Locking Patterned Carbon Nanotube Cages by Nanofibrous Mats to Construct Cucurbituril[n]-Based Ultrapermselective Dye/Salt Separation Membranes.

Surface patterning is a promising strategy to overcome the trade-off effect of separation membranes. Herein, a bottom-up patterning strategy of locking micron-sized carbon nanotube cages (CNCs) onto a nanofibrous substrate is developed. The strongly enhanced capillary force triggered by the abundant narrow channels in CNCs endows the precisely patterned substrate with excellent wettability and antigravity water transport. Both are crucial for the preloading of cucurbit[n]uril (CB6)-embeded amine solution to form an ultrathin (∼20 nm) polyamide selective layer clinging to CNCs-patterned substrate. The CNCs-patterning and CB6 modification result in a 40.2% increased transmission area, a reduced thickness, and a lowered cross-linking degree of selective layer, leading to a high water permeability of 124.9 L·m-2 h-1 bar-1 and a rejection of 99.9% for Janus Green B (511.07 Da), an order of magnitude higher than that of commercial membranes. The new patterning strategy provides technical and theoretical guidance for designing next-generation dye/salt separation membranes.

Voltage-Gated Membranes Incorporating Cucurbit[n]uril Molecular Containers for Molecular Nanofiltration.

Smart voltage-gated nanofiltration membranes have enormous potential for on-demand and precise separation of similar molecules, which is an essential element of sustainable water purification and resource recovery. However, the existing voltage-gated membranes are hampered by limited selectivity, stability, and scalability due to electroactive monomer dimerization. Here, for the first time, the host-guest recognition properties of cucurbit[7]uril (CB[7]) are used to protect the viologen derivatives and promote their assembly into the membrane by interfacial polymerization. Viologen functions as a voltage switch, whereas CB[7] complexation prevents its dimerization and improves its redox stability. The inhibited diffusion of the CB[7]-viologen complex enables the precise patterning of the surface structure. The resultant voltage-gated membrane displays 80% improved rejection performance, excellent recovery accuracy for similar molecules, and anti-fouling properties. This work not only provides an innovative strategy for the preparation of voltage-gated smart nanofiltration membranes but also opens up new avenues for ion-selective transmission in water treatment, bionic ion channels, and energy conversion.

Constructing π-Stacked Supramolecular Cage Based Hierarchical Self-Assemblies via π···π Stacking and Hydrogen Bonding.

Constructing supramolecular cages with multiple subunits via weak intermolecular interactions is a long-standing challenge in chemistry. So far, π-stacked supramolecular cages still remain unexplored. Here, we report a series of π-stacked cage based hierarchical self-assemblies. The π-stacked cage (π-MX-cage) is assembled from 16 [MXL]+ ions (M = Mn2+, Co2+; X = Br-, SCN-, Cl-; and L = tris(2-benzimidazolylmethyl)amine) via 18 intermolecular π-stacking interactions. The tetrahedral cage, consisting of four [MXL]+ ions as the vertexes and six pairs of [MXL]+ ions as the edges, features 48 exterior N-H hydrogen bond donors for hydrogen bond formation with guest molecules. By variation of the M2+/X- pair, the π-MX-cage demonstrates unique versatility for incorporating a wide variety of species via different hydrogen-bonding modes during the assembly of hierarchical superstructures. In specific, the π-MnBr-cages encapsulate acetonitrile (CH3CN) or cis-1,3,5-cyclohexanetricarbonitrile (cis-HTN) molecules in the central voids, while a core-shell tetrahedral inorganic cluster [Mn(H2O)6]@([Mn(H2O)4]4[Br42-]6) (Mn@Mn4-cage) is captured within the interstitial regions between cages. The π-CoSCN-cages are capable of stabilizing reactive sulfur-containing species, such as S2O42-, S2O62-, and HSO3- ions, in the hierarchical superstructure. Finally, H2PO4- ions are incorporated between π-CoCl-cages, resulting in an inorganic mesoporous framework. These results provide insights into further exploring the chemistry and hierarchical assembly of supramolecular cages based on π-π stacking intermolecular interactions.

Encapsulated Polyethyleneimine Enables Synchronous Nanostructure Construction and In Situ Functionalization of Nanofiltration Membranes.

Highly permselective nanostructured membranes are desirable for the energy-efficient molecular sieving on the subnanometer scale. The nanostructure construction and charge functionalization of the membranes are generally carried out step by step through the conventional layer-by-layer coating strategy, which inevitably brings about a demanding contradiction between the permselective performance and process efficiency. For the first time, we report the concurrent construction of the well-defined molecular sieving architectures and tunable surface charges of nanofiltration membranes through precisely controlled release of the nanocapsule decorated polyethyleneimine and carbon dioxide. This novel strategy not only substantially shortens the fabrication process but also leads to impressive performance (permeance up to 37.4 L m-2 h-1 bar-1 together with a rejection 98.7% for Janus Green B-511 Da) that outperforms most state-of-art nanofiltration membranes. This study unlocks new avenues to engineer next-generation molecular sieving materials simply, precisely, and cost efficiently.

Precisely Patterned Nanostrand Surface of Cucurbituril[n]-Based Nanofiltration Membranes for Effective Alcohol-Water Condensation.

Low concentration alcohols produced by state-of-the-art biological fermentation restrict subsequent purification processes for chemical, pharmaceutical, biofuel, and other applications. Herein, a rarely reported cucurbituril[n] (n = 6, 8) is employed to pattern the thin-film composite membranes with controllable and quantifiable nanostrand structures through a host-guest strategy. The resulting nanofiltration membrane with such morphology is the first report that exhibits excellent separation performance for isopropyl alcohol (IPA) and water, condensing the initial 0.5 wt % IPA aqueous solution to 9.0 wt %. This not only provides a novel strategy for patterning nanostructural morphology but also makes nanofiltration membranes promising for alcohol condensation in the biological fermentation industry that may reduce energy consumption and postprocessing costs.

A Well-Established POM-based Single-Crystal Proton-Conducting Model Incorporating Multiple Weak Interactions.

Three new proton conductors with simple structures based on isolated olyoxometalate anions as well as protonated imidazole and benzimidazole, namely, NNU-6-8, have been successfully prepared by hydrothermal reaction. We could control the number of proton sources by selecting different types and changing the charges of POM anions. The single crystal sample of NNU-6 along a-axis shows a highest proton conductivity of 1.91×10-2  S cm-1 , which is two and three orders of magnitude higher than that of 2.42×10-4 and 8.90×10-5  S cm-1 along b- and c-axes, respectively, due to the more unobstructed H-bonding network and stronger π-π stacking between benzimidazole rings as proton-transferring pathway along a-axis than that along b and c axes. It is a straightforward model to understand the metaphysical proton-conducting process, and this is the first time to put forward the idea that π-π stacking could assist proton transfer and be in favor of proton conduction, which has been demonstrated by calculating potential energy surfaces of proton transfer between benzimidazole molecules.

The Enhancement on Proton Conductivity of Stable Polyoxometalate-Based Coordination Polymers by the Synergistic Effect of MultiProton Units.

Two novel polyoxometalate (POM)-based coordination polymers, namely, [Co(bpz)(Hbpz)][Co(SO4 )0.5 (H2 O)2 (bpz)]4 [PMo(VI) 8 Mo(V) 4 V(IV) 4 O42 ]⋅13 H2 O (NENU-530) and [Ni2 (bpz)(Hbpz)3 (H2 O)2 ][PMo(VI) 8 Mo(V) 4 V(IV) 4 O44 ]⋅8 H2 O (NENU-531) (H2 bpz=3,3',5,5'-tetramethyl-4,4'-bipyrazole), were isolated by hydrothermal methods, which represented 3D networks constructed by POM units, the protonated ligand and sulfate group. In contrast with most POM-based coordination polymers, these two compounds exhibit exceptional excellent chemical and thermal stability. More importantly, NENU-530 shows a high proton conductivity of 1.5×10(-3)  S cm(-1) at 75 °C and 98 % RH, which is one order of magnitude higher than that of NENU-531. Furthermore, structural analysis and functional measurement successfully demonstrated that the introduction of sulfate group is favorable for proton conductivity. Herein, the syntheses, crystal structures, proton conductivity, and the relationship between structure and property are presented.

Explorations of New SHG Materials in the Alkali-Metal-Nb(5+)-Selenite System.

Standard high-temperature solid-state reactions of NaCl, Nb2O5, and SeO2 resulted in two new sodium selenites containing a second-order Jahn-Teller (SOJT) distorted Nb(5+) cation, namely, Na2Nb4O7(SeO3)4 (P1̅; 1) and NaNbO(SeO3)2 (Cmc21; 2). Compound 1 exhibits an unusual 3D [Nb4O7(SeO3)4](2-) anionic network composed of 2D [Nb4O11(SeO3)2](6-) layers which are further bridged by additional SeO3(2-) anions via corner sharing; the 2D [Nb4O11(SeO3)2](6-) layer is formed by unusual quadruple [Nb4O17](14-) niobium oxide chains of corner-sharing NbO6 octahedra being further interconnected by selenite anions via Nb-O-Se bridges. The polar compound 2 features a 1D [NbO(SeO3)2](-) anionic chain in which two neighboring Nb(5+) cations are bridged by one oxo and two selenite anions. The alignments of the polarizations from the NbO6 octahedra in 2 led to a strong SHG response of ∼7.8 × KDP (∼360 × α-SiO2), which is the largest among all phases found in metal-Nb(5+)-Se(4+)/metal-Nb(5+)-Te(4+)-O systems. Furthermore, the material is also type I phase matchable. The above experimental results are consistent with those based on DFT theoretical calculations. Thermal stabilities and optical properties for both compounds are also reported.

Cs(TaO2)3(SeO3)2 and Cs(TiOF)3(SeO3)2: structural and second harmonic generation changes induced by the different d(0)-TM coordination octahedra.

Two new cesium selenites containing TaO6 or TiO4F2 octahedra, namely, Cs(TaO2)3(SeO3)2 (1) and Cs(TiOF)3(SeO3)2 (2), have been prepared using standard high temperature solid-state method and hydrothermal reaction, respectively. Compound 1 crystallizes in P3̅m1 and features an unusual [(TaO2)3(SeO3)2](-) sandwich-like double layer in which two [Ta(1)O3(SeO3)](3-) layers are bridged by central Ta(2)O6 octahedra via corner-sharing, whereas Cs(TiOF)3(SeO3)2 with a polar space group P63mc features an interesting hexagonal tungsten oxide (HTO) layered topology and presents a strong second harmonic generation (SHG) of about 5 × KDP (KH2PO4), which is much larger than those of A(VO2)3(QO3)2 (A = K, Tl, Rb, Cs, or NH4; Q = Se, Te) with a similar HTO layered structure. Cs(TiOF)3(SeO3)2 is also type-I phase matching. The SHG of above-mentioned HTO materials can be enhanced greatly with the replacement of VO6 octahedra by TiO4F2 octahedra. Furthermore, thermal stabilities, UV-vis diffuse reflectance spectra, infrared spectra, relationship between crystal structure and SHG, and theoretical calculations were also reported.

Pb4V6O16(SeO3)3(H2O), Pb2VO2(SeO3)2Cl, and PbVO2(SeO3)F: new lead(II)-vanadium(V) mixed-metal selenites featuring novel anionic skeletons.

Hydrothermal reactions of PbCO3 (or PbCl2), V2O5, and SeO2 in KOH solution or HF solution resulted in three new lead(II)-vanadium(V) mixed-metal selenites, namely, Pb4V6O16(SeO3)3(H2O) (1), Pb2VO2(SeO3)2Cl (2), and PbVO2(SeO3)F (3). Compounds 1 and 2 are polar (space group P21), whereas compound 3 is centrosymmetric (space group Pbca). Compound 1 displays an unusual [V6O16(SeO3)3](8-) anionic chain, which is composed by a 1D [V4O12](2-) anionic chain that is further decorated by dimeric [V2O6(SeO3)3](8-) units via corner-sharing. Compound 2 features two types of 1D chains, a cationic [Pb2Cl](3+) chain and a [VO2(SeO3)2](3-) anionic chain, whereas compound 3 contains dimeric [V2O4(SeO3)2F2](2-) units. The powder second-harmonic-generating (SHG) measurements indicate that compound 1 shows a weak SHG response of about 0.2 × KDP (KH2PO4) under 1400 nm laser radiation. Thermal stability and optical properties as well as theoretical calculations based on density functional theory methods were also performed.

Conductive nanofiltration membranes via in situ PEDOT-polymerization for electro-assisted membrane fouling mitigation.

Nanofiltration (NF) membranes play a pivotal role in water treatment; however, the persistent challenge of membrane fouling hampers their stable application. This study introduces a novel approach to address this issue through the creation of a poly(3,4-ethylenedioxythiophene) (PEDOT)-based conductive membrane, achieved by synergistically coupling interfacial polymerization (IP) with in situ self-polymerization of EDOT. During the IP reaction, the concurrent generation of HCl triggers the protonation of EDOT, activating its self-polymerization into PEDOT. This interwoven structure integrates with the polyamide network to establish a stable selective layer, yielding a remarkable 90 % increase in permeability to 20.4 L m-2 h-1 bar-1. Leveraging the conductivity conferred by PEDOT doping, an electro-assisted cleaning strategy is devised, rapidly restoring the flux to 98.3 % within 5 min, outperforming the 30-minute pure water cleaning approach. Through simulations in an 8040 spiral-wound module and the utilization of the permeated salt solution for cleaning, the electro-assisted cleaning strategy emerges as an eco-friendly solution, significantly reducing water consumption and incurring only a marginal electricity cost of 0.055 $ per day. This work presents an innovative avenue for constructing conductive membranes and introduces an efficient and cost-effective electro-assisted cleaning strategy to effectively combat membrane fouling.

Bandgap-universal passivation enables stable perovskite solar cells with low photovoltage loss.

The efficiency and longevity of metal-halide perovskite solar cells are typically dictated by nonradiative defect-mediated charge recombination. In this work, we demonstrate a vapor-based amino-silane passivation that reduces photovoltage deficits to around 100 millivolts (>90% of the thermodynamic limit) in perovskite solar cells of bandgaps between 1.6 and 1.8 electron volts, which is crucial for tandem applications. A primary-, secondary-, or tertiary-amino-silane alone negatively or barely affected perovskite crystallinity and charge transport, but amino-silanes that incorporate primary and secondary amines yield up to a 60-fold increase in photoluminescence quantum yield and preserve long-range conduction. Amino-silane-treated devices retained 95% power conversion efficiency for more than 1500 hours under full-spectrum sunlight at 85°C and open-circuit conditions in ambient air with a relative humidity of 50 to 60%.

Fabrication and optical properties of mesoporous SnO2 nanowire arrays.

Large-scale SnO2 mesoporous nanowires have been successfully synthesized by an improved sol-gel method within the nanochannels of porous anodic alumina templates. In this method, chloride of stannic and urea are used as precursors, chloride of stannic is acting as source of tin ions, and urea offers a basic medium through its hydrolysis. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and selected-area electron diffraction are used to characterize the SnO2 mesoporous nanowires. It is found that the as-prepared nanowires consist of SnO2 nanoparticles and pores. They can be indexed as rutile structures and diameters are about 50-70 nm. The growth mechanism of the mesoporous nanowires is also been discussed. The band gap of the as-prepared mesoporous nanowires is 3.735 eV, determined by UV/visible absorption spectral results. The SnO2 mesoporous nanowires show strong and stable photoluminescence with emission peak centered at 3.730 eV, which has never been reported in nanowires. It could be attributed to the exciton recombination.

Self-Cleaning Nanofiltration Membranes by Coordinated Regulation of Carbon Quantum Dots and Polydopamine.

Performance declination of nanofiltration (NF) membranes caused by concentration polarization (CP) and membrane fouling has severely restricted their practical application in many fields. This work reports the construction of a novel interlayer between the substrate and the selective layer of conventional composite membranes by coordinating regulation of carbon quantum dots (CQDs) and polydopamine (PDA). Unlike traditional methods that treat CP and fouling separately, the new strategy grants the membrane with dual functions at one time. First, the insertion of the PDA-CQDs layer reformulates the interfacial polymerization process that reduces the solute transport resistance and mitigates the CP issue. Second, the sandwiched photoactive CQDs can degrade organic molecules adsorbed on the membrane surface under visible light, which is promising for low-cost fouling remediation. This study may offer valuable insights into the preparation of durable self-cleaning NF membranes for the effective treatment of complex wastewater in various industries.

Novel and potent inhibitors of fatty acid synthase derived from catechins and their inhibition on MCF-7 cells.

Fatty acid synthase (FAS) is a potential target for cancer, but potent inhibitors against FAS are scarce. In this study, we found that activities of catechins on inhibiting FAS increased greatly by heating them in acid. The enhancement was positively correlated to H(+) concentration. The inhibitory activities of the final products from different catechins were similar, all of which were less than 1 microg/mL. The product from (-)-epigallocatechin gallate (EGCG) was stable at room temperature, and its inhibitory kinetics and reacting sites on FAS were obviously different from the known FAS inhibitors. It also affected the viability of MCF-7 cells more obviously than EGCG. A putative route of the reaction progress was proposed and the effective inhibitors were deduced to be oligomers of 2-hydroxy-3-(3', 4', 5'-trihydroxyphenyl) propenoic acid by analysis of their spectra. The work affords new and potent FAS inhibitors that would be promising candidates for the treatment of cancer.

[Anti-tumor activity of Erythrina variegata L. extract and its mechanism of action].

The anti-tumor activities and mechanism of Erythrina variegata L. extract were investigated. Firstly, the MTT method was used to evaluate the inhibitory activity of the Erythrina variegata L. extract on proliferation of cancer cell lines. Moreover, in order to determine its anti-tumor effect in vivo, the Lewis lung cancer mice model was established. By comparing the relative tumor proliferation rates, growth curves, inhibition rates of different groups, the anti-tumor effect was evaluated. Furthermore, the anti-tumor mechanism of Erythrina variegata L. extract was studied by using G-quadruplex stability experiment. In the in vitro anti-liver cancer experiment, the Erythrina variegata L. extract has shown obvious anti-tumor effect on various tumor cells. And in the in vivo experiment, it exhibited significant anti-tumor effect. Besides, from the result of G-quadruplex stability experiment, we can see that the quadruplex structure show increasing T(m) values with increasing amounts of Erythrina variegata L. extract.

Contamination of soils with organochlorine pesticides in urban parks in Beijing, China.

Urban parks are an integral component of healthy urban living. Since they are frequently visited, an understanding of the environmental quality of these urban facilities is crucial. Here, a study was conducted on the contamination of soils in the parks of Beijing. Organochlorine pesticides (OCPs), which have the potential to cause endocrine disturbances, were considered study objectives. Hexachlorocyclohexanes (HCHs) were found at concentrations of 0.2490-197.0 ng g(-1) and dichlorodiphenyltrichloroethanes (DDTs) were found at concentrations of 5.942-1039 ng g(-1) in the soils investigated. The preliminary pollution assessment indicated that DDTs have caused high pollution levels in the soils of some parks. Analysis of the sources of contamination showed that HCHs in the soils were derived from an old mixed source of technical HCHs and lindane and that DDTs, which were suspected to have recent application to the soils at some sites, were derived mainly from a mixture of technical DDTs and dicofol containing DDT impurities. An independent sample t-test proved that pesticides containing DDTs had been used in large amounts in the soils of parks before 1983 (p<0.05) and that the levels of DDTs in the soils of parks administered by the Beijing municipal government were significantly higher than the levels in those administered by the district government (p<0.05). However, the main difference in this situation needs to be further studied. This study suggested that open spaces like urban parks were not as sound as was expected and that there was potential for exposure of visitors/workers in the parks to organochlorine pesticides.

Mixer-settler counter-current chromatography with a barricaded spiral disk assembly with glass beads.

A novel spiral disk is designed by placing barricades at 6 mm intervals in the middle of the spiral channel to divide the channel into multiple sections. Glass beads are placed in every other section so that the planetary motion produces repetitive mixing and settling of polymer phase systems. Performance of this mixer-settler spiral disk assembly was examined for separation of lysozyme and myoglobin with a polymer phase system. The best results were obtained with a spiral disk equipped with barricades with openings ranging from 1.2 to 0.4 mm on each side at a high revolution speed up to 1200 rpm.

Controllable porosity conversion of metal-organic frameworks composed of natural ingredients for drug delivery.

Two extremely rare ß-cyclodextrin (ß-CD) supported metal-organic frameworks (MOFs), CD-MOF-1 and CD-MOF-2, were induced to crystallize for the first time through a template-induced approach. The targeted CD-MOFs were employed to perform controlled drug delivery and cytotoxicity assays that confirmed their favourable biological potential of being used as drug carriers.

Purification of coenzyme Q10 from fermentation extract: high-speed counter-current chromatography versus silica gel column chromatography.

High-speed counter-current chromatography (HSCCC) is applied to the purification of coenzyme Q(10) (CoQ(10)) for the first time. CoQ(10) was obtained from a fermentation broth extract. A non-aqueous two-phase solvent system composed of heptane-acetonitrile-dichloromethane (12:7:3.5, v/v/v) was selected by analytical HSCCC and used for purification of CoQ(10) from 500 mg of the crude extract. The separation yielded 130 mg of CoQ(10) at an HPLC purity of over 99%. The overall results of the present studies show the advantages of HSCCC over an alternative of silica gel chromatography followed by recrystallization. These advantages extend to higher purity (97.8% versus 93.3%), recovery (88% versus 74.3%) and yield (26.4% versus 23.4%). An effort to avoid the toxic, expensive solvent CH(2)Cl(2) was unsuccessful, but at least its percentage is low in the solvent system.