Formaldehyde Dimethyl Acetal Research Articles

Bi-phenyl derived hyper-crosslinked polymer as a metal-free adsorbent for the removal of pharmaceuticals from water

The global concern of emergent aquatic pollutants, especially pharmaceutical contaminants, emphasizes the necessity for metal-free adsorbents to tackle water contamination issues. In this direction, a biphenyl-derived hyper-crosslinked polymer (poly-biph) was utilized as an adsorbent for the removal of ciprofloxacin (CPX) and doxycycline (DOX) from water. Micro-mesoporous hyper-crosslinked polymeric adsorbent (poly-biph) was synthesized by using bi-phenyl as precursor and formaldehyde dimethyl acetal (FDA) as crosslinker via microwave assisted method. It exhibits specific surface area (SABET) and pore volume of 1088 m2/g and 1.3 cm3/g, respectively. The spectral analysis confirmed the successful crosslinking of biphenyl with the linker FDA. The sorption efficiency of metal-free poly-biph for CPX and DOX was evaluated via batch and continuous flow modes under various operational parameters. poly-biph exhibited swift removal efficiency (>80 %) for CPX and DOX within a min. The batch mode sorption modeling revealed a chemisorption process and remarkable maximum sorption capacity of 470.8 and 425.1 mg/g for CPX and DOX, respectively. The continuous-flow studies of poly-biph revealed the better applicability of the Clark kinetic model with a maximum bed capacity of 313.5 and 372.4 mg/g for CPX and DOX, respectively. Synergistic mechanisms, including π-π interaction, electrostatic interaction, and pore-filling effect, were found to be the main driving forces for the sorptive removal of CPX and DOX onto poly-biph. The findings indicated that poly-biph possesses the ability to effectively eliminate DOX and CPX from the aquatic environment.

Economical and rapid mechanochemical synthesis of porous organic adsorbents with high hydrophilicity for ultra-fast removal of organic micro-pollutants from water

Various porous adsorbent materials have shown excellent adsorption performance for the removal of organic micro-pollutants in water. However, the practical application was hindered by the high cost or slow adsorption kinetics for most of porous adsorbents. Therefore, it is of great significance to develop economic adsorbent materials with characteristic like low-cost, easier preparation method, excellent adsorption kinetics etc.Herein, based on the Friedel-Crafts alkylation reaction, we reported three novel hydrophilic organic porous adsorbent frameworks (PAF-210, PAF-211 and PAF-212) with high Brunauer-Emmet-Teller (BET) surface area (956 ∼ 1384 m2/g) for phenolic micro-pollutants (bisphenol A (BPA), 2,4-dichlorophenol (2,4-DCP) and 2-naphthol (2-NO)) adsorption in water, which were prepared by using cheap trimethyl orthoformate (TMOF) as crosslinker and one-step simple ball milling synthetic method under room temperature within 15 min. Rich oxygen content promotes the resulting polymers to possess excellent hydrophilicity and wettability through water vapor adsorption and water contact angle analysis. The excellent hydrophilicity and proper porous properties made the resulting frameworks suitable as porous organic adsorbents to rapidly remove organic phenolic micro-pollutants from water. Among the resulting polymers, the PAF-210 exhibited ultra-fast adsorption (>94.0 % within 5 s), ultra-rapid adsorption kinetics with pseudo-second-order rate constants (K2, up to 7.72g/mg min−1 for 2,4-DCP), high pollutant adsorption capacity (up to 867.03 mg g−1 for BPA) and excellent recyclability (10 cycles with slight loss in adsorption capacity) through systematically characterization. The adsorption performances of PAF-210 are much better than these of the commercial activated carbons and β-cyclodextrin-based porous adsorbents (K2 = 1.50g/mg min−1 for P-CDP) etc. The favorable hydrophilicity, surface wettability, and adsorption performance of PAF-210 were significantly better than the comparative material constructed by using benzene and formaldehyde dimethyl acetal (FDA) through conventional thermal synthetic method, which is a very classic synthesis strategy in the field of porous materials. More importantly, the PAF-210 exhibited relatively superior adsorption performance on BPA, and it still presented excellent adsorption performance (removal efficiency ≥ 96.8 % within 5 s after 10 cycles) even at the safe range of BPA quantified in drinking water (BPA≤10 μg L−1, Standards for drinking water quality, GB5749-2022, China). XPS analysis and theoretical simulations proved that the excellent adsorption performance and ultra-fast adsorption rate stem from interactions including π-π interactions, hydrogen bonding and van der Waals interactions between PAF-210 and micro-pollutants.

Synthesis of magnetic hyper-crosslinked polymer from waste-expanded polystyrene as efficient sorbent for removal of Congo red and crystal violet

Given that water contaminants pose a huge threat to the environment and human health, the significance of water pollution treatments becomes increasingly evident. In the meantime, white pollution is still a huge headache to the surroundings. Herein, based upon the concept of turning trash into treasure, a series of hyper-crosslinked polymers (named as EPS-HCPs: EPS-FDA, EPS-DCX, EPS-BCMBP) were fabricated through one-step Friedel-Crafts alkylation by adopting wasted expanded polystyrene (EPS) as the raw material and taking formaldehyde dimethyl acetal (FDA), dichloroxylene (DCX) and 4,4′-bis(chloromethyl)-1,1′-biphenyl (BCMBP) as cross-linker, respectively. EPS-HCPs were applied to remove Congo red and crystal violet from aqueous solution, and the EPS-BCMBP exhibited distinctly excellent removal performance. For the convenient separation and recycling of the sorbent, the EPS-BCMBP was modified with magnetism to produce magnetic EPS-BCMBP (M-EPS-BCMBP). The maximum adsorption capacity of M-EPS-BCMBP reached 2160 mg g−1 for Congo red and 303 mg g−1 for crystal violet, with extremely fast adsorption equilibrium time (5 min). The M-EPS-BCMBP could be served as one of ideal candidates for removal of dye pollutants. This work sheds light on establishing a facile strategy for converting wasted EPS into robust sorbents for dyes removal, which plays a key part in sustainable treatment of wastewater.

Green preparation of magnetic pyrene-based hyper-cross-linked polymer using dual-purpose ferric chloride reagent for extraction of polycyclic aromatic hydrocarbons from natural water bodies

A magnetic hyper-cross-linked polymer Fe3O4/HCPPYR was prepared using pyrene as the monomer and formaldehyde dimethyl acetal (FDA) as the cross-linking agent. The objective of green chemistry was achieved by employing FeCl3 during the synthesis, as it played a dual role of a catalyst for the Friedel-Crafts reaction and an iron source for the synthesis of magnetic Fe3O4, thus maximizing efficiency and minimizing waste. Fe3O4/HCPPYR was applied as a sorbent for magnetic solid-phase extraction (MSPE) to extract fifteen polycyclic aromatic hydrocarbons (PAHs) from water. The effects of different parameters such as the quantity of adsorbent, the extraction time, the desorption conditions, the pH value and the effect of the salt concentration on the extraction efficiency were optimized. A simple and efficient method in combination with gas chromatography-mass spectrometry (GC–MS) (Fe3O4/HCPPYR−MSPE/GC–MS) was developed and successfully applied for the detection of PAHs in environmental water samples The analytical method showed LODs in the range of 0.004−0.06 µg L−1, which proved to be adequate for the detection all 15 PAHs at trace concentration. Spiked recoveries of PAHs in actual water samples ranged from 85.2 % to 118.5 % with relative standard deviations (RSDs) below 10.2%. These results indicate that the method has a good potential for reusability and possesses excellent sensitivity. This study showcased the potential of Fe3O4/HCPPYR composites in effectively removing organic pollutants from the aqueous environments, demonstrating their ability for water treatment applications.

Assessing the environmental impacts of flow and batch syntheses of hypercrosslinked polymers for low-pressure CO2 adsorption

The microporosity of hypercrosslinked polymers (HCPs) renders such materials ideal adsorbents for carbon capture. We recently showed that the CO2/N2 selectivity of HCPs synthesised by internal crosslinking of poly-α,α′-dichloro-p-xylene (p-DCX) in continuous flow synthesis was 850 % higher than those produced in batch reactions. We hypothesised that this could potentially reduce the amount of HCP adsorbents required for delivering the same carbon capture performances, hence improving the environmental impacts of carbon capture. This was evaluated here where we analysed the environmental impacts of using both batch- and flow-synthesised HCPs for adsorbing 40 mg of CO2 with the life-cycle assessment method. We also deployed this approach to evaluate HCPs synthesised via post-crosslinking of polystyrene crosslinked with DCX (p-PS-DCX) and externally crosslinking of polystyrene with formaldehyde dimethyl acetal (FDA) crosslinker (p-PS-FDA). Amongst all HCPs studied in this work, the changes in environmental impact of deploying internally crosslinked HCPs for carbon capture were the worst. This was mostly attributed to its low product yield (7 %), which had a larger influence on the environmental impacts than its adsorption performance as verified by sensitivity analysis. To offset the adverse effects of low product yield, the product yield from flow synthesis of HCPs should ideally reach 25 %. By identifying that product yield is key for promoting environmental sustainability in carbon capture using flow-derived HCPs, future work should focus on optimising continuous flow synthesis to deliver ideal product yield. Hypercrosslinked polymers (HCPs) can be deployed adsorbents for carbon capture. Here we hypothesise that one can use HCPs with better CO2/N2 selectivity to deliver the same carbon capture performances, hence improving the environmental impacts of carbon capture. This was evaluated here using batch- and flow-synthesised HCPsvia internal, external and post-crosslinking strategies with the life cycle assessment method. The environmental impacts of internally crosslinked HCPs were worst due to a low product yield of 7 % Sensitivity analyses indicated that this limitation can be overcome when HCP yield from flow synthesis reach 25 %. Future work should focus on optimising continuous flow synthesis to deliver ideal product yield for minimising environmental impacts of deploying HCPs in carbon capture.

Fe-N-Doped Conjugated Organic Polymer Efficiently Enhanced the Removal Rate of Cr(VI) from Water.

A Fe-N conjugated organic polymer (SMP-Fr-Py) was prepared from ferrocene and pyrrole using a Scholl coupling reaction, which significantly improved the performance of Cr(VI) removal compared to the polymer (HCP-Fr-Py) prepared by adding the cross-linker formaldehyde dimethyl acetal (FDA). The results showed that at a pH of 2 and at 25 °C, the removal of Cr(VI) reached 90% for SMP-Fr-Py and only 58% for HCP-Fr-Py after 20 min of reaction. Subsequently, 99% and 78% were achieved after 120 min of reaction, respectively. The test results showed that the removal reaction followed a pseudo-second-order kinetic model. The removal efficiency decreased with increasing solution pH and initial Cr(VI) concentration, but increased with increasing SMP-Fr-Py dosage, reaching three cycles. The characterization of the reaction complexes and measurements of Cr species conversion revealed the near absence of Cr(VI) species in the solution. Approximately 38% of Cr(VI) was found to be adsorbed on the material surface, with another fraction present in solution (24%) and on the material surface (38%) in the form of Cr(III). The overall study showed that the direct connection of ferrocene and pyrrole in SMP-Fr-Py through C-C bonding increased the conjugated structure of the polymer backbone, which facilitated electron transfer and transport. Furthermore, the Fe-N elements worked synergistically with each other more easily, which improved the removal performance of Cr(VI) and provided a reference for the subsequent work.

Neutral and Cationic Phenothiazine‐Based Porous Organic Polymers via a Simple and Cost‐Effective Method for Iodine Capture

AbstractThe phenothiazine‐based porous organic polymers (PTA‐POPs) were constructed through a facile and cost‐effective method. We used commercial phenothiazine as aromatic building units, formaldehyde dimethyl acetal (FDA) as a crosslinker under the catalysis of anhydrous FeCl3, which afford PTA‐POPs with high yield. The phenothiazine‐based porous organic polymers possessed good porosity, excellent thermal stability, and rich heteroatom sites in the skeleton. Cationic PTA‐POP (C‐PTA‐POP) was further synthesized via a simple process. Interestingly, the C‐PTA‐POP exhibited highly effective iodine vapor capture up to 3.69 g g−1, which is ranked the excellent performance among the reported POPs.

Synthesis and characterization of waste Styrofoam hypercrosslinked polymer as an adsorbent for CO2 capture

AbstractIn this work, we used waste Styrofoam as a precursor to synthesize a hypercrosslinked polymeric (HCP) adsorbent for CO2 adsorption utilizing the Friedel–Craft procedure. The hypercrosslinked adsorbent was designed using formaldehyde dimethyl acetal (FDA) as the crosslinker. The precursor to crosslinker to catalyst ratio was 1:3:3, and the HCP synthesis was carried out for 12 h at 312.6 K. Fourier‐transform infrared spectroscopy, field emission scanning electron microscopy, and thermogravimetric analysis were used to analyze the waste Styrofoam hypercrosslinked (WSHC) adsorbent. The adsorbent attained an 802.84 m2/g Brunauer–Emmett–Teller (BET) surface area and an average pore diameter of 2.869 m3/g. The CO2 adsorption process was studied under different operating conditions, temperature between 298 and 328 K and pressure between 2 and 10 bar. WSHC adsorbent has the maximum CO2 uptake with a value of 11.053 mmol/g at 298 K and 10 bar. The behavior of the adsorption process was investigated using isotherm, kinetic, and thermodynamic models. Experimental findings indicated that the Sips isotherm and the second‐order kinetic models provided the best fit. The isotherm data indicated that adsorption occurs in multi‐layers and is heterogeneous. According to the thermodynamic characteristics, the process is exothermic and spontaneous. Finally, the kinetic findings established that the process happened physically. Additionally, a regeneration study after seven cycles revealed a 96.1% success rate. The current research may attempt to use waste Styrofoam as a gas separation adsorbent in the industry.

High porosity cyclotriphosphazene-based hyper-crosslinked polymers as efficient cationic dye MB adsorbents

Inspired by triptycene unit, the rigid paddle wheel compounds tris(o-phenylenedioxy)cyclotriphosphazene (TPP) and tris(2, 3-naphthalenedioxy)cyclotriphosphazene (TNP) were synthesized and employed as core building blocks to construct high porosity hyper-crosslinked polymers ( HCP-TPP and HCP-TNP ) via Friedel-Crafts alkylation reaction with formaldehyde dimethyl acetal (FDA). The bulk of HCP-TPP and HCP-TNP were comprised of nano-particles and exhibited hierarchical pore structures with remarkable high BET specific surface area of 1641.9 and 1700.2 m 2 g −1 , respectively. The adsorption capacities of HCP-TPP and HCP-TNP toward cationic dye methylene blue (MB) run up to 504.6 and 409.1 mg g −1 at 25 °C, respectively, but they hardly adsorbed anionic dye methyl orange (MO), exhibiting charge selectivity. The adsorption behaviors on MB were in consistence with the pseudo-second-order model and Langmuir model. The estimated thermodynamic parameters indicated the adsorption process was spontaneous and exothermic. Inspired by triptycene unit, the rigid paddle wheel compounds tris(o-phenylenedioxy)cyclotriphosphazene (TPP) and tris(2, 3-naphthalenedioxy)cyclotriphosphazene (TNP) were synthesized and employed as core building blocks to construct high porosity hyper-crosslinked polymers ( HCP-TPP and HCP-TNP ) via Friedel-Crafts alkylation reaction with formaldehyde dimethyl acetal (FDA). The bulk of HCP-TPP and HCP-TNP were comprised of nano-particles and exhibited hierarchical pore structures with remarkable high BET specific surface area of 1641.9 and 1700.2 m 2 g −1 , respectively. The adsorption capacities of HCP-TPP and HCP-TNP toward cationic dye methylene blue (MB) run up to 504.6 and 409.1 mg g −1 at 25 °C, respectively, but they hardly adsorbed anionic dye methyl orange (MO), exhibiting charge selectivity. The adsorption behaviors on MB were in consistence with the pseudo-second-order model and Langmuir model. The estimated thermodynamic parameters indicated the adsorption process was spontaneous and exothermic. • Two novel cyclotriphosphazene-based hyper-crosslinked polymers were prepared from low cost raw materials. • They exhibited hierarchical structures with the highest BET specific surface areas among cyclotriphosphazene -based porous materials. • They charge-selectively absorbed cationic dye methylene blue (MB) with absorption capacities of 504.6 and 409.1 mg g −1 at 25 °C.

Fabrication of fire-retardant building materials via a hyper-crosslinking chemical conversion process from waste polystyrenes

• Waste PS was used for the preparation of fire-retardant building materials. • Hypercross-linking reaction induced high value-added use of waste PS. • The preparation process can be facilely scaled up. Polystyrene (PS) is rich in plastic materials, but it produces a large amount of waste every year, causing a huge burden on the environment. Although PS plastic is the source of a common "white pollution" in daily life, it still has a high utilization value. At the same time, the flammability of PS material determines that it cannot be applicated in places where fire accidents occur frequently. As a result, its application has been greatly limited. In order to realize the efficient utilization of waste PS and broaden its scope of application, PS was modified by hyper-crosslinking in order to improve its fire-retardant performance. In this method, the PS solution with high purity was obtained by dissolving waste PS foam with 1,2-dichloroethane (DCE), and then the hyper-crosslinked polymer with high specific surface area was prepared by adding cross-linking agent formaldehyde dimethyl acetal (FDA) and a Lewis-acid catalyst ferric chloride (FeCl 3 ). Further studies showed that the effects of the amount of cross-linking agent FDA, catalyst FeCl 3 and PS on the reaction products were different. In addition, compared the as-prepared fire-retardant materials with PS foam from the aspects of flame retardancy and thermal insulation, it can be concluded that the fire-retardant performance of the materials prepared by this method has been significantly enhanced. And it is proved that this method is feasible towards the preparation of a large number of fire-retardant composite materials by using a scale-up experiment.

Efficient and Economical Preparation of Hypercrosslinked Polymers-palladium Based on Schiff Base as Recyclable Catalyst for Suzuki-Miyaura Reactions

A novel hypercrosslinked polymer (HCP) was prepared via Friedel-Crafts alkylation reaction of Schiff base with benzene and formaldehyde dimethyl acetal (FDA) promoted by FeCl3. The HCP was then metalated with Pd(II) to form heterogeneous catalyst. The protocol featured low cost, mild conditions, readily available materials, easy separation and high yield. Physicochemical methods, including IR, N2 sorption, ICP, TGA, XPS, SEM, EDX, and TEM, were used to characterize the catalyst structure and composition. The results reveal that the heterogeneous catalyst possesses high specific surface area, large pore volume, good chemical and thermal stability, and highly dispersed palladium. The heterogeneous catalysts were applied in Suzuki-Miyaura coupling reaction to evaluate their catalytic performance. The experiments reflected that the HCPs-Pd(OAc)2 was an efficient catalyst for Suzuki-Miyaura reactions with the yield of biaryl up to 99%, while the TON could reach 2250. The reusability test showed the catalyst was easily recovered and reused for at least six times without obvious decrease in activity.

Effective Removal of Dyes by Synthesized and Characterized by Anthracene Hypercross Linked Polymer

The preliminary introduction of synthetic polymers in the 1830’s is today reflect by an inestimable number of structural variations that have finished in key components in products to rally the requirements of contemporary society. Due to their practical applications in the field of biology, chemistry, and medical field. Hyper cross-linked polymers are of great importance. Synthetic hyper cross-linked polymer will have high surface area with improved pore size and mild operating condition that can be used for amputation of dyes. Hyper crossed linked polymer is synthesized by using Friedel craft reaction used for aromatic network for the formation with highest surface area and microprousity which is suited for the Methane and carbon dioxide even at low pressure and temperature starting from the anthracene and Formaldehyde Dimethyl Acetal (FDA) with different concentration yield highly porous polymers which approximate the separation and Storage for the adsorption of carbon dioxide and methane. This polymer exhibits several elementary properties like that biodegradable property, regeneration property, separation efficiency and high adsorbent capacity. FTIR technique is used to study vibrational energy levels of molecules. As each atom in a molecule or functional group has its unique vibration so they can absorb different wavelength of IR.

Tunable construction of biphenyl-based porous polymeric nanostructures and their synergistically enhanced performance in pollutant adsorption and energy storage

Morphological diversity and porosity of porous organic polymers (POPs) exert vital influence on their potential applications. Herein, we demonstrate the morphology and porosity design of biphenyl-based hyper-cross-linked porous organic polymers by using a Lewis acid catalyzed Friedel–Crafts polymerization in the presence of formaldehyde dimethyl acetal (FDA) as cross-linker. The chemical composition of POPs is tunable by simply varying monomer to FDA ratio, leading to considerable morphological diversity such as the nanospheres, nanofibers, and flower-like nanostructures. High specific surface areas with mostly microporous nature, stable organic frameworks and tunable morphologies coupled with facile synthetic protocol let the hyper-cross-linked polybiphenyl (HCPbPh) based POPs exhibit the outstanding adsorption capacity and efficiency towards p-cresol based pollutant. The obtained carbon materials by direct pyrolysis of corresponding POPs can be used as the electrode materials for supercapacitors, exhibiting outstanding electrochemical performance with specific capacitance up to 421 F g−1 at 1 A g−1, and capacitance retention of 97% even after 10,000 cycles at 12 A g−1. This methodology delivers a new platform for the fabrication of microporous and mesoporous materials for various potential applications including energy storage, adsorption, and catalysis.

Direct synthesis of hypercrosslinked microporous poly(para-methoxystyrene) for removal of iron(III) ion from aqueous solution

Abstract Introduction of functional groups on the hypercrosslinked microporous polymer can significantly enhance its performances and applications, but direct synthesis of the hypercrosslinked microporous functional polymer by an “external crosslinking” technique remains highly challenging. Herein, we reported initial synthesis of hypercrosslinked microporous functional polystyrene (HCPMOS) originated from poly(para-methoxystyrene) (PMOS) by a Friedel-Crafts alkylation reaction using formaldehyde dimethyl acetal (FDA) as an external crosslinker. The hypercrosslinked structure of HCPMOS was fully characterized, and HCPMOS had a microporous structure (0.64–1.37 nm) and high surface area (813 m2/g). The hypercrosslinked microporous poly(para-methoxystyrene) (HCPMOS) showed selective and good adsorption capability for Fe3+ removal from aqueous solution. FTIR and X-ray photoelectron spectroscopy (XPS) proved that enhanced adsorption capability of HCPMOS toward Fe3+ was contributed by both chelating capability of methoxy groups toward metal and large surface areas. Adsorption performances of HCPMOS were investigated at different Fe3+ concentrations, contact times, and temperatures. Adsorption equilibrium and kinetic process of Fe3+ on HCPMOS were well described by the Langmuir isotherm model and the pseudo-second-order kinetic model. HCPMOS showed great potential as a selective and good adsorbent for removal of Fe3+ from polluted water.

Catalytic application of sulfamic acid-functionalized magnetic Fe3O4 nanoparticles (SA-MNPs) for protection of aromatic carbonyl compounds and alcohols: experimental and theoretical studies.

Protection techniques of functional groups within the structure of organic compounds are important synthetic methods against unwanted attacks from various reagents during synthetic sequences. Acetal and thioacetal groups are well known as protective functional groups in organic reactions. In this study, acetalization of carbonyl compounds with diols and dithiols and methoxymethylation of alcohols with formaldehyde dimethyl acetal (FDMA) have been carried out using sulfamic acid-functionalized magnetic Fe3O4 nanoparticles (SA-MNPs) as a heterogeneous solid acid catalyst. Products were characterized by FT-IR and NMR spectroscopies. The structural and electronic properties of some products were computed by quantum mechanical (QM) methods. Depending on the stereochemistry and electronic properties that were obtained by computational results, we have suggested that hyperconjugation plays a key role in the structural properties of 2-phenyl-1,3-dioxolane derivatives, and also the electron transfer between π-electrons of the aromatic ring with the 3d orbital of S-atoms influences the 2-phenyl-1,3-dithiane derivatives' structure.

Hyper-Cross-Linked Polymers for the Capture of Aromatic Volatile Compounds

Hyper-cross-linked porous polymers (HCPs) are proposed as sorbents for the removal of aromatic volatile pollutants by using toluene as a representative of the BTX family. The hierarchical (micro and meso) porous architecture of the HCPs has been established by N2 physisorption at 77 K while the toluene adsorption capacities were determined by volumetric adsorption at 308 K. The HCPs display very high toluene uptakes, reaching adsorption capacities as high as 154% in weight for the polymer obtained with a tetraphenylmethane (TPM) and a formaldehyde dimethyl acetal (FDA) ratio of 1/16, whereas only very low uptakes were observed for aliphatic molecules such as n-hexane. HCP materials experience swelling effects evaluated by comparing the volume assessed via N2 physisorption with the volume occupied by toluene molecules in volumetric adsorption experiments. A multispectroscopic approach involving FT-IR and solid-state NMR techniques gave direct proof of the close spatial proximity between the polymeric host ...

Hydroxyl-Based Hyper-Cross-Linked Microporous Polymers and Their Excellent Performance for CO2 Capture

A series of benzyl alcohol (BA)-based hyper-cross-linked microporous polymers (HCPs) were designed and synthesized via facile Friedel–Crafts alkylation using formaldehyde dimethyl acetal (FDA) as external cross-linker promoted by anhydrous ferric chloride (FeCl3). Results demonstrated that Brunauer–Emmett–Teller (BET) specific surface area and pore volume for the HCPs could be controlled by adjusting the amount of FDA and FeCl3. The HCPs obtained under optimal conditions showed a BET specific surface area up to 1101 m2/g, whose capacity of CO2 uptake could be as high as 3.03 mmol/g at 273 K/1.0 bar. The isosteric heats of CO2 sorption for the BA-based HCPs exceed 27 kJ/mol at the low coverage. In addition, the polymer networks possessed high CO2/N2 selectivity of 42. Compared with those BA-based HCPs which is without FDA, the prepared material has higher BET specific surface area and superior CO2 adsorption properties. These results demonstrated that these prepared HCPs are promising for CO2 capture and s...

Hyper-crosslinked porous polymer based on bulk rigid monomer for gas and dye absorptions

Using the rigid 3,3-bis(4-hydroxyphenyl)-2-(4-tritylphenyl)isoindolin-1-one with polar functional groups as a building block and formaldehyde dimethyl acetal(FDA) as a crossinglinker, a new hyper-crosslinked polymer (HCP) was synthesized via Friedel-Crafts alkylation reaction promoted by anhydrous FeCl3. The synthesized HCP is insoluble in boiled water and common organic solvents. Moreover, it shows a good CO2 capture capacity even if its surface area is not very high, and the absolute CO2 uptake capacity of it is 3.05 mmol/g. This can be attributed to the introduction of polar hydroxyl and lactam groups into the skeleton of the polymer which provides effective adsorption sites for CO2. In addition, the synthesized HCP also exhibits good adsorption capacity for organic dyes in water, especially for crystal violet.

Efficient removal of Pb(II) by amine functionalized porous organic polymer through post-synthetic modification

Abstract Porous organic polymers (POPs), a new class of porous materials constructed by organic molecular building blocks, have attracted much attention. To design POPs with both good porosity and specific-task functionalization is still a critical challenge. In this work, using a simple Friedel-Crafts one-step reaction, one of the most common organic compound methylbenzene monomers were polymerized through the cross-linker formaldehyde dimethyl acetal (FDA) to produce a cost-effective non-functionalized porous polymer (POP-CH 3 ). Moreover, amine groups were further incorporated into the network by the post-synthetic modification method. The resulted porous polymer POP-NH 2 presented highly effective in removing Pb(II) from aqueous solution. The maximum Pb(II) adsorption capacity, q max , evaluated from the Langmuir model was 523.6 mg g −1 . The combination of FT-IR experimental results and the theoretical quantum calculations illustrated that the amine groups ( NH 2 ) can easily form coordination complexes with Pb(II), which were responsible for efficient adsorption. The generated POP-NH 2 could be regenerated effectively and recycled at least four times without significant loss of adsorption efficiency. Hence, the outstanding Pb(II) adsorption capacity, excellent reusability as well as low cost of synthesis create potential polymer POP-NH 2 to be an attractive adsorbent for removing toxic metal ions from aqueous solution.

Triphenylamine-based porous organic polymers: Synthesis and application for supporting phosphomolybdate to fabricate efficient olefin oxidation catalysts

Two kinds of triphenylamine-based porous organic polymers (POPs) were synthesized by FeCl3-triggered Friedel-Crafts polymerization of triphenylamine (TPA) and formaldehyde dimethylacetal (FDA) in the absence or presence of benzene (Ph), which are denoted as POP-I (without additional Ph) and POP-II (with additional Ph as linker), respectively. Various characterization results confirm the successful synthesis of TPA-based polymers with different bridged linkers and hierarchical pore structure. Phosphomolybdic acid (HPMA) and cobalt phosphomolybdate (CoPMA) were immobilized onto the POPs, to form phosphomolybdate (PMA) functionalized POPs catalysts, and their catalytic properties were investigated for the selective oxidation of olefins with H2O2. All the PMA functionalized POPs materials are catalytically active for the epoxidation/oxidation of olefins, while CoPMA/POP-II shows the highest activity, stability and recyclability. TPA-based POPs have distinctive electron-donating and transferring ability, which can be further tuned by introducing more bridged linkers of -Ph and -CH2 groups. Multi-interactions between PMA and POPs supports could be built through the electronic and geometric effects exerted by the 3-D POPs supports on the PMA clusters. Moreover, the existence of Co cations may further strengthen the interactions between PMA and POPs supports by forming electrostatic or coordination interactions with the TPA ligands, thus resulting in the high stability of the CoPMA/POP-II against leaching of active species during the H2O2 mediated catalytic oxidation process.