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A gradual amide truncation strategy was presented to tune the pore chemistry and CO

By shortening the previous shortest tetracarboxylate ligand, the first ligand-to-ligand and axial-to-axial pillaring method was realized in the prototype MOF

Despite a lot of research on the antibacterial effect of Fe

Imaging platforms that enable long-term, high-resolution imaging of biofilms are required to study cellular level dynamics within bacterial biofilms. By combining high spatial and temporal resolution and low phototoxicity, lattice light sheet microscopy (LLSM) has made critical contributions to the study of cellular dynamics. However, the power of LLSM has not yet been leveraged for biofilm research because the open-on-top imaging geometry using water-immersion objective lenses is not compatible with living bacterial specimens; bacterial growth on the microscope's objective lenses makes long-term time-lapse imaging impossible and raises considerable safety concerns for microscope users. To make LLSM compatible with pathogenic bacterial specimens, we developed hermetically sealed, but optically accessible, microfluidic flow channels that can sustain bacterial biofilm growth for multiple days under precisely controllable physical and chemical conditions. To generate a liquid- and gas-tight seal, we glued a thin polymer film across a 3D-printed channel, where the top wall had been omitted. We achieved negligible optical aberrations by using polymer films that precisely match the refractive index of water. Bacteria do not adhere to the polymer film itself, so that the polymer window provides unobstructed optical access to the channel interior. Inside the flow channels, biofilms can be grown on arbitrary, even nontransparent, surfaces. By integrating this flow channel with LLSM, we were able to record the growth of S. oneidensis MR-1 biofilms over several days at cellular resolution without any observable phototoxicity or photodamage.

The metal-organic framework (MOF) NTUniv-54 (NTUniv = Nantong University) was assembled via utilizing click chemistry with densely decorated trizole units and exposed metal sites, which exhibited the best methane working ability (197 cm3·cm-3 from 100 to 5 bar and 177 cm3·cm-3 from 65 to 5 bar at 298 K), and the lowest CO2Qst of 22.8 kJ·mol-1 in all triazole-MOFs at room temperature.

Conventional aromatic compounds tend to exhibit the formation of sandwich-shaped excimers and exciplexes between their excited and ground states at high concentrations or in their aggregated states, causing their fluorescence to weaken or disappear due to the aggregation-caused quenching (ACQ) effect. This limits their applications in concentrated solutions or solid materials. Herein, for the first time, ACQ-based pyrene (Py) units are covalently connected to the surface of polyethylene/polypropylene nonwoven fabric (PE/PP NWF) via electron beam preradiation-induced graft polymerization followed by chemical modification. The matrix can be considered a solid solvent and Py units as a solid solute, such that the amount of Py units can be controlled by varying the reaction time. The obtained fluorescent fabric not only exhibits remarkable fluorescence properties with high fluorescence intensity, high quantum yield (>90%), and excellent fluorescence stability after laundering or in harsh chemical environments, but the fluorescence color and intensity, quantum yield, and lifetime can also be regulated by employing the ACQ effect. Additionally, the as-prepared fluorescent fabric can effectively distinguish common monocyclic aromatic hydrocarbons via a simple fluorescence response test.

A mixed water-organic solvent used for amidoximation increased the production cost of an amidoxime-based polymer sorbent and was not environmentally friendly as well. In this work, the amidoximation of an ultrahigh molecular weight polyethylene fiber co-grafted with acrylonitrile and methacrylic acid was carried out in aqueous solution without the use of an organic solvent. The effects of amidoximation parameters including NH2OH concentration, temperature, time, and various solvents on the uranium adsorption performances in both uranium-spiked brine and simulated seawater were investigated. Results indicated that the optimal amidoximation parameters were 5% (w/v) NH2OH, 80 °C, and 24 h. The uranium adsorption capacities of the sorbents amidoximated in aqueous solution were comparable with those of sorbents amidoximated in the various mixed water-organic solvents. Moreover, in comparison with both acidic (pH ∼3) and alkalic (pH ∼11) aqueous solution, the sorbent amidoximated in neutral (pH ∼7) NH2OH aqueous solution achieved higher uranium adsorption capacities in both uranium-spiked brine (112.4 mg/g) and simulated seawater (7.4 mg/g). Additionally, potassium hydroxide (KOH) treatment was a necessary process and indeed significantly increased the uranium adsorption capacity.

Waste printed circuit boards (WPCBs) contain certain amounts of valuable metals such as gold, and so recycling the gold from WPCBs is necessary. Based on our previous study, gold can be selectively...

Finding efficient actinide decorporation agents is crucial for public health and the development of the nuclear industry. The current inventory of decorporation agents is predominately limited to a handful of ligands. In this work, a two-dimensional (2D) covalent organic nanosheet (CON) material was rationally designed and tested for in vivo uranium decorporation. This material is extensively grafted with amidoxime (AO), a classic uranium-recognition ligand, which not only provides selective binding sites for uranyl but also expands the interlayer spacing of CON, making the active sites more accessible. Significantly, the results of in vivo experiments demonstrate that, in both prophylactic and prompt administration groups, CON-AO exhibits a higher excretion ratio of uranium from kidneys than that of ZnNa

A new technique is proposed for the in situ printing of fluorescent fabrics with superior fluorescent properties that have the potential for continuous roll-to-roll production in the industry. Nonconjugated chemical moieties were covalently connected to polyethylene/polypropylene nonwoven fabric (PE/PP NWF) to successfully prepare fluorescent PE/PP NWF, which emits a bright blue light and has a high quantum yield (∼83.35%) that can be attributed to a unique aggregation-induced emission effect. The fluorescent PE/PP NWF exhibits excellent fluorescent stability under high shear forces during accelerated laundering and in harsh chemical environments. The fluorescent PE/PP NWF can also be tailored into diverse shapes and printed in situ with high resolution. The versatility of the method was also demonstrated by fabricating fluorescent materials with different polymer matrices such as Nylon 66 fiber and PE terephthalate membrane.

Pincer-type main-group complexes have attractive properties and excellent potential as catalysts. A set of sterically hindered trianionic pincer-type phosphorus complexes have been shown to activat...

Molecular deposition (MD) filming flooding has proved to be an effective enhanced oil recovery (EOR) method in reservoirs where recovery was relatively difficult. The B425 block with a low permeabi...

Crystalline porous materials such as covalent organic frameworks (COFs) are advanced materials to tackle challenges of catalysis and separation in industrial processes. Their synthetic routes often require elevated temperatures, closed systems with high pressure, and long reaction times, hampering their industrial applications. Here we use a traditionally unperceived strategy to assemble highly crystalline COFs by electron beam irradiation with controlled received dosage, contrasting sharply with the previous observation that radiation damages the crystallinity of solids. Such synthesis by electron beam irradiation can be achieved under ambient conditions within minutes, and the process is amendable for large-scale production. The intense and targeted energy input to the reactants leads to new reaction pathways that favor COF formation in nearly quantitative yield. This strategy is applicable not only to known COFs but also to new series of flexible COFs that are difficult to obtain using traditional methods.

Textiles with fire detection will appeal for the interior decoration of houses and play a critical role in public security. Herein, we fabricated a sandwichlike fire alarm fabric (Ag@Fe3O4-MS) base...

On the basis of the [Fe3(μ3-O)(COO)6] cluster and 3,3′,5,5′-diphenyltetracarboxylic acid (H4BPTC), three novel metal–organic frameworks (MOFs), NJU-Bai25, NJU-Bai26, and NJU-Bai27 (NJU-Bai for Bai’...

A pure-supramolecular-linker (PSL) approach for the formation of metal–organic frameworks (MOFs) was initially given, which was demonstrated by syntheses of two highly connected and isostructural M...

A new amide-functionalized metal-organic framework (AFMOF) with the combined feature of highly selective CO2 adsorption and high thermal and chemical stability, [Sc3(μ3-O)(L)1.5(H2O)3Cl] n [NJU-Bai49; NJU-Bai for Nanjing University Bai's group, H4L = 5-(3,5-dicarboxybenzamido)isophthalic acid], was synthesized that exhibits 4.5 wt % CO2 uptake at 298 K and 0.15 bar and the highest selectivity for CO2/N2 (166.7) among all AFMOFs. Grand canonical Monte Carlo simulations further indicate that both the decorated amide group and the open metal site act as CO2 binding sites, which may contribute to its highly selective CO2 uptake.

A new kind of highly durable, electrically conductive UHMWPE fibers coated with copper was fabricated through a novel, simple, and universal process in this paper. Poly(acrylic acid) was anchored o...

The in situ growth of one-dimensional magnetite (Fe3O4) nanowire (NW) arrays with deterministic and tunable control over their orientation and morphology on a wide range of flexible and low heat resistance substrates is still a challenge. Herein, a facile method of controlling the orientation of Fe3O4 NW arrays on a polypropylene (PP) nonwoven fabric surface (PP-g-PAO/Fe3O4) through simultaneous radiation induced graft polymerization and coprecipitation processes was realized. We demonstrated a control over the orientation and geometric properties of coprecipitated Fe3O4 NWs via complex iron ion using amidoxime groups, which not only endow the material with high durability but also lead to the oriented growth of Fe3O4 NWs. The results showed that Fe3O4 NWs were only grown on the surface of the PP nonwoven fabric (length:diameter ratio ≈ 10), whereas the Fe3O4 produced in the solution exhibited a spherical structure under identical conditions. The PP-g-PAO/Fe3O4 composite presented a good saturated magneti...

A new approach of finely tuning multinuclear clusters of metal–organic frameworks (MOFs) through symmetry-upgradingly isoreticular transformation was first presented and a bcu-type MOF, {[Cu4(μ4-O)Cl2(IN)4][CuCl2]}∞ (NJU-Bai35; NJU-Bai for Nanjing University Bai group), with cluster [Cu4(μ4-O)Cl2(COO)4N4] of higher symmetry compared to the pristine MOF, was successfully synthesized. The symmetry upgrading implemented on the inorganic part triggers the adjustment of channels in NJU-Bai35 to fit CO2 molecules, leading to a high CO2 adsorption capacity (7.20 wt % at ∼0.15 bar and 298 K) and high selectivity of CO2 over N2 and CH4 (275.8 for CO2/N2 and 11.6 for CO2/CH4) in NJU-Bai35. Breakthrough experiments further confirmed that NJU-Bai35 might be an excellent candidate for CO2 capture and natural gas purification.

Low-salinity water (LSW) flooding has become a quite simple, effective, and economically feasible enhanced oil recovery (EOR) technology under the background of low oil price. The B425 block with a low permeability in Shengli oilfield, China, has achieved an excellent LSW flooding performance, but the main EOR mechanisms in the block are still not clear. Therefore, in order to investigate the LSW flooding mechanisms in the B425 block, a set of core-flooding experiments were conducted. The water contact angle on core slice and the zeta potential of rock particle were also measured. Then the main EOR mechanisms of LSW flooding in the block were discussed. The experimental results show that the LSW injection can indeed enhance the oil recovery in the low-permeability oil reservoir. Compared with the direct high salinity water (HSW) injection, direct LSW injection and HSW–MSW (medium salinity water)–LSW successive injection can increase the oil recovery factor by 10% and 29.52%, respectively (when the core pe...

The halogen-substituted derivatives and the parent aniline tetramer as organic semiconductors have been theoretically investigated with a focus on the electronic properties and charge transport properties through density functional theory and Marcus–Hush theory methods. The study on the transport properties of holes and electrons can obtain insight into the effect of halogenation substitution on injection of charge carriers and transport character. The equilibrium geometries, reorganization energies, frontier molecular orbitals, intermolecular electronic couplings, electrostatic potential isosurfaces, and angular resolution anisotropic mobilities were calculated. The calculated results revealed that perfluorination and perchlorination can induce stronger structure relaxation and effectively lower the highest occupied molecular orbital and lowest unoccupied molecular orbital levels. The angle dependence mobilities of the three crystals show remarkable anisotropic character. The carrier mobility curves for ...

On the basis of the ligand of 5-(pyridin-3-yl)isophthalic acid (H2L), a new distorted [Mn2(COO)4N2] cluster based metal–organic framework with (3,3,6) topology, [Mn2(L)2DMF]·DMF·MeOH (NJU-Bai33; DMF = N,N- dimethylformamide), was synthesized, which exhibits a new point (Schlafli) symbol of (4·62)2(42·68·85), contains open metal sites, and shows selective adsorption of CO2 over N2 and CH4 with CO2 uptake amounts high up to 7.9 and 4.2 wt % at 0.15 bar and at 273 and 298 K, respectively.

Two new (3,6)-connected and eea topological MOFs without open metal sites, NJU-Bai30 and NJU-Bai31, from Cu-paddelwheel units and 5-[4′-(pyridin-4-yl)phenyl]isophthalic acid (L1) and 5-[3′-amino-4′-(pyridin-4-yl)phenyl]isophthalic acid (L2) have been synthesized, and interestingly, they exhibit relatively high surface area and large CH4 adsorption uptake.

Amidoximated nylon-66 fiber containing double amidoxime groups per repeating unit (coded as PA66-g-PGMA-IDPAO) for the purpose of removing low uranium concentrations (1–25 mg/L) from aqueous solutions and application in simulated nuclear industry effluents was prepared by a simultaneous radiation-induced emulsion graft polymerization method. It was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and single fiber tensile strength tester. Batch adsorption experiments were conducted to investigate the effect of initial pH, sorption isotherm, adsorption kinetics, and thermodynamics. It was found that the optimum initial pH is 5.0. The sorption isotherm followed the Langmuir isotherm. The adsorption kinetics fit the pseudo-second-order model. The thermodynamics parameters revealed that the adsorption process was spontaneous and endothermic. The sorption test performed in a simulated nuclear industry effluent demonstrated a high adsorption effi...

In this study, a label-free electrochemical immunosensor was developed for detection of cytokine tumor necrosis factor-alpha (TNF-α). First, AuNPs loaded reduced graphene oxides nanocomposites (RGO-ph-AuNP) were prepared, and then, a mixed layer of 4-carbxyphenyl and 4-aminophenyl phosphorylcholine (PPC) was modified to the surface of AuNPs for the subsequent modification of anti-TNF-α capture antibody (Ab1) to form the capture surface (Au-RGO-ph-AuNP-ph-PPC(-ph-COOH)) for the analyte TNF-α with the antifouling property. For reporting the presence of analyte, the anti-TNF-α detection antibody (Ab2) was modified to the graphene oxides which have been modified with the 4-ferrocenylaniline through diazonium chemistry to form Ab2-GO-ph-Fc. Then, a sandwich assay was formed on gold surfaces for the quantitative detection of TNF-α based on the electrochemical signal of ferrocene. X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), UV–vis, a...

Upon the basis of a bifunctional organic ligand with two carboxyl groups and one N donor, 5-(quinolin-4-yl)isophthalic acid (H2L), a new (3,6)-connected metal–organic framework with pyr topology, [Cu(L)·DMF]n (NJU-Bai32), has been synthesized and exhibits highly selective CO2 adsorption.

On the basis of a new topology, a novel yttrium metal–organic framework [Y2(TPBTM)(H2O)2]·xG (TPBTM = N,N′,N″-tris(isophthalyl)-1,3,5-benzenetricarboxamide and G = guest molecule) (NJU-Bai11) has been synthesized and structurally characterized. NJU-Bai11 crystallizes in a chiral space group and in its topological net and exists left of the helical rods, which are constituted from edge-sharing pyramidal polyhedra with points of extension as carboxylic carbon atoms along the a axis. NJU-Bai11 exhibits excellent adsorption capacity for CO2 (130.0 cm3/g at 273 K, 1 bar) and H2 (160.0 cm3/g at 77 K, 1 bar). Remarkably, NJU-Bai11 possesses high H2 adsorption enthalpy (7.05 kJ/mol), which is approaching the highest value (7.3 kJ/mol) reported among rare-earth metal–organic frameworks (RE-MOFs). In addition, a high selectivity ratio of 30.2 for CO2 over N2 makes NJU-Bai11 possess a potential practical application in gas purification.

The 90° and 60° bimetallic platinum complexes with special structures are widely used in coordination-driven self-assembled metallosupramolecular architectures, and these complexes are the key components of triangular, rectangular, and polygonal metallacycle and metallocage supramolecules. Therefore, spectroscopic techniques and quantum chemistry calculations were employed in this article to investigate the photophysical properties of these bimetallic platinum complexes. Compared with spectra for the ligands, the absorption spectra of these Pt complexes are red-shifted, and the fluorescence spectra become wider and are also red-shifted. Moreover, the reasons for the low fluorescence quantum yields and short fluorescence lifetimes of these compounds were investigated using quantum chemistry calculations. We demonstrate that the fluorescent states of the bimetallic platinum complexes can be considered as local excited states, and that they possess a ligand-centered π-π* transition feature. Meanwhile, the platinum metals act as perturbation for these transitions, whereas the nonfluorescent states are classified as intramolecular charge-transfer states. Furthermore, a new fluorescence modulation mechanism is developed to explain the different emission processes of these complexes with different ligands.

In this work, we have carried out theoretical investigation aiming to clarify heteroatomic effect on the electron-transfer mobility of dianthra[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DATT) and its three derivatives by quantum chemistry calculations combined with the Marcus–Hush electron transfer theory. Partial charge differences of heteroatoms are indicated to be the largest among all atoms of the molecule, which confirms the significant influence of heteroatoms on the mobility, since partial charge changes are related to reorganization energies during the process of charge transfer. Heteroatoms are demonstrated to influence the mobility by two novel parameters: the longitudinal off of heteroatoms in each packing style and the angle among close heteroatoms. The little longitudinal offset and appropriate position between orbitals of S atoms determined by the suitable angle among close S atoms are responsible for the largest charge carrier mobility of DATT among the four systems we investigated. On the othe...