Hypercrosslinked Polymers Research Articles

Novel magnetic porous organic polymer containing amino and triazine bifunctional groups for efficient adsorption of nitroimidazoles

In this paper, a novel magnetic hyper-crosslinked polymer with amino and triazine bifunctional groups (M-NH2-THCP) was developed. M-NH2-THCP has strong nitroimidazoles (NDZs) enrichment effect, and therefore it was used as an adsorbent to extract five NDZs from lake water, catfish and shrimp meat prior to HPLC. Polar interaction, π-π stacking interaction, hydrogen bond and Lewis acid-base interaction were attested to be the major adsorption mechanism. The method has a good linearity in the range of 0.1–100 ng mL−1 for lake water, 10–400 ng g−1 for catfish and shrimp muscle with R2 > 0.9964. The limits of detection of NDZs were 0.03–0.04 ng mL−1 for lake water, 1.0–2.0 ng g−1 for catfish and 2.0–2.5 ng g−1 for shrimp, which is superior to most reported method. The method recoveries were 87.6–119 %, and relative standard deviations were less than 8.7 %. M-NH2-THCP holds great application potential in pollutants enrichment, separation and removal.

Boosting the feasibility of heterogeneous telomerization of 1,3-butadiene with methanol by low-surface-area N-heterocyclic carbene-functionalized hypercrosslinked polymers

The main bottlenecks for the industrial application of existing heterogeneous telomerization catalysts are inferior activity, low stability, and poor selectivity. Herein, we develop a heterogeneous catalyst system to obstacle these issues. A low-surface-area hypercrosslinked polymer fabricated by 1,3-diary-imidazolium chlorides IXy·HCl (aryl = 1,6-dimethylphenyl) via the Scholl coupling method was prepared and utilized as solid ligand in pseudo-heterogeneous telomerization of 1,3-butadiene with methanol. Superior catalytic performance (high linear to branched regioselectivity up to 66:1, chemoselectivity up to 98.5%, and a recorded turnover number (TON) up to 3.1 × 105) for the linear product 1-methoxyocta-2,7-diene (1-MOD) was achieved. Moreover, the heterogeneous Pd catalyst could be in situ generated during the telomerization process, which could be reused at least 10 runs without catalytic activity and selectivity loss. Full characterization of catalysts and control experiments results demonstrated that the synergistic effect of low-surface-area hypercrosslinked skeleton and the coordination environment of Pd in heterogeneous catalyst modified by diene ligands such as 1,3-butadiene or 1-MOD was beneficial to boost the feasibility of heterogeneous telomerization. This innovation is a significant step toward the development of high-performance heterogeneous telomerization catalysts for industrial applications.

Novel chiral composite membranes coated by microporous hyper-crosslinked polymer for efficiently enantioselective separation

With the rapid development of the pharmaceutical industry, efficient enantiomeric resolution is of great significance for the preparation of single enantiomer drugs. Herein, several kinds of chiral hyper-crosslinked polymer composite membranes (CHCPs/PSS) were fabricated by surface-initiated Friedel-crafts alkylation reaction on the porous SiO2 substrate for enantioseparation. The membrane fabrication conditions were optimized by changing various monomer concentrations, polymerization times and substrate pore sizes using phenylalanine as separated substance and the percent enantiomeric excess (ee%) reached 91.2 % with a permeability up to 6.31 × 10−2 m2/h which was 1012 folders higher than the traditional chiral polymer membranes. Besides, the enantioseparation of disparate enantiomers including clinical drug were also evaluated using CHCPs/PSS membranes to expand its application scope. The ee% and permeability reached 9.48 % and 5.13 × 10−1 m2/h for tryptophan and 24.4 % and 1.56 m2/h for ibuprofen, respectively. Static adsorption and quantum chemical computation were utilized to analyze the separation mechanism and the results indicated that the adsorption energy difference which resulted from the multiple interactions contributed to the effective separation of enantiomers. Consequently, this work will provide a new method for the application of chiral hyper-crosslinked polymer membranes in enantiomeric separation.

Preparation of the 2,2′-biimidazole-based hypercrosslinked polymers by bottom-up synthetic strategy and their application for adsorping and fluorescence sensing 2,4-dinitrophenol

The 2,2′-biimidazole-based hypercrosslinked polymers (2,2′-biimidazole-based HCPs, BIMM-3 and BIMM-4) were prepared by the synthetic strategy of one-pot bottom-up with nitrogen-rich 2,2′-biimidazole and triiodomethane or tetra-iodine methane for the first time. This new strategy offers the resulting HCPs presented nitrogen-rich and electron-rich. The as-synthesized 2,2′-biimidazole-based HCPs exhibit high iodine uptake capacities up to 8.04 and 4.57 g g-1, representing efficient adsorbents for wider environmental applications. The main reason for chemical sorption happening in 2,2′-biimidazole-based HCPs. Furthermore, BIMM-3 and BIMM-4 can sense nitroaromatic compounds (NACs, such as 2,4-dinitrophenol, DNP) with high quenching constants (Ksv) of 5.69 × 104 and 4.71 × 104 L mol-1 and low limits of detection (LODs) of 5.27 × 10-9 and 6.37 × 10-9 mol L-1. The quenching mechanisms of the 2,2′-biimidazole-based HCPs by DNP include both electron transfer process and resonance energy transfer process. Our work provided promising conclusions for HCPs as adsorbents and sensors for the capture of iodine and the detection of DNP for environmental remediation applications.

Synthesizing Hypercrosslinked Polymers with Deep Eutectic Solvents to Enhance CO2 /N2 Selectivity.

Hypercrosslinked polymers (HCPs) are widely used in ion exchange, water purification, and gas separation. However, HCP synthesis typically requires hazardous halogenated solvents e. g., dichloroethane, dichloromethane and chloroform which are toxic to human health and environment. Herein we hypothesize that the use of halogenated solvents in HCP synthesis can be overcome with deep eutectic solvents (DES) comprising metal halides-FeCl3 , ZnCl2 that can act as both the solvent hydrogen bond donor and catalyst for polymer crosslinking via Friedel Crafts alkylation. We validated our hypothesis by synthesizing HCPs in DESs via internal and external crosslinking strategies. [ChCl][ZnCl2 ]2 and [ChCl][FeCl3 ]2 was more suitable for internal and external hypercrosslinking, respectively. The specific surface areas of HCPs synthesized in DES were 20-60 % lower than those from halogenated solvents, but their CO2 /N2 selectivities were up to 453 % higher (CO2 /N2 selectivity of poly-α,α'-dichloro-p-xylene synthesized in [ChCl][ZnCl2 ]2 via internal crosslinking reached a value of 105). This was attributed to the narrower pore size distributions of HCPs synthesized in DESs.

Dibromomethane Knitted Highly Porous Hyper-Cross-Linked Polymers for Efficient High-Pressure Methane Storage.

Hyper-cross-linked polymers (HCPs) with ultra-high porosity, superior physicochemical stability, and excellent cost-effectiveness are attractive candidates for methane storage. However, the construction of HCPs with BET surface areas exceeding 3000 m2 g-1 remains extremely challenging. In this work, a newly developed DBM-knitting method with a slow-knitting rate is employed to increase the cross-linking degree, in which dichloromethane (DCM) is replaced by dibromomethane (DBM) as both solvent and electrophilic cross-linker, resulting in highly porous and physicochemically stable HCPs. The BET surface areas of DBM-knitted SHCPs-Br are 44%-120% higher than that of DCM-knitted SHCPs-Cl using the same building blocks. Remarkably, SHCP-3-Br exhibits an unprecedentedly high porosity (SBET = 3120m2g-1) among reported HCPs, and shows a competitive volumetric 5-100bar working methane capacity of 191 cm3 (STP) cm-3 at 273K calculated by using real packing density, which outperforms sate-of-art metal-organic framework (MOFs) at comparable conditions. This facile and versatile low-knitting-rate strategy enables effective improvement in the porosity of HCPs for porosity-desired applications.

Fabrication of chitin based hydrophilic hyper-crosslinked porous polymer for efficiently removing bisphenol A from water

Water pollution caused by bisphenol A (BPA) has become the world problem. Designing and preparing cost-effective and biodegradable sorbents for the effectively adsorptive removal of bisphenol A from wastewater is of immense significance. Herein, a natural polysaccharide (chitin) was used as raw materials to be grafted with styrene (GS), then crosslinked with α,α'-dichloro-p-xylene (DCX) to form the hyper-crosslinked polymer (labeled as CGS@DCX). The CGS@DCX showed high adsorptive affinity for bisphenol A, with adsorption capacity of 441 mg g−1. Various studies gave an insight into the adsorption process, demonstrating that the highly efficient adsorption of BPA by the CGS@DCX is mainly based on the π-π stacking, hydrogen-bond interaction, polar interaction and pore adsorption. Moreover, the CGS@DCX had high chemical stability, good reusability (9 cycles) and fast adsorption kinetics (10 min) for adsorption of BPA. This work provides a promising strategy for the design and synthesis of novel yet eco-friendly sorbents to solve environmental problems.

Carboxylic acid functionalized para-xylene based hypercrosslinked polymer as a novel and high performance adsorbent for heavy metal removal

In this work, hypercrosslinked polymeric adsorbent (HCP) was synthesized from para-Xylene precursor through Friedel-Crafts reaction. Additionally, heavy metal adsorption experiments from a multi component system including lead, cadmium, nickel, and copper ions were conducted. To enhance lead uptake selectivity over other metallic ions, the resulting HCP sample was functionalized through carboxylic acid incorporation into the HCP adsorbent skeleton. The adsorption process modeling was carried out by using Central Composite Design- Response Surface Methodology technique. In addition, the adsorption capability dependency of the resulting samples to the operational condition including temperature from 25 °C to 65 °C, solution pH value from 4 to 10, and solution initial concentration from 20 mg/l to 100 mg/l was investigated. Additionally, process optimization was applied aim to maximize the lead uptake selectivity, the optimal condition including a temperature of 31.8 °C, pH of 5.0, and initial concentration of 82.50 mg/l were obtained for HCP sample, also the optimal condition namely a temperature of 30 °C, pH of 5.5, and initial concentration of 100 mg/l were obtained for modified HCP sample. As a result of isotherm modeling, the Hill model was obtained as the best model, additionally, thermodynamically investigation of the process resulted in spontaneously and physically adsorption of the metallic ions by HCP samples, with respect to Gibbs free energy (ΔG0 < 0) and adsorption process enthalpy (ΔH0 < 20 kJ/mol). Finally, adsorbents regeneration were evaluated and minor losses in the adsorption capacity of samples were yielded after ten cycles.

Efficient DMF-assisted synthesis of formamides from amines using CO2 catalyzed by heterogeneous metal-free imidazolium-hypercrosslinked polymers

CO2 emissions are constantly increasing, so it is necessary to continue working to mitigate the excess of CO2 in the atmosphere and reduce the effects it has on the environment. In this regard, we have developed novel catalysts by synthesizing ionic liquids based on imidazolium chloride, supported on hyper-crosslinked polymers (HCP-BzmimCl and HCP-Bis(BzmimCl)). These catalysts enable the highly selective N-formylation of secondary amines, utilizing CO2 as a carbon source, phenylsilane as a hydrogen donor, and DMF as a crucial polar additive. The reactions were carried out under mild conditions, with CO2 pressure at 5 bar and a temperature of 35ºC, yielding formamides in excellent yields. HCP-Bis(BzmimCl) has emerged as a particularly promising catalyst, boasting shorter reaction times, exceptional recyclability, and scalability for potential industrial applications.

Nanoporous hypercrosslinked polymers as cost-effective catalysts to significantly promote the CO2 absorption performance of water-lean solvents for post-combustion CO2 capture

In most cases, the slow CO2 sorption kinetics of water-lean solvents—which include low-volatile organic diluents—are the limiting factor when it comes to post-combustion CO2 capture. This study offers a solution by suggesting the use of catalysts based on nanoporous hypercrosslinked polymers (HCPs) to improve the removal efficiency of water-lean solvents based on diethanolamine (DEA) and to increase CO2 mass transfer. Simple and inexpensive monomers were used to prepare three HCPs: HCP-C, HCP-S, and HCP-B, which stand for benzene, polystyrene, and carbazole, respectively. Blends of DEA and Glycerol (Gly) were used to disperse these polymers. Addition of 0.5 wt% HCP to a solvent mixture of 20% DEA and 30% Gly considerably boosts removal efficiency and increases the amount of CO₂ that can be absorbed until the breakthrough point by as much as 3000%, according to the results. Additionally, various gas flow rates, DEA concentrations, and glycerol concentrations were also investigated to determine the HCP-C catalytic effect on the CO2 absorption. A volumetric overall mass transfer coefficient enhancement of up to 319 % is possible in the investigated ranges when using HCP-C, according to the findings. Moreover, a possible catalytic mechanism was suggested.

Hypercrosslinked porous and coordination polymer materials for electrolyte membranes in lithium‐metal batteries

AbstractRechargeable lithium‐metal batteries (LMBs) hold great promise for providing high‐energy density. However, their widespread commercial adoption has been inhibited by critical challenges, for example, the capacity fading from irreversible processes at electrolyte/electrode interfaces and safety concerns originating from the inhomogeneous lithium deposition. Polymer electrolytes benefiting from enhanced electrolyte/electrode contact and low interfacial impedance provide a variable solution to address these challenges and enable a high‐energy and flexible battery system. Although promising, inefficient bulky ionic conductivity and poor mechanical stability confront the stable operation of polymer electrolytes in tangible batteries, which highly requires the development of innovative polymer electrolyte chemistries. Among various polymer materials, microporous polymers stand out due to their abundant porosity and customizable micropore structure, positioning them as promising candidates for next‐generation electrolyte membranes. This review, therefore, summarizes recent advances in electrolyte membranes based on two new chemistries, hypercrosslinked polymers (HCPs) and porous coordination polymers (PCPs). Other microporous polymers, such as covalent organic polymers, porous organic cages, and polymers of intrinsic microporosity, are also discussed with an emphasis on their applications in LMBs. Most importantly, by reviewing the design strategies, synthesis protocols, and performance in LMBs, we gain insights into the design principles of high‐performance electrolyte membranes based on HCPs and PCPs and highlight potential future research directions.

Insight into the factors affecting the reactivity of sulfonic acid species anchored on hyper-cross-linked polymers in esterification

The global market for organic esters was estimated at around $89.4 billion in 2022, and is expected to continue to grow, reaching $127.4 billion in 2029. The wide application of mineral acids as homogeneous catalysts for the synthesis of organic esters causes several economic and environmental problems. For this reason, a lot of effort is undertaken to make esterification a more sustainable process. Nowadays, particular attention is paid to the development of new solid acid catalysts containing sulfonic acid groups (–SO3H) supported on organic polymers. This study fits into this scientific trend and aims at providing insight into the factors affecting the reactivity of –SO3H species anchored on hyper-cross-linked polymers (HCPs). For this purpose, polymers characterized by different cross-linking densities but with a comparable surface area of ca. 540–620 m2/g and a similar pore size of ca. 3.7 nm were applied as supports for anchoring of –SO3H through post-synthetic sulfonation. The loading of sulfonic acid species in all prepared catalysts varied from 1.19 to 2.22 mmol/g. Catalytic activity of the sulfonated HCPs (sHCPs) was evaluated in esterification of acetic acid with different alcohols. It was found that the key factors affecting the reactivity of –SO3H supported on HCPs are hydrophilicity of the polymer surface and the localization of the sulfonic acid species on the external surface of the polymer matrix. The latter was the most favoured during the post-synthetic sulfonation of the polymer characterized by the highest cross-linking density. In the case of this material, the –SO3H species were approximately 7 times more reactive than those of Amberlyst-15 (TOF = 11.36 vs. 1.57 h−1, respectively). The most efficient sHCP used in this study reached approximately two times higher conversion of n-butanol than Amberylst-15 (53.6 vs. 27.5 %) despite of the significantly lower loading of sulfonic acid species in the former polymer (2.22 vs. 4.66 mmol/g, respectively). It was also established that the catalytic esterification on the surface of sHCPs proceeded according to the Langmuir-Hinshelwood mechanism, in which chemisorption of the alcohol is the rate-determining step. Moreover, sHCP catalysts could be reused four times without significant deactivation.

Rigidity with Flexibility: Porous Triptycene Networks for Enhancing Methane Storage.

In the pursuit of advancing materials for methane storage, a critical consideration arises given the prominence of natural gas (NG) as a clean transportation fuel, which holds substantial potential for alleviating the strain on both energy resources and the environment in the forthcoming decade. In this context, a novel approach is undertaken, employing the rigid triptycene as a foundational building block. This strategy is coupled with the incorporation of dichloromethane and 1,3-dichloropropane, serving as rigid and flexible linkers, respectively. This combination not only enables cost-effective fabrication but also expedites the creation of two distinct triptycene-based hypercrosslinked polymers (HCPs), identified as PTN-70 and PTN-71. Surprisingly, despite PTN-71 manifesting an inferior Brunauer-Emmett-Teller (BET) surface area when compared to the rigidly linked PTN-70, it showcases remarkably enhanced methane adsorption capabilities, particularly under high-pressure conditions. At a temperature of 275 K and a pressure of 95 bars, PTN-71 demonstrates an impressive methane adsorption capacity of 329 cm3 g-1. This exceptional performance is attributed to the unique flexible network structure of PTN-71, which exhibits a pronounced swelling response when subjected to elevated pressure conditions, thus elucidating its superior methane adsorption characteristics. The development of these advanced materials not only signifies a significant stride in the realm of methane storage but also underscores the importance of tailoring the structural attributes of hypercrosslinked polymers for optimized gas adsorption performance.

Synthesis of “all-in-one” hypercrosslinked organic polymers: experimental and kinetic models for CO2 chemical fixation and iodine adsorption

A series of “all-in-one” hypercrosslinked polymers have been constructed by Friedel–Crafts alkylation and quaternization reactions, which exhibit superior CO2 conversion performance and effective iodine adsorption capacity.

Non-cationic hyper-crosslinked ionic polymers with hierarchically ordered porous structures: facile synthesis and applications for highly efficient CO2 capture and conversion.

Hyper-crosslinked porous ionic polymers (HCPIPs) have garnered significant attention due to their unique ionic properties and high specific surface areas. However, the limited variety of monomers, low ionic density, and difficulty in functionalization restrict their development. Herein, a series of functionalized non-cationic HCPIPs with high ionic density are designed and directly synthesized via an innovative and straightforward approach - anion (and cation) hyper-crosslinking of tetraphenylborate-based ionic liquids (ILs). These HCPIPs offer controllable hydroxyl group content (0-2.40 mmol g-1), high IL content (1.20-1.78 mmol g-1), and large specific surface area (636-729 m2 g-1) with hierarchically ordered porous structures. These HCPIPs demonstrate exceptional CO2 adsorption capacities and CO2/N2 adsorption selectivities, reaching up to 2.68-3.01 mmol g-1 and 166-237, respectively, at 273 K and 1 bar. Furthermore, these ionic porous materials serve as highly efficient heterogeneous catalysts for CO2 cycloaddition to epoxides under mild conditions (1 bar CO2, 60-80 °C, 12-24 h). Notably, the CO2 adsorption performances and catalytic activities of these HCPIPs are regulated by the hydroxyl groups within their structures, with enhancements observed as the number of hydroxyl groups increases. This work presents a facile and widely applicable method for constructing high-performance and task-specific HCPIPs.

Cobalt porphyrin-based hypercrosslinked ionic polymers as biomimetic nanoreactors for CO2 conversion to cyclic carbonates.

A simple and low-cost approach to construct one type of cobalt porphyrin-based hypercrosslinked ionic polymer with high specific surface areas, densely located ionic groups and highly dispersed cobalt sites has been demonstrated, which act as bifunctional catalysts for the solvent-additive-free conversion of CO2 into cyclic carbonates with outstanding biomimetic catalytic performance and good recyclability.

A novel bifunctional metalloporphyrin-based hyper-crosslinked ionic polymer as heterogeneous catalyst for efficiently converting CO2 into cyclic carbonates

A novel bifunctional metalloporphyrin-based hyper-crosslinked ionic polymer as heterogeneous catalyst for efficiently converting CO2 into cyclic carbonates

Tuneable Sulfonated Hypercrosslinked Polymers for Selective Esterification: Insights into Performance and Stability

We report sulfonated hypercrosslinked polymers (SHCPs) as heterogeneous catalysts for the selective esterification of hexanoic acid with benzyl alcohol. The SHCPs demonstrate tuneable catalytic activity and selectivity, outperforming conventional acid...

Non-noble metal coordinated hypercrosslinked polymers based on porphyrin for efficient electrocatalytic OER

Electrochemical catalysts for the oxygen evolution reaction (OER) with abundant reserves, high catalytic activity, and robust stability are highly crucial for efficient electrocatalytic water splitting.

Cobalt-tetraphenylporphyrin-based hypercrosslinked polymer for efficient CO2 photoreduction to CO

One of the main impediments during the CO2 photocatalytic reduction process is controlling a particular product’s selectivity while keeping a high conversion rate. The adsorption and affinity of the catalyst...