Polymer Framework Research Articles

Adsorptive desulphurization of fuels by hypercrosslinked nanoporous polymers derived from polycyclic aromatic hydrocarbons

A sustainable method is employed to remove polycyclic aromatic sulphur heterocycles (PASHs) from fuels by using a series of high surface area nanoporous adsorbents synthesized from polycyclic aromatic hydrocarbons (PAHs). The hypercrosslinking of PAHs has been used to synthesize high surface area (SABET of 620–1565 m2 g−1) nanoporous polymeric materials via a microwave assisted method. The adsorbent poly-naph (highest SABET, i.e., 1565 m2 g−1) display best performance for desulphurization of fuels from batch to fixed bed column mode. In batch mode, the adsorption capacity of 12.1 (up to 9 ppm sulphur) and 8.9 mgS g−1 (up to 43 ppm sulphur), has been estimated for model (100 ppm sulphur) and real fuels (110 ppm sulphur), respectively. Furthermore, from ultra-low sulphur model (10 ppm sulphur) and real fuel (9 ppm sulphur), the adsorption capacity of 16.1 (up to 0.3 ppm sulphur) and 10 mgS g−1 (up to 3 ppm sulphur) has been estimated. In fixed-bed column mode, the high concentrated model and real fuel have been desulphurized to final concentration of 1 and 12 ppm, respectively. While, at low concentrations, the final concentration of 100 ppb and 1 ppm is achieved for model and real fuels, respectively. The adsorption mechanism revealed that π-electron density in the polymeric framework plays prominent role in the adsorption process apart from high surface area. This approach to control carcinogenic aromatic pollutants like PAHs and PASHs can be sustained over time through technological advancement, financial assistance and governmental regulation.

Evaluation of stresses on mandible bone and prosthetic parts in fixed prosthesis by utilizing CFR-PEEK, PEKK and PEEK frameworks

Fixed prostheses are appropriate treatment solutions for edentulous patients. In fixed prostheses, following “All on four”, titanium frameworks are commonly used to support the implants. However, the limitations of titanium have prompted researchers to search for alternative materials (e.g. polymers). This study applied finite element investigation to evaluate the stress distribution in the parts of fixed prosthesis and the surrounding bone tissue, using polymeric frameworks in place of titanium, and different densities of spongy bone. As, the success of fixed prosthesis was predicted to be influenced also by bone quality, particularly spongy bone density. Fixed prosthesis was constructed on edentulous mandible, then different frameworks (CFR-PEEK 60%, CFR-PEEK 30%, PEKK, and PEEK) were stimulated instead of titanium, under 300N unilateral and bilateral forces. Three densities of spongy bone were stimulated which are normal, low and high. The choice of framework material depended on the density of spongy bone. Moreover, PEEK framework showed the lowest stress values on bone tissues and the highest stress values on mucosa. All frameworks could be used in the fixed prosthesis, in the cases of normal and high densities of spongy bone. In low-density case, soft frameworks (PEKK and PEEK) were recommended to reduce the stresses generated on bone tissues.

Preparation, Characterization, and Release Kinetics of Zanthoxylum bungeanum Leaf Polyphenol–Chitosan Films

This study aimed to prepare a composite film with antioxidant activity for fruit and vegetable preservation. Polyphenols were extracted from Zanthoxylum bungeanum leaves (ZMP), and their composition was studied. ZMP-chitosan film (ZMP/C-film) was prepared by tape casting and the film properties were evaluated. The results revealed that ZMP was mainly composed of seven components: epicatechin (3.24 mg/g), chlorogenic acid (3.59 mg/g), coumarin acid (1.40 mg/g), ferulic acid (4.36 mg/g), quercetin (7.61 mg/g), quercetin (4.52 mg/g), and kaempferol (2.51 mg/g). The opacity of the film incorporated with ZMP significantly increased by 2.28 times. Flexibility (elongation at break) increased by 72%, while the ZMP/C-films had lower tensile strength (32.15–40.3 MPa). Microstructurally, scanning electron microscopy results indicated that ZMP and Chitosan (CS) were compatible. Fourier transform infrared spectroscopy revealed the formation of a dense structure between ZMP and CS. Analysis of X-ray diffraction indicated a tendency toward an increase in the amorphous characteristic of the ZMP/C-film. The kinetic results of polyphenol release indicate that ZMP release was mainly achieved through the dissolution of CS-based polymer frameworks. The release rate and rate of ZMP in the membrane were highest in 3.0% acetic acid (v/v) (33.62%). The scavenging rates of DPPH and ABTS+ free radicals by the 1 g/dL ZMP/C-film were 0.83 and 0.82 times higher than those of 1.0 mg/mL vitamin C (Vc) under the same conditions. In addition, ZMP/C-film was used for strawberry preservation. When stored at 25 °C for 7 d, the weight loss rate and VC content of strawberries preserved with ZMP/C-film decreased by 23.4% and increased by 14.2% compared to C-film, respectively. ZMP/C-film prolonged the shelf life of strawberries by more than 4 days.

Discrete Cu-Metalloporous Polycarbazole as a Nanoelectromediator for Effective Electrocarboxylation of Benzyl Bromide with CO2

The electrochemical fixation of carbon dioxide (CO2) into organic halides is one of the most prominent strategies for mitigating atmospheric CO2 emission, along with the difficulties associated with the toxic and carcinogenic halogenated compounds. Cu-based nanomaterials have been explored for numerous applications in nanotechnology, including electrocatalysis, organic catalytic transformations, and photocatalysis. In this work, we have designed and developed a Cu-embedded carbazole-derived porous organic polymer (Cu@Cz-POP) nanohybrid by utilizing the Friedel–Crafts alkylation approach and employing 1,4-dimethoxybenzene as the cross-linking agent comprising unique characteristic features of the extended π-conjugated system along with an active metal center with tunable electrochemical properties. The Brunauer–Emmett–Teller surface area of the conjugated Cz-POP is found to be 1060 m2 g–1. The X-ray photoelectron spectroscopy (XPS) study demonstrates the formation of CuO nanoparticles in the polymeric framework. X-ray absorption fine structure analysis (EXAFS) also reveals the existence of CuO with a smaller fraction of Cu in the polymeric framework, which is corroborated with the XPS analysis. The Cu@Cz-POP nanohybrid is fabricated by drop-casting over a Ni foam, showing promising electrocatalytic activity toward electrocarboxylation of benzyl bromide in 0.1 M TBA·BF4/CH3CN with saturated CO2 medium with a current density of 120 mA cm–2 delivering 65% yield of phenylacetic acid (PAA) as the primary product along with traces of benzyl 2-phenylacetate (BPA) and 1,2-diphenylethane (DPE), and the turnover frequency is found to be 8.556 × 10–7 s–1. Density functional theory calculations demonstrate that CuO is adsorbed more favorably at the N1 nitrogen atom of Cz-POP. An electron transfer from the N1 atom and the aromatic rings of Cz-POP to the CuO center is observed and confirmed by the overlap of alpha orbitals.

Conductive Polymer Frameworks in Silicon Anodes for Advanced Lithium-Ion Batteries

Silicon anode is endowed with a high theoretical specific capacity. Unfortunately, its applicability in lithium-ion batteries is hindered by several inevitable problems, which are associated with volume changes (i.e., particle pulverization, solid electrolyte interphase layer instability, and electrode failure) and low electrical conductivity of silicon. Among the accessible strategies to enhance the anode performance, conductive polymer frameworks have been envisioned as solutions to overcome the problems. Conductive polymers can jointly bind and electronically connect silicon particles to regulate extensive volume changes while providing pathways for charge transport in a low-cost fashion. This review starts with a detailed summary of conductive polymer framework features in silicon anodes. The main section presents an in-depth discussion and current advancements of the most widely used conductive polymers in silicon anodes [i.e., polyfluorene, polyaniline, polypyrrole, polythiophene, and poly(3,4-ethylenedioxythiophene)] and several other conductive polymers. In the penultimate part, we review the performance evaluation of silicon anodes with five main conductive polymers and provide perspectives on future challenges of batteries from the standpoint of device manufacturing scale-up. In the final part, we briefly summarize the discussed advancements of conductive polymer frameworks in silicon anode for lithium-ion batteries.

Side-Chain Modification in Conjugated Polymer Frameworks for the Electrocatalytic Oxygen Evolution Reaction.

Conjugated polymer frameworks (CPFs) have recently sparked tremendous research interest due to their broad potentials in various frontline application areas such as photocatalysis, sensing, gas storage, energy storage, etc. These framework materials, without sidechains or functional groups on their backbone, are generally insoluble in common organic solvents and less solution processable for further device applications. There are few reports on metal-free electrocatalysis, especially oxygen evolution reaction (OER) using CPF. Herein, we have developed two triazine-based donor-acceptor conjugated polymer frameworks by coupling a 3-substituted thiophene (donor) unit with a triazine ring (acceptor) through a phenyl ring spacer. Two different sidechains, alkyl and oligoethylene glycol, were rationally introduced into the 3-position of thiophene in the polymer framework to investigate the effect of side-chain functionality on the electrocatalytic property. Both the CPFs demonstrated superior electrocatalytic OER activity and long-term durability. The electrocatalytic performance of CPF2, which achieved a current density of 10 mA/cm2 at an overpotential (η) of 328 mV, is much superior to CPF1, which reached the same current density at an overpotential of 488 mV. The porous and interconnected nanostructure of the conjugated organic building blocks, which allowed for fast charge and mass transport processes, could be attributed to the higher electrocatalytic activity of both CPFs. However, the superior activity of CPF2 compared to CPF1 may be due to the presence of a more polar oxygen-containing ethylene glycol side chain, which enhances the surface hydrophilicity, promotes better ion/charge and mass transfer, and increases the accessibility of the active sites toward adsorption through lower π-π stacking compared to hexyl side chain present in CPF1. The DFT study also supports the plausible better performance toward OER for CPF2. This study confirms the promising potentiality of metal-free CPF electrocatalysts for OER and further sidechain modification to improve their electrocatalytic property.

Evaluating the emerging adsorbents for water production potential and thermodynamic limits of adsorption-based atmospheric water harvesting systems

In the context of global water scarcity, adsorption-based atmospheric water harvesting (AWH) is an emerging technology for providing potable water at anytime/anywhere. In this regard, the study evaluates silica-gel, zeolite, ionogel, polymer, membrane, and metal-organic framework based ten kinds of emerging adsorbents for the AWH systems. A thermodynamic modeling framework comprising of adsorption equilibrium models and governing steady-state equations is performed. Performance of AWH systems is always judged on water production potential (WPP), energy consumption (EC) whereas thermodynamic correctness can be measured by first (ηI) and second law (ηII) efficiencies. Thereby, the adsorbents are evaluated from perspectives of WPP, EC, ηI and ηII. As per results, ionogel based adsorbent enables maximum WPP ranging up to 1.55 kg/kg/cycle, EC of 4214.96 kJ/kgw/cycle, ηI of 0.54, and ηII of 0.21. Whereas MIL-101(Cr) observe WPP ranging up to 0.87 kg/kg/cycle, EC of 4499.84 kJ/kgw/cycle, ηI of 0.50, and ηII of 0.19. Parametric analyses results show that ηI of ionogel and MIL-101(Cr) can be increased up to 0.65 and 0.69 while ηII up to 0.23 and 0.25, respectively. Furthermore, ηI and ηII of dual-stage system can improve by 33% as compared to single-stage that can improve by 68-74% as compared to vapor compression system.

Hybrid nanoarchitectonics of molybdenum dioxide (MoO2) and doxorubicin (DOX) for synergistic chemo-photothermal-based breast carcinoma therapy

Cancer has emerged as one of the severe ailments due to the uncontrolled proliferation rate of cells, accounting for millions of deaths annually. Despite the availability of various treatment strategies, including surgical interventions, radiation, and chemotherapy, tremendous advancements in the past two decades of research have evidenced the generation of different nanotherapeutic designs toward providing synergistic therapy. In this study, we demonstrate the assembly of a versatile nanoplatform based on the hyaluronic acid (HA)-coated molybdenum dioxide (MoO2) assemblies to act against breast carcinoma. The hydrothermal approach-assisted MoO2 constructs are immobilized with doxorubicin (DOX) molecules on the surface. Further, these MoO2-DOX hybrids are encapsulated with the HA polymeric framework. Furthermore, the versatile nanocomposites of HA-coated MoO2-DOX hybrids are systematically characterized using various characterization techniques, and explored biocompatibility in the mouse fibroblasts (L929 cell line), as well as synergistic photothermal (808-nm laser irradiation for 10 min, 1 W/cm2) and chemotherapeutic properties against breast carcinoma (4T1 cells). Finally, the mechanistic views concerning the apoptosis rate are explored using the JC-1 assay to measure the intracellular mitochondrial membrane potential (MMP) levels. In conclusion, these findings indicated excellent photothermal and chemotherapeutic efficacies, exploring the enormous potential of MoO2 composites against breast cancer.

Slow Cooling and Transfer Dynamics of Hot Excitons in CsPbBr3 Perovskite Quantum Dots/g-CN Nanosheet Heterostructures: Implications for Optoelectronic Applications

Slow cooling and long-lived hot carrier (HC) population plays a crucial role in crossing the Shockley–Queisser limit and achieving high-efficiency perovskite photovoltaic devices up to 66%. Herein, we investigated the slow cooling of HCs via charge transfer in in-situ synthesized CsPbBr3 perovskite quantum dots-decorated graphitic carbon nitride nanosheet (CsPbBr3 PQDs/g-CN NS) heterostructures using ultrafast transient absorption (UTA) spectroscopy. Halide perovskites showed excitation energy-dependent HC cooling. We examined the HC dynamics at two different excitation energies with varying excitation pump fluences. UTA revealed significantly higher slow cooling and slow bleach recovery in CsPbBr3 PQDs/g-CN NSs (i.e., 632 fs and 845 ps) compared to pure CsPbBr3 PQDs (i.e., 512 fs and 371 ps) at an excitation energy of 3.54 eV and a fluence of 250 μW, suggesting that HCs transfer through the heterostructure interface. The observed slow cooling can be explained by the stronger interaction between the organic polymeric frameworks of g-CN NSs and CsPbBr3 PQDs, which passivates the trap states of CsPbBr3 PQDs and offers slow electron–hole recombination by slowing down the Auger recombination or the hot-phonon bottleneck effect. Additionally, density functional theory (DFT) calculations were carried out to shed light on band alignment at the interface to reveal the mechanism of efficient charge transfer in CsPbBr3 PQDs/g-CN NSs and validate the experimental findings. The insight of this study is quite beneficial for designing modified perovskite nanostructures for realization in perovskite solar cells in the near future.

Oxidation-Responsive PolyMOF Nanoparticles for Combination Photodynamic-Immunotherapy with Enhanced STING Activation.

Stimulator of interferon genes (STING) activation by STING agonists has been recognized as one of the potent and promising immunotherapy strategies. However, the immunosuppressive tumor microenvironment always hinders the therapeutic efficacy of cancer immunotherapy. In this report, we present polymeric metal-organic framework (PMOF) nanoparticles (NPs) for the combination of photodynamic therapy (PDT) and enhanced STING activation to improve the immunotherapeutic efficacy. The PMOF NPs with poly(ethylene glycol) (PEG) shells were obtained via coordination between the block copolymer ligand PEG-b-PABDA consisting of 1,4-bezenedicarboxylic acid-bearing polyacrylamide (PABDA), meso-tetra(carboxyphenyl)porphyrin (TCPP), thioketal diacetic acid, and zirconyl chloride. Subsequently, the STING agonist SR-717 was loaded into the porous structure of PMOF to obtain SR@PMOF NPs which show excellent stability under the physiological conditions. After intravenous injection and tumor accumulation, light irradiation on the tumor sites results in efficient singlet oxygen (1O2) production from TCPP and cellular apoptosis to release fragmented DNA and tumor-associated antigens. Simultaneously, thioketal bonds can be broken by 1O2 to destroy the PMOF structure and rapidly release SR717. SR-717 and PDT synergistically enhance the antitumor immunity via combination photodynamic-immunotherapy due to reversal of the immunosuppressive tumor microenvironment and enhanced endogenous STING activation, which can suppress the growth of the primary and distant tumors efficiently. The oxidation-responsive SR@PMOF NPs represent a promising delivery system of STING agonists and efficient PDT NPs for simultaneous suppression of the primary and metastatic tumors via the rational combination of PDT and enhanced STING activation.

Investigation of hydrogen adsorption sites in ferrocene-based hypercrosslinked polymers by DFT calculations

Herein, two types of Fc-based hypercrosslinked polymers (HHCP and DHCP) with high BET surface area (953.9 and 1062.7 m2 g−1) were prepared by direct one-step phenolic polycondensation aiming at high uptake capacity towards H2. As expected, the hydrogen uptake values of HHCP and DHCP were notably higher than those of porous polymers with a higher surface area under the same conditions. The maximum H2 uptake of HCPs at 77 K/1.0 bar are determined to be 2.51 wt % for HHCP and 2.74 wt % for DHCP, respectively. Despite the pore structure playing a determinant role in hydrogen adsorption, the adsorption sites in the polymer framework can be another essential factor to influence the hydrogen adsorption capacity. The interactions between the Fc building block and H2 are revealed by DFT calculation to fully illustrate the role of Fc in H2 adsorption. The results indicate that both iron atoms and benzene rings in Fc-based HCPs contribute to the adsorption of hydrogen. Moreover, it is interesting to find that the most stable adsorption site around the Fc building unit is the position directly above the Cp ring. The results in this work may more reasonably explain the phenomenon that the introduction of Fc units could enhance the adsorption of H2 in many studies, which also provides possible insights into the application of metallocene compounds in H2 adsorption.

A high-voltage Zn-air battery based on an asymmetric electrolyte configuration

Rechargeable Zn-air batteries promise safe energy storage. However, they are limited by the redox potential of O2/O2- chemistry in an alkaline electrolyte, resulting in low operating voltages and therefore insufficient energy density to compete with lithium-ion batteries. The O2/O2- redox potential increases by 0.8 V in an acidic medium, hinting at a way to boost the voltage: an asymmetric electrolyte configuration decoupling acidic and alkaline electrolytes for the air cathode and zinc anode. Such configuration requires a thin and ionically conductive membrane to separate two mutually incompatible electrolytes. Here, we report a Zn ion-exchange membrane with high ionic conductivity of 1.1 mS cm-1, which prevents acid-base neutralization. The highly reversible O2/O2- reaction in the acid is made possible by compositing a cobalt-coordinated porphyrin-based polymeric framework with MXene as a bifunctional electrocatalyst. The asymmetric Zn-air battery operates at voltages up to 1.85 V and cycles for more than 200 h with a material-level energy density of 1350 Wh kg-1, projected to a high device-level energy density of 50 Wh kg-1 (coin cell diameter: 20 mm). The asymmetric configuration withstands pressure up to 4 MPa (∼1200 N), demonstrating excellent structural stability for production and practical applications.

Near-frictionless ion transport within triazine framework membranes.

The enhancement of separation processes and electrochemical technologies such as water electrolysers1,2, fuel cells3,4, redox flow batteries5,6 and ion-capture electrodialysis7 depends on the development of low-resistance and high-selectivity ion-transport membranes. The transport of ions through these membranes depends on the overall energy barriers imposed by the collective interplay of pore architecture and pore-analyte interaction8,9. However, it remains challenging to design efficient, scaleable and low-cost selective ion-transport membranes that provide ion channels for low-energy-barrier transport. Here we pursue a strategy that allows the diffusion limit of ions in water to be approached for large-area, free-standing, synthetic membranes using covalently bonded polymer frameworks with rigidity-confined ion channels. The near-frictionless ion flow is synergistically fulfilled by robust micropore confinement and multi-interaction between ion and membrane, which afford, for instance, a Na+ diffusion coefficient of 1.18 × 10-9 m2 s-1, close to the value in pure water at infinite dilution, and an area-specific membrane resistance as low as 0.17 Ω cm2. We demonstrate highly efficient membranes in rapidly charging aqueous organic redox flow batteries that deliver both high energy efficiency and high-capacity utilization at extremely high current densities (up to 500 mA cm-2), and also that avoid crossover-induced capacity decay. This membrane design concept may be broadly applicable to membranes for a wide range of electrochemical devices and for precise molecular separation.

Magnetic Ionotropic Hydrogels Based on Carboxymethyl Cellulose for Aqueous Pollution Mitigation

In this work, stabilized ionotropic hydrogels were designed using sodium carboxymethyl cellulose (CMC) and assessed as inexpensive sorbents for hazardous chemicals (e.g., Methylene Blue, MB) from contaminated wastewaters. In order to increase the adsorption capacity of the hydrogelated matrix and facilitate its magnetic separation from aqueous solutions, sodium dodecyl sulfate (SDS) and manganese ferrite (MnFe2O4) were introduced into the polymer framework. The morphological, structural, elemental, and magnetic properties of the adsorbents (in the form of beads) were assessed using scanning electron microscopy (SEM), energy-dispersive X-ray analysis, Fourier-transform infrared spectroscopy (FTIR), and a vibrating-sample magnetometer (VSM). The magnetic beads with the best adsorption performance were subjected to kinetic and isotherm studies. The PFO model best describes the adsorption kinetics. A homogeneous monolayer adsorption system was predicted by the Langmuir isotherm model, registering a maximum adsorption capacity of 234 mg/g at 300 K. The calculated thermodynamic parameter values indicated that the investigated adsorption processes were both spontaneous (ΔG < 0) and exothermic (ΔH < 0). The used sorbent can be recovered after immersion in acetone (93% desorption efficiency) and re-used for MB adsorption. In addition, the molecular docking simulations disclosed aspects of the mechanism of intermolecular interaction between CMC and MB by detailing the contributions of the van der Waals (physical) and Coulomb (electrostatic) forces.

Development of a Data-Driven Integrative Model of a Bacterial Chromosome.

The chromosome of archetypal bacteria E. coli is known for a complex topology with a 4.6 × 106 base pairs (bp) long sequence of nucleotides packed within a micrometer-sized cellular confinement. The inherent organization underlying this chromosome eludes general consensus due to the lack of a high-resolution picture of its conformation. Here we present our development of an integrative model of E. coli at a 500 bp resolution (https://github.com/JMLab-tifrh/ecoli_finer), which optimally combines a set of multiresolution genome-wide experimentally measured data within a framework of polymer based architecture. In particular the model is informed with an intragenome contact probability map at 5000 bp resolution derived via the Hi-C experiment and RNA-sequencing data at 500 bp resolution. Via dynamical simulations, this data-driven polymer based model generates an appropriate conformational ensemble commensurate with chromosome architectures that E. coli adopts. As a key hallmark of the E. coli chromosome the model spontaneously self-organizes into a set of nonoverlapping macrodomains and suitably locates plectonemic loops near the cell membrane. As novel extensions, it predicts a contact probability map simulated at a higher resolution than precedent experiments and can demonstrate segregation of chromosomes in a partially replicating cell. Finally, the modular nature of the model helps us devise control simulations to quantify the individual role of key features in hierarchical organization of the bacterial chromosome.

Long cycle performance of NC@VN/MnO cathode for AZIBs based on Mn/V relay type collaboration

Aqueous zinc ion batteries (AZIBs) have received great attention because of their non-toxicity, high safety, low cost, high abundance, and high specific power. However, their specific capacity is still low compared with lithium ion battery, and current academic research interesting has been focused on developing new cathode materials with high specific capacity. In this study, a Mn/V hybrid polymer framework is designed by a simple self-polymerization scheme. During subsequent calcination, ultrafine VN quantum dots and MnO nanoparticles are generated in situ and stably encapsulated inside N-doped carbon (NC) shells to obtain a novel hybrid cathode NC@VN/MnO for AZIBs. According to the density functional theory (DFT) calculation, the hybrids of MnO and VN can generate both interfacial effects and built-in electric fields that significantly accelerate ion and electron transport by tuning the intrinsic electronic structure, thus enhancing electrochemical performance. A synergistic strategy of composition and structural design allows the rechargeable AZIBs to achieve low-cost and excellent long-cycle performance based on a relay type collaboration at different cycling stages. Consequently, the NC@VN/MnO cathode has output a capacity of 108.3 mA h g−1 after 12,000 cycles at 10 A g−1. These results clearly and fully demonstrate the advantages of the hybrid cathode NC@VN/MnO.

Cation Charge as a Tool to Change Dimensionality in Organic–Inorganic Hybrids Based on Copper Thiocyanate Templated by 1,4-Diazabicyclo[2.2.2]octane

The first three compounds based on a {copper-thiocyanate-dabco} combination, namely, (Hdabco)[Cu2(NCS)3] (1), (H2dabco)[Cu(NCS)3] (2), and [Cu(Hdabco)2(NCS)4]∙2dmso (3), where dabco = 1,4-diazabicyclo[2.2.2]octane were synthesized and characterized by single-crystal XRD, elemental analysis, Raman, and partial IR spectroscopy. In copper(I) derivatives, the influence of the charge of the organic cation on the dimensionality of the crystal structure is observed. Thus, in the case of 1, monoprotonated Hdabco+ cations provide the template for the formation of a polymeric anionic 3D framework {[Cu2(NCS)3]-}n, while in the case of 2, diprotonated H2dabco2+ cations together with discrete [Cu(SCN)3]2- anions generate a simple ionic 0D structure with an island-like crystal lattice. The anionic {[Cu2(SCN)3]-}n framework has infinite square channels of 10 × 10 Å size running along the 001 crystallographic direction. In 3, both the Hdabco+ and thiocyanato units behave as terminal monodentate ligands attached to copper(II) centers via N-donor atoms, forming neutral molecular complexes with an elongated (4+2) octahedral environment. The crystallization molecules of dmso are hydrogen bonded to the protonated parts of the coordinated dabco molecules. A series of by-products Cu(SCN)2(dmso)2 (4), (Hdabco)SCN (5), (H2dabco)(SCN)2 (6), and (H2dabco)(SCN)2∙H2O (7) were identified and characterized.

Flexible Organic Framework‐Modified Membranes for Osmotic Energy Harvesting

Comprehensive SummaryBioinspired membranes are advantageous in capturing the osmotic energy. However, the conventional hybrid membranes possess low harvesting power density due to their low interfacial ionic transport efficiency and high internal resistance. Herein, a new kind of hybrid membranes consisting of porous polymer and flexible organic frameworks was developed. The 3D porous framework enables ions to flux with high efficiency at the polymer‐framework interface, resulting in high osmotic energy harvesting efficiency. By systematically screening the pore size of the frameworks, the output power density as high as 5.7 W/m2 was achieved under 50‐fold KCl salinity gradient.

Dual-Functional Super-Assembled Mesoporous Carbon-Titania/AAO Hetero-Channels for Bidirectionally Photo-Regulated Ion Transport.

Photo-regulated nanofluidic devices have attracted great attention in recent years due to their adjustable ion transport in real time. However, most of the photo-responsive nanofluidic devices can only adjust the ionic current unidirectionally, and cannot simultaneously increase or decrease the current signal intelligently by one device. Herein, a mesoporous carbon-titania/ anodized aluminum hetero-channels (MCT/AAO) is constructed by super-assembly strategy, which exhibits dual-function of cation selectivity and photo response. The polymer and TiO2 nanocrystals jointly build the MCT framework. Polymer framework with abundant negatively charged sites endows MCT/AAO with excellent cation selectivity, and TiO2 nanocrystals are responsible for the photo-regulated ion transport. High photo current densities of 1.8mAm-2 (increase) and 1.2mAm-2 (decrease) are realized by MCT/AAO benefiting from the ordered hetero-channels. Significantly, MCT/AAO can also achieve the bidirectionally adjustable osmotic energy by alternating the configurations of concentration gradient. Theoretical and experimental results reveal that the superior photo-generated potential is responsible for the bidirectionally adjustable ion transport. Consequently, MCT/AAO performs the function of harvesting ionic energy from the equilibrium electrolyte solution, which greatly expands its practical application field. This work provides a new strategy in constructing dual-functional hetero-channels toward bidirectionally photo-regulated ionic transport and energy harvesting.

Studies on bond relationship between energy of activation and catalytic activity of azomethine polymer framework enveloped over mesquite carbon hybrid composite electrodes for energy production applications

Studies on bond relationship between energy of activation and catalytic activity of azomethine polymer framework enveloped over mesquite carbon hybrid composite electrodes for energy production applications