Microwave Irradiation Research Articles

Numerical Simulation of Microwave-Induced Cracking of Coal Containing Pyrite Powder Based on a Multi-Field Coupling Model

Microwave irradiation has become a potential technical method for coalbed degassing, which can effectively improve its permeability. A coupled electromagnetic—thermomechanical damage (ETMD) model was established to study the damage characteristics of coal containing pyrites. Under microwave irradiation, the temperature increase rate of pyrite was significantly higher compared to the coal matrix. The coal matrix was cracked by expansion stress in high-temperature spots. In the rotational heating mode, the coal matrix was easier to damage than under the static heating mode. The coal matrix damage efficiency was also related to the position of the sample under the static heating mode. Uniform centripetal pressure could inhibit coal matrix damage. Moreover, the pressure distribution affected the damage paths. Compared to no confining pressure, the percentage of areas damaged in coal was lower under low parallel pressure and higher under high parallel pressure.

The Potential of Microwave Technology for Glycerol Transformation: A Comprehensive Review

Glycerol is a major by-product in biodiesel manufacturing, which accounts for around 10% of the biodiesel volume. A surplus of glycerol has led to the development of technologies for production of value-added products using glycerol as a raw material, following the “waste as a resource” strategy. Various techniques are available to carry out glycerol transformation, viz. carrying out processes under thermal heating, application of ultrasonic or hydrodynamic cavitation, microchannel technologies, etc. Microwave-assisted organic synthesis (MAOS) is a simple and innovative technology, which can be considered as a means of intensifying these processes. This review describes microwave irradiation as a valuable energy-efficient alternative to conventional heating for the production of value-added chemicals from glycerol via dehydration, hydrogenolysis, esterification, transesterification, etherification, and oxidation. In general, innovative and potential catalysts, approaches, and technologies are discussed and critically evaluated in terms of the possibilities and potential for further industrial implementation

Combination of phenylsilsesquioxane and acetate ligands as an approach to a record high nuclear Cu13Na2-cage. Synthesis, unique structure, and catalytic activity.

Self-assembly synthesis of mixed-ligand (silsesquioxane/acetate) complex allows to isolate record high nuclear copper(II) Cu13-cage (1). In the presence of two additional sodium ions, a unique molecular architecture, with triple combination of ligands (cyclic and acyclic silsesquioxanes as well as acetates), has been formed. The structure was established by single-crystal X-ray diffraction based on the use of synchrotron radiation. Complex 1 was evaluated as precatalyst in the Baeyer-Villiger oxidation of cyclohexanone towards ε-caprolactone, employing hydrogen peroxide, tert-butyl hydroperoxide (TBHP) or m-chloroperoxybenzoic acid (mCPBA) as oxidants, in an aqueous acidic acetonitrile medium. The direct formation of the lactone from cyclohexane via a tandem peroxidative oxidation/Baeyer-Villiger oxidation was also studied. For both substrates, the best results (ε-caprolactone yields up to 100% or 26%, from cyclohexanone or cyclohexane, respectively) were achieved with mCPBA under considerably mild conditions, i.e., conventional heating at 50 °C for 4 h or microwave (MW) irradiation at 80 °C for only 30 minutes.

Direct access to 5,6 dihydropyrido[2',1':2,3]/pyrido fused imidazo[4,5-c]quinolines via consecutive C-N and C-C bond formations in deep eutectic solvent under microwave irradiation

Deep eutectic solvents (DESs) are a novel class of ionic liquids that have recently gained considerable attention as a sustainable, non-toxic substitute of traditional organic solvent. Recent years have seen an increasing demand for DES system to synthesize various heterocyclic moieties. However, scaffolds containing polyheterocycles in their structural framework makes them a potential therapeutic agent. Herein, we have reported a tandem methodology for synthesizing rarely explored 5,6 dihydropyrido[2',1':2,3]imidazo[4,5-c]quinolines and pyrido[2',1':2,3]imidazo[4,5-c]quinolines in a choline chloride based DES medium under microwave irradiation. This sustainable approach offers a clean, straightforward synthetic strategy with mild reaction conditions and a wide range of desired compounds are afforded in excellent yields.

Diastereomeric N,S-Dialkyl Dithiocarbamates Derived from (E)-Chalcones and ʟ-Tryptophan: Microwave-Assisted Synthesis and In Vitro Studies Against Fusarium oxysporum

The synthesis of indole phytoalexin-like analogs related to alkyl (((1-(4-substitutedphenyl)-3-oxo-3-phenylpropyl)thio)carbonothioyl)-ʟ-tryptophanate 1a–d and the evaluation of their antifungal activity against the phytopathogen Fusarium oxysporum is reported. The target compounds were synthesized in the following two stages: (1) the initial esterification of ʟ-tryptophan, which reacted with trimethyl silane chloride and simple aliphatic alcohols (R = Me, Et) under microwave irradiation (MWI) at 100 °C to obtain the respective alkyl ester 2a–b; (2) the resulting mixture of ʟ-tryptophanates 2a–b with carbon disulfide and (E)-chalcone 3a–b under MWI at 50 °C during 60 min, followed by purification through classical column chromatography (55–76% yields). The products were obtained as mixtures of (S,R) and (S,S) diastereoisomers. An LC-DAD-MS analysis allowed us to establish the ratio of these diastereoisomers, and subsequent DFT/B3LYP-based computational calculations of the NMR 1H chemical shifts suggested that the major diastereoisomer involved an (S,R) absolute configuration, comprising more than 60% of the mixture. The compounds 1a–d were subjected to an antifungal activity test against the phytopathogen F. oxysporum using an amended medium-based assay. Compound series 1 showed inhibition percentages of 80% at the first concentration and IC50 values between 0.33 and 5.71 mM, demonstrating greater potential as antifungal agents compared to other ʟ-tryptophan derivatives like alkyl (2S)-3-(1H-indol-3-yl)-2-{[(1Z)-3-oxobut-1-en-1-yl]amino}propanoate, which presented lower inhibition percentages. In summary, phytoalexin analogs derived from ʟ-tryptophan and (E)-chalcones significantly inhibited the mycelial growth of Fusarium oxysporum, indicating their potential as effective antifungal agents.

Impact of Microwave Pre-Curing on Pore Structure and Environmental Performance of Metakaolin- and Fly Ash-Based Geopolymers

Microwave technology in geopolymer synthesis offers a transformative, sustainable alternative to traditional methods, enhancing material properties and production efficiency. However, the effects of microwave-induced changes on pore structure and their relationship with mechanical strength and environmental performance, such as heavy metal leachability, are not fully understood. This study investigates the impact of microwave pre-curing on geopolymers, focusing on how microwave power and duration influence their pore structure and environmental performance. A total of 48 mixtures were prepared using sodium silicate and sodium hydroxide as alkali activators, with metakaolin and fly ash as raw materials. The modulus was adjusted to 1.5, and the liquid-to-solid ratio was set at 1.6 for metakaolin and 0.7 for fly ash. Microwave irradiation power settings of 100 W, 300 W, 440 W, 600 W, and 800 W were tested. The heating times ranged from 30 s to 90 s at intervals of 15 s. Our findings reveal that optimal microwave settings (100 watts for 45 s) can significantly enhance mechanical properties, with compressive strengths reaching 15.9 MPa for fly ash-based and 9.094 MPa for metakaolin-based geopolymers. However, excessive microwave energy leads to increased porosity, with adverse effects on structural integrity. Moreover, microwave pre-curing effectively reduces heavy metal leachability. Chromium (III) was used in leaching tests and it was demonstrated that ion concentrations as low as 0.097 mg/L enhance environmental safety. Advanced techniques like Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray CT were applied for the analysis of the atomic bonding, phases and pore structure of the studied geopolymers along with their ability to withstand compression (MPa). Chromium (III) was encapsulated and its leached concentration was measured by ICP-MS to evaluate the performance of the synthesized geopolymers. These results underscore the need for precise control over microwave irradiation parameters to maximize the benefits while mitigating negative impacts. This study provides valuable insights into the controlled use of microwave technology for geopolymer synthesis, recommending optimal irradiation conditions for improved performance and sustainability and advancing sustainable construction materials. The developed geopolymers show promise for applications in construction, waste stabilization, and heavy metal immobilization, contributing to more sustainable and environmentally friendly materials in these industries.

Disruption of the Conjugated π-Electron System of Graphene Oxides Diminishes Their Microwave Reactivity.

Graphenes and graphene-based adsorbents have the potential to be thermally regenerated by microwave irradiation due to their electronic mobility and propensity to absorb microwaves. This article investigates the effect of oxidation on their ability to heat during microwave irradiation in conjunction with their ability to adsorb a polycyclic aromatic hydrocarbon. For this, a series of graphene oxides (GOs) were synthesized, and their chemical properties and surface structures were analyzed systematically. As the oxidation levels increased, the microwave reactivity of GOs decreased notably. This was attributed to the disruption of the sp2-hybridized basal plane despite the introduction of polar oxygen-containing functional groups. The findings of this work indicated the role of the conjugated π-electron system on microwave reactivity, possibly posing a juxtaposition with the influence of polar C-O bonds on dielectric reactivity. In addition, the adsorption of the model compound decreased by oxidation, confirming the decrease in π-π electron donor-acceptor interactions and the increase in the formation of water clusters around oxygen-containing functional groups. This study provides the first mechanistic insight into the relationship between the conjugated π-electron network of graphenes and their microwave reactivity. It paves the way for utilizing microwave irradiation to regenerate spent graphenic adsorbents for water treatment.

A Resilient and Reusable Ion-Tagged Cu(II) Catalyst for the Microwave-Assisted Synthesis of 2-(N-Arylamino)benzothiazoles

AbstractA simple, quick, and cost-effective protocol is presented herein for the sustainable synthesis of 2-(N-arylamino)benzothiazoles from 2-haloanilines and arylisothiocyanates by using an ionic liquid supported heterogeneous Cu(II) catalyst derived from N-methylimidazole. Compared to the use of homogeneous catalysts and additives, which require long reaction times and high reaction temperatures, this methodology has a broad substrate scope and proceeds in short reaction times to afford compounds in excellent yields under microwave irradiation. In addition, the catalyst can be extracted easily and is recyclable up to five times with no significant loss in catalytic activity.

Effect of microwave irradiation on the breaking and linear cutting of hard rock

Microwave technology, emerging as a novel approach to rock-breaking, holds significant promise in the realm of auxiliary mechanical pick rock breaking. In view of the problems existing in the hard rock breaking such as low efficiency and difficulty in one-time cutting, this study conducted experimental research using a method combining microwave irradiation and linear cutting with conical picks. The comprehensive temperature distribution of the rock is reproduced by 3D technology after microwave irradiation, defined the high-temperature zone and calculated the surface area. Moreover, analyzing the relationship between temperature and cutting force. And the effect of microwave-assisted conical pick rock breaking was quantified in terms of cutting force, rock breaking effect, and energy consumption. The results indicate that microwave irradiation induces heating in hard rock, leading to the formation of fissures and even partial fragmentation of rocks. The thermal damage effect of microwave is determined by the differences in the physical and mechanical properties of different rocks. In the experiment, basalt has the best heating effect and sandstone has the best fracturing effect. Compared to non-microwave, microwave (6 kW,60 s) irradiation reduces the cutting force, improves the effect of rock breaking, and reduces the work done (E) by the cutting force and the mechanical specific energy (MSE). Microwave irradiation-assisted mechanical rock breaking is better for sandstone, moderate for basalt, and inferior for granite in this study.

Exploration of microwave absorptivity and catalysis of CMF@Co-MoS2 for microwave-initiated depolymerization of lignin

Obtaining key platform chemicals from lignin is a sustainable refining concept of the non-petroleum route. Rapid pyrolysis is a potential refining technology, and microwave-assisted catalytic depolymerization with low energy consumption is preferred. Herein, we reported the strategy of microwave-initiated depolymerization using a self-designed dynamic vapor flow reaction system with a facilely prepared CMF@Co-MoS2-0.18 catalyst, achieving efficient conversion of lignin (Dealkalize) to monophenol. Under constant microwave irradiation (2.45 GHz), the CMF@Co-MoS2-0.18 catalyst had excellent dielectric properties (Dielectric loss factor: 0.56) and microwave heating properties (∼140 s rise to ∼ 600℃). Therefore, microwave-initiated depolymerization of lignin showed that the CMF@Co-MoS2-0.18 catalyst can improve the monophenol content (54.72 %) and phenol selectivity (35.84 %) under the synergistic effect of microwave absorptivity and catalysis. The reaction of the lignin model and kinetics analysis show that the CMF@Co-MoS2-0.18 catalyst increases the yield of monophenol by reducing depolymerization activation energy and selectively breaking the β-O-4 bond. The finite element analysis pointed out that under microwave irradiation, CMF@Co-MoS2-0.18 continuously conducted heat to lignin and the lignin vapor would have sufficient energy to collide with the catalyst active site at a high frequency, which led to an increase in the pre-exponential factor and initiated catalytic depolymerization lignin. In summary, we provide a potential pathway for the rapid conversion of lignin into key platform chemicals.

Microwave irradiation as an instrument for tuning of physicochemical and catalytic properties of MFe2O4 spinels

Microwave irradiation as an instrument for tuning of physicochemical and catalytic properties of MFe2O4 spinels

High-pressure CO2 adsorption on MCM-41: Efficiency of microwave-assisted synthesis

The rapid increase in atmospheric CO2 concentrations, driven by human activities, has become a critical factor in global climate change, posing severe risks to sustainable development. Addressing this challenge necessitates substantial CO2 removal, which demands innovative and efficient technologies. Carbon dioxide adsorption on porous materials is a promising strategy to mitigate this issue. This study investigates the synthesis of ordered mesoporous silica MCM-41 by microwave irradiation, a technique that offers significant advantages over conventional hydrothermal methods. By optimizing the synthesis conditions, we produced MCM-41 silica with superior structural properties in just 30 min. Characterization techniques, including X-ray diffraction, FTIR, N2 adsorption/desorption isotherms, and transmission electron microscopy, confirmed the formation of well-defined pores and hexagonal channels. Notably, the synthesized MCM-41 exhibited a high CO2 adsorption capacity of 12.78 mmol g−1 at 25 °C and 50 bar, outperforming silicas produced via conventional methods and comparable to amine-modified silicas. These results highlight the potential of microwave-assisted synthesis to improve CO2 capture efficiency, offering a promising approach for future carbon capture and storage applications.

Modified Microwave-assisted Solid-liquid Halex Reaction using Phosphonium Salt as Efficient and Robust Phase Transfer Catalyst

: A modified solid-liquid halex reaction was developed in the presence of a robust phase transfer catalyst under microwave conditions. A fast, mild, and practical microwave- assisted synthesis of 2,3-difluoro-5-chloropyridine 3 starting from 2,3,5- trichlorpyridine 1 and spray-dried KF in polar aprotic solvent was developed. The addition of Tetrakis (piperidino) phosphonium chloride as phase transfer catalyst A was studied under microwave irritation (450W) and increased the yield and significantly reduced the reaction time in contrast to the conventional heating procedure. The highest reaction rate was observed at 5 wt% phase transfer phosphonium salt catalyst to 2,3,5-trichloropyridine 1.

Ciprofloxacin degradation over Co3O4 catalysts by the microwave-assisted persulfate oxidation: a critical role of coordination composition

The combination of catalysts and microwave (MW) effects presents an emerging approach for persulfate (PS) activation, while the effect of active sites of catalysts on the synergistic reaction remains poorly understood. Here, we regulated the coordination composition of Co3O4 by strategically controlling the oxygen atmosphere during fabrication. We found that Co3+ and Co2+ acted as reactive centers for microwave absorption and catalytic activation of persulfate, respectively. By altering the ratio between Co3+ and Co2+, we explored the Co3O4 (2.23)-550 catalysts with significantly improved synergistic activity for degrading ciprofloxacin (CIP), which was 33.0 and 26.8 times higher than PS- Co3O4 (2.23)-550 (without microwave) and MW- Co3O4 (2.23)-550 (without persulfate), respectively. Meanwhile, Co3O4 (2.23)-550 catalyst (0.5mgL-1) showed the highest degradation rate of CIP 92.6% (0.5mgL-1) within 10min under microwave. According to the radical identification and intermediate analysis, the efficient degradation of CIP was ascribed to both free radical and non-free radical pathways. Thus, this work raises new insights into the structure-activity relationship of catalysts, and provides an efficient way to eliminate antibiotics via synergistic catalysis.

A novel mesoporous Bi2MoO6/g-C3N4 nanocomposite as an effective photocatalyst against toxic organic pollutants

This study used microwave irradiation technique to synthesize a sequence of Bi2MoO6@g-C3N4 nanocomposite as photocatalysts. The two narrow band gap nanomaterials used were g-C3N4 and Bi2MoO6. The nanocomposites were thoroughly characterized by XRD, FESEM, EDS, HRTEM, Raman spectroscopy, UV–visible spectra, PL and XPS. Moreover, using sunlight radiation, two distinct dyes including Malachite Green (MG) and Acid Blue 113 (AB 113) were degraded using as synthesized photocatalyst. The outcomes indicated that the photocatalytic degradation efficiency of Bi2MoO6@ g-C3N4 was higher than that of pure g-C3N4. A 95 % degradation efficiency towards Malachite Green and an 84 % degradation efficiency towards Acid Blue 113 shown the great effectiveness of Bi2MoO6@ g-C3N4. This enhanced efficiency is attributed to the increased visible light absorption, effective charge separation due to the heterojunction interface between Bi2MoO6 and g-C3N4, and the increased surface area facilitating greater active site availability. According to these results, the synthesized Bi2MoO6@ g-C3N4 would be very beneficial for the removal of organic contaminants in a variety of industrial environments.

Microwave assisted treatment of carpentry waste wood flour with natural deep eutectic solvents for nanocellulose production and removal of organic pollutants.

Row carpentry waste wood flour, constituted of poplar (∼60%) and fir (∼30%) biomass, was subjected for the first time to microwave-assisted deep eutectic solvent (DES) treatment, with the purposes of solubilizing lignin and hemicellulose, leaving cellulose as solid residue, thus performing a biorefinery. Several acidic (choline chloride/oxalic acid; choline chloride/citric acid; betaine hydrochloride/oxalic acid) and alkaline (urea/choline chloride; glycerol/K2CO3) DESs were employed under the same reaction conditions. Since the highest extraction yield was obtained by using choline chloride/oxalic acid DES, the use of the latter was investigated by varying some parameters (temperature, manner of microwave irradiation, addition of water) aiming at increasing the solubilization yield, which in fact in some cases reached satisfying values (60%) under mild conditions. The solid residues (SRs) recovered after all treatments with all tested DESs were characterized by Thermogravimetric Analysis (TGA), Attenuated Total Reflectance-Fourier Tranform Infrared Spectroscopy, Solid-State NMR Spectroscopy, and titration of surface acid groups. All SRs were also ultrasonicated to produce cellulose nanoparticles which were in turn characterised by transmission electron microscopy (TEM) and dynamic light scattering (DLS) analyses. In addition, the solid residues recovered from acidic DESs were able to decontaminate water from organic pollutants, such as p-nitrophenol, by an adsorption process. Thus, the proposed DES treatment efficiently converted carpentry waste wood flour into a valuable biomaterial useful for environmental decontamination.

A novel strategy for obtaining essential oil and flavonoids from Thymus vulgaris L. using polyethylene glycol-ultrasonic pretreatment followed by microwave hydrodistillation and extraction

As a medicinal plant with high economic value, the green and efficient separation of the main components (essential oil (EO) and flavonoids) from Thymus vulgaris L. can enhance its application prospects. The present study developed a polyethylene glycol-ultrasonic pretreatment followed by microwave hydrodistillation and extraction (PEG-U-MHDE) technique to distill EO and extract flavonoids simultaneously. The parameters involved in the PEG-ultrasonic pretreatment and microwave irradiation processes were investigated using single factor and BBD experiments, from which 25 % PEG200/400/600 (1:1:1, v/v/v) was found to have the highest extraction ability. Under the optimal conditions, the yield of EO, apigenin, and baicalein was 3.72 ± 0.15 μL/g, 0.76 ± 0.03 mg/g, and 0.96 ± 0.03 mg/g, respectively. The PEG-U-MHDE showed good stability, recovery, and repeatability for apigenin and baicalein. In addition, the separation efficiency of EO, apigenin, and baicalein obtained by PEG-U-MHDE was 0.19 μL/g/min, 37.85 μg/g/min, and 48.03 μg/g/min, respectively, and the EO contained 81.77 % oxygenated compounds, which were higher than other reference methods. The inhibition rate of EO (concentration of 0.5 μL/mL) against the agricultural pathogenic fungus (Fusarium graminearum) was 36.65 ± 1.28 %, which was speculated to be closely related to its main oxygenated compounds (thymol and carvacrol). In general, PEG-U-MHDE has the advantages of short time and high efficiency, and can realize the simultaneous separation of volatile EO and non-volatile components, which provides a theoretical basis for the comprehensive utilization of natural medicinal plants and crops.

Bifurcation and multi-stability analysis of microwave engineering systems: Insights from the Burger–Fisher equation

The present article depicts the research being done on the microwave effect realized by the often-used Burger-Fisher equation. A particular view is on the emergence of multi-stability and the bifurcations associated with microwave engineering systems. A novel rational, trigonometric, and hyperbolic form of the traveling waves is furnished by the resolution of the non-linear issue with the aid of the advanced exp (−Ψ(η))-expansion function parameterization. Firstly, we will solve the exact form of the Burger-Fisher equation, which clarifies the behavior of the equation in different conditions. Subsequently, bifurcation analysis techniques will be employed to study the nuanced relationship between the system parameters and the emergence of multistability phenomena. Through our results, we exposed the complicated essential features of microwave physics and established crucial parameters that determine a system’s behavior. Next, we cover control principle issues and practical applications in microwave engineering problems. This model accommodates the essential features of multi-stable dynamic systems and provides an important framework for creating microwave devices and circuits.The main aim of this research work is to analyze the phenomenon of multi-stability and bifurcation in microwave engineering systems by applying Burger-Fisher equation. The study intends to obtain new solutions to the PDEs through the application of a new method, the exp (−Ψ(η))-expansion function method that uses rational, trigonometric, and hyperbolic traveling wave solutions. Existing research of the Burger-Fisher equation is not explicit and by solving the exact form the research aims at exploring the different conditions under which the equation behaves and studying the delicate interactions between the parameters of the multistable system.

Rapid Immobilisation of Chemical Reactions in Alkali-Activated Materials Using Solely Microwave Irradiation

Efflorescence, a time-dependent and water-driven phenomenon, is a major concern in alkali-activated materials (AAMs), impacting their practical use and preservation in a time-frozen state for post-characterisation. Although a method for stopping chemical reactions in conventional cements exists, it is time-consuming and not chemical-free. Therefore, this study explored the effects of low-power microwave-induced dehydration on efflorescence, mechanical performance, and structural integrity in AAMs, to create an alternative and more “user-friendly” dehydration method. For this purpose, several mixtures based on secondary raw (slag, fly ash, glass wool, and rock wool) and non-waste (metakaolin) materials were activated with a commercial Na-silicate solution in ratios that promoted or prevented efflorescence. Characterisation techniques, including Fourier-transform infrared spectroscopy and X-ray diffraction, showed that microwave dehydration effectively removed water without altering crystallinity, while mercury intrusion porosimetry and compressive strength tests confirmed increased porosity. In addition to being an efficient, time-saving, and solvent-free manner of stopping the reactions in AAMs, microwave irradiation emerged as an innovative, chemical-free method for evaluating curing finalisation and engineering foams in a stage when all other existing methods fail. However, the artificially provoked efflorescence in aged dehydrated AAMs connected the slipperiness of AAM with the instant extraction of Na, which raised the need for further research into alternative alkali replacements to evaluate the practical use of AAM.

Microwave Irradiation-Assisted Synthesis of Anisotropic Crown Ether-Grafted Bamboo Pulp Aerogel as a Chelating Agent for Selective Adsorption of Heavy Metals (Mn+)

Crown ether is widely used in water purification because of its ring structure and good selective adsorption of specific heavy metals. However, its high cost and difficulty in recycling limit the purification of heavy metals in water. The anisotropic [2,4]-dibenzo-18-crown-6-modified bamboo pulp aerogel (DB18C6/PA) is successfully synthesized by microwave irradiation and directional freezing technology. The physical and chemical properties of DB18C6/PA are analyzed by FTIR, XPS, SEM, TEM, TGA, surface area and porosity analyzers. Single or multivariate systems containing Pb2+, Cu2+ and Cd2+ are used as adsorbents. The effects of the DB18C6 addition amount, pH, initial concentration and adsorption temperature on the adsorption of DB18C6/PA are systematically explored. Pseudo-first-order kinetic models, pseudo-second-order kinetic models and the isothermal adsorption models of Langmuir and Freundlich are used to fit the experimental data. The adsorption selectivity is analyzed from the distribution coefficient and the separation factor, and the adsorption mechanism is discussed. The results show that anisotropic DB18C6/PA has the characteristics of 3D directional channels, high porosity (97.67%), large specific surface area (103.7 m2/g), good thermal stability and regeneration (the number of cycles is greater than 5). The surface has a variety of functional groups, including a hydroxyl group, aldehyde group, ether bond, etc. In the single and multivariate systems of Pb2+, Cu2+ and Cd2+, the adsorption process of DB18C6/PA conforms to the pseudo-second-order kinetic model, and the results conform to the Freundlich adsorption isothermal model (a few of them conformed to the Langmuir adsorption isothermal model), indicating that chemical adsorption and physical adsorption are involved in the adsorption process, and the adsorption process is a spontaneous endothermic process. In the single solution system, the maximum adsorption capacities of Pb2+, Cu2+ and Cd2+ by DB18C6/PA are 129.15, 29.85 and 27.89 mg/g, respectively. The adsorption selectivity of DB18C6/PA on Pb2+, Cu2+ and Cd2+ is in the order of Pb2+ >> Cu2+ > Cd2+.