Calix[4]pyrrole-based Crosslinked Polymer Networks for Highly Effective Iodine Adsorption from Water

A series of calix[4]pyrrole-based crosslinked polymer networks designed for iodine capture is reported. These materials were prepared by Sonogashira coupling of α,α,α,α-tetra(4-alkynylphenyl)calix[4]pyrrole with bishalide building blocks with different electronic properties and molecular sizes. Despite their low Brunauer–Emmett–Teller surface areas, iodine vapor adsorption capacities of up to 3.38 g g^?1 were seen, a finding ascribed to the presence of a large number of effective sorption sites including macrocyclic π-rich cavities, aryl units, and alkyne groups within the material. One particular system, C[4]P-BTP , was found to be highly effective at iodine capture from water (uptake capacity of 3.24 g g^?1 from a concentrated aqueous KI/I₂ solution at ambient temperature). Fast capture kinetics (k_obs=7.814 g g^?1 min^?1) were seen. Flow-through adsorption experiments revealed that C[4]P-BTP is able to remove 93.2 % of iodine from an aqueous source phase at a flow rate of 1 mL min^?1.     

Triarylboron‐Linked Conjugated Microporous Polymers: Sensing and Removal of Fluoride Ions

A luminescent conjugated microporous polymer (BCMP‐3) has been synthesized in high yield by a carbon–carbon coupling reaction using triarylboron as a building unit. BCMP‐3 was fully characterized by using powder X‐ray diffraction analysis, Fourier transform infrared spectroscopy, ¹³C solid‐state NMR spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, and nitrogen and carbon dioxide adsorption. The new three‐dimensional conjugated framework possess a high Brunauer–Emmett–Teller (BET) specific surface area up to 950 m² g^?1 with a pore volume of 0.768 cm³ g^?1, good stability, and abundant boron sites in the skeleton. Under excited‐light irradiation, BCMP‐3 exhibits strong fluorescent emission at 488 nm with a high absolute quantum yield of 18 % in the solid state. Polymer BCMP‐3 acts as a colorimetric and fluorescent chemosensor with high sensitivity and selectivity for F^? over other common anions. In addition, the polymer also works as an adsorbent for F^? removal and shows good adsorption capacities of up to 24 mg g^?1 at equilibrium F^? concentrations of 16 mg L^?1 and a temperature of 298 K. The adsorption kinetics and isotherm were analyzed by fitting experimental data with pseudo‐second‐order kinetics and Langmuir equations. Furthermore, we highlight that BCMP‐3 is an adsorbent for fluoride removal that can be efficiently reused many times without loss of adsorption efficiency.     

High capacity and cycling stability of poly(diaminoanthraquinone) as an organic cathode for rechargeable lithium batteries

Poly(1,5‐diaminoanthraquinone) is synthesized by oxidative polymerization of diaminoanthraquinone monomers and investigated as an organic host for Li‐storage reaction. Benefiting from its high density of redox‐active, Li⁺‐associable benzoquinone groups attached to conducting polyaniline backbones, this polymer undergoes its cathodic reaction predominately through Li⁺‐insertion/extraction processes, delivering a very high reversible capacity of 285 mAh g^?1. In addition, the PDAQ polymer cathode exhibits an excellent rate capability (125 mAh g^?1 at 800 mA g^?1) and a considerable cyclability with a capacity retention of ～160 mAh g^?1 over 200 cycles, possibly serving as a sustainable, high capacity Li⁺ host cathode for Li‐ion batteries. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 235–238     

Synthesis of Two‐dimensional Microporous Carbonaceous Polymer Nanosheets and Their Application as High‐performance CO2 Capture Sorbent

The synthesis of two‐dimensional (2D) polymer nanosheets with a well‐defined microporous structure remains challenging in materials science. Here, a new kind of 2D microporous carbonaceous polymer nanosheets was synthesized through polymerization of a very low concentration of 1,4‐dicyanobenzene in molten zinc chloride at 400–500 °C. This type of nanosheets has a thickness in the range of 3–20 nm, well‐defined microporosity, a high surface area (～537 m² g^?1), and a large micropore volume (～0.45 cm³ g^?1). The microporous carbonaceous polymer nanosheets exhibit superior CO₂ sorption capability (8.14 wt % at 298 K and 1 bar) and a relatively high CO₂ selectivity toward N₂ (25.6). Starting from different aromatic nitrile monomers, a variety of 2D carbonaceous polymer nanosheets can be obtained showing a certain universality of the ionothermal method reported herein.     

Fabrication and characterization of electrochemical double layer capacitors using ionic liquid-based gel polymer electrolyte with chemically treated activated charcoal electrodes

The present investigation deals with electrochemical double layer capacitors (EDLCs) made up of ionic liquid (IL)-based gel polymer electrolytes with chemically treated activated charcoal electrodes. The gel polymer electrolyte comprising of poly(vinylidine fluoride-co-hexafluropropylene) (PVdF-HFP)–1-ethyl-2,3-dimethyl-imidazolium-tetrafluroborate [EDiMIM][BF₄]–propylene carbonate (PC)–magnesium perchlorate (Mg(ClO₄)₂) exhibits the highest ionic conductivity of ~8.4?×?10^?3?S?cm^?1 at room temperature (~20 °C), showing good mechanical and dimensional stability, suitable for their application in EDLCs. Activation of charcoal was done by impregnation method using potassium hydroxide (KOH) as activating agent. Brunauer–Emmett–Teller (BET) studies reveal that the effective surface area of treated activated charcoal powder (1,515 m²?g^?1) increases by more than double-fold compared to the untreated one (721 m²?g^?1). Performance of EDLCs has been tested using cyclic voltammetry, impedance spectroscopy, and charge–discharge techniques. Analysis shows that chemically treated activated charcoal electrodes have almost triple times more capacitance values as compared to the untreated one.     

Nitrogen-Linked Hexaazatrinaphthylene Polymer as Cathode Material in Lithium-Ion Battery

Nitrogen-linked hexaazatrinaphthylene polymer ( N²-HATN ) as organic cathode material with low HOMO–LOMO gap was synthesized and was observed to possess reversible high capacity and unexpected long-term cycling stability. The pre-treated N²-HATN and pRGO combination demonstrated good structure compatibility and the resultant cathode exhibited a constant increment of capacity during the redox cycles. The initial capacity at 0.05 A g⁻¹ was 406 mA h⁻¹ g⁻¹, and increased to 630 mA h⁻¹ g⁻¹ after 70 cycles. At 0.5 A g⁻¹ discharging rate, the capacity increased from an initial value of 186 mA h⁻¹ g⁻¹ to 588 mA h⁻¹ g⁻¹ after 1600 cycles. The pseudocapacitance-type behavior is postulated to be attributed to the structure compatibility between the active material and pRGO.     

Tunable Surface Area,Porosity, and Function in Conjugated Microporous Polymers

Simple inorganic salts are used to tune N‐containing conjugated microporous polymers (CMPs) synthesized by Buchwald–Hartwig (BH) cross‐coupling reactions. Poly(triphenylamine), PTPA, initially shows a broad distribution of micropores, mesopores, and macropores. However, the addition of inorganic salts affects all porous network properties significantly: the pore size distribution is narrowed to the microporous range only, mimicking COFs and MOFs; the BET surface area is radically improved from 58 m² g^?1 to 1152 m² g^?1; and variations of the anion and cation sizes are used to fine‐tune the surface area of PTPA, with the surface area showing a gradual decrease with an increase in the ionic radius of salts. The effect of the salt on the physical properties of the polymer is attributed to adjusting and optimizing the Hansen solubility parameters (HSPs) of solvents for the growing polymer, and named the Beijing–Xi'an Jiaotong (BXJ) method.     

A Robust Solid Electrolyte Interphase Layer Augments the Ion Storage Capacity of Bimetallic‐Sulfide‐Containing Potassium‐Ion Batteries

Metal–organic framework‐derived NiCo_2.5S₄ microrods wrapped in reduced graphene oxide (NCS@RGO) were synthesized for potassium‐ion storage. Upon coordination with organic potassium salts, NCS@RGO exhibits an ultrahigh initial reversible specific capacity (602 mAh g^?1 at 50 mA g^?1) and ultralong cycle life (a reversible specific capacity of 495 mAh g^?1 at 200 mA g^?1 after 1 900 cycles over 314 days). Furthermore, the battery demonstrates a high initial Coulombic efficiency of 78 %, outperforming most sulfides reported previously. Advanced ex situ characterization techniques, including atomic force microscopy, were used for evaluation and the results indicate that the organic potassium salt‐containing electrolyte helps to form thin and robust solid electrolyte interphase layers, which reduce the formation of byproducts during the potassiation–depotassiation process and enhance the mechanical stability of electrodes. The excellent conductivity of the RGO in the composites, and the robust interface between the electrodes and electrolytes, imbue the electrode with useful properties; including, ultrafast potassium‐ion storage with a reversible specific capacity of 402 mAh g^?1 even at 2 A g^?1.     

Ultrastable Surface-Dominated Pseudocapacitive Potassium Storage Enabled by Edge-Enriched N-Doped Porous Carbon Nanosheets

The development of ultrastable carbon materials for potassium storage poses key limitations caused by the huge volume variation and sluggish kinetics. Nitrogen-enriched porous carbons have recently emerged as promising candidates for this application; however, rational control over nitrogen doping is needed to further suppress the long-term capacity fading. Here we propose a strategy based on pyrolysis–etching of a pyridine-coordinated polymer for deliberate manipulation of edge-nitrogen doping and specific spatial distribution in amorphous high-surface-area carbons; the obtained material shows an edge-nitrogen content of up to 9.34 at %, richer N distribution inside the material, and high surface area of 616 m² g⁻¹ under a cost-effective low-temperature carbonization. The optimized carbon delivers unprecedented K-storage stability over 6000 cycles with negligible capacity decay (252 mA h g⁻¹ after 4 months at 1 A g⁻¹), rarely reported for potassium storage.     

Hyper-cross-linked polymers based on triphenylsilane for hydrogen storage and water treatment

The present research focuses on the synthesis and applications of a series of hyper-cross-linked polymer networks obtained from the one-step Friedel–Crafts reaction of triphenylsilane and formaldehyde dimethyl acetal. The materials were characterized through FTIR, ¹³C NMR, PXRD, TGA, N₂ adsorption-desorption isotherms, H₂ sorption and dye adsorption. These materials exhibited increased surface areas of approximately 441–1101 m² g^?1 with increasing ratio of monomer to cross-linker. The H₂ storage capacity of the polymer networks reached 1.19 wt % (5.96 mmol g^?1) under 1.03 bar and 77.3 K. In addition, the material showed excellent adsorption capacity of 806 mg g^?1 for Congo Red and retained their adsorption capacity after recycling nine times. Taken together, the results demonstrate that the obtained hyper-cross-linked polymers could be applied to H₂ storage and water treatment.     

Preparation of a Yb(III)‐Incorporated porous polymer by post‐Coordination: Enhancement of gas adsorption and catalytic activity

We synthesized a Yb(III)‐incorporated microporous polymer (Yb‐ADA) and studied its gas adsorption property and catalytic activity. The adamantane‐based porous polymer (ADA) was obtained from an ethynyl‐functionalized adamantane derivative and 2,5‐dibromoterephthalic acid through Sonogashira–Hagihara cross‐coupling. ADA had two carboxyl groups which were used for Yb(III) coordination under basic conditions. The Brunauer‐Emmett‐Teller (BET) surface area of ADA was 970 m² g^?1. As Yb(III) ions were incorporated into ADA, the surface area of the polymer (Yb‐ADA) was reduced to 885 m² g^?1. However, Yb‐ADA exhibited a significantly enhanced CO₂ adsorption capacity despite the reduction of surface area. The CO₂ uptakes of ADA and Yb‐ADA were 1.56 and 2.36 mmol g^?1 at 298 K, respectively. The H₂ uptake of ADA also increased after coordination with Yb(III) from 1.15 to 1.40 wt % at 77 K. Yb‐ADA showed high catalytic activity in the acetalization of 4‐bromobenzaldehyde and furfural with trimethyl orthoformate and could be reused after recovery without severe loss of activity. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5291–5297     

A Nitrogen‐Rich 2D sp2‐Carbon‐Linked Conjugated Polymer Framework as a High‐Performance Cathode for Lithium‐Ion Batteries

A two‐dimensional (2D) sp²‐carbon‐linked conjugated polymer framework (2D CCP‐HATN) has a nitrogen‐doped skeleton, a periodical dual‐pore structure and high chemical stability. The polymer backbone consists of hexaazatrinaphthalene (HATN) and cyanovinylene units linked entirely by carbon–carbon double bonds. Profiting from the shape‐persistent framework of 2D CCP‐HATN integrated with the electrochemical redox‐active HATN and the robust sp² carbon‐carbon linkage, 2D CCP‐HATN hybridized with carbon nanotubes shows a high capacity of 116 mA h g^?1, with high utilization of its redox‐active sites and superb cycling stability (91 % after 1000 cycles) and rate capability (82 %, 1.0 A g^?1 vs. 0.1 A g^?1) as an organic cathode material for lithium‐ion batteries.     

Porous carbon synthesized by direct carbonization of potassium biphthalate for high-performance supercapacitors

Porous carbons have been synthesized by a direct carbonization of potassium biphthalate without an activation process. The experimental results demonstrate that the carbonization temperature plays a crucial role in determining the surface area and pore structure as well as the correlative capacitive performance. The carbon-700/800/900 samples display surface areas of 672, 1,023, and 1,380 m² g^?1 and total pore volumes of 0.38, 0.56, and 0.78 cm³ g^?1, respectively. The specific capacitances of the carbon-700/800/900 samples are 300.4, 272.3, and 243.4 F g^?1, respectively, at a current density of 0.5 A g^?1. More importantly, the carbon-900 sample possesses the highest capacitance retention (~98.4 %) even undergoing charge–discharge 10,000 times. The potassium biphthalate used as a carbon source is inexpensive and commercially available, making it promising for the large-scale production of porous carbons as an excellent electrode material for supercapacitors.     

Activated carbon aerogels with high bimodal porosity for lithium/sulfur batteries

Activated carbon aerogels (ACAs) with high bimodal porosity were obtained for lithium/sulfur batteries by potassium hydroxide (KOH) activation. Then sulfur–activated carbon aerogels (S–ACAs) composites were synthesized by chemical deposition strategy. The S–ACAs composites were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy, and N₂ adsorption/desorption measurements. It is found that the activated carbon aerogels treated by KOH activation presents a porous structure, and sulfur is embedded into the pores of the ACAs network-like matrix after a chemical deposition process. The Li/S–ACAs (with 69.1 wt% active material) composite cathode exhibits discharge capacities of 1,493 mAh g^?1 in the first cycle and 528 mAh g^?1 after 100 cycles at a higher rate of C/5 (335 mA g^?1). The S–ACAs composite cathode exhibits better electrochemical reversibility, higher active material utilization, and less severe polysulfide shuttle than S–CAs composite cathode because of high bimodal porosity structure of the ACAs matrix.     

Preparation of a Porous polymer by a catalyst‐free diels‐alder reaction and its structural modification by post‐reaction

A microporous polymer is prepared by a catalyst‐free Diels–Alder reaction. A cyclopentadiene with both a diene and a dienophile functionality and a dienophilic maleimide are used for the Diels–Alder reaction. 1,3,5‐Tris(bromomethyl)‐2,4,6‐trimethylbenzene is reacted with sodium cyclopentadienide to produce the multicyclopentadiene‐functionalized monomer. A crosslinked polymer ( CDAP ) is obtained by the reaction of the cyclopentadiene monomer with N,N′‐1,4‐phenylenedimaleimide. The thermal dissociation of the cyclopentadiene dimeric unit and the subsequent Diels–Alder reaction with the maleimide group are investigated by the model reaction. We are able to restructure the crosslinked polymer network by taking advantage of the thermal reversibility of the Diels–Alder linkage. After the post thermal treatment, the BET surface area of the polymer ( CDAP‐T ) is greatly increased from 317 to 1038 m² g^?1. CDAP‐T is functionalized with pyrene by bromination with N‐bromosuccinimide and the subsequent substitution reaction with aminopyrene. The adsorption property of the pyrene‐functionalized polymer for an aromatic dye is investigated using malachite green. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3646–3653     

Facile Synthesis of Nitrogen‐Containing Mesoporous Carbon for High‐Performance Energy Storage Applications

Porous carbon with high specific surface area (SSA), a reasonable pore size distribution, and modified surface chemistry is highly desirable for application in energy storage devices. Herein, we report the synthesis of nitrogen‐containing mesoporous carbon with high SSA (1390 m² g^?1), a suitable pore size distribution (1.5–8.1 nm), and a nitrogen content of 4.7 wt % through a facile one‐step self‐assembly process. Owing to its unique physical characteristics and nitrogen doping, this material demonstrates great promise for application in both supercapacitors and encapsulating sulfur as a superior cathode material for lithium–sulfur batteries. When deployed as a supercapacitor electrode, it exhibited a high specific capacitance of 238.4 F g^?1 at 1 A g^?1 and an excellent rate capability (180 F g^?1, 10 A g^?1). Furthermore, when an NMC/S electrode was evaluated as the cathode material for lithium–sulfur batteries, it showed a high initial discharge capacity of 1143.6 mA h g^?1 at 837.5 mA g^?1 and an extraordinary cycling stability with 70.3 % capacity retention after 100 cycles.     

Free‐Standing Conducting Polymer Films for High‐Performance Energy Devices

Thick, uniform, easily processed, highly conductive polymer films are desirable as electrodes for solar cells as well as polymer capacitors. Here, a novel scalable strategy is developed to prepare highly conductive thick poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (HCT‐PEDOT:PSS) films with layered structure that display a conductivity of 1400 S cm^?1 and a low sheet resistance of 0.59 ohm sq^?1. Organic solar cells with laminated HCT‐PEDOT:PSS exhibit a performance comparable to the reference devices with vacuum‐deposited Ag top electrodes. More importantly, the HCT‐PEDOT:PSS film delivers a specific capacitance of 120 F g^?1 at a current density of 0.4 A g^?1. All‐solid‐state flexible symmetric supercapacitors with the HCT‐PEDOT:PSS films display a high volumetric energy density of 6.80 mWh cm^?3 at a power density of 100 mW cm^?3 and 3.15 mWh cm^?3 at a very high power density of 16160 mW cm^?3 that outperforms previous reported solid‐state supercapacitors based on PEDOT materials.     

Determination of amorphous silica and total silica in plant materials

Amorphous silica in plant material was dissolved with potassium carbonate solution, after nitric acid/hydrogen peroxide digestion. Total silica in plant material and some minerals was obtained after ashing and fusing in nickel crucibles with potassium hydroxide containing potassium tetraborate/nitrate. The relative standard deviation for determinations of silicon by these methods in plant material was <2% for plant material containing 2–2100 μmol Si g^?1 (dry weight).     

Determination of reference interval values for inorganic elements in whole blood samples of humans and laboratory animals by X-ray fluorescence spectrometry

Inorganic elements are responsible for essential bodily functions, such as osmotic regulation, cardiac frequency and contractibility, blood clotting and neuromuscular excitability. The determination of inorganic elements in corporeal fluids such as blood, serum, plasma and urine is used as a monitor for a part or the whole organism; their values, then, are compared with reference interval values. In this study, the energy dispersive X-ray fluorescence spectrometry (EDXRF), applying the Fundamental Parameters method, for the determination of inorganic elements in whole blood samples from humans and laboratory animals, was used. Peripheral blood samples were collected and, before coagulation, 100 μL of sample were deposited onto Whatman No. 41 filter paper and dried, using infrared spotlight. The reference interval values for healthy Brazilian population of Na were found to be 1,788–1,826 μg g^?1, of Mg 63–75 μg g^?1, of P 602–676 μg g^?1, of S 1,519–1,718 μg g^?1, of Cl 2,743–2,867 μg g^?1, of K 1,508–1,630 μg g^?1, of Ca 214–228 μg g^?1, of Fe 170–184 μg g^?1, of Cu 4–6 μg g^?1 and of Zn 1–3 μg g^?1. The reference interval values for golden hamster (Mesocricetus auratus) of Na were found to be 1,714–1,819 μg g^?1, Mg 51–79 μg g^?1, P 970–1,080 μg g^?1, S 1,231–1,739 μg g^?1, Cl 2,775–2,865 μg g^?1, of K 1,968–2,248 μg g^?1, of Ca 209–257 μg g^?1, of Fe 145–267 μg g^?1, of Cu 4–6 μg g^?1 and of Zn 3–5 μg g^?1. A comparative study between EDXRF and instrumental neutron activation analysis data was carried out and the results for both techniques are statistically equal (α = 0.05). The results contribute for the establishment of reference interval values for Na, Mg, P, S, Cl, K, Ca, Cu and Zn in the healthy Brazilian population and the referred laboratory animal species.     

Challenge and Solution of Characterizing Glass Transition Temperature for Conjugated Polymers by Differential Scanning Calorimetry

Thermomechanical properties of polymers highly depend on their glass transition temperature (T _g). Differential scanning calorimetry (DSC) is commonly used to measure T _g of polymers. However, many conjugated polymers (CPs), especially donor–acceptor CPs (D–A CPs), do not show a clear glass transition when measured by conventional DSC using simple heat and cool scan. In this work, we discuss the origin of the difficulty for measuring T _g in such type of polymers. The changes in specific heat capacity (Δc _p) at T _g were accurately probed for a series of CPs by DSC. The results showed a significant decrease in Δc _p from flexible polymer (0.28 J g^?1 K^?1 for polystyrene) to rigid CPs (10^?3 J g^?1 K^?1 for a naphthalene diimide‐based D–A CP). When a conjugation breaker unit (flexible unit) is added to the D–A CPs, we observed restoration of the Δc _p at T _g by a factor of 10, confirming that backbone rigidity reduces the Δc _p. Additionally, an increase in the crystalline fraction of the CPs further reduces Δc _p. We conclude that the difficulties of determining T _g for CPs using DSC are mainly due to rigid backbone and semicrystalline nature. We also demonstrate that physical aging can be used on DSC to help locate and confirm the glass transition for D‐A CPs with weak transition signals. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 1635–1644