Porous Resin Research Articles

Quantitative Determination of Metal Center Coordination Numbers in Resin‐Based Supported Catalysts via CO2 Adsorption

ABSTRACTA novel method was described for quantitatively determining the metal centers' average coordination numbers in as‐prepared supported metal catalysts using polyamine‐modified resin carriers via CO2 adsorption. Using porous resin (PS) and pentaethylenehexamine (PEHA) as starting materials, a new polyamine‐modified resin carrier PS‐PEHA was obtained to anchor various metals (Cu, Pd, Co, Ni, and Zn), thereby preparing a range of supported catalysts. The structures of the metal catalysts were characterized through FT‐IR, XPS, SEM, EDS, BET, and ICP‐OES. DVS was employed to study the carrier and catalyst performance of CO2 adsorption. The average coordination numbers of the metal centers were quantitatively determined based on their differences in CO2 adsorption capacities. The coordination numbers determined were Co (3.5), Ni (3.5), Pd (4.8), Zn (3.6), and Cu (5.9).

Solid-Phase Synthesis of Well-Defined Multiblock Copolymers by Atom Transfer Radical Polymerization.

Solid-phase polymer synthesis, historically rooted in peptide synthesis, has evolved into a powerful method for achieving sequence-controlled macromolecules. This study explores solid-phase polymer synthesis by covalently immobilizing growing polymer chains onto a poly(ethylene glycol) (PEG)-based resin, known as ChemMatrix (CM) resin. In contrast to traditional hydrophobic supports, CM resin's amphiphilic properties enable swelling in both polar and nonpolar solvents, simplifying filtration, washing, and drying processes. Combining atom transfer radical polymerization (ATRP) with solid-phase techniques allowed for the grafting of well-defined block copolymers in high yields. This approach is attractive for sequence-controlled polymer synthesis, successfully synthesizing di-, tri-, tetra-, and penta-block copolymers with excellent control over the molecular weight and dispersity. The study also delves into the limitations of achieving high molecular weights due to confinement within resin pores. Moreover, the versatility of the method is demonstrated through its applicability to various monomers in organic and aqueous media. This straightforward approach offers a rapid route to developing tailored block copolymers with unique structures and functionalities.

3D liquid-based porous coating integrated with oleophilic MXene nanoflakes for durable ultra-low ice adhesion and exceptional photothermal slippery properties

The accumulation of ice on the surfaces of equipment/facilities can result in energy wastage, substantial economic losses, and even pose a threat to personal safety. In this work, a three-dimensional (3D) liquid-based porous resin coating doped with oleophilic molybdenum carbide (Mo2C) MXene nanoflakes was fabricated on a pre-coated oleogel sealer layer of aluminum plate. The results showed a reduction of approximately 99.1 % in ice adhesion strength (∼4.66 kPa) compared to the sandblasted aluminum plate and consistently maintained ice adhesion strength below 10 kPa for 70 days. Moreover, the coating exhibited excellent photothermal properties, with icing time delayed by a factor of 33.2 under simulated solar radiation power of 96 mW/cm2 (1 sun) at an ambient temperature of − 15 °C. The ice adhered to the coating could easily slide off without the external force under “1 sun” at − 10 °C. The superior anti/de-icing performance of the coating can be primarily attributed to the low interfacial modulus of the porous structure, the exceptional retention of silicone-oil, and the excellent photothermal effect of embedded MXene nanoflakes. The 3D liquid-based porous coating, possessing extremely low ice adhesion and remarkable de-icing stability, demonstrates the substantial potential for practical applications that require sustained anti/de-icing performance.

Photothermal responsive porous hollow microneedles as Chinese medicine versatile delivery system for wound healing.

Chinese medicine is identified as a candidate for wound healing. Attempts in this field tend to develop efficient dosage forms for delivering Chinese medicine with low side effects. In this paper, we proposed novel photothermal responsive porous hollow microneedles (PRPH-MNs) as a versatile Chinese medicine delivery system for efficient antibacterial wound treatment. The PRPH-MNs are composed of porous resin shells with good mechanical property, hydrogel cores, and a photothermal graphene oxide hybrid substrate. The hollow structure provides sufficient space for loading the drug dispersed hydrogel, while the porous resin shells could not only block the direct contact between drugs and wound sites but also provide channels for facilitating the drug release from the core. In addition, benefiting from the photothermal effect of their substrate, the PRPH-MNs could be heated under near-infrared (NIR) irradiation for controllable promotion of drug release. Based on these features, we have proved that the antibacterial Chinese medicine Rhein loaded PRPH-MNs were effective in promoting wound healing due to their good antibacterial property and on-demand drug release. Thus, we believe that the proposed PRPH-MNs are valuable for delivery of different drugs for clinical applications.

Adjustable nanoarchitectonics of N-doping Yolk-Shell carbon spheres via “Pyrolysis-Capture” method for High-Performance supercapacitor

The energy storage capacity of porous carbon materials is closely tied to their surface structure and chemical properties. However, developing an innovative and straightforward approach to synthesize yolk-shell carbon spheres (YCs) remains a great challenge till date. Herein, we prepared a series of porous nitrogen-doped yolk-shell carbon spheres (NYCs) via a “pyrolysis-capture” method. This method involves coating the resorcinol–formaldehyde (RF) resin sphere with a layer of compact silica shell induced by 2-methylimidazole (ME) catalysis to produce a confined nano-space. Based on the confined effect of compact silica shell, volatile gases emitted from the RF resin and ME during pyrolysis can not only diffuse into the pores of the RF resin but can also be captured to form an outer carbon shell. This results in the tunable structures of NYCs materials. As the pyrolysis temperature rises, the shell thickness of NYCs reduces, the pore size expands, the roughness increases, and the N/O content of surface elements is enhanced. Notably, as an electrode material used forsupercapacitors,the optimized NYCs-800 exhibits excellent performance with a capacitance of 301.2F g−1 at the current density of 1 A/g and outstanding cycling life stability of 96.1% after 10,000 cycles. These results signify that controlling the surface structure and chemical properties of NYCs materials is an effective approach for constructing advanced energy storage materials.

Designing and Screening of Moisture‐Swing Porous Adsorbents for Rapid CO2 Capture from Air

AbstractQuaternary amine(QA)‐functionalized adsorbents using moisture swing method are demonstrated to have vast application prospect in capturing CO2 from the ambient air. However, the poor kinetic performance and limited sorbents remain a great challenge. In this work, the porous resins were screened and membrane with controllable porous structure was designed for CO2 air capture, and the effects of the varieties of QA‐based resins and external environmental conditions (humidity and temperature) on CO2 adsorption performance were quantitatively investigated. The results show that the kinetic performance of porous resins are far superior to the existing QA‐based direct air capture(DAC) materials, and the half‐time of D290 type membrane is only 102 s, much less than that of gelatinous resin, which is about 2400 s. The effect of microporous structure on CO2 adsorption rate increases with the increase of humidity, while only slightly effect was found on macroporous adsorbents. The research results can provide basic data for the application of CO2 capture in different occasions.

Regularities of epoxidized alkyl oleates ring-opening reactions with alcohols, water and organic acids in the presence of commercial sulfonated resins as catalysts

Current paper deals with the use of sulfonated resins, distinguished by the porous structure (macroreticular Purolite CT275 and gel-type CU-2-8ChS), as solid acid catalysts for syntheses of perspective components of biolubricants via oxirane ring-opening reactions of fatty epoxides with water (hydrolysis), ethanol and i-propanol (alkoxylation), and levulinic and oleic acids (acylation). Epoxidized ethyl and i-propyl oleates as ring opening substrates were synthesized from used cooking oil. Reactions were carried out in batch reactor for 3 h at 100 °C under stirring with epoxide: resin acid sides molar ratio 1 : 0.05. Reagent to epoxide ratio was 10 : 1 (alkoxylation, hydrolysis) or 1.5 : 1 (acylation). Products composition was determined by GC, conversion and selectivity were calculated. Number of side ring-opening reaction were revealed, main of which were isomerization to ketone and dimerization. General observation is that porous Purolite CT275 provides higher conversion, but facilitates side processes. Non-porous CU-2-8-CHs provided notably higher selectivity (up to 90 % for hydroxyl esters in ethoxylation), but with many-times slower conversion, especially in case of alkoxylation with secondary alcohol. In hydrolysis, water soaked cationites did not provide any conversion, while epoxide introduction first on catalyst made transformation possible. Acylation proceeded in a great extent without separate catalyst and was accompanied by dimerization, while isomerization was not observed. Gel-type resin provided only negligible growth of conversion and selectivity. Porous resin enhanced the conversion, but mainly by side reactions intensification. Cyclohexane as solvent facilitated slightly selective catalyst-free acylation, but with significant conversion drop. Purolite CT275 in ethyl levulinate media favored the ring opening of epoxide with ketone function, yielding ketal-type product.

Cross-linked amidoxime porous resin for selective gallium separation in Bayer solutions: Reaction mechanism and kinetic study

The commercial resin suffers from slow diffusion rates and long mass transfer times, limiting its practical application in gallium extraction in Bayer solution. A novel amidoxime grafted polyacrylonitrile-styrene–divinylbenzene (A-PSD) resin was prepared by suspension acrylonitrile-styrene–divinylbenzene resins and subsequent electrophilic addition of hydroxylamine hydrochloride with amidoxime. Adsorption sites and mechanism study proved that the Ga3+ reacted with the amidoxime groups (CNOH) on the A-PSD resins. The A-PSD resins for Ga3+ adsorption followed the Langmuir model and exhibited excellent adsorption performance in Bayer solution with a Ga3+ capacity of 14.67 mg/g at 25 °C. The kinetic adsorption experiment showed that the adsorption process was controlled by chemical reaction and followed the pseudo-second-order kinetic model. The penetration curves of the column experiments indicate the possibility of industrial application of A-PSD resins, which may lay the groundwork for a new alternative to Ga3+ adsorption resins.

Conveniently synthesis of porous crown-based resin with efficient 90Sr capture from highly acidic wastewater

Effective removal of radioactive 90Sr is crucial for both management of spent nuclear fuel and recovery of radioactive strontium resources, while it’s still a great challenge due to the presence of high acid levels and intense radiation. Herein, a novel porous resin (DtBuCH18C6@CG-71) were synthesized by introducing 4′,4″(5″)-di-tert-butyldicyclohexano-18-crown-6 onto CG-71 resin using vacuum impregnation. The DtBuCH18C6@CG-71 resin maintains superior adsorption abilities in extreme conditions, including high acid resistance (3–12 mol/L HNO3), substantial γ-irradiation (200 kGy 60Co), and elevated temperatures (50–100 ℃). Impressively, even when exposed to a high concentration of matrix ions (59 elemental ions), the Sr(II) adsorption ratio onto DtBuCH18C6@CG-71 resin remains near 100 % even in highly acidic condition, which performance outpaces most of commercial resins. Dynamic column tests using an automated separation system further confirmed the superior ability of DtBuCH18C6@CG-71 in term of extracting Sr(II) from wastewater. Given its impressive features, cost-effectiveness, and scalability, DtBuCH18C6@CG-71 resin holds promising potential for 90Sr disposal in nuclear wastewater.

Adsorption of sulfadiazine on novel bilayer porous resin: Synergism of micropore filling and anion exchange

A novel bilayer porous resin with micropore filling and anion exchange (PsCH2BP) was synthesized. The aim was to investigate the adsorption of sulfadiazine on PsCH2BP. The micropore area of PsCH2BP was reduced by 73.91 % after the adsorption of sulfadiazine. PsCH2BP exhibited the synergism of micropore filling and anion exchange in the adsorption of sulfadiazine. Within the pH range of 7.29–13.31, the adsorption capacity trend of sulfadiazine on PsCH2BP was consistent with its ionization curve of pka 6.48. The adsorption of sulfadiazine on PsCH2BP was endothermic, spontaneous, entropy increase and heterogeneous multilayer adsorption, reflecting the bilayer pore structure of PsCH2BP. 100 % C2H5OH and 4 % NaCl could desorb 75.13 % and 65.06 % of sulfadiazine adsorbed on PsCH2BP, respectively, reflecting the synergism of the micropore filling and anion exchange in the adsorption of sulfadiazine on PsCH2BP. 100 % of desorption ratio of sulfadiazine adsorbed by PsCH2BP was achieved with 4 mol/LNaOH.

Two-stage reaction rates in transesterification of palm oil with methanol catalysed by anion-exchange resin with tetrahydrofuran as a co-solvent

Several heterogeneous catalysts have been proposed as recoverable catalysts for transesterification in place of homogeneous hydroxide or methoxide. Anion-exchange resin is a potential recoverable and reusable catalyst but its industrial use is still barred by its low catalytic activity. Transesterification of refined palm oil with methanol catalysed by anion-exchange resin was studied. A phenomenon limiting the reaction rates was discovered and is presented. Two types of anion-exchange resins were used as the catalysts: dense IRA402 and macroporous A26. With IRA402, an oil conversion of only 6.1 % was obtained from 4 h transesterification at 60 °C with a methanol-to-oil molar ratio of 9.5:1 and 4 cm3 resin per 42 cm3 reaction mixture. Severe mass transfer resistance in this three-phase system appeared to be the limiting factor. Addition of tetrahydrofuran (THF) as a co-solvent helped form a single liquid phase. The oil conversion was improved to 19.3 %. The reaction between oil and adsorbed methoxide at resin’s ion-exchange sites seemed to be the rate-determining step. When A26 was used, the rate of FAME production was boosted due to the porous nature of the resin. Nevertheless, the reaction rate fell sharply after a while into a slower second stage. The formation of a secondary liquid phae in resin pores triggered by glycerol generation was proposed as the cause of this drop in the reaction rate. A higher oil conversion of 63.4 % was obtained. Diluting the reaction mixture with more THF eliminated the slower second stage and sustained the firststage’s faster reaction rate. An oil conversion of 84.7 % was achieved from 3 h transesterification. A finite-volume model was developed to simulate the reaction and internal mass transport in A26 resin beads. The proposed secondary liquid phase formation and a branching pore structure in resin beads were required in the model to reproduce experimental data. The findings suggested improvement directions for anion-exchange resin as a catalyst for transesterification.

Evolution mechanism of freezing in porous media at the pore scale: Numerical and experimental study

The phase change problem in porous media has attracted extensive attention due to its complexity of both the heat transfer process and pore structure. This study investigates the mechanisms governing the freezing of water at the pore scale in a porous model, employing a combination of experimental and numerical approaches. Mathematical-physical model is used to simulate the phase change process in porous structures. Experiments are conducted on water freezing in porous resin and steel, with a pore distance of 500 μm. The evolutions of the phase interface and temperature field during the freezing process are analyzed. Results demonstrate good agreement between the simulations and experiments. Moreover, when the thermal conductivity of the solid skeleton is lower than that of the fluid (porous resin), the phase interface in the pore evolves from concave to convex, with a non-linear change in relative curvature. The temperature gradient of the fluid and skeleton within the pore channels first decreases and then increases. However, when solid skeletons have higher thermal conductivities than the fluid (porous steel), the evolution of the phase interface and its relative curvature, as well as the temperature gradient in the pore are different from the other case.

A Functionalized Heterogeneous Catalyst from Atomically Precise Pd1 Au8 Clusters Facilitates Carbon-Carbon Bond Construction.

It has become possible to establish a connection between homogeneous and heterogeneous catalysis with atomically precise metal clusters. Due to their defined coordination geometry, in this work, atomically precise Pd1 Au8 (PPh3 )8 2+ clusters are exploited to identify the crucial factor that can impact the catalytic efficiency for the Suzuki-Miyaura cross-coupling process and further gain valuable insight into the exclusive cooperative effect of the central Pd atom and the peripheral Au atoms of the Pd1 Au8 (PPh3 )8 2+ cluster on controlling the cross-coupling reaction. Specifically, a heterogeneous catalyst, namely Pd1 Au8 @Resin, is designed by exchanging positively charged Pd1 Au8 (PPh3 )8 2+ clusters into the porous resin, thereby not only facilitating catalyst recyclability when performed in a batch reactor, but also realizing time-on-stream performance for the Suzuki-Miyaura cross-coupling reaction carried out in a fixed-bed reactor. The integrated advantages of homogeneous complexes and heterogeneous catalysts are expected to advance the usability of atomically precise metal clusters as heterogeneous catalysts for important bond constructions in homogeneous systems.

Development of a new hyper crosslinked resin based on polyamine-isocyanurate for the efficient removal of endocrine disruptor bisphenol-A from water

Bisphenol A (BPA) is a diphenylmethane derivative often used as a building block of polycarbonate in the production of plastic and plastic additives. Different sectors of the chemical industry release daily high concentrations of BPA in treatment plants, leading to polluting the environment. Due to chemical characteristics, BPA is considered highly toxic to animals and humans health. Adsorption is considered one of the promising techniques for the removal of BPA from water. In this study, we report the synthesis of a new polyamine-isocyanurate-based hyper crosslinked resin (ICYAN-PA) for the adsorptive removal of BPA from aqueous solution. The porous resin showed good thermal stability with a surface marked by smooth porous layers covered by particles of different sizes. The resin exhibited optimum removal of BPA at pH 5, with an adsorption capacity of 260 mg g−1. The isothermal studies suggested that adsorption was favored with increasing temperature (318 K). The Koble-Corrigan model was more adequate to represent the isothermal data. Moreover, the adsorption process was favorable, spontaneous, and endothermic (ΔH0 = 50.9 kJ mol−1). Furthermore, the magnitude of ΔH° was compatible with physical adsorption. The kinetic profiles indicated that the adsorption equilibrium was attained in <180 min of contact time, and the pseudo-first order model best represented the kinetic data. Given the relatively fast kinetics and high thermal stability (Td < 220 °C), ICYAN-PA holds a promise in the decontamination of effluents containing BPA.

Coupling of gaseous toluene adsorption and heterogeneous oxidative degradation by iron-based porous polymeric resin LXQ-10

The effective removal of toluene from waste gas remains a significant and challenging task. In this study, one novel iron-based porous resins were successfully synthesized by loading iron element onto hyper crosslinked polymeric resin (LXQ-10) through a static impregnation method. Factors affecting the toluene adsorption capacity were investigated in a self-made adsorption device. The results showed that 2-Fe/LXQ-10 possessed the biggest gaseous toluene adsorption capacity of 49.16 mg/g. Besides, the coupling effects of reaction temperature, hydrogen peroxide concentration, initial pH, and iron load of the resins on the oxidation efficiency of adsorbed toluene were studied in a heterogeneous Fenton-like reactor. The results showed that under the low temperature of 303 K, even 50 mmol/L H2O2 could obtain the adsorbed toluene oxidation efficiency of 89 % by 2-Fe/LXQ-10. This indicated that loading iron into the porous resins not only improves the saturated adsorption capacity of toluene, but also making porous resin has a good toluene removal efficiency. In addition, the degradation toluene pathways were proposed according to the detected intermediates. This can be assured that this study will provide a new perspective in terms of reducing toluene emissions and lay the foundation for further deepening application of adsorption resins in the area of gaseous toluene control.

Ant nest-like hierarchical porous imprinted resin-dispersive solid-phase extraction for selective extraction and determination of polychlorinated biphenyls in milk

Polychlorinated biphenyls (PCBs) are persistent toxic, organic chemicals that tend to accumulate in the food chain. This study reports the rapid and selective extraction and determination of PCBs (PCB81, 153, 105, 126, and 157) in milk samples by a dispersive solid-phase extraction (DSPE) coupled with gas chromatography-tandem mass spectrometry (GC–MS/MS). An ionic liquid-molecularly imprinted porous resin (IL-MIPPR) as a DSPE adsorbent was synthesized from m-aminophenol, formaldehyde, and 2,2′-benzidinedisulfonic acid as the monomer, crosslinker, and virtual template, respectively. The IL-MIPPR had a fast mass transfer (1.0 min) and good selectivity (imprinting factors of 1.8–3.0). The IL-MIPPR − DSPE − GC–MS/MS method exhibited good linearity (R2 ≥ 0.9995), the limit of detections (LODs) < 0.6 pg/g, and the recoveries ranged from 82.8 % to 106 % with relative standard deviations ≤ 6.6 %. This method is thus better than previously reported methods in terms of the LOD, the adsorbent dosage, and the extraction time.

Effects of Rotational Speed and Processing Time on Bonding Strength of Porous Aluminum and Thermoplastic Resin during Friction Welding

Effects of Rotational Speed and Processing Time on Bonding Strength of Porous Aluminum and Thermoplastic Resin during Friction Welding

Humic acid-coated hydrated ferric oxides-polymer nanocomposites for heavy metal removal in water

Water pollution by toxic heavy metals poses a threat to the environment and human bodies. Herein, a novel hydrated ferric oxide nanoparticle (HFO) based hybrid adsorbent was fabricated for the removal of toxic Cu(II), Cd(II) and Pb(II) from water. HFOs were immobilized into a porous resin D-201, and then this nanocomposite HFO-D201 was coated with humic acid (HA) to enhance the binding sites of target metals. Both HFOs and HA contribute to the sequestration of heavy metals. The as-synthesized hybrid adsorbent HA-HFO-D201 exhibited excellent performance on the removal of Cu(II), Cd(II), and Pb(II) in a pH range of 3–9, while no Fe leaching was observed. The presence of natural organic matter (20 mg C/L) has limited influences on the adsorption, and more than 85% of the target metals can be removed after treatment. HA-HFO-D201 showed preferable adsorption toward Cu(II) and Pb(II) (1 mg/L) from the background Ca2+ solution at much higher concentrations (100 mg/L), while the retention of Cd(II) (1 mg/L) decreased to some extent. Fixed-bed column experiments exhibited that the treatment capacities of HA-HFO-D201 are 90 bed volumes (BV) for Cd(II), 410 BV for Pb(II) and > 800 BV for Cu(II) of simulated contaminated water to meet the WHO drinking water standard. Meanwhile, depleted HA-HFO-D201 can be readily regenerated by a chelating agent Na2EDTA for repeated use. The hybrid adsorbent HA-HFO-D201 has excellent potential to remove heavy metals in water treatment systems.

High-throughput LC-MS method for the rapid characterisation and comparative analysis of multiple ingredients of four hawthorn leaf extracts.

The comprehensive component characterisation of Chinese herbal medicine is the premise of effectively driving the discovery of pharmacodynamic substances or new drugs in recent years. To use the high-throughput liquid chromatography-mass spectrometry (LC-MS) approach to systematically characterise phytochemical compounds from four hawthorn leaf extracts, along with evaluating their classification. In the present study, the compounds from 50% ethanol extract, macro porous resin extract, ethyl acetate extract and standard decoction of hawthorn leaves were completely analysed by ultrahigh-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS). Eight-nine compounds were putatively identified by comparison with secondary MS data and available references. Of these compounds identified, 56 compounds were found for the first time in hawthorn leaves, which was somewhat inconsistent with the findings of other studies. It could be inferred that falconoid, organic acids and nitrogenous compounds were the most abundant in 50% ethanol extract and standard decoction extract, which were considered as better choices for extracting hawthorn leaves. This work developed a simple, accurate and rapid method for the compound identification of hawthorn leaves, which laid the basis for further discovering pharmacodynamic material basis or new drugs from hawthorn leaves.

Preparation and oil absorption performance of ATP/P(MMA-BMA-St)/Fe

In this paper, oil-in-water-in-oil (O/W/O) double Pickering emulsions were prepared by purified and modified attapulgite (ATP), and modified nano-Fe3O4 as stable particles. By using the Pickering emulsion as a template and using methyl methacrylate (MMA), butyl methacrylate ester (BMA) and styrene (St) as monomers, ATP/P(MMA-BMA-St)/Fe3O4 composite porous resins were then prepared. The oil absorption performance of the composites was investigated. The results showed that the composite materials prepared by the double Pickering emulsion template method exhibited a three-dimensional (3D) porous structure. When using the optimal conditions (mMMA:mBMA = 3:2, m(MMA+BMA):mSt = 1:2, initiator = 5.33%, crosslinking agent = 20%, modified attapulgite = 0.33% and oil phase/water phase = 1:4), the prepared porous material had the best oil absorption performance, resulting in a diesel oil absorption rate and oil retention rate of 897.29 and 84.76% respectively. This study provides a simple, economic and environmentally friendly method for the preparation of inorganic–organic composite porous materials, which has great application potential in the field of oil treatment.