al2O3 substrate. This study promotes the practical applications of MOF-based proton conductors in various devices.
Co-reporter:Gongping Liu, Wanqin Jin and Nanping Xu
Chemical Society Reviews 2015 - vol. 44(Issue 15) pp:NaN5030-5030
Publication Date(Web):2015/05/18
DOI:10.1039/C4CS00423J
Graphene is a well-known two-dimensional material that exhibits preeminent electrical, mechanical and thermal properties owing to its unique one-atom-thick structure. Graphene and its derivatives (e.g., graphene oxide) have become emerging nano-building blocks for separation membranes featuring distinct laminar structures and tunable physicochemical properties. Extraordinary molecular separation properties for purifying water and gases have been demonstrated by graphene-based membranes, which have attracted a huge surge of interest during the past few years. This tutorial review aims to present the latest groundbreaking advances in both the theoretical and experimental chemical science and engineering of graphene-based membranes, including their design, fabrication and application. Special attention will be given to the progresses in processing graphene and its derivatives into separation membranes with three distinct forms: a porous graphene layer, assembled graphene laminates and graphene-based composites. Moreover, critical views on separation mechanisms within graphene-based membranes will be provided based on discussing the effect of inter-layer nanochannels, defects/pores and functional groups on molecular transport. Furthermore, the separation performance of graphene-based membranes applied in pressure filtration, pervaporation and gas separation will be summarized. This article is expected to provide a compact source of relevant and timely information and will be of great interest to all chemists, physicists, materials scientists, engineers and students entering or already working in the field of graphene-based membranes and functional films.
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