The performance of mixed matrix membranes (MMMs) is usually limited by thick separation layer, low filler loading, and boundary defect between polymer and filler. Herein, a new two-dimensional metal-organic framework (2D MOF), named BUT-203, is designed and synthesized. Remarkably, the micron-sized crystals of this MOF could be readily delaminated into nanosheets with thickness of ca. 3 nm and lateral size of hundreds of nanometers to several microns. This delaminated nanosheets with high dispersibility in ethanol have a good compatibility with the polycation polymer polyethyleneimine (PEI). Under the optimum condition, a thin (ca. 70 nm) and high filler loading (up to ca. 73%) MMM, named BUT-203/PEI-HPAN(73) can be fabricated on macroporous hydrolyzed polyacrylonitrile (HPAN) substrate by a simple blending-spin coating method. This membrane shows a high water permeance up to 870 L/(m2·h·MPa) and high rejections (over 97.9%) for anionic dye molecules. In addition, this membrane exhibits a long term running stability, high dye desalination ability, and excellent antifouling property. These results suggest the usefulness of the membrane in nanofiltration, and simultaneously this work demonstrates that rationally designed 2D MOFs have great potential as filler materials in fabricating MMMs for various applications.

Nanofiltration (NF) is widely used in water treatment; however, the fabrication of NF membranes with high permeability and selectivity still remain a challenge. Here, we propose a facile and feasible approach to design and prepare nanoporous polymeric membranes (NPMs) by using soluble molecular coordination complexes as pore-forming agents for the removal of dyes from water. Enhanced porosity and tuned pore sizes of the membranes were achieved by using several selected coordination complexes with different compositions and structures. The resulting membranes display high permeance without compromising rejection compared with corresponding pristine membranes. Particularly, one of membranes, with tBu-MOP acting as the pore-forming agent, shows an optimal separation performance of the water permeance over 209 L/(m(2).h.MPa) and a rejection about 98% toward both methyl blue (MB) and eriochrome black T (EBT). This permeance is 4.5-fold higher than that in the pristine membrane fabricated without using any pore-forming agent. This method is expected to extend to the fabrication of other polymeric membranes with required pore properties by selecting suitable coordination complexes as pore-forming agents for different separation applications.

The separation of aromatic/aliphatic hydrocarbon mixtures is a significant process in chemical industry, but challenged in some cases. Compared with conventional separation technologies, pervaporation is quite promising in terms of its economical, energy-saving, and eco-friendly advantages. However, this technique has not been used in industry for separating aromatic/aliphatic mixtures yet. One of the main reasons is that the separation performance of existed pervaporation membranes is unsatisfactory. Membrane material is an important factor that affects the separation performance. This review provides an overview on the advances in studying membrane materials for the pervaporation separation of aromatic/aliphatic mixtures over the past decade. Explored pristine polymers and their hybrid materials (as hybrid membranes) are summarized to highlight their nature and separation performance. We anticipate that this review could provide some guidance in the development of new materials for the aromatic/aliphatic pervaporation separation.

Organic solvent nanofiltration (OSN) is one of the fast development areas of membrane separation. The nano filtration performances of membranes are mainly depended on the thickness of separation layers and the orientation of separation channels. Herein, an ultrathin alpha-Co(OH)(2) film was fabricated through the in situ growth of alpha-Co(OH)(2) nanosheets on alumina tubular substrate for OSN. The thickness of the film was approximately 300 nm and the alpha-Co(OH)(2) nanosheets were vertically grown to leave channels perpendicular to the substrate. The orientation growth and interlayer gallery of the alpha-Co(OH)(2) layer were confirmed by SEM, PXRD and SAXS characterization. The resulting composite membrane exhibits high fluxes for organic solvents. Particularly, in separating eriochrome black T from methanol solution, the permeance could reach 127 L m(-2) h(-1) bar(-1). We anticipate that the facile fabrication method and excellent separation performances make the alpha-Co(OH)(2) composite membrane have a great application potential in OSN.

Pervaporation membranes have been proved to have potential uses in the separation of aromatic/aliphatic mixtures.Herein,Co-MOF-74/W3000 hybrid membranes are designed and fabricated on the porous Al2O3 substrate for the recovery of toluene from its n-heptane co-mixture.The Co-MOF-74 contains rich open metal unsaturated sites and benzene rings,which not only enable them to be compatible well with the polymer but also could improve the adsorptive selectivity of the membrane towards toluene.Pervaporation results demonstrated that the incorporation of Co-MOF-74 indeed contributed to the significant improvements of these membranes for the separation performance.Particularly,the Co-MOF-74/W3000-6.0 membrane showed an optimal separation performance with the separation factor of 7.6 and the permeation flux of 89 g/(m2 · h) for the recovery of toluene from its mass fraction 50％ n-heptane mixture.Especially,the hybrid membrane could keep at a stable separation level after 30 h,which indicated that it has potential applications in industry.

In this paper, we consider a single cell model of pre-Bötzinger complex, which is derived by adding an external tonic drive ([Formula: see text]) to the model developed by Park and Rubin. Using fast–slow geometric decomposition and bifurcation analysis, we study firing activities of the system and try to reveal the mechanisms underlying the bursts related to the mean level of excitatory input ([Formula: see text]) and the maximal conductance associated with the sodium ([Formula: see text]). Since a regular bursting requires at least two timescales, we consider the effects of timescale, especially of the slow timescale, on the bursting oscillations. Unlike the previous works, in this paper, we conduct our investigation by choosing different slow variables. We show how [Formula: see text] and [Formula: see text] affect bifurcations of the fast subsystem and how the bifurcations further determine firing activities of the full system with different slow variables.

Introducing another chromophore into a luminescent MOF is a potential way to assembling novel dual-emissive luminescent materials. Putting the chromophore, for which luminescence can be enhanced by Zn2+ ion, into MOF-5 by the "bottle around ship" strategy is a simple but efficient synthesis method to realize such dual-emissive materials. According to this strategy, a novel dual-emissive luminescent composite material [Zn2(HL)3]+@MOF-5 was constructed by loading the [La3(HL)2L2(NO3)3H2O] (1) (H2L = 7,7'-(ethane-1,1'-diyl)8-hydro-quinoline) into MOF-5, in which the [Zn2(HL)3]+ anions were transformed from 1 with the existence of Zn2+. The dual-emissive composite materials show excellent luminescence with two emissions of MOF-5 at 410 nm and [Zn2(HL)3]+ at 524 nm. Furthermore, by combining characteristics of MOF-5 and the guest chromophore, the composite material is highly selectively sensitive toward Al3+ and monoethanolamine, which makes [Zn2(HL)3]+@MOF-5 a potential self-calibrated fluorescence sensor.

The separation of aromatic/aliphatic mixtures is significant in chemical industry. Pervaporation has attracted increasing attention due to its low energy consumption and environmentally friendly process. However, the formation of membranes mostly use toxic organic solvents, whereas in this study water was used instead to prepare membrane in separating aromatic/aliphatic mixtures. W3000 were dispersed in water to form micelles, which were then deposited onto the surface of the tubular porous ceramic substrate through the negative pressure-driven assembly method. The emulsion and composite membranes were characterized by TEM, SEM and FTIR. The crosslinking density of W3000 was also tested using NMR XLD analyzing system. The membranes were used for separating aromatic/aliphatic mixtures through pervaporation. The results showed that compared with the membrane prepared by DMF, the pervaporation separation index (PSI) of the composite membrane formed using water as solvent was 3.3-fold increased for separating toluene/n-heptane mixtures. The as-prepared composite membranes showed a better comprehensive pervaporation performance. This facile strategy may have a potential in the application of pervaporation for separating aromatic/aliphatic mixtures in industry. (C) 2017 Elsevier B.V. All rights reserved.

A novel porous anionic metal–organic framework, (Me2NH2)2[Zn2L1.5bpy]·2DMF (BUT-201; H4L=4,8-disulfonaphthalene-2,6-dicarboxylic acid; bpy=4,4-bipyridine; DMF=N,N-dimethylformamide), with pillared double-layer structure has been synthesized through the reaction of a sulfonated carboxylic acid ligand and Zn(NO3)2·6H2O with 4,4-bipyridine as a co-ligand. It is found that BUT-201 can rapidly adsorb cationic dyes with a smaller size such as Methylene Blue (MB) and Acriflavine Hydrochloride (AH) by substitution of guest (CH3)2NH2+, but has no adsorption towards the cationic dyes with a lager size such as Methylene Violet (MV), the anionic dyes like C. I. Acid Yellow 1 (AY1) and neutral dyes like C. I. Solvent Yellow 7 (SY7), respectively. The results show that the adsorption behavior of BUT-201 relates not only to the charge but also to the size/shape of dyes. Furthermore, the adsorbed dyes can be gradually released in the methanol solution of LiNO3.

Pervaporation membranes are potentially useful in the separation of aromatic/aliphatic mixtures. Wherein, the membrane material plays a key role. Herein, a series of functionalized metal-organic polyhedra (MOPs)/hyperbranched polymer hybrid membranes are molecularly designed and fabricated for the recovery of aromatic hydrocarbons. The isostructural MOP molecules with different functional groups are uniform in shape/size and soluble in solvents, which enable them to disperse well and be compatible in/with the polymer. Pervaporation results demonstrated significant improvements of these membranes in separation performances. Particularly, the membrane with MOP-SO 3 Na n H m showed the separation factor of 8.03 and the permeation flux of 528 g/m 2 h for the recovery of toluene from its 50 wt % n-heptane mixture, and those values are 8.4 and 540 g/m 2 h for benzene/cyclohexane mixture. We propose that the selectivity of these membranes is affected primarily by the polarity of functional groups in MOPs, which were further explained by the adsorption experiments and molecular simulations. © 2016 American Institute of Chemical Engineers AIChE J , 62: 3706–3716, 2016

In this work, Co(II)-formate (Co(HCOO)2) has been demonstrated feasible to be used as stable aromatic hydrocarbon transport carrier for facilitating aromatic hydrocarbon transport membranes. Metal-organic framework Co(HCOO)2 materials with different particle sizes were prepared through a solvothermal synthetic method, and then were doped into poly(ether-block-amide) (PEBA). The resulting hybrids were finally deposited on the outer surface of tubular ceramic substrate with a dynamic pressure-driven assembly method. The morphologies and structures of the resulting Co(HCOO)2/PEBA membranes were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDX), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), positron annihilation lifetime spectroscopy (PALS), and nanoindentation. These membranes were then used in separating aromatic/aliphatic hydrocarbon mixtures through pervaporation. When the feed solution is 10wt% toluene/n-heptane mixtures, the permeate flux of the membrane is 771g/(m2h) with a separation factor of 5.1. Meanwhile, due to the immobilization effect of the Co(HCOO)2 for Co(II) ions, the Co(HCOO)2/PEBA membrane showed stable separation performances.

The stability of membrane is a key issue for pervaporation separation of aromatic/aliphatic hydrocarbon mixtures. In this study, in order to enhance the stability, composite membrane with “pore-filling” structure was formed on porous ceramic tubular substrate. A simple self-crosslinking strategy based on the unique hyperbranched macromolecule, Boltorn W3000, was utilized in the preparation procedure. The hydroxyl and carboxyl groups on Boltorn W3000 molecules reacted at intramolecular and intermolecular during thermal cross-linking process, and then hyperbranched polymers were assembled onto the top layer and sublayer of the ceramic substrate. The morphologies and structures of “pore-filling” composite membrane were characterized by FTIR, SEM, and Nano Indenter. Moreover, “non-pore-filling” membrane was also prepared by the same method with an additional “plugging-holes” step. Both of these two composite membranes were used for separating toluene/n-heptane mixtures. The results indicated that the “pore-filling” membrane showed more stable separation performance, due to its excellent anti-swelling properties. This work thus not only illustrated a new approach for the preparation of “pore-filling” membrane, but also produced a potentially useful organic/inorganic composite membrane for aromatic/aliphatic hydrocarbon mixtures separation.

The structure and magnetism of three cobalt(ii)-azide complexes, [Co(N3)2(bepy)2]n (), [Co2(N3)4(vipy)4]n (), and [Co(N3)2(bipy)]n () were tuned by three structurally related 4-substituent pyridines, 4-benzylpyridine (bepy), 4-vinyl pyridine (vipy), and 4,4'-bipyridine (bipy) as co-ligands in solvothermal reactions. With flexible benzyl as a substituent group of the pyridine co-ligand, a one-dimensional (1D) complex with double end-to-end (EE) azide-bridging Co(ii) chain is formed. While using a rigid but small vinyl group as the substituent, a distinct Co(ii)-azide chain with alternate double end-on (EO) and double EE azide bridges was obtained. Finally, when another pyridine group was used instead of the substituent incapable of coordinating in and , a bipyridine, it gave rise to a chiral complex with a three-dimensional (3D) diamondoid Co(ii)-azide framework further reinforced by the bipy ligand. Magnetic studies indicate antiferromagnetic interactions between the Co(ii) ions in the three complexes, but interestingly, weak antiferromagnetism origin of spin canting exists in at low temperatures.

As a new type of filler for nanohybrid membranes, metal–organic frameworks (MOFs) have attracted intense interest in recent years. In this work, MOF-based Cu3(BTC)2/PVA (BTC=benzene-1,3,5-tricarboxylate, PVA=poly(vinyl alcohol)) nanohybrid membranes were fabricated on a ceramic tubular substrate by using a pressure-driven assembly method. The morphology and structure of the resulting membranes were characterized by scanning electron microscope, energy dispersive X-ray spectrometer, and powder X-ray diffraction. The Cu3(BTC)2/PVA membranes were then used in separating 50wt% toluene/n-heptane mixtures through pervaporation. The effects of PVA concentration, Cu3(BTC)2 loading, feed composition, and operating temperature on membrane performances were explored. The results indicate that, compared with pristine PVA membrane, the separation factor and permeate flux of optimized Cu3(BTC)2/PVA membranes are improved from 8.9 and 14g/(m2h) to 17.9 and 133g/(m2h), respectively. A speculation of the transport process of permeating components in the selective layer of Cu3(BTC)2/PVA membrane was proposed. Enhanced affinity between toluene and the membrane through incorporating Cu3(BTC)2 particles plays a key role in improving separation performances.

Hybrid membranes composed of porous metal-organic molecule nanocages as fillers embedded in a hyperbranched polymer (Boltorn W3000) were fabricated, which exhibit excellent pervaporation separation performances towards aromatic/aliphatic hydrocarbons. The unique nature of the molecule-based fillers and their good dispersion and compatibility in/with the polymer are responsible for the good membrane properties.

A counter diffusion assisted secondary growth method is developed for the fabrication of inner skin ZIF-8 tubular membranes.

A novel three-dimensional chiral heterometallic 3d–3d azido complex, [Co2Zn(N3)4(pyzc)2]∞(1) (pyzc=2-pyrazinecarboxylate), was obtained by assembling CoII, ZnII, azido, and pyrazine carboxylate under solvothermal condition. The structure of the complex can be described as end-on (EO) azido, end-to-end (EE) azido mixed bridged alternate Co–Zn chains linked by the 2-pyrazinecarboxylate. Magnetic studies indicate that dominant anti-ferromagnetic coupling interactions exist in the complex.

A microbial consortium M19,originated from four degrading bacteria for degrading pyridine(Shinellazoogloeoides BC026),quinoline(Pseudomonas sp.BW004),and carbazole(Pseudomonas sp.BC039 and BC046) were used to explore the simultaneous degradation mechanism of nitrogen heterocyclic compounds(NHCs).The experimental results showed that the simultaneous degradation efficiency of the three NHCs by M19 was higher than those by any single strain.The intermediate products from quinoline degraded by M19 were the same as those by BW004.All four bacterial strains grew well in the media containing three NHCs,and the quinoline degradation gene(qorL) and carbazole degradation gene(carAa) had been held and expressed.The mechanism of NHCs' simultaneous degradation by M19 was the simple superposition of the 3 degradation processes carried by each strain,however,the strains benefited from each other due to the rapid reduction of toxicity from NHCs.

详细介绍利用饮料瓶制作蚯蚓牧场的方法,并通过实验证明制作的蚯蚓牧场有利于蚯蚓的饲养以及便于观察蚯蚓的运动方式。该蚯蚓牧场的制作方法简单、取材经济实惠。

A novel heterometallic complex, [Ni2Mn(N-3)(2)(nic)(4) center dot (H2O)(2)](n) (1) (nic=nicotinate), was obtained by assembling MnCl2 center dot 4H(2)O, Ni(NO3)(2)-6H(2)O, NaN3 and nicotinic acid with a "one step" synthetic strategy-hydrothermal reaction. The 3D structure of the complex can be described as end-on (EO) azido and syn, syn carboxylates mixed bridged by alternate Ni-Mn-Ni trimers linked by the nicotinate. Dominant ferromagnetic interactions were observed between the Ni-II and Mn-II ions in the trimer. (C) 2013 Elsevier Inc. All rights reserved.