Separation Properties Research Articles

Development of a magnetic separation method for rapid isolation and enrichment of bacteria in raw pork using chitosan functionalized magnetic Fe3O4@MIL-100(Fe) composites.

In this study, a pretreatment method based on a magnetic capture probe for the rapid isolation and enrichment of bacteria from raw pork was developed. The chitosan immobilized Fe3O4@MIL-100(Fe) was prepared as a capture probe for total bacterial counts through the electrostatic interaction of positively charged chitosan and the negatively charged substances on the surface of bacteria. The interference of matrix in pork samples on this method was studied and removed by differential centrifugation. The results showed the capture probe had a great selectivity binding and magnetic separation properties for the tested six common bacteria in pork. Under the optimal conditions, the capture efficiency of the bacteria (105 CFU mL-1) from pork surface samples was all above 90%. The capture efficiency of the bacteria in a homogenate system was greatly decreased due to the interference of sarcoplasmic protein and myofibrillar protein in pork. The matrix effect was mitigated by a differential centrifugation method, and the capture efficiency of all six bacteria was >80%. The developed magnetic separation method took 40min and showed good isolation and enrichment properties of bacteria. Thus, the proposed method is expected to provide a simple, convenient, and time-saving pretreatment method for the detection of total bacterial counts in pork.

Imidazolium and pyridine bifunctionalized hypercrosslinked polymers as efficient and recyclable catalysts for CO2 cycloaddition

Converting CO2 into precious chemicals is considered to be a fundamental and effective tool for controlling the abundant CO2 emitted. One of the most compelling methods for CO2 conversion is the synthesis of cyclic carbonates by cycloaddition of CO2 with epoxides. However, the development of materials with specific functionalities for CO2 capture and conversion is still considered to be a significant challenge. Herein, a novel imidazolium salts and pyridine skeleton bifunctionalized hypercrosslinked polymers were prepared by FeCl3-catalyted Friedel-Crafts alkylation reaction. Various analytical techniques were used to investigate the properties of the catalysts. The bifunctionalized heterogeneous catalysts exhibited outstanding catalytic performances for CO2 cycloaddition under mild conditions with an excellent yield of up to 99 %. Besides, the catalyst could bear various epoxides and no significant loss of activity after 6 cycles. The properties of metal-free, solvent-free, cocatalyst-free, easy-to-prepare, mild conditions, facility separation and recyclability make the bifunctionalized hypercrosslinked polymers useful for CO2 cycloaddition.

Magnetic iron-based waterworks sludge modified by chitosan and FeS for aqueous Cr(vi) adsorption and reduction.

Heavy metals have been considered an evolving environmental concern due to their harmful and long-lasting impacts. We synthesized a composite of FeS/CS@MIBWS for aqueous Cr(vi) adsorption and reduction utilizing the iron-based waterworks sludge modified by chitosan and FeS. After determining the optimal conditions for the FeS/CS@MIBWS preparation, its Cr(vi) removal capability was evaluated using material characterisation and static Cr(vi) adsorption assays. Cr(vi) elimination by the composite was a pH-dependent process, with pH 2 being the optimum in the range of 2-10. The adsorption process was befitted a pseudo-second-order model, and the equilibrium results agreed well with the Langmuir model. The thermodynamics investigation showed that Cr(vi) removal by the composite has both spontaneous and endothermic nature. Considering the ionic effects, Cl-, SO4 2- and PO4 3- decreased Cr(vi) elimination in the sequence of Cl- < SO4 2- < PO4 3-. The key mechanisms for Cr(vi) elimination were physical and chemical adsorption, chelation, and Cr(vi) reduction into Cr(iii). Furthermore, FeS/CS@MIBWS demonstrated steady reusability (removal effectiveness of 70% after 5 cycles). FeS/CS@MIBWS's rapid, high-performance, reusable, and easily separable adsorption properties make it a promising choice for heavy metal environmental cleaning.

Uncovering the membrane and pore formation mechanisms of the lysozyme membrane made via the amyloid-like assembly

Biomimetic protein membranes have attracted increasing interests because of their distinctive separation properties in the membrane field. Low-cost and stable protein lysozyme has been intensively invetigated to fabricate high-performance sepration membranes via a facile and scalable method of amyloid-like assembly. However, the pore formation mechnism of the lysozyme membrane remains unclear. Herein, the lysozyme membranes were fabricated and the membrane formation mechnism and separation properties were investigated experimentally. Molecular dynamics simulation (MDS) was also employed to reveal the pore formation mechanism of the lysozyme membrane. The fabricated lysozyme membrane achieved a stable high water permeance of 10.2 L m−2 h−1 bar−1, as well as a relatively high separation factor (9.5) towards antibiotic and sodium chloride. MDS results found that the membrane pore size is governed by the amino acid compositions and is negatively dependent on the intermolecular forces among amino acids around the pores. Selective pores with 0.54 nm in diameter are primarily formed by these amino acids including alanine (35 %), aspartic acid (25 %), arginine (15 %), phenylalanine (11 %), and lysine (7 %), in which half of them have hydrophobic side chains with no charge, and another half have hydrophilic side chains with balanced charges. This work may stimulate the development of highly permeable and selective protein membranes by carefully engineering their amino acid compositions with optimal charges and hydrophobicity for generation of numerous selective pores.

INVESTIGATION OF USAGE OPPORTUNITIES OF DIFFERENT PROPORTIONS OF WHEY AND CHIA SEED FLOUR IN BUTTERMILK

In this study, it was aimed to obtain a functional beverage with high nutritional value by using whey and chia seed flour in the production of buttermilk. In addition to its high nutritional value, while preventing whey from causing environmental pollution as a waste material, it is aimed to obtain a new dietary product with chia seed flour containing 34-40g fiber per 100g, antioxidant, omega-3 fatty acid and rich protein content. Experimental buttermilk samples were prepared by adding whey (PAS) and chia seed flour at different rates. K (control group), K2 (%1 Chia seed meal), K3 (%0,5 Chia seed meal), Group 1 (25% Whey + %1 Chia seed meal), Group 2 (25% Whey + %0,5 Chia seed meal), 3. Group (50% Whey + %1 Chia seed meal), 4.Experimental groups prepared as a group (50% Whey + %0,5 Chia seed flour) were kept at +4 ̊C and their physical, chemical and sensory properties were examined on the 1st, 3rd, 5th, 7th and 14th days. In the experimental buttermilk samples we researched, the use of whey and chia seed flour was found to have a significant effect on psychrophilic bacteria count (log cfu/ml), coliform group bacteria (log cfu/ml), yeast-mold count (log cfu/ml), lactobacil spp. (log cfu/ml) and lactococ spp. (log cfu/ml), pH, acidity (lactic acid), water-soluble dry matter (%), serum separation (%), color values (L*, a*, b*) and sensory properties (p

High-efficiency photocatalytic H2-evolution in water/seawater over a novel noble metal free Ni3C/Mn0.5Cd0.5S Schottky junction

Solar-powered seawater production of clean hydrogen fuel is highly prospective. In this work, Ni3C/Mn0.5Cd0.5S (NCMCS) Schottky junctions with excellent visible-light correspondence and photogenerated carrier separation properties are constructed using electrostatic attraction. The material achieves a hydrogen evolution rate of 6472.9 μmol h−1 g−1 in simulated seawater, which is 11 times higher than that of a single Mn0.5Cd0.5S (MCS). More attractively, the composite exhibits excellent hydrogen evolution rates in natural river water, groundwater and tap water, with significantly enhanced practical applicability. The underlying hydrogen evolution mechanism was extrapolated from a combination of experimental and theoretical calculations. The present work provides a low-cost and efficient hydrogen evolution photocatalyst for practical application, which can help promote the efficient conversion of solar-hydrogen energy.

Planar Group Functionalization of Quasi-Discrete Pores in Metal-Organic Frameworks for Enhanced Isomeric Separation in Simulated Moving Bed Processes.

The efficient separation of 4-methyl-1-pentene (4MP1) from its structural isomers is crucial for industrial applications but remains challenging due to the similar physicochemical properties of these compounds. This study introduces a novel strategy using metal-organic frameworks (MOFs), specifically an engineered variant of ZIF-108, which demonstrates remarkable improvements in the thermodynamic and kinetic properties for 4MP1 separation. By substituting the methyl groups in ZIF-8 with planar nitro groups, we achieved a strategic resizing of the pore windows and cavity dimensions in ZIF-108. This adjustment not only enhanced the molecular affinity and selectivity toward 4MP1 but also facilitated a diffusion rate that is 164 times faster than that observed in ZIF-8. These properties significantly elevated the performance of ZIF-108 in simulated moving bed (SMB) processes, achieving up to 96.5% recovery of high-purity 4MP1, outperforming traditional adsorbents. Comprehensive characterization, including density functional theory (DFT) calculations and molecular dynamics (MD) simulations, provided insights into the interactions and the stability of the adsorption process. The findings suggest that the strategic modification of the pore architecture in MOFs holds significant potential for optimizing the separation processes of industrially relevant mixtures.

Effect of anionic groups in zwitterionic hydrophilic stationary phases on their chromatographic characteristics

The structure of zwitterion has great impact on the separation properties of zwitterionic hydrophilic stationary phases. To better understand the role of anionic groups of zwitterions, a novel carboxybetaine-based zwitterionic monolithic column was first prepared through thermo-initiated copolymerization of functional monomer (3-acrylamidopropyl)-dimethyl-(2-carboxymethyl) ammonium (CBAA) and crosslinker ethylene dimethacrylate (EDMA) within 100 μm ID capillary. The optimal poly(CBAA-co-EDMA) monolithic column exhibited satisfactory mechanical and chemical stability, good repeatability, high column efficiency (96,000 plates/m), and excellent separation performance for different classes of polar compounds (i.e., phenols, monophosphate nucleotides, urea and allantoin). A comparative study was then performed among three zwitterionic hydrophilic stationary phases containing different anionic groups, i.e. poly(CBAA-co-EDMA) (carboxybetaine), poly(2-{2-(methacryloyloxy) ethyldimethylammonium}ethyl n-butyl phosphate-co-EDMA) (phosphocholine), and poly(N,N-dimethyl-N-(3-methacrylamidopropyl)-N-(3-sulfopropyl) ammonium betaine-co-EDMA) (sulfobetaine) using benzoic acid derivatives, amine compounds, nucleobases and nucleosides as model analytes. The carboxybetaine-based monolithic column exhibited much higher positive zeta-potential and hydrophilicity, which endows it with a stronger retention capacity for acidic and neutral compounds, but sulfobetaine-based monolithic column exhibited much higher selectivity and retention capacity for the amines. Moreover, their enrichment efficiencies for N-glycopeptides were also evaluated based on their different hydrophilicity, and it was observed that the poly(CBAA-co-EDMA) monolithic material captured 4-8 times more N-glycopeptides compared to the other two materials.

Reinforced facilitated transport PEBA membrane by 2D Fe-doped TiO2 macroporous nanosheets for CO2 separation: Utilizing cationic and non-ionic surfactants

In this study, macroporous nanosheets of 2D Fe-Doped TiO2 were synthesized, and subsequently, membranes composed of polyether block amide (PEBA) were prepared. These membranes were incorporated with the nanosheets mentioned above, as well as two distinct types of surfactant. The structure and gas separation properties of the membranes were studied using different methods, including atomic force microscopy (AFM), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), as well as gas permeation analyses and tensile test. The findings indicated that the nanosheets underwent a porous transformation following the doping process. This occurrence improved the bonding between the nanosheets and PEBA chains, consequently boosting the mechanical strength of the membranes embedded with these nanosheets. Incorporating these nanosheets into the membrane (4 wt%) established a more efficient facilitated transport mechanism via Lewis acid centers, resulting in a 12.5 % increase in CO2 permeability and a 136 % rise in the selectivity of CO2/N2 compared to the pure PEBA membrane. Two different surfactants were introduced to the PEBA/FeTiO2 matrix, resulting in varying impacts on membrane structure and performance. The Cetyl trimethyl ammonium bromide (CTAB) as a cationic surfactant led to membrane stiffening and a significant 241 % enhancement in CO2/N2 selectivity at 1 wt%. On the other hand, the Polysorbat (Tween) as a non-ionic surfactant softened the membrane and boosted CO2 permeability by 53 % at 6 wt% compared to the pure membrane.

Disruption of nuclear speckle integrity dysregulates RNA splicing in C9ORF72-FTD/ALS

Expansion of an intronic (GGGGCC)n repeat within the C9ORF72 gene is the most common genetic cause of both frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) (C9-FTD/ALS), characterized with aberrant repeat RNA foci and noncanonical translation-produced dipeptide repeat (DPR) protein inclusions. Here, we elucidate that the (GGGGCC)n repeat RNA co-localizes with nuclear speckles and alters their phase separation properties and granule dynamics. Moreover, the essential nuclear speckle scaffold protein SRRM2 is sequestered into the poly-GR cytoplasmic inclusions in the C9-FTD/ALS mouse model and patient postmortem tissues, exacerbating the nuclear speckle dysfunction. Impaired nuclear speckle integrity induces global exon skipping and intron retention in human iPSC-derived neurons and causes neuronal toxicity. Similar alternative splicing changes can be found in C9-FTD/ALS patient postmortem tissues. This work identified novel molecular mechanisms of global RNA splicing defects caused by impaired nuclear speckle function in C9-FTD/ALS and revealed novel potential biomarkers or therapeutic targets.

Adsorption of ionic contaminants from complex water matrices by versatile chitosan-based beads

Most adsorbents are currently restricted by their single function in pollutant removal from complex wastewater. Herein, we constructed a versatile chitosan-based adsorbent (MC-DA) by grafting amphoteric copolymers with high pH-responsiveness property, aiming at the removal of multiple ionic contaminants. Specifically, the surface charge and hydrophobicity/hydrophilicity of MC-DA can be finely tuned under different pH conditions. As a result, the effective adsorption of cationic methylene blue (MB) and anionic Acid Orange 7 (AO7) with capacities of 627.4 mg/g and 1146.8 mg/g were achieved respectively, superior to most reported materials. Regarding the characterization results, the adsorption mechanisms for MB adsorption were electrostatic and hydrophobic interactions, while the electrostatic attraction was the main driving force for AO7 adsorption. Apart from the versatile adsorption performance, high acid resistance (pH ≥ 2.0), good reusability and rapid separation property under an external magnetic field suggested MC-DA’s promising environmental benefits and practical application potential in water remediation.

Ultrathin titanium carbide-modified separator for high-performance lithium–sulfur batteries

Despite a high theoretical capacity, the practical application of lithium-sulfur batteries has been primarily limited by the migration of long-chained polysulfide species during the charge/discharge processes. One effective approach to address the issues is to design a functional separator or interlayer. Here, we prepared a modified separator with an ultrathin layer of titanium carbide (TiC) using radio-frequency sputtering on a commercial Celgard polypropylene membrane. The 240-nm TiC coating layer can enhance the interfacial properties of Celgard separators in porosity, wettability, roughness, etc. Hence, via experimental and theoretical investigation, we discovered that TiC can efficiently adsorb polysulfides and boost charge transfer via strong covalent C–S bonds. Using a TiC-modified separator can impede the shuttle effect and improve the kinetics of sulfur conversion reactions. Thus, the Li–S batteries with TiC separator deliver excellent electrochemical performances with a good rate capability (717 mAh g−1 at 7.0C) and an ultra-low decay rate of 0.058 % per cycle over 800 cycles at a C-rate of 2.0C. Furthermore, a high areal capacity of 4.3 mAh cm−2 was achieved with a high mass-loading of sulfur cathode up to 7.0 mg cm−2.

Composite organic ionic plastic crystal membranes: The effect of ether-functionalized cations on light-gas separation performance

In light of increasing concerns about climate change, there is a growing need for innovative solutions to address CO2 emissions. Addressing this urgency, this work presents a unique approach to CO2 separation utilizing composite membranes of organic ionic plastic crystals (OIPCs) with ether-functionalized cations and poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Here we report the gas separation performance of OIPC-based membranes of 3,3-dimethyloxazolidinium [C1moxa]+, 4-ethyl-4-methylmorpholinium [C2mmor]+ and 4-isopropyl-4-methylmorpholinium [Ci3mmor]+ cations paired with the bis(fluorosulfonyl)imide [FSI]- anion. These composites demonstrated very good gas separation properties, especially [C1moxa][FSI] which produced a permeability of 63 barrer for CO2 and an overall selectivity (CO2/N2) of 205, which is the highest amongst all the OIPCs reported so far. Additionally, a large change in separation performance was observed for the [Ci3mmor][FSI] membrane upon heating above the solid-solid phase transition (II - I) at 48 °C; the CO2 permeability increased from 7 to 163 barrer and an approximately 3-fold increase in selectivity was observed. These findings advance the design of composite membranes based on OIPCs towards increased selectivity and sustained effectiveness in the separation of light gases.

Functionalized Triblock Copolymers with Tapered Design for Anion Exchange Membrane Fuel Cells.

Triblock copolymers such as styrene-b-(ethylene-co-butylene)-b-styrene (SEBS) have been widely used as an anion exchange membrane for fuel cells due to their phase separation properties. However, modifying the polymer architecture for optimized membrane properties is still challenging. This research develops a strategy to control the membrane morphology based on quaternized SEBS (SEBS-Q) by dual-tapering the interfacial block sequences. The structural and transport properties of SEBS-Q with various tapering styles at different hydration levels are systematically investigated by coarse-grained molecular simulations. The results show that the introduction of the tapered regions induces the formation of a bicontinuous water domain and promotes the diffusivity of the mobile components. The interplay between the solvation of the quaternary groups and the tapered fraction determines the conformation of polymer chains among the hydrophobic-hydrophilic subdomains. The strategy presented here provides a new path to fabricating fuel cell membranes with controlled microstructures.

Superhydrophobic cellulose-nanofiber aerogels from waste cotton stalks for superior oil–water and emulsion separation

Cellulose aerogel, a sustainable material characterized by low density and high porosity, demonstrates promising potential for addressing oil spill incidents. In this study, waste cotton stalk biomass was processed using formic acid and hydrogen peroxide to extract cellulose, resulting in the successful creation of a cost-effective aerogel. This material exhibits notable attributes: low density (21.1 mg cm−3), high porosity (91.5%), significant hydrophobicity (water contact angle of 147°), exceptional adsorption capacity (47.61 g g−1), and robust cycling performance (maintaining 94% adsorption capacity after 15 cycles). Moreover, the CNF/CS biomass aerogel boasts high mechanical strength and exceptional oil–water and emulsion separation properties. These characteristics position this aerogel as a promising solution for mitigating various sudden oil spill incidents, indicating its potential for widespread application.

Efficient hydrogen production performance of 1T-2H MoSe2/ MnxCd1-xS Z-type heterojunction photocatalysts under visible light

Finding suitable co-catalysts to help metal sulfides achieve effective bulk phase and surface charge separation is the key to improving their photocatalytic performance. In this paper, two-phase 1T-2H MoSe2 was loaded onto the surface of Mn0.4Cd0.6S solid solution with a twin crystal structure, and the 1T-2H MoSe2/Mn0.4Cd0.6S Z-type heterojunction structure was successfully constructed to realize the high efficiency of hydrogen production in the visible light. The metallic properties of the 1T phase can significantly improve the catalytic activity of MoSe2. The transition from the 2H to the 1T phase can lead to the creation of extra defects, such as unsaturated Mo and Se, thereby increasing the number of active sites on the photocatalyst surface. The two crystalline phases are staggered and form homogeneous junctions within them in the twin crystalline structure Mn0.4Cd0.6S prepared under an alkaline environment, which gives it excellent bulk and charge separation properties. After loading, the 1T phase MoSe2 at the interface of MoSe2 and Mn0.4Cd0.6S can accelerate the charge separation between the interfaces, and the Z-type heterojunctions formed by the two and the better retention of useful excitation electrons and holes. The 1% 1T-2H MoSe2/Mn0.4Cd0.6S could achieve a notable hydrogen production rate of 12.34 mmol ∙ g−1∙ h−1, surpassing that of the Mn0.4Cd0.6S solid solution. This non-precious metal-loaded homojunction photocatalyst effectively harnesses solar energy to produce clean H2 under mild conditions, giving a promising prospect for practical applications and laying the groundwork for further exploration of MnxCd1-xS photocatalysts.

Huge improved gas separation performance of carbon molecular sieve membrane by forming a double crosslinked polyimide precursor

A vital issue in searching for advanced gas separation membranes is understanding the precursor structure-gas separation properties of carbon molecular sieve (CMS) membranes. Here, we reported two crosslinked polyimides and used as CMS precursors, in which, the DCPI-4 is a double cross-linkable polyimide with 4 % triptycene triamine as a crosslinker (Type I) and COOH group that can be crosslinked at 350 °C by decarboxylation (Type II), whereas the DCPI-0 with COOH (Type II). After pyrolysis at 550 °C, the DCPI-4-CMS showed a higher SBET (812 vs 713 m2g-1), larger ultra-microporosity ratio (26.6 % vs 17.8 %), larger d-spacing (4.08 vs 3.94 Å), less graphitization (sp3/sp2 of 0.156 vs 0.118), 5.5 times higher CO2 permeability (7573 vs 1391 Barrer) and same CO2/CH4 selectivity (∼62) than DCPI-0-CMS. We consider this is due to the type I crosslinking enhances the rigidity of the polyimide backbone, and inhibits the collapse of micropores during the carbonization, which causes improved ultra-microporosity and ultra-micropore ratio that both enhances the gas diffusion and solubility coefficient as well activation energy difference of gas pairs. Conclusively, this double crosslinking method provides a good perspective for achieving CMS membranes with excellent gas separation performance.

Asymptotic behaviour of a phase field system derived from a generalization of Maxwell–Cattaneo’s law with a singular potential

Abstract In this paper, we study the asymptotic behaviour of a Caginalp-type phase field system derived from a heat conduction law which is a generalization of the Maxwell–Cattanéo law and whose potential is singular. This type of law has the advantage of correcting the paradox of heat conduction that appears when the Fourier law is considered. The potential considered is typically logarithmic. Using such a potential makes the model much more relevant from a physical point of view. However, from a theoretical point of view, it is essential to obtain the strict separation property of the phase field in order to give sense of the equations. We first prove the existence and uniqueness of the solution thanks to the separation property. We also address the question of the dissipativity of the system. Finally, we obtain the existence of the global attractor.

The Legal Certainty no Longer Applies to a Nation's Wealth that Has Been Transferred to a State-Owned Enterprise (BUMN)

The inclusion of Separated State Wealth within the scope of State Finance remains an interesting issue to study. The law enforcement agency (APH) has a different view when dealing with cases involving separate State Property Managers. The entire entity in which there is Separated State Property is considered to be BUMN. Separate State Properties held at the International Financial Institution are not touched by the APH. This shows the inconsistency and the minimality of understanding of the BOMN. This situation is becoming more complex due to the disharmonization of various regulations relating to Separation State Properties. Article 2 of Act No. 28 of 1999 on the Maintenance of a State Clean and Free from Corruption, Collusion, and Nepotism states that the Directorate is the Organizer of the State. General Explanation of Law No. 31 of 1999 extends the meaning of “Civil Public Officer, that is, the person who receives salary, salary from a corporation that uses the capital/facilities of the state or society. It is difficult for a profit-seeking director to perform his duties properly if he is embedded in the status of State Organizer and PNS as it is in the Ministry/State Authority. The research was conducted using a method of normative jurisprudence, i.e. testing and using secondary data to obtain clarity of the problem. Disharmonization of various regulations and the minimum understanding of APH in dealing with issues of Separated State Property creates legal uncertainty.

A Theoretical Study on the Influence of Five- and Six-Membered N-Heterocyclic Ring Side Chains of the N-Donor Extractants on Am(III)/Eu(III) Extraction and Separation.

According to the green development requirements of carbon neutrality and carbon peaking, the effective separation of lanthanides and actinides is one of the key factors for nuclear energy to become a sustainable energy source. In recent years, o-phenanthroline-based ligands have been proven to be effective in the separation of lanthanides and actinides. In this work, based on 5,9b-dihydro-4aH-cyclopenta[1,2-b:5,4-b']dipyridines, we designed six N-heterocyclic ring ligands and theoretically studied their extraction capacity and separation selectivity for the Am(III) and Eu(III) ions. Various theoretical methods were used to analyze the properties of the ligands and study the bonding nature of the ligands with the metal ions. Thermodynamic parameters were calculated to measure the extraction ability of the ligands to the metal ions and to explore the separation capacity of the ligand for the Am(III) and Eu(III) ions. The calculated results show that the five- and six-membered N-heterocyclic ring side chains of the ligands and the distribution of the N atoms on the side chain rings have obvious effects on the bonding of the ligands to metal ions and on the extraction and separation properties of the ligands for the metal ions. It was found that the extractants with six-membered ring side chains possess an extraction ability slightly better than that of the ligands with five-membered ring side chains and that the ligands with a pair of adjacent N atoms on the side chains have a stronger separation selectivity for the Am(III)/Eu(III) ions. The theoretical research in this work will help to understand the details of binding and extraction properties of similar ligands and provide insights for the future design of five- and six-membered heterocyclic ligands.