A task-specific functionalized hyper-cross-linked polymer (HCP) with hollow spherical structure was synthesized by an easily accessible Friedel–Crafts reaction-based approach. A harmonious coexistence of acid (sulfonic acid) and base (amine) sites on a microporous organic material was achieved. The acid–base bifunctional HCP catalyst (HCP–A–B) structure was fully characterized by many physicochemical methods. In the subsequent tandem reactions (hydrolysis/Henry and hydrolysis/Knoevenagel reactions), the HCP–A–B catalyst displayed high catalytic efficiency and chemical stability toward water or organic solvent. These HCP–A–B catalyst characteristics led to the development of a previously unreported transformation of 2-ethoxy-3,4-dihydropyran derivative to a 2-cyclohexen-1-one derivative through a tandem reaction involving water-assisted ring-opening hydrolysis of the dihydropyran, an intramolecular aldol reaction, and a dehydration reaction. In all of these reactions, the bifunctional HCP–A–B catalyst can be recovered and reused more than 10 times without significant loss of activity.Keywords: bifunctionalized catalyst; cyclohexenone; hollow sphere; hyper-cross-linked polymers (HCPs); tandem reactions; water-stable;

Microporous organic capsules with hollow interiors have received enormous attention due to their unusual encapsulation efficiency to confine chemicals within their hollow cavities and prompted controlled release by circumventing their ripening or poisoning. To this end, herein, we report the design and synthesis of carboxylic group functionalized hollow microporous organic capsules (HMOCs) using a facile emulsion polymerization technique that show extraordinary high encapsulation efficiency (up to 98%) of morphine·HCl and its promising prolonged release. The functionalized HMOCs are found to release the drug at a rate which is proportional to the amount of drug remaining in its interior. Due to the presence of hollow and porous morphologies, they possess high BET surface areas, i.e. up to 974 m2 g−1. Moreover, the in vivo results showed that functionalized HMOCs can offer slow release of active drug molecules and attenuate the level of writhing response over 72 h of intraperitoneal injection. The functionalized HMOCs, therefore, present a new class of potential drug delivery systems that can maintain the slow and prolonged release of analgesics by lowering the dosage and avoid frequent administration.

Here we choose a dihydronaphthyl-functionalized C60 fullerene as a building block and utilize a novel solvent knitting strategy based on Friedel–Crafts alkylation reaction to construct two kinds of novel porous materials by using dichloromethane (DCM) and 1,2-dichloroethane (DCE) as solvents and external crosslinkers. The resulting porous materials show relatively high apparent BET surface areas and gas uptake abilities.

A novel metalporphyrin-based microporous organic polymer (HUST-1-Co), which possesses a high surface area of 1360 m2 g−1 and a high CO2 uptake of 21.39 wt% (1 bar and 273 K) for CO2 capture and storage (CCS) and the efficient chemical conversion of CO2 under ambient conditions, is reported. This polymer incorporated both ultra-micropores and catalytic sites, and was synthesized by a novel solvent knitting hypercrosslinked polymers method, using 5,10,15,20-tetraphenylporphyrin (TPP) as the building block. The N2 sorption isotherms of the polymers show that HUST-1-Co possesses abundant ultra-micropores (centered at 0.68 nm), and a continuous mesoporous and macroporous structure, which not only enhances the interaction between the pore walls and CO2, but is also favourable for the catalysis process. The synergy of the ultra-micropores, abundant nitrogen atoms and Co2+ ions makes HUST-1-Co one of the highest CO2 uptake MOP materials reported so far and further endows it with efficient catalytic performance. HUST-1-Co is one of the most efficient catalysts for the coupling of CO2 with substituted epoxides with various functional groups at room temperature and atmospheric pressure, with an excellent recycling performance (more than 15 times). Moreover, the role of the mesoporous and macroporous structure of HUST-1-Co gives it a unique catalytic performance for different molecular sizes of epoxide substrates with excellent yields (>93%).

Microporous organic polymers (MOPs) have attracted considerable research interest because of their well-defined porosity, high surface area, lightweight nature, and tunable surface chemistry. The morphology of MOPs are demonstrated to play a significant role in various applications although limited examples manifesting the importance of the MOP morphology in numerous applications have been reported. This review summarizes the recent progress in the design of MOPs using different techniques, including hard and soft template and direct synthesis methods. In addition, their applications, which possibly attribute to their shape, are discussed. Furthermore, the advantages and disadvantages of different methods are discussed, as well as their development and future challenges.

AbstractCovalent triazine frameworks (CTFs) are normally synthesized by ionothermal methods. The harsh synthetic conditions and associated limited structural diversity do not benefit for further development and practical large-scale synthesis of CTFs. Herein we report a new strategy to construct CTFs (CTF-HUSTs) via a polycondensation approach, which allows the synthesis of CTFs under mild conditions from a wide array of building blocks. Interestingly, these CTFs display a layered structure. The CTFs synthesized were also readily scaled up to gram quantities. The CTFs are potential candidates for separations, photocatalysis and for energy storage applications. In particular, CTF-HUSTs are found to be promising photocatalysts for sacrificial photocatalytic hydrogen evolution with a maximum rate of 2647 μmol h−1 g−1 under visible light. We also applied a pyrolyzed form of CTF-HUST-4 as an anode material in a sodium-ion battery achieving an excellent discharge capacity of 467 mAh g−1.

•SA-MMNPs are synthesized combining microporous polymer with magnetic nanoparticles.•SA-MMNPs can be easily separated by magnet and well dispersed in water.•SA-MMNPs have better adsorption performance than hydrophobic one.Microporous organic polymers (MOPs) are promising adsorbents for water treatment owing to their nanoporous structure with high surface areas. However, their hydrophobic nature, high cost and difficulty in recycling limit their practical application in water treatment. Here, we report the synthesis of new MOPs which combine sodium acrylate (SA) functionalized hypercrosslinked polymer (HCPs) with magnetic Fe3O4 nanoparticles to form a hybrid material (SA-MMNPs). The magnetic hybrid material can be directly aggregated and separated by applying an external magnetic field because of Fe3O4. More importantly, after introducing carboxyl group on the skeleton of HCP, the hydrophilic nature of SA-MMNPs is improved, thus SA-MMNPs can disperse in water well after vigorous shaking. The adsorption property of SA-MMNPs towards water-soluble contaminants was studied by using Rhodamine B (RhB) as adsorbates. The maximum adsorption capacity for RhB of this polymer is up to 216 mg g−1 which is better than hybrid materials without modification (MMNPs). The results constitute a new HCP paradigm with hydrophilic segments for removal of water soluble contaminants with high efficiency and good recyclability in water treatment.Download high-res image (95KB)Download full-size image

Gold nanoclusters are used as excellent scaffolds for the development of chemical and biological sensors due to their outstanding physical and chemical properties. In this study, a facile and green method has been employed for the preparation of highly fluorescent Au NCs by simply heating the gold precursor solution in the presence of a specially designed multidentate polymer ligand PTMP–PMAA. Herein, PTMP–PMAA functions as a reducing agent as well as a protecting agent. The Au NCs were characterized by fluorescence spectroscopy, ultraviolet absorption spectroscopy, dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), and powder X-ray diffraction (PXRD) and were found to exhibit yellow fluorescence (λem = 553 nm), a high quantum yield (22.6%), excellent stability and water-solubility. Based on aggregation-induced fluorescence quenching, the Au NCs@PTMP–PMAA fluorescent NCs were used for the detection of Fe3+ with an acceptable sensitivity having a detection limit of 3.0 μM and high selectivity. Moreover, Au NCs were also explored for the fluorescence imaging of Fe3+ in living H9c2 cardiac muscle cells presenting internalization with green fluorescence from the cells, suggesting their potential applicability as bioimaging agents.

•S-doped graphene oxide hybrid nanosheets were prepared by a facile method.•Hybrid nanosheets exhibits good capacitive performance.•Large energy density of the GO-TB-based three-electrode device was obtained.S-doped graphene oxide hybrid nanosheets are prepared by a facile in situ-polymerization method. The electrochemical performance is evaluated using cyclic voltammetry, galvanostatic charge/discharge techniques and impedance spectroscopy in 2 M KOH. As an electroactive material, it exhibits good capacitive performance in alkali aqueous electrolyte, high specific capacitance (up to 296 F g−1) at a current density of 0.3 A g−1, which is calculated via charge/discharge curve in three electrode systems. The electrical conductivity is also measured. More importantly, over 91.86% of the long-term stability is retained after repeating the galvanostatic charge/discharge over 4000 cycles. Furthermore, larger energy density (up to 148 W h kg−1 at a power density of 41.6 W kg−1) of the GO-TB-based three-electrode device is obtained with alkali aqueous electrolytes.

An N-heterocyclic carbene (NHC)–copper complex supported on hypercrosslinked polymers (HCPs) was successfully synthesized through a simple external cross-linking reaction. The structure and composition of the catalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and atomic emission spectrometry (AES). The obtained HCP–NHC–Cu catalyst possesses a large BET surface area, large pore volume, and good chemical and thermal stability. Hence, it was used as a solid catalyst for some organic transformations. An oxidative condensation reaction of indoles, 1,3-dicarbonyl compounds and phenylglyoxal monohydrate was developed with the aid of the HCP–NHC–Cu catalyst, which produced various polysubstituted olefins in high yield. The three-component click reaction of NaN3, phenylacetylene and benzyl halide, the Ullmann C–N coupling and the Glaser coupling reaction proceeded satisfactorily under the action of the HCP–NHC–Cu catalyst. At the end of these reactions, the catalyst was easily recovered and reused several times without significant loss of activity in all the reactions.

By encaging the Pd nanoparticles in the interior space of the hypercrosslinked microporous organic polymer, we successfully prepared a novel eco-friendly heterogeneous catalyst for Suzuki cross-coupling reaction. The catalyst afforded fast conversions for the Suzuki cross-coupling reaction even at a loading of 0.05 mmol% Pd, and the turnover frequency for the reaction could be up to 61,353 h−1. Furthermore, this catalyst is stable enough to be reused more than five times with no appreciable activity decrease. This work provides a method for fabricating highly active microporous organic polymer encapsulated Pd catalysts for Suzuki cross-coupling reaction and resolve the problem of industrialization in traditional active carbon catalysts.

Three N-heterocyclic carbenes (NHCs) were successfully integrated into the skeleton of hyper-crosslinked polymers (HCPs) via an external cross-linking reaction. The structure and composition of the solid catalyst was characterized by SEM, N2 sorption, FT-IR, XPS and CP/MAS NMR. Depending on the nature of the NHCs, the Brunauer–Emmett–Teller (BET) surface area of HCPs could be tuned and a BET surface area as high as 1229 m2 g−1 was achieved. The Poly-NHC-2–Pd2+ catalyst afforded rapid conversion for the Suzuki–Miyaura cross-coupling reactions of various aryl halides and arylboronic acids even at a Pd loading of 0.057 mmol% in aqueous media. In particular, because of the substantial porosity and individual pore structure toward the entrapped Pd species, Poly-NHC-2–Pd2+ showed outstanding stability and recyclability, which could be reused at least 5 times without significant loss of activity. The developed microporous catalyst combined with the NHC-functionalize is one of the most efficient heterogeneous systems for Suzuki–Miyaura cross-coupling reactions of aryl halides.

Two kinds of POSS-based organic–inorganic hybrid porous materials have been synthesized via Friedel–Crafts and Scholl coupling reactions, for the first time, using low-cost building blocks i.e., octaphenylsilsesquioxanes and simple knitting approaches to obtain high Brunauer–Emmett–Teller (BET) surface area porous polyhedral oligomeric silsesquioxane (POSS)-based hybrid materials. N2 sorption isotherms of the polymers show that both these materials are predominantly microporous and mesoporous with BET surface areas of 795 m2 g−1 for the polymer of octaphenylsilsesquioxanes-1 (POPS-1) and 472 m2 g−1 for the polymer of octaphenylsilsesquioxanes-2 (POPS-2). Moreover, POPS-1 can reversibly adsorb 9.73 wt% CO2 (1 bar and 273 K) and 0.89 wt% H2 (1.13 bar and 77 K), and POPS-2 shows moderate gas uptake with 8.12 wt% CO2 (1 bar and 273 K) and 0.64 wt% H2 (1.13 bar and 77 K). In addition, the structural integrity of POSS based building blocks was completely preserved under relatively strong acidic conditions.

Novel dual-porous carbon-supported palladium nanoparticle (Pd NP) catalysts were prepared by sequential carbonization and reduction of microporous organic polymer-encaged PdCl2. The diverse pore structure of microporous organic polymers provides a reservoir for the palladium precursors and prevents Pd NPs from sintering during the carbonization and reaction. The microporous structure has a significant effect on the size and dispersion of palladium NPs. The average size of the Pd NPs (in the range of 4–6 nm) was tuned by changing the pore size distribution and the carbonization temperature. The resulting carbon-supported Pd NPs were characterized by TEM, BET, XRD, and XPS and the Pd loading was calculated by AAS. The encaged Pd NP catalysts prepared by this methodology exhibited outstanding stability and reusability in the Heck reaction and could be reused at least 10 times without appreciable loss of activity.

The key challenge in the formation of stable CO2-in-water (C/W) emulsions has always been the availability of effective surfactants. Most of the surfactants being used for this purpose are expensive and difficult to synthesize, rendering the formation of C/W emulsions an uneconomical and unfavorable process. In this work, we report the use of commercial polyvinyl alcohol as an effective stabilizer for the formation of C/W emulsions at low temperatures. Porous emulsion-templated materials were prepared by the polymerization of the continuous phase of C/W emulsions. The open-cell morphology of the emulsion-templated materials was observed by scanning electron microscopy. To tune the morphology of the porous structures, the influence of the stabilizer concentration and the process of polymerization were investigated. These porous PAM materials were further evaluated for cellular growth and proliferation to demonstrate their applications in tissue engineering.

•A surfactant-free approach was found to generate PHIPEs without using any organic solvents.•PHIPEs with tunable pore size and interconnected pores were prepared.•These PVA hydrogels were evaluated for cellular culture to demonstrate their applications in tissue engineering.For tissue engineering, pore structure is an essential element in the development of scaffolds. In this paper, we obtained highly porous cross-linked partially hydrolyzed poly (vinyl alcohol) (PVA) hydrogels by templating concentrated CO2-in-water (C/W) emulsions, which avoid the use of traditional organic solvents and additional surfactants. This method is very convenient for the formation of biocompatible PVA hydrogels, because redundant crosslinking agent and catalyst could be easily removed by washing with the absence of organic solvent and surfactants, and would have widespread applications due to the biocompatibility of the resulting materials. These PVA hydrogels were further evaluated for cellular growth and proliferation to demonstrate their applications in tissue engineering.

This study provides a new method to prepare CO2-philic amphiphilic surfactants by copolymerizing a less activated monomer (VAc) with an activated monomer (DMAEMA). Initially, the difunctional RAFT agent S-(1-methyl-4-hydroxyethyl acetate) O-ethyl dithiocarbonate, containing the xanthate group and 2-bromopropionyl group in its structure, was synthesized. By successive living radical polymerization, a series of new cationic surfactants poly(vinyl acetate)-block-poly(dimethylaminoethyl methacrylate) (PVAc-b-PDMAEMA) was obtained. PVAc-b-PDMAEMA cationic surfactants can emulsify CO2–H2O systems effectively to obtain high internal phase emulsion that remains stable up to 12 h. Further study indicates that the emulsifying ability of the surfactant is affected by the pH of solution, pressure, etc. After the high internal phase CO2-in-water (40% w/v, acrylamide solution) emulsion was polymerized, polyacrylamide-based highly porous emulsion-templated materials were obtained with tunable size and interconnected pores. These porous materials were then used as scaffolds to guide cellular growth.

Functional microporous organic polymers (MOPs) are attractive in a wide range of applications including gas separation, catalysis, and energy storage. There is a lack of cost-effective processes to produce functional MOPs at industrial scale, which in fact limits their practical applications. Here, we propose a new low-cost strategy, based on the Scholl reaction, which can directly link rigid building blocks to obtain MOPs with high surface area and highly microporous structures. More importantly, this method is suitable for various building blocks and can be used as a general bottom-up approach to produce a variety of multifunctional MOPs. Multifaceted applications of these materials are also demonstrated by their large gas storage capacity, high catalytic activity, luminescence and semiconducting properties.

Nitrogen-doped activated carbons (N-ACs) with controlled nitrogen doping and analogous microporous structures were prepared by pyrolysis of poly[(pyrrole-2,5-diyl)-co-(benzylidene)] (PPCB). The obtained N-ACs were thoroughly characterized using HRTEM, FESEM, BET, FTIR and XPS for their morphology, surface area and chemical composition. The N-ACs were further used to fabricate supercapacitors, and their comprehensive electrochemical properties, such as cyclic voltammograms, galvanostatic charge–discharge, electrochemical impedance spectrum, electrochemical capacitive performance, power density and long cyclic stability, were studied. The galvanostatic charge–discharge (GC) measurements on N-ACs produced at 700 °C and 800 °C show a high specific capacitance (up to 525.5 F g−1 and an energy density of ca. 262.7 W h kg−1 at 0.26 A g−1) in alkaline media (2 M KOH). More importantly, the capacitance remains practically identical when the scan rate was increased from 0.26 to 26.31 A g−1. The observed capacitance retention (∼99.5%) of N-ACs is remarkably stable for electrodes even after 4000 cycles, due to the presence of nitrogen at the surface and in the graphitic edge planes. The nitrogen content plays a significant role in producing micropore dominated ACs and in facilitating the transfer of ions through pores on the surface. The precursor (PPCB) used is cheap and can easily be prepared, making it promising for the large-scale production of N-ACs as excellent electrode materials for supercapacitors.

Diarylmethane derivatives, essential building blocks in organic synthesis, are usually synthesized through the traditional electrophilic substitution reaction i.e., Friedel–Crafts reaction, which suffers from the rearrangement and weak reactivity of aromatic compounds with deactivating/electron-withdrawing groups. The Suzuki–Miyaura coupling reaction of low-cost benzyl chloride as an alternative method overcomes these defects. Pd(II) organometallic catalysts immobilized on the triphenylphosphine-functionalized microporous knitting aryl polymer (KAPs(Ph-PPh3)-Pd) as a novel heterogeneous catalyst was employed in Suzuki–Miyaura coupling reaction of benzyl chloride and exhibited excellent catalytic activity under mild conditions with a turnover frequency (TOF) up to 76 min−1 (4569 h−1). This work reveals that the microporous structure of the catalyst can rapidly adsorb substrates, consequently facilitating their interaction, and eventually promoting the catalytic efficiency.

Blue emission fluorescent Au5 clusters with maximum quantum yield of 20.1% were synthesized by a simple photoreduction method using three specially designed tridentate polymer ligands. The evolution of fluorescent Au nanoclusters (Au NCs) under UV irradiation was studied by fluorescence, UV-Vis and X-ray photoelectron spectroscopic techniques, suggesting that the fluorescence of Au NCs is size-dependent and is associated with the presence of Au(I) ions in the Au NCs. The effect of polymer structure on the fluorescent Au NCs has also been discussed. These highly fluorescent Au NCs have potential applications in the fabrication of optoelectronic devices and light emitting materials.

We report a simple one step protocol for the preparation of fairly monodisperse and highly water-soluble magnetic iron oxide nanoparticles (MIONs) through a co-precipitation method using a novel multifunctional, biocompatible and water-soluble polymer ligand dodecanethiol–polymethacrylic acid (DDT–PMAA). DDT–PMAA owing to its several intrinsic properties, not only efficiently controls the size of the MIONs but also gives them excellent water solubility, long time stability against aggregation and oxidation, biocompatibility and multifunctional surface rich in thioether and carboxylic acid groups. The molecular weight and concentration of the polymer ligand were optimized to produce ultrasmall (4.6 ± 0.7 nm) MIONs with high magnetization (50 emu g−1). The MIONs obtained with 1.5 mM DDT–PMAA (5330 g mol−1) are highly stable in solution as well as in dry powder form for an extended period of time. These MIONs show a high degree of monodispersity and are superparamagnetic at room temperature. The polymer ligand and MIONs@Polymer were characterized by GPC, 1H NMR, DLS, TEM, FTIR-Raman, XRD, TGA and VSM. In order to demonstrate the bio-applications of these magnetic nanoparticles (NPs), their toxicity was determined by MTT assay and they were found to be non-toxic and biocompatible. Finally, MIONs were conjugated with the anti-cancer drug doxorubicin (DOX) and its efficacy, as a model drug delivery system, was determined using HepG2 cells. The efficiency of the drug–NP conjugates i.e., covalently bound DOX–MIONs and electrostatically loaded DOX/MIONs, was found to be significantly higher than that of the free drug (DOX).

Highly stable water-soluble fluorescent Ag5 clusters with a quantum yield of 9.7% were synthesized using a specially designed tridentate polymer ligand by one-step reduction. The fluorescence may be associated with the dominant Ag+ species on the surface of the clusters. The resultant Ag nanoclusters were used as biomarkers to label mouse liver tissues successfully for the first time.

A novel method is developed to functionalize the oligo(vinyl acetate) (OVAc) via a bipyridine (bpy) moiety. A bifunctional xanthate bis[2-(2-(O-ethyl dithiocarbonate)propionate ethoxy)-4,4′-dicarbonyl-2,2′-bipyridine] (X-bpy-X) was synthesized as a RAFT/MADIX agent to control vinyl acetate (VAc) polymerization, and then the bpy moiety was introduced into the OVAc chain successfully. A series of oligo(vinyl acetate)-bipyridine-oligo(vinyl acetate) (OVAc-bpy) with a PDI of 1.5 and a molecular weight range of 1000–3500 were obtained. The phase behaviour of OVAc-bpy in supercritical carbon dioxide (sc-CO2) was determined by the cloud point method. Compared with OVAc homopolymers with a similar degree of polymerization (DP), OVAc-bpy has lower solubility due to the existence of bpy moieties. The lowest cloud point pressure was achieved in sc-CO2 at Mn,GPC = 1900. OVAc-bpy was used as a ligand to extract the metal ions by using sc-CO2 as the solvent. The extraction rate can be as high as 98% (for Ni2+) and reasonably good for other metal ions (Cu2+ and Co2+) without using any additive.

Magnetic microporous polymer nanoparticles (MMPNs) with high surface area and superparamagnetic properties have been designed and synthesized successfully. Their application in removing toxic organic compound by adsorption and magnetic separation have been proved. The MMPNs were also evaluated for their ability to uptake and control the release of ibuprofen.

Two hypercross-linked polymer networks have been synthesized by the self-condensation of bishydroxymethyl monomer, 1,4-benzenedimethanol (BDM), and monohydroxymethyl compound, benzyl alcohol (BA). This is different from the previous reports where multifunctional monomers or cross-linkers are crucial for constructing the porous polymer networks. N2 sorption isotherms for the polymers show that both materials are predominantly microporous with Brunauer–Emmett–Teller (BET) surface areas of 847 m2 g−1 for HCP–BDM and 742 m2 g−1 for HCP–BA. A network based on BA can also store a significant amount of CO2 (8.46 wt%) and H2 (0.97 wt%) at 1.0 bar, and at 273 K and 77 K respectively, despite its relatively modest surface area. Based on these results, this study opens up the possibility of synthesizing porous materials using monofunctional monomers.

Poly(vinyl acetate) (PVAc) has been shown to exhibit anomalously high solubility in CO2 as compared to other vinyl hydrocarbon polymers. Understanding the phase behaviour of PVAc with different topologies in CO2 is very important for its potential applications as suitable surfactant, or phase transfer agent in a CO2 solvent process. In this study, a series of PVAcs with different topologies (bi-arms, tri-arms, tetra-arms) were synthesized by RAFT/MADIX method. The structures and molecular weights of these polymers were characterized by 1H NMR and GPC. The phase behaviours of PVAcs in dense carbon dioxide fluid were determined, and the results show that the PVAc with more arms has lower cloud point pressure.

Water-soluble fluorescent copper, silver and gold nanoclusters with quantum yields of 2.2, 6.8 and 5.3%, respectively, are prepared by a robust photoreduction of their inorganic precursors in the presence of poly (methacrylic acid) functionalized with pentaerythritol tetrakis 3-mercaptopropionate.

Catalyzed hydrogen spillover for hydrogen storage on microporous organic materials has been studied in this work. The method, i.e. “preparation of Pt nanoparticle first and then in situ formation of microporous materials” has been developed for the synthesis of microporous hypercrosslinked polymers with highly dispersed Pt nanoparticles. Hydrogen adsorption isotherms are measured at 77.3 K and up to 1.13 bar, and 298.15 K and up to 19 bar. By containing 2 wt % Pt nanoparticles, the hydrogen storage capacity of hypercrosslinked polymers is enhanced to 0.21 wt % at 298.15 K and 19 bar. Compared to the similar materials without Pt nanoparticles, the H2 adsorption amount has been enhanced by a factor of 1.75.Highlights► Catalyzed hydrogen spillover for hydrogen storage on microporous organic materials. ► Highly disperse nanoparticles of Pt on microporous hypercrosslinked polymers. ► Hydrogen storage capacity of hypercrosslinked polymers was enhanced by spillover.

A multifunctional polymer ligand, containing thiol, thioether, and ester functional groups, is designed and used to prepare intense blue fluorescent gold nanoclusters (AuNCs) with a diameter of ∼1.2 nm and high quantum yield (QY) of 24.3% in organic media without using additional phase-transfer reagents. The size and QY of AuNCs can be fairly controlled by adjusting the molecular weight (Mn) and concentration of multifunctional polymer ligand. The AuNCs retain their fluorescence in various organic solvents and are fairly stable for several months. The same polymer can also be used to prepare silver and platinum nanoclusters (AgNCs and PtNCs), which are not very fluorescent. All of these metal nanoclusters (MNCs) have been characterized thoroughly using TEM, XPS, MALDI-TOF, and other common optical techniques. Apart from the diverse applications of silver and platinum NCs, the highly fluorescent AuNCs may have potential applications in thermal gradient optical imaging, single molecule optoelectronics, sensors and optical components of the detectors.

At present, thiol ligands are generally used whenever the classical Brust–Schiffrin two-phase method is employed to prepare metal nanoparticles. In general, the previous research was mainly focused on utilizing small molecular thiol compounds or thiol polymers as the stabilizers in organic phase to obtain small sized and uniform gold nanoparticles (Au NPs). Such preparations are usually associated with the problems of ligand exchange on the nanoparticle's surface due to strong Au–thiol interaction. Herein, we report an approach to produce fairly uniform Au NPs with diameters about 2–6 nm using thioether end-functional polymer ligands (DDT–PVAc and PTMP–PVAc) as the capping agents. These nanoparticles are thoroughly characterized using DLS, TEM, UV-Vis spectroscopy and other complementary techniques. The results indicate that multidentate thioether polymeric ligands (PTMP–PVAc) lead to formation of smaller but special ‘multimer’ morphology in organic phase; whereas fairly uniform nanoparticles are produced using monodentate thioether functionalized ligands (DDT–PVAc). Further modification of such polymer ligands to introduce the hydrophilic functionalities realizes the phase transfer of Au NPs from organic to aqueous media.

Porous polyimide (PI) networks with surface area up to 660 m2 g−1 were synthesized by planar structure monomers without detrimental catalysts.

We report here a practical method to tailor the pore size of hypercrosslinked poly(divinylbenzene-co-vinylbenzyl chloride) (HCP-DVB-VBC) by adjusting the DVB content in poly(divinylbenzene-co-vinylbenzyl chloride) (DVB-VBC) precursors, and then hypercrosslinking these DVB-VBC precursors. With the DVB content varying from 0–10%, the pore size of HCP-DVB-VBC decreases, the pore size distribution becomes narrower and the micropore volume content increases from 6.82 to 61.90%. When the DVB content is higher than 7%, the HCP-DVB-VBC changes to pure microporous organic polymer.

Sulfonic acid-modified microporous hypercrosslinked polymers (SAM-HCPs) synthesized by sulfonation of microporous hypercrosslinked polymers (HCPs, also known as “Davankov Resins”) have been investigated as a high-capacity adsorbent for toxic metal ions. The materials were characterized using proton magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA), thermogravimetric analysis (TGA), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption method. The results show that the modified resins retained their original microporous structure and spherical morphology, and possess sulfonic acid groups as hydrophilic groups and active sites. Sulfonic acids-modified hypercrosslinked “Davankov Resins” (SAM-HCP-DR) have been found to attain very good adsorption capacity for metal ions (e.g., Cu2+ 51.45 mg g−1 at 303 K, 54.82 mg g−1 at 313 K, and 57.68 mg g−1 at 323 K), which is due to the synergic effect of microporous structure and active sites. The kinetic data obtained from adsorption experiments supports a pseudo-second order model and adsorption isotherms obtained at different temperatures (303 K, 313 K and 323 K) are all fitted with the Langmuir isotherms. In addition, the thermodynamic parameters, i.e., Gibbs free energy change (ΔG0), enthalpy change (ΔH0), entropy change (ΔS0) of the adsorption process were calculated, and the results confirmed the adsorption to be spontaneous and endothermic. Moreover, these modified resins can be recycled several times with minimal loss of adsorption capacity and thus may have potential industrial applications.Graphical abstractResearch highlights► Hydrophilic microporous hypercrosslinked polymer is a novel high-capacity adsorbent for toxic metal ion. ► Sulfonic acid-modified microporous hypercrosslinked polymers has been prepared. ► Microporous materials could be better adsorbent than mesoporous and macroporous materials.

A series of microporous polymers has been obtained via a low-cost versatile strategy, which involves “knitting” rigid aromatic building blocks, such as benzene, biphenyl, 1,3,5-triphenylbenzene, methylbenzene, chlorobenzene, and phenol using an external cross-linker. These materials are predominantly microporous and exhibit high surface areas. Moreover, different building blocks can generate materials with different pore structures, functional groups and application properties, which are significant for materials design.

Highly bright fluorescent gold nanoclusters (Au NCs) have been prepared by one-step reduction of aqueous precursor solution in the presence of multidentate thioether-terminated poly(methacrylic acid) (PTMP-PMAA). The fluorescence quantum yield of the resultant Au NCs is 4.8% higher than that of the similarly sized Au NCs prepared by the etching method (1.8–4.0%). These Au NCs show excellent photostability and have been successfully applied to label the hematopoietic cells first. The results show that Au NCs were endocytosed by the cancer cells significantly more than the normal cells, in comparison with control experiments labeled with fluorescent quantum dots (CdTe). The cytotoxicity experiments demonstrate the excellent biocompatibility of Au NCs, proven by a relatively lower cytotoxicity than CdTe. These robust near-infrared Au NCs show great potential in biolabeling, tracking, and imaging of other cells and diseases, especially in the diagnosis and treatment of chronic myeloid leukemia.

This work is aimed at producing uniform microporous polymer nanoparticles (MPNs) and studying their hydrogen storage properties. Synthesis of vinylbenzyl chloride (VBC)/divinylbenzene (DVB) copolymers by emulsion polymerization yield fairly uniform gel-type precursor nanoparticles and the particle size can be tuned from 36 to 131 nm by adjusting the emulsifier dose. These are analogous to gel-type suspension polymerized particles typically of 10–500 μm in diameter and are essentially non-porous in the dry state having only a very nominal surface area (1–2 m2/g, BET surface area). Friedel–Crafts-type hyper-cross-linking reaction of these precursors yields uniform MPNs with extremely high surface area up to ca. 1500 m2/g (BET surface area). Moreover, MPNs present more micropore volume (0.56 cm3/g), higher hydrogen adsorption capacity (1.59 wt%, 77.3 K, 1.13 bar), higher isosteric heats for hydrogen and faster adsorption rate as compared to polydisperse micro-size analogues previously reported.

Amphiphilic block copolymers poly(ethylene glycol)-block-oligo(vinyl acetate) (PEG-b-OVAc) and OVAc-b-PEG-b-OVAc have been demonstrated to be effective surfactants for CO2-in-water (C/W) emulsions. However, the high cost and difficulty of synthesis process can render the economics of CO2 process unfavorable. In this work, by reversible addition−fragmentation chain transfer (RAFT) polymerization, a series of well-defined CO2-philic triblock copolymers X−OVAc-b-PEG-b-OVAc−X (where X stands for xanthate group) were synthesized. The structures and molecular weights of these copolymers were characterized by 1H NMR and GPC. The results of GPC analysis exhibited relatively narrow polydispersity (PDI < 1.35). The process of preparation of X−OVAc-based surfactants was much more simple, inexpensive and also easy to control, which could promote industrial-scale applications. The X−OVAc-based surfactants were found effectively to produce highly concentrated stable C/W emulsions. Porous emulsion-templated materials were prepared by the polymerization of the continuous phase of C/W emulsions. The open-cell morphology of the emulsion-templated materials was evidenced by scanning electron microscope. To tune the morphology of the porous structures, the influence of the surfactant concentration and molecular weight of OVAc block were also investigated. It was shown that X−OVAc-based surfactants can outperform perfluorinated surfactants and approach OVAc-based surfactants for such applications.

Poly(vinyl acetate) (PVAc) is an inexpensive, high-tonnage bulk commodity polymer which, unlike most vinyl polymers, is moderately biodegradable. PVAc has been shown to exhibit anomalously high solubility in CO2 with respect to other vinyl hydrocarbon polymers. Understanding the phase behavior of PVAc in CO2 and its variation with structure is very important for its potential application as suitable surfactant, ligand, or phase transfer agent in a CO2 solvent process. In this article, PVAc has been fractionated using a supercritical fluid extraction method (SCFE) to provide low molecular weight fractions with narrow polydispersity. The phase behavior of hydroxyl terminated poly(vinyl acetate)s (PVAc-OH) were determined by a high throughput gravimetric extraction (HTGE) screening method and a cloud-point pressure method using a variable volume view cell (VVVC). The solubility of PVAc in CO2 strongly depends on the molecular weight. Oligomer PVAc-OH (Mw < 3000 g·mol−1) is soluble in CO2 at low pressures but decreases in solubility with increasing molecular weight. End-group modification of oligomer PVAc-OH alters the phase behavior of the oligomers.

•A simple strategy for preparing heterogeneous acid or base catalyst is proposed.•The acid or base sites are introduced directly by the functional monomers.•The loading of catalytic sites can be controlled accurately by the monomers.•Acid and base coexisted catalysts are applied in one-pot cascade reactions.Heterogeneous microporous acid (sulfonic acid) and base (benzylamine) catalysts with high surface areas were synthesized using simple aromatic compounds through one-step external cross-linking reaction. The direct induction and control of catalytic sites were achieved by functionalized monomers using an appropriate amount of acid/base monomers. This strategy provides an easy approach to produce highly stable and acid/base functionalized microporous organic polymers. The structure and composition of the catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption, Fourier transform infrared spectroscopy (FT-IR), solid-state 13C cross polarization magic angle spinning (CP/MAS) NMR, thermogravimetric analysis (TGA), and element mapping analysis. The stable porous skeleton and the accurate manipulation of the catalyst structure allowed us to use the obtained polymers as compatible and efficient acid/base co-catalysts for one-pot cascade reactions. We demonstrated the use of these microporous heterogeneous catalysts for the cascade deacetalization/Henry and deacetalization/Knoevenagel reactions. The results demonstrated that preparing microporous materials from simple aromatic compounds through one-step external cross-linking reaction is indeed a cost-effective and easy-to-handle method to produce functionalized heterogeneous catalysts. The microporous heterogeneous catalysts produced by this method are highly stable and the amount of catalytically active sites can easily be controlled to form a catalytic system with two antagonistic centers.Download high-res image (97KB)Download full-size image

We report a simple one step protocol for the preparation of fairly monodisperse and highly water-soluble magnetic iron oxide nanoparticles (MIONs) through a co-precipitation method using a novel multifunctional, biocompatible and water-soluble polymer ligand dodecanethiol–polymethacrylic acid (DDT–PMAA). DDT–PMAA owing to its several intrinsic properties, not only efficiently controls the size of the MIONs but also gives them excellent water solubility, long time stability against aggregation and oxidation, biocompatibility and multifunctional surface rich in thioether and carboxylic acid groups. The molecular weight and concentration of the polymer ligand were optimized to produce ultrasmall (4.6 ± 0.7 nm) MIONs with high magnetization (50 emu g−1). The MIONs obtained with 1.5 mM DDT–PMAA (5330 g mol−1) are highly stable in solution as well as in dry powder form for an extended period of time. These MIONs show a high degree of monodispersity and are superparamagnetic at room temperature. The polymer ligand and MIONs@Polymer were characterized by GPC, 1H NMR, DLS, TEM, FTIR-Raman, XRD, TGA and VSM. In order to demonstrate the bio-applications of these magnetic nanoparticles (NPs), their toxicity was determined by MTT assay and they were found to be non-toxic and biocompatible. Finally, MIONs were conjugated with the anti-cancer drug doxorubicin (DOX) and its efficacy, as a model drug delivery system, was determined using HepG2 cells. The efficiency of the drug–NP conjugates i.e., covalently bound DOX–MIONs and electrostatically loaded DOX/MIONs, was found to be significantly higher than that of the free drug (DOX).

Highly stable water-soluble fluorescent Ag5 clusters with a quantum yield of 9.7% were synthesized using a specially designed tridentate polymer ligand by one-step reduction. The fluorescence may be associated with the dominant Ag+ species on the surface of the clusters. The resultant Ag nanoclusters were used as biomarkers to label mouse liver tissues successfully for the first time.

Functional microporous organic polymers (MOPs) are attractive in a wide range of applications including gas separation, catalysis, and energy storage. There is a lack of cost-effective processes to produce functional MOPs at industrial scale, which in fact limits their practical applications. Here, we propose a new low-cost strategy, based on the Scholl reaction, which can directly link rigid building blocks to obtain MOPs with high surface area and highly microporous structures. More importantly, this method is suitable for various building blocks and can be used as a general bottom-up approach to produce a variety of multifunctional MOPs. Multifaceted applications of these materials are also demonstrated by their large gas storage capacity, high catalytic activity, luminescence and semiconducting properties.

The preparation of soluble microporous polymers for large-scale gas storage and separation with low cost, scalability and synthetic diversification is extremely challenging. Here, we report the synthesis of solution-processable hypercrosslinked polymers (SHCPs) by folding polystyrene molecules at high dilution. A low cost knitting method is employed and by slowly adding an external crosslinker, intramolecular cross-links were introduced. Despite being highly cross-linked, the resulting hypercrosslinked polymers dissolve in a range of organic solvents to form thermodynamically stable homogenous liquids. By increasing the concentration of polystyrene and the amount of crosslinker, the BET surface area of SHCPs increased with the largest surface area of 724 m2 g−1. Moreover, they also show comparable gas uptake properties reaching 8.11 wt% CO2 adsorption (1.13 bar and 273 K), 1.01 wt% H2 adsorption (1.13 bar and 77 K), and 0.14 wt% CH4 adsorption (1.13 bar and 273 K). The reaction offers a route to new classes of solution-processable microporous polymers as promising materials for gas storage and separation.

Microporous organic capsules with hollow interiors have received enormous attention due to their unusual encapsulation efficiency to confine chemicals within their hollow cavities and prompted controlled release by circumventing their ripening or poisoning. To this end, herein, we report the design and synthesis of carboxylic group functionalized hollow microporous organic capsules (HMOCs) using a facile emulsion polymerization technique that show extraordinary high encapsulation efficiency (up to 98%) of morphine·HCl and its promising prolonged release. The functionalized HMOCs are found to release the drug at a rate which is proportional to the amount of drug remaining in its interior. Due to the presence of hollow and porous morphologies, they possess high BET surface areas, i.e. up to 974 m2 g−1. Moreover, the in vivo results showed that functionalized HMOCs can offer slow release of active drug molecules and attenuate the level of writhing response over 72 h of intraperitoneal injection. The functionalized HMOCs, therefore, present a new class of potential drug delivery systems that can maintain the slow and prolonged release of analgesics by lowering the dosage and avoid frequent administration.

Gold nanoclusters are used as excellent scaffolds for the development of chemical and biological sensors due to their outstanding physical and chemical properties. In this study, a facile and green method has been employed for the preparation of highly fluorescent Au NCs by simply heating the gold precursor solution in the presence of a specially designed multidentate polymer ligand PTMP–PMAA. Herein, PTMP–PMAA functions as a reducing agent as well as a protecting agent. The Au NCs were characterized by fluorescence spectroscopy, ultraviolet absorption spectroscopy, dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), and powder X-ray diffraction (PXRD) and were found to exhibit yellow fluorescence (λem = 553 nm), a high quantum yield (22.6%), excellent stability and water-solubility. Based on aggregation-induced fluorescence quenching, the Au NCs@PTMP–PMAA fluorescent NCs were used for the detection of Fe3+ with an acceptable sensitivity having a detection limit of 3.0 μM and high selectivity. Moreover, Au NCs were also explored for the fluorescence imaging of Fe3+ in living H9c2 cardiac muscle cells presenting internalization with green fluorescence from the cells, suggesting their potential applicability as bioimaging agents.

Novel dual-porous carbon-supported palladium nanoparticle (Pd NP) catalysts were prepared by sequential carbonization and reduction of microporous organic polymer-encaged PdCl2. The diverse pore structure of microporous organic polymers provides a reservoir for the palladium precursors and prevents Pd NPs from sintering during the carbonization and reaction. The microporous structure has a significant effect on the size and dispersion of palladium NPs. The average size of the Pd NPs (in the range of 4–6 nm) was tuned by changing the pore size distribution and the carbonization temperature. The resulting carbon-supported Pd NPs were characterized by TEM, BET, XRD, and XPS and the Pd loading was calculated by AAS. The encaged Pd NP catalysts prepared by this methodology exhibited outstanding stability and reusability in the Heck reaction and could be reused at least 10 times without appreciable loss of activity.

Water-soluble fluorescent copper, silver and gold nanoclusters with quantum yields of 2.2, 6.8 and 5.3%, respectively, are prepared by a robust photoreduction of their inorganic precursors in the presence of poly (methacrylic acid) functionalized with pentaerythritol tetrakis 3-mercaptopropionate.

This work is aimed at producing uniform microporous polymer nanoparticles (MPNs) and studying their hydrogen storage properties. Synthesis of vinylbenzyl chloride (VBC)/divinylbenzene (DVB) copolymers by emulsion polymerization yield fairly uniform gel-type precursor nanoparticles and the particle size can be tuned from 36 to 131 nm by adjusting the emulsifier dose. These are analogous to gel-type suspension polymerized particles typically of 10–500 μm in diameter and are essentially non-porous in the dry state having only a very nominal surface area (1–2 m2/g, BET surface area). Friedel–Crafts-type hyper-cross-linking reaction of these precursors yields uniform MPNs with extremely high surface area up to ca. 1500 m2/g (BET surface area). Moreover, MPNs present more micropore volume (0.56 cm3/g), higher hydrogen adsorption capacity (1.59 wt%, 77.3 K, 1.13 bar), higher isosteric heats for hydrogen and faster adsorption rate as compared to polydisperse micro-size analogues previously reported.

A novel metalporphyrin-based microporous organic polymer (HUST-1-Co), which possesses a high surface area of 1360 m2 g−1 and a high CO2 uptake of 21.39 wt% (1 bar and 273 K) for CO2 capture and storage (CCS) and the efficient chemical conversion of CO2 under ambient conditions, is reported. This polymer incorporated both ultra-micropores and catalytic sites, and was synthesized by a novel solvent knitting hypercrosslinked polymers method, using 5,10,15,20-tetraphenylporphyrin (TPP) as the building block. The N2 sorption isotherms of the polymers show that HUST-1-Co possesses abundant ultra-micropores (centered at 0.68 nm), and a continuous mesoporous and macroporous structure, which not only enhances the interaction between the pore walls and CO2, but is also favourable for the catalysis process. The synergy of the ultra-micropores, abundant nitrogen atoms and Co2+ ions makes HUST-1-Co one of the highest CO2 uptake MOP materials reported so far and further endows it with efficient catalytic performance. HUST-1-Co is one of the most efficient catalysts for the coupling of CO2 with substituted epoxides with various functional groups at room temperature and atmospheric pressure, with an excellent recycling performance (more than 15 times). Moreover, the role of the mesoporous and macroporous structure of HUST-1-Co gives it a unique catalytic performance for different molecular sizes of epoxide substrates with excellent yields (>93%).

Two kinds of POSS-based organic–inorganic hybrid porous materials have been synthesized via Friedel–Crafts and Scholl coupling reactions, for the first time, using low-cost building blocks i.e., octaphenylsilsesquioxanes and simple knitting approaches to obtain high Brunauer–Emmett–Teller (BET) surface area porous polyhedral oligomeric silsesquioxane (POSS)-based hybrid materials. N2 sorption isotherms of the polymers show that both these materials are predominantly microporous and mesoporous with BET surface areas of 795 m2 g−1 for the polymer of octaphenylsilsesquioxanes-1 (POPS-1) and 472 m2 g−1 for the polymer of octaphenylsilsesquioxanes-2 (POPS-2). Moreover, POPS-1 can reversibly adsorb 9.73 wt% CO2 (1 bar and 273 K) and 0.89 wt% H2 (1.13 bar and 77 K), and POPS-2 shows moderate gas uptake with 8.12 wt% CO2 (1 bar and 273 K) and 0.64 wt% H2 (1.13 bar and 77 K). In addition, the structural integrity of POSS based building blocks was completely preserved under relatively strong acidic conditions.

An N-heterocyclic carbene (NHC)–copper complex supported on hypercrosslinked polymers (HCPs) was successfully synthesized through a simple external cross-linking reaction. The structure and composition of the catalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and atomic emission spectrometry (AES). The obtained HCP–NHC–Cu catalyst possesses a large BET surface area, large pore volume, and good chemical and thermal stability. Hence, it was used as a solid catalyst for some organic transformations. An oxidative condensation reaction of indoles, 1,3-dicarbonyl compounds and phenylglyoxal monohydrate was developed with the aid of the HCP–NHC–Cu catalyst, which produced various polysubstituted olefins in high yield. The three-component click reaction of NaN3, phenylacetylene and benzyl halide, the Ullmann C–N coupling and the Glaser coupling reaction proceeded satisfactorily under the action of the HCP–NHC–Cu catalyst. At the end of these reactions, the catalyst was easily recovered and reused several times without significant loss of activity in all the reactions.

Three N-heterocyclic carbenes (NHCs) were successfully integrated into the skeleton of hyper-crosslinked polymers (HCPs) via an external cross-linking reaction. The structure and composition of the solid catalyst was characterized by SEM, N2 sorption, FT-IR, XPS and CP/MAS NMR. Depending on the nature of the NHCs, the Brunauer–Emmett–Teller (BET) surface area of HCPs could be tuned and a BET surface area as high as 1229 m2 g−1 was achieved. The Poly-NHC-2–Pd2+ catalyst afforded rapid conversion for the Suzuki–Miyaura cross-coupling reactions of various aryl halides and arylboronic acids even at a Pd loading of 0.057 mmol% in aqueous media. In particular, because of the substantial porosity and individual pore structure toward the entrapped Pd species, Poly-NHC-2–Pd2+ showed outstanding stability and recyclability, which could be reused at least 5 times without significant loss of activity. The developed microporous catalyst combined with the NHC-functionalize is one of the most efficient heterogeneous systems for Suzuki–Miyaura cross-coupling reactions of aryl halides.

Porous polyimide (PI) networks with surface area up to 660 m2 g−1 were synthesized by planar structure monomers without detrimental catalysts.

Nitrogen-doped activated carbons (N-ACs) with controlled nitrogen doping and analogous microporous structures were prepared by pyrolysis of poly[(pyrrole-2,5-diyl)-co-(benzylidene)] (PPCB). The obtained N-ACs were thoroughly characterized using HRTEM, FESEM, BET, FTIR and XPS for their morphology, surface area and chemical composition. The N-ACs were further used to fabricate supercapacitors, and their comprehensive electrochemical properties, such as cyclic voltammograms, galvanostatic charge–discharge, electrochemical impedance spectrum, electrochemical capacitive performance, power density and long cyclic stability, were studied. The galvanostatic charge–discharge (GC) measurements on N-ACs produced at 700 °C and 800 °C show a high specific capacitance (up to 525.5 F g−1 and an energy density of ca. 262.7 W h kg−1 at 0.26 A g−1) in alkaline media (2 M KOH). More importantly, the capacitance remains practically identical when the scan rate was increased from 0.26 to 26.31 A g−1. The observed capacitance retention (∼99.5%) of N-ACs is remarkably stable for electrodes even after 4000 cycles, due to the presence of nitrogen at the surface and in the graphitic edge planes. The nitrogen content plays a significant role in producing micropore dominated ACs and in facilitating the transfer of ions through pores on the surface. The precursor (PPCB) used is cheap and can easily be prepared, making it promising for the large-scale production of N-ACs as excellent electrode materials for supercapacitors.