Mesoporous Polymer Research Articles

A dual-template synergistic assembly strategy towards the synthesis of extra-small nitrogen-doped mesoporous carbon nanospheres with large pores.

Functional mesoporous carbon nanomaterials with large pores and small particle sizes have broad accessibility, but remain challenging to achieve. This study proposed a dual-template synergistic assembly strategy to facilely synthesize extra-small nitrogen-doped mesoporous carbon nanospheres with large pores in a low-cost manner. Directed by the synergistic effect of the combination of surfactants, sodium oleate (anionic surfactant) and triblock copolymer-P123 (nonionic surfactant) were selected as templates to construct nanomicelles (nanoemulsions), which were co-assembled with melamine-based oligomers to form composite nanomicelles, thus obtaining nitrogen-doped mesoporous polymer nanospheres (NMePS) and then nitrogen-doped mesoporous carbon nanospheres (NMeCS). Based on Schiff base chemistry, the melamine-based oligomers with self-assembly capability were synthesized as precursors, which is different from the conventional synthetic route of melamine-formaldehyde resin. The key parameters involved in the route were investigated comprehensively and correlated with the characterization results. Furthermore, the 50 nm-scale particle size and the large mesoporous size of 5.5 nm of NMeCS can facilitate effective mass transport, coupled with their high nitrogen content (15.7 wt%), contributing to their excellent performance in lithium-ion batteries.

Triazine‐based mesoporous organic polymers as palladium supports: physicochemical properties, porosity and catalytic performance in Suzuki coupling reaction

AbstractThis article reports the preparation of new mesoporous triazine‐based organic polymers and their characterization. The polymers were synthesized via a nucleophilic condensation reaction between cyanuric chloride and bisphenols or aromatic diamine linkers. As a result, two types of triazine‐based polymers were prepared: triazine‐ether and triazine‐amine polymers. The polymers reveal a mesoporous nature with surface area values ranging between 345 and 1275 m2 g−1 and mesopore volume between 0.273 and 1.03 cm3 g−1. These values were determined from argon gas isotherms at 87 K. The pore size distribution also confirmed the micro–mesoporosity, which reached up to 3.0 nm for all polymers. The triazine‐amine polymer shows good thermal oxidative stability up to 450 °C. Motivated by the mesopore size, the new polymers were also employed as palladium nanoparticle supports. The X‐ray diffraction technique indicated the successful incorporation of palladium nanoparticles, and Fourier transform infrared measurements proved that the framework of the polymers was retained after forming palladium supports. To ensure the catalytic reactivity of palladium nanoparticles, we employed one example as a catalyst in a Suzuki coupling reaction. The catalyst exhibited remarkable recyclability, maintaining catalytic efficiency through seven cycles, thereby enabling the use of palladium‐loaded triazine‐based polymeric catalysts in a variety of organic reactions in future. © 2023 Society of Industrial Chemistry.

Acidic ionic liquid-functionalized ordered mesoporous polymers: Highly efficient solid acid catalysts for water-medium organic reactions

Strong acidic ionic liquid-functionalized mesoporous organic material (MPOM-T-AIL) has been created by quaternary ammonization of mesoporous organic material (MPOM) with 1,3-propane sultone and subsequent strong acid (H2SO4 or HSO3CF3) acidification. The novel supporting material, MPOM, had high nitrogen content and was synthesized by direct high-temperature (400–550 °C) polymerization of an easily prepared and low cost protic salt [pPDA][2HSO4], which was obtained by simple neutralization of p-phenylenediamine with two equivalents of H2SO4. MPOM-T-AIL possesses high BET specific surface area, ordered and uniform mesoporosity, hydrophobic property, and highly active acidic ionic liquid components. Catalytic tests in the water-medium Prins reactions and acetalization of benzaldehyde with ethylene glycol showed that MPOM-T-AIL exhibits much better catalytic activities and reusabilities than commercially available solid acid catalysts Amberlyst 15 and H-ZSM-5, and mineral acid H2SO4. Additionally, MPOM-T-AIL significantly improved the catalytic selectivity of the water-medium Prins reaction, which was strongly related to its hydrophobic property. MPOM-T-AIL with excellent catalytic performance is a promising new solid acid catalyst for various acid-catalyzed reactions.

A screen-printed carbon electrode modified with bismuth nanoparticles and conjugated mesoporous polymer for simultaneous determination of Pb(II) and Cd(II) in seafood samples

A disposable sensor for the simultaneous detection of Pb(II) and Cd(II) ions utilizing square wave anodize stripping voltammetry (SWASV) was developed. Bismuth nanoparticles (BiNPs) were electrodeposited onto screen-printed carbon electrodes (SPCE), then conjugated mesoporous polymer (CMP) was dropped to obtain CMP/BiNPs/SPCE. The modified electrode was thoroughly characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV), demonstrating excellent conductivity and a large surface area. Under optimized conditions, the sensor exhibited exceptional response and peak separation. The currents were linear within the concentration range of 1–100 μg L−1 for Pb(II) and Cd(II), with detection limits of 0.1 μg L−1 for Pb(II) and 0.2 μg L−1 for Cd(II) (S/N = 3). The method's effectiveness was successfully demonstrated by simultaneously determining Pb(II) and Cd (II) in seafood samples.

Mesoporous Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) as Efficient Iodine Host for High-Performance Zinc-Iodine Batteries.

Here, by introducing polystyrenesulfonate (PSS) as a multifunctional bridging molecule to synchronously coordinate the interaction between the precursor and the structure-directing agent, we developed a mesoporous conductive polymer of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) featuring adjustable size in the range of 105-1836 nm, open nanochannels, large specific surface area (105.5 m2 g-1), and high electrical conductivity (172.9 S cm-1). Moreover, a large-area ultrathin PEDOT:PSS thin film with well-defined mesopores can also be obtained by controllable growth on various functional interfaces. As an example, we demonstrated that the iodine-loaded mesoporous PEDOT:PSS nanospheres can serve as a promising cathode for aqueous zinc-iodine batteries with high specific capacity (241 mAh g-1), excellent rate performance, and superlong 20,000 cycle life. In-depth theoretical calculations and systematic experimental results together reveal that the exposed sulfur- and oxygen-containing functional groups hold strong interactions with iodine species, resulting in effectively anchoring iodine species and inhibiting the shuttling of polyiodide intermediates, thus ensuring the long-term stability of the batteries. This work introduces a member to the family of mesoporous materials as well as porous polymers with versatile applications.

Alkaloid Precipitant Reaction Inspired Controllable Synthesis of Mesoporous Tungsten Oxide Spheres for Biomarker Sensing.

Highly porous sensitive materials with well-defined structures and morphologies are extremely desirable for developing high-performance chemiresistive gas sensors. Herein, inspired by the classical alkaloid precipitant reaction, a robust and reliable active mesoporous nitrogen polymer sphere-directed synthesis method was demonstrated for the controllable construction of heteroatom-doped mesoporous tungsten oxide spheres. In the typical synthesis, P-doped mesoporous WO3 monodisperse spheres with radially oriented channels (P-mWO3-R) were obtained with a diameter of ∼180 nm, high specific surface area, and crystalline skeleton. The in situ-introduced P atoms could effectively adjust the coordination environment of W atoms (Wδ+-Ov), giving rise to dramatically enhanced active surface-adsorbed oxygen species and unusual metastable ε-WO3 crystallites. The P-mWO3-R spheres were applied for the sensing of 3-hydroxy-2-butanone (3H2B), a biomarker of foodborne pathogenic bacteria Listeria monocytogenes (LM). The sensor exhibited high sensitivity (Ra/Rg = 29 to 3 ppm), fast response dynamics (26/7 s), outstanding selectivity, and good long-term stability. Furthermore, the device was integrated into a wireless sensing module to realize remote real-time and precise detection of LM in practical applications, making it possible to evaluate food quality using gas sensors conveniently.

The preparation, characterization and catalytic activity of porous tragacanth gum -g-poly (p-styrene sulfonamide-co-acrylamide)

A straightforward and practical method for the synthesis of 4-aryl-NH-1,2,3-triazoles and of quinoxalines is described. This method provides a new approach to prepare various N-containing heterocycles, using mesoporous polymer based on tragacanth gum (TG) and polysulfonamide (TG-PSSA-co-ACA). The notable advantages of TG-PSSA-co-ACA organo-catalyst are nontoxic, inexpensive, high surface area, and recyclability.

Correction to “Uniform Gold Nanoclusters Supported on Mesoporous Polymer Beads Decorated with Polyaminophosphine Patches for the Catalytic Reduction of 4-Nitrophenol”

Correction to “Uniform Gold Nanoclusters Supported on Mesoporous Polymer Beads Decorated with Polyaminophosphine Patches for the Catalytic Reduction of 4-Nitrophenol”

Production of ethyl esters using municipal sewage sludge and porous ionic liquid coordinated with Burkholderia lipase

Lipase from Burkholderia species immobilized onto novel mesoporous polymeric ionic liquids (MO(Poly)Cn–BLE) could be utilized as a low–cost biocatalyst for the lipase-catalyzed synthesis of free fatty acid esters from dried municipal sewage sludge. To assess this, this investigation has focused on three main parts of this process: (i) the development of a series of large surface polymer synthesis; (ii) mesoporous polymeric biocatalyst preparation using lipase from Burkholderia sp. immobilization onto MO(Poly)Cn, and supports for this alongside Mesoporous polymer ionic liquid–1–bromooctane–lipase from Burkholderia sp. enzyme (MO(Poly)C18–BLE) were characterized using FT-IR, SEM, XPS, N2, and TGA; (iii) Response surface methodology was used to determine the optimal conditions for ester production from municipal sewage sludge lipids using a central composite design. Four process variables were assessed at three levels; a total of 13 experiments were performed to study the effects of the lipids: ethanol molar ratio, catalyst concentration, reaction time, and temperature on the ester’s yield. A 91.25% ester yield was obtained under optimal conditions: a 1:12 molar ratio of municipal sewage sludge lipid to ethanol, 225 wt% MO(Poly)C18–BLE, 5 h reaction time, 45 ℃ reaction temperature, and a constant 150 rpm agitation. This novel biocatalyst synthesis method and ester production process from municipal sewage sludge lipids may provide ecological and economic support for industrial biodiesel production in the future.

NH2-MIL-125 MOF integrated translucent mesoporous polymer monolith as dual-light responsive new-generation photocatalyst for the expeditious decontamination of perennial pharmaceuticals

We have synthesized a dual (UV-Visible) light-responsive heterocomposite photocatalyst of NH2-MIL-125 metal-organic framework (MOF) integrated on a translucent bimodal macro-/meso-porous polymer monolith for decontaminating pharmaceutical pollutants from aqueous medium. FE-SEM-EDAX, HR-TEM-SAED, p-XRD, BET/BJH, XPS, UV-Vis-DRS and PLS instrumental analysis were used to characterize the structural and morphological features of the synthesized MOF-poly(EGDMA) photocatalyst. The electron microscopic analysis confirmed the homogeneous dispersion of MOF across the well-defined porous network of polymer monolith, ensuring easy transport/interaction of pollutant molecules to the photoactive sites for faster dissipation. The hetero composite photocatalyst offered an intriguing band gap energy state that favored excellent dual light-responsive performance for fast decontamination of perennial pharmaceutical organic compounds. The superior photocatalytic performance was guaranteed by optimizing parameters such as solution pH, drug concentration, photocatalyst dosage, sensitizers, matrix tolerance, and light intensity. Under UV and visible light illumination, the maximum drug degradation was achieved using 50 mg of photocatalyst within 0.5 h in the pH range of 6.0–7.0. The drug degradation pathway was monitored using HRMS analysis, and the toxicity evaluation of the identified photoproducts was studied using the ECOSAR program. The MOF-poly(EGDMA) photocatalyst had excellent reusability and durability apart from its superior photocatalytic performance in clean-up applications.

Synthesis of Ion-Exchange Catalysts by Introduction of Fluorinated Ponytails into Novel Mesoporous Polymers.

A novel synthetic procedure for the functionalisation of styrenic cross-linked polymers with perfluorinated acyl chains has been reported. The effective significant grafting of the fluorinated moieties is supported by {1H}-13C and {19F}-13C NMR characterisations. This kind of polymer appears promising as catalytic support for a variety of reactions requiring a highly lipophilic catalyst. Indeed, the improved lipophilicity of the materials resulted in enhanced catalytic properties of the corresponding sulfonic materials in the reaction of esterification of a solution in a vegetable oil of stearic acid with methanol.

Amidoxime-Based Polymer Microspheres with High Selectivity for Uranium from Saline Lake Brine

Uranium is the most basic ingredient for nuclear energy production, and its sources are mainly concentrated in mineral, as well as seawater and saline lake brine. Amidoxime-based functional adsorbents play an indispensable role in the efficient recovery of uranium from varied sources. However, it is empirically considered that for amidoxime adsorbents, balancing adsorption capacity and selectivity is challenging in the presence of complex interfering ions, especially for vanadium. Herein, a kind of amidoxime-modified mesoporous polymer microsphere with an optimized distance among functional groups was synthesized, which has remarkable chemical stability and ion selectivity. It is impressive that the adsorption capacity of the above-mentioned amidoxime microspheres for uranium in natural saline lake brine reached 15.9 mg/g, which was two orders of magnitude higher than that of vanadium. Combined with enhanced adsorption capacity, excellent selectivity, and ultra-high stability, amidoxime-functionalized mesoporous polymer microspheres emerge as a promising adsorbent for uranium extraction from natural saline lake brine.

Highly efficient removal of Pb2+ from wastewater by a maleic anhydride modified organic porous adsorbent

Sorption is prominent in low price, high efficiency, availability, and eco-friendliness. Organic porous materials have the characteristics of easy functionalization, diverse structure and stability, and show great potential in adsorption, energy storage, catalysis, and other fields. A mesoporous phenolic resin-type polymer (PRP) was successfully synthesized and modified by solid state reaction with maleic anhydride to prepare adsorbent (called as PRP-MAH) for sorption of Pb2+. The impact of reaction conditions (the pH value, reaction temperature, fresh concentration of solution, ionic strength and reaction time, etc.) was systematically studied. Characterization methods such as SEM, FTIR, and XPS indicated that the synthesized adsorbent PRP-MAH had regular morphology and good stability. The fitting of isothermal adsorption experiment data conforms to Langmuir sorption isotherm, and the sorption capacity reached 366.40mg·g-1 at 308K. The kinetic data were consistent with the quasi-second-order model, which indicated that the chemisorption might play the main role in the sorption process. Thermodynamic research manifested that the sorption of Pb2+ by PRP-MAH was carried out by a spontaneous process at the study temperature. The studies show that PRP-MAH can remove Pb2+ from water solution through ion exchange, electrostatic attraction, and surface complexation.

Rational Design of Mesoporous Coordination Polymer Nanophotosensitizers for Photodynamic Tumor Ablation

Effective clinical practice of precise photodynamic therapy (PDT) is severely impeded by the inherent drawbacks and aggregation propensity of conventional photosensitizers. An all-in-one approach is highly desired to optimize structural features, photophysical properties, and pharmacokinetic behaviors of photosensitizers. Herein, we have fabricated mesoporous boron dipyrromethene-bridged coordination polymer nanophotosensitizers (BCP-NPs) for high-performance PDT via a unique solvent-assisted assembly strategy. Distinctive photophysical and structural characteristics of BCP-NPs confer enhanced photodynamic activities, together with high cellular uptake and ultrahigh stability. Moreover, BCP-NPs showed excellent tumor accumulation and prolonged tumor retention, achieving eradication of the triple-negative breast cancer (TNBC) model under low-power-density LED irradiation. This work has provided a valuable paradigm for the construction of mesoporous photoactive nanomaterials for biophotonic applications.

Polyoxometalate-Bridged Synthesis of Superstructured Mesoporous Polymers and Their Derivatives for Sodium-Iodine Batteries.

Despite the impressive progress in mesoporous materials over past decades, for those precursors having no well-matched interactions with soft templates, there are still obstacles to be guided for mesoporous structure via soft-template strategies. Here, a polyoxometalate-assisted co-assembly route is proposed for controllable construction of superstructured mesoporous materials by introducing polyoxometalates as bifunctional bridge units, which weakens the self-nucleation tendency of the precursor through coordination interactions and simultaneously connects the template through the induced dipole-dipole interaction. By this strategy, a series of meso-structured polymers, featuring highly open radial mesopores and dendritic pore walls composed of continuous interwoven nanosheets can be facilely obtained. Further carbonization gave rise to nitrogen-doped hierarchical mesoporous carbon decorated uniformly withultrafine γ-Mo2 N nanoparticles. Density functional theory proves that nitrogen-doped carbon and γ-Mo2 N can strongly adsorb polyiodide ions, which effectively alleviate polyiodide dissolving in organic electrolytes. Thereby, as the cathode materials for sodium-iodine batteries, the I2 -loaded carbonaceous composite shows a high specific capacity (235mA h g-1 at 0.5 A g-1 ), excellent rate performance, and cycle stability. This work will open a new venue for controllable synthesis of new hierarchical mesoporous functional materials, and thus promote their applications toward diverse fields.

Regiospecific Synthesis of a Reprocessable Galactan-Mimic via Topochemical Polymerization

We synthesized a designed monomer with azide and alkyne units that mimic α-d-galactose for topochemical azide-alkyne cycloaddition polymerization to produce a cross-linkable galactan-mimic. The monomer molecules pre-organize in the crystals in a linear head-to-tail fashion, with the reactive units properly aligned for topochemical reaction. When the monomer crystals are heated, they undergo regiospecific topochemical azide-alkyne cycloaddition polymerization, resulting in a galactan-mimic with two vicinal diol units per repeating unit. We covalently cross-linked this galactan-mimic using bis-dioxaborolane as the dynamic covalent cross-linker. When compared to the parent galactan-mimic, the mesoporous cross-linked polymer had a sevenfold increase in porosity, a 200-fold increase in particle size, and higher thermal stability. We demonstrated that by varying the temperature, the extent of cross-linking and thus particle size can be reversibly tuned. Our findings show that topochemical polymerization can be used to create polymers with improved properties from monomers derived from naturally available feedstock materials.

A porphyrin derivative with highly red shifted and intensified absorption bands immobilized into the mesopores of nanostructured amberlite: Synthesis, characterization and photocatalytic activity

The BF3 complex of meso-tetra(4-sulfonatophenyl)porphyrin (H2TPPS4), immobilized into the pores of a new nano-structured mesoporous anion exchange polymer, nanoAmbN(Me)3Cl (Amb = Amberlite IRA-410(Cl)) was used as the photosensitizer for aerobic oxidation of organic compounds. NanoAmbN(Me)3Cl, nanoAmbN(Me)3@H2TPPS4 and nanoAmbN(Me)3@H2TPPS4(BF3)2, were characterized by IR and UV–vis diffuse reflectance spectroscopy (UV–vis DRS) methods, TGA, FESEM, elemental mapping (SEM-EDX) and BET. The nanocomposite was used as photosensitizer in the aerobic oxidation of 1,5-dihydroxynaphthalene (DHN) and cyclohexene in acetonitrile. The results were compared with those obtained in the presence of the BF3 complex of meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (H2TMPyP) immobilized on nanostructured amberlyst 15. The observed red shifts in the UV–vis DRS UV–vis spectrum upon the formation of nanoAmbN(Me)3@H2TPPS4(BF3)2 were much larger than those of nanoAmbSO3@H2TMPyP(BF3)2. The singlet quatum yield of nanoAmbN(Me)3@H2TPPS4 and nanoAmbN(Me)3@H2TPPS4(BF3)2 was determined by using 1,3-diphenylisobenzofuran (DPBF) and DHN as the quenchers of singlet oxygen, for the excitation of the photosensitizers in the Q and Soret band regions, respectively.

Diazo-coupled porous organic polymers as efficient catalysts for metal-free Henry and Knoevenagel reactions

Owing to linkage and building block diversity, Porous Organic Polymers (POPs) are versatile materials with high potential in organic catalysis. Herein, nitrogen-rich POPs bearing –OH phenolic groups were synthesized via the diazo-coupling reactions between phloroglucinol and benzidine (PgBd-POP), and between 1,3,5-tris(4-aminophenyl)triazine and 4,4'-[1,1′-biphenyl]-4,4′-diylbis(diazene-2,1-diyl))diphenol (TAPT-Bd(PhOH)2-POP), under mild reaction conditions. The mesoporous polymers exhibited a BET surface area of 276 ± 4 m2 g−1 and 1.94 ± 0.06 m2 g−1, and chemical stability up to 315 °C and 330 °C, respectively. Both POPs were used as catalysts in metal-free Henry and Knoevenagel condensation reactions between aromatic aldehydes and nitromethane and ethyl cyanoacetate, respectively, under mild conditions. PgBd-POP showed a remarkable efficiency of up to 99% conversion and >99% selectivity, for the Henry nitroaldol reaction between 4-nitrobenzaldehyde and nitromethane, after only 1 h at room temperature, whereas TAPT-Bd(PhOH)2-POP generally exhibited the highest catalytic activity towards the Knoevenagel reaction, with up to 99% conversion for the condensation of 4-nitrobenzaldehyde with ethyl cyanoacetate, after 1 h at room temperature. These results confirm the potential of this class of porous materials as green catalysts for organic reactions.

Uniform Gold Nanoclusters Supported on Mesoporous Polymer Beads Decorated with Polyaminophosphine Patches for the Catalytic Reduction of 4-Nitrophenol

In the jigsaw puzzle of quality gold nanoclusters (AuNCs), those protected by weak ligands or coligands are still rarely available. Here, we provide an example in the case of supported AuNCs. Branched polyethylenimine (PEI, diameter of 1.86 nm) is introduced as discrete molecular patches onto the support of mesoporous polymer beads. Each patch is derived into polyaminophosphine with 2-(diphenylphosphino) benzaldehyde (dppb). The molecular patch is of nanoscale and uniform size. The polymer beads after PEI loading bear unimodal pores (3.9 nm), and the specific surface area is of 390 m2 g–1. AuNCs are obtained by mildly heating the mixture of the functionalized beads and aqueous chloroauric acids. Uniform AuNCs with a diameter of 1.2 ± 0.2 nm (∼53 Au atoms) are obtained when each PEI patch bears 17 dppb ligands, smaller than that of 3.5 nm in the absence of any dppb, suggesting that dppb enhances the nucleation of AuNCs. The heteroleptic AuNCs show ultrahigh catalytic performance (TOF = 391 h–1) for the reduction of 4-nitrophenol, where the dppb ligands hardly suppress the catalytic activity. The catalyst is well recoverable and durable for the reduction of 4-nitrophenol.

Two-dimensional sandwich-like MXene–conductive polymer nanocomposite with in-plane cylindrical mesopores for long cycling lithium-sulfur batteries

Li-S batteries have received much attention due to their high energy density, low cost and environmental friendliness. However, the poor conductivity of sulfur and the ‘shuttle effect’ of polysulfides still impede their practical applications. In this study, thin layered MXene nanosheets sandwiched by conductive poly(m-phenylenediamine) with in-plane cylindrical mesochannels (mPmPD/MXene) are constructed as sulfur hosts for the cathode materials of Li–S batteries. The polar active sites on MXene and mesoporous conductive PmPD polymers synergistically alleviate the polysulfide shuttling through chemisorption and physical confinement; the high metallic conductivity of MXene and conductive PmPD ensure the transport of electrons and promote the redox kinetics; the in-plane cylindrical mesochannels on mPmPD/MXene provide hosting space for high sulfur loading (∼71 wt%) and facilitate smooth electrolyte transport in the internal space of the cathode. Profiting from these advantages, the Li–S battery based on the mPmPD/MXene cathode exhibits a capacity decay of 0.0593% after 800 cycles at 1 C (53% capacity retention). The optimized battery shows stable cycling performance even at high sulfur loading (6.8 mg cm−2) with 5.6 mAh cm−2 capacity remained after 60 cycles at 0.1 C. This study provides insights for the rational design of 2D heterostructures with in-plane mesochannels for high-performance Li-S batteries.