A robust computational investigation on C60 fullerene nanostructure as a novel sensor to detect SCN−

This study explored on the adsorption properties and electronic structure of SCN^? via density functional theory analysis on the exterior surfaces of C₆₀ and CNTs using B3LYP functional and 6-31G** standard basis set. Then adsorption of SCN^? through nitrogen atom on the C₆₀ fullerene is electrostatic (?48.02 kJ mol^?1) in comparison with the C₅₉Al fullerene that shows covalently attached to fullerene surface (?389.10 kJ mol^?1). Our calculations demonstrate that the SCN^? adsorption on the pristine and Al-doped single-walled CNTs are ?173.13 and ?334.43 kJ mol^?1, indicating that the SCN^? can be chemically bonded on the surface of Al-doped CNTs. Moreover, the adsorption of SCN^? on the C₆₀ surface is weaker in comparison with C₅₉B, C₅₉Al, and C₅₉Ga systems but its electronic sensitivity improved in comparison with those of C₅₉B, C₅₉Al, and C₅₉Ga fullerenes. The evaluation of adsorption energy, energy gap, and dipole moment demonstrates that the pure fullerene can be exploited in the design practice as an SCN^? sensor and C₅₉Al can be used for SCN^? removal applications.     

Comparative study on ciprofloxacin removal in sulfur-mediated biological systems

The removal of ciprofloxacin(CIP) in sulfur-mediated bio processes,e.g.,sulfate-reducing bacteria(SRB)-mediated process and sulfur-oxidizing bacteria(SOB)-mediated process,was examined for the first time.The results showed that the SRB-mediated process had more efficient CIP removal than that in SOB-mediated process.Adsorption was the primary removal pathway of CIP in SRB-mediated process and SOB-mediated process with the specific adsorption removal rate of 131.4±1.1 μg/g-SS/d and30.1±1.4 μg/g-SS/d,respectively,at influent CIP concentration of 500 μg/L.In addition,extracellular polymeric substances(EPS) also played an important role on CIP migration and removal in both types of sludge.Further study was conducted to specify the different adsorption of CIP in these two sludge systems from the perspective of sludge properties.The results indicated that there are more potential adsorption sites exist on the SRB-mediated sludge for CIP adsorption than SOB-mediated sludge since the higher protein(PN) content and more kinds of aromatic amino acid substances in EPS,more negative zeta-potential and stronger and more numbers of functional groups in SRB-mediated sludge compared to SOB-mediated sludge.The findings of this study provide insights into the sludge properties affecting CIP removal in sulfur-mediated bioprocesses,and are of guiding significance to employ sulfur-mediated biological systems for treating CIP-containing wastewaters.     

Adsorption kinetics,isotherms and mechanisms of three-component covalent organic polymer/sodium alginate beads for ciprofloxacin removal from aqueous solution

Ciprofloxacin (CIP), an important representative fluoroquinolone antibiotic, has been frequently detected in water sources, thus threatening aquatic organisms and human health. In this work, a porous three-component covalent organic polymer (SLEL-6) was synthesized through multi-component (MC) reaction systems for adsorptive removal of CIP from aqueous solution, followed by an encapsulation process to achieve SLEL-6/sodium alginate (SA) beads with boosted adsorption ability, reusability and recyclability. By virtue of the hierarchical porous natures, functional groups as well as π-rich skeletons, SLEL-6 and SLEL-6/SA beads could deal with CIP contamination effectively. Moreover, the adsorption isotherms of CIP by SLEL-6 and SLEL-6/SA beads follow the Langmuir model showing high theoretical maximum adsorption capacities of 57.47 and 163.93 mg g⁻¹, respectively. Furthermore, the plausible mechanisms are proposed according to experimental studies of influencing factors, coupled with characterizations before and after adsorption. This work therefore highlighting the immense potential of COP-based SA composite beads as new-type globular adsorbents for eliminating fluoroquinolones from aqueous solution.     

Effective removal of ciprofloxacin from aqueous solutions using magnetic metal–organic framework sorbents: mechanisms,isotherms and kinetics

Metal–organic framework sorbents [MIL-100(Fe), MOF-235(Fe)], Fe₃O₄ nanoparticles and metal–organic framework loaded on iron oxide nanoparticles [Fe₃O₄@MIL-100(Fe) and Fe₃O₄@MOF-235(Fe)] were prepared and examined for ciprofloxacin (CIP) removal. The results showed that sorption kinetics of CIP by Fe₃O₄@MIL-100(Fe) follows the Elovich and pseudo-second-order models indicating that the sorption is both chemisorption and physical adsorption, whereas the sorption to other sorbents occurs mainly by physical sorption. The sorption isotherm studies revealed that Langmuir model provided the best fit to all the experimental data. The thermodynamic studies showed that CIP removal is spontaneous (ΔG° = 2.28 kJ/mol) and endothermic (ΔH° = 18.39 kJ/mol). It was also found that among the sorbents investigated for CIP removal, Fe₃O₄@MIL-100(Fe) has the highest maximum monolayer adsorption capacity of 322.58 mg/g.     

Magnetic Fe3O4/ZIF-8 optimization by Box-Behnken design and its Cd(II)-adsorption properties and mechanism

In this study, the preparation of magnetic Fe₃O₄/ZIF-8 (MFZ) and its adsorption properties for Cd(II) from water were investigated. Various characterizations demonstrate that the as-prepared MFZ has well magnetic-separation performance and thermal stability. In batch adsorption tests, the effects of pH, initial concentration, and adsorbent dosage were evaluated. According to the findings, when the pH is 7 and the dosage is 150 mg/L, the adsorption capacity for a 40 mg/L Cd(II) solution reaches 102.3 mg/g in 180 min. The Cd(II) adsorption processes was found to correspond to pseudo-first-order kinetics and Langmuir model according to the adsorption kinetics and isotherms. The Langmuir model predicted a maximal saturation adsorption capacity of 160.26 mg/g at 298 K. Thermodynamic analysis revealed that the Cd(II) adsorption is an endothermic, spontaneous process. Ion exchange, coordination reaction, and electrostatic interaction are all involved in Cd(II) adsorption by MFZ. The optimum conditions for Cd(II) adsorption were proposed and confirmed in accordance with the results of the response surface optimization experiments. Furthermore, regeneration tests demonstrate the great repeated regeneration ability of MFZ. According to the anticipated production cost, treating wastewater with a Cd(II) concentration of 40 mg/L would cost roughly US$ 8.35/m³. MFZ showed good potential for Cd(II) removal from water.     

Zr-Based MOFs with High Drug Loading for Adsorption Removal of Anti-Cancer Drugs: A Potential Drug Storage

A robust and highly water stable series of UiO-66-drived MOFs including UiO-66-NH₂, glycidyl methacrylate functionalized UiO-66-NH₂ (UiO-66-GMA) and ethylenediamine functionalized UiO-66-NH₂ (UiO-66-EDA) were synthesized solvothermally and studied their adsorption performances toward two anti-cancer drugs, methotrexate (MTX) and curcumin (CUR) in the case of overdose. It was found that functionalizing the surface of UiO-66-NH₂ nanoparticles with different functional groups remarkably changes the adsorption capacity and the ideal adsorption selectivity of MTX over CUR. Particularly, the UiO-66-EDA exhibited the highest adsorption capacities for both drugs, 540.78 and 423.85 mg/g for MTX and CUR, respectively, because of the strong interaction between drug molecules and adsorbent via hydrogen bonding due to the existence of different polar functional groups. The kinetics of drugs adsorption was investigated by three well-known kinetic models, which the output indicates that the adsorption of both drugs onto the synthesized MOFs follow the pseudo-second-order model. Moreover, it was found that the equilibrium adsorption results were well fitted with the Langmuir isotherm models, revealing that the adsorption of both drugs onto the synthesized MOFs is a monolayer adsorption process. Further investigation illustrated that the synthesized MOFs could be easily activated and reused after four successive adsorption–desorption cycles. The output of the present work is of main important for biomedical and environmental applications of MOFs as an outstanding adsorbent for adsorption removal of hazardous drugs from contaminated aqueous solutions.     

Polyamine chitosan adsorbent for the enhanced adsorption of anionic dyes from water

A simple synthesis route for amine protected-introduced-released chitosan (APIR-CS) was investigated to improve the adsorption of anionic dyes. The C₂ amine groups of the chitosan (CS) were initially protected via a Schiff-base reaction by benzaldehyde. They were then synthesized by the introduction of ethylenediamine into C₆ hydroxyl groups on CS via epichlorohydrin. The final product was obtained after removal of the Schiff base with dilute hydrochloride solution. Amine-introduced chitosan (AI-CS) was directly synthesized at the C₂ amine groups. The adsorbents were characterized by FTIR, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). For Congo red (CR) and methyl orange (MO), most of the amine groups in CS were converted to–N?CH₂ groups after the benzaldehyde treatment. Hydrochloric acid treatment after the cross-linking reaction released protected nitrogen atoms into the form of the primary amine again. APIR-CS had significantly greater adsorption capacities than AI-CS. The increased adsorption performance was attributed to the large number of primary amine groups on the surfaces. The adsorption mechanism was based on electrostatic interaction, while the adsorption process was mainly physisorption.     

Nanostructured spinel-type M(M = Mg,Co, Zn)Cr2O4 oxides: novel adsorbents for aqueous Congo red removal

Nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides with novel adsorbents for aqueous Congo red removal were synthesized by a polyacrylamide gel method and studied for their phase structure, microstructure, adsorption performance, and multiferroic behavior. The phase structure and purity analysis revealed that the nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides presented a spinel-type cubic structure, and the formation of a secondary phase such as Cr₂O₃, MgO, ZnO, or Co₃O₄ was not observed. The microstructure characterization confirmed that the spinel-type MCr₂O₄ oxides grew from fine spherical particles to large rhomboid particles. Adsorption experiments of spinel-type MCr₂O₄ oxides for adsorption of Congo red dye were fitted well with the pseudo-second-order kinetics. The adsorption capacity of the ZnCr₂O₄ oxide (44.038 mg/g, pH 7, temperature 28 °C, initial dye concentration 30 mg/L) was found to be higher than that of MgCr₂O₄ oxide (43.592 mg/g, pH 7, temperature 28 °C) and CoCr₂O₄ oxide (28.718 mg/g, pH 7, temperature 28 °C). The effects of initial adsorbent concentration, initial dye concentration, pH, and temperature between the ZnCr₂O₄ oxide and Congo red dye at which optimal removal occurs, were performed. The thermodynamic studies confirmed that a high temperature favors the adsorption of Congo red dye onto ZnCr₂O₄ oxide studied. The nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides that exhibited high adsorption performance for adsorption of Congo red dye can be ascribed to the synergistic effect of electrostatic interaction, pore filling, and ion exchange. The present work suggested that the nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides have excellent adsorption performance and multiferroic behavior, which shows potential applications for removal of the Congo red dye from wastewater, magnetic memory recording media, magnetic sensor, energy collection and conversion device, and read/write memory.     

Simultaneous adsorption of tetracycline,amoxicillin, and ciprofloxacin by pistachio shell powder coated with zinc oxide nanoparticles

A new adsorbent formed from pistachio shell powder that was coated with ZnO nanoparticles (CPS) was examined in terms of simultaneous adsorption of tetracycline (TEC), amoxicillin (AMO), and ciprofloxacin (CIP) from an aqueous solution. Initially, the characterization properties of a CPS-like surface morphology, functional groups, and structure were obtained using advanced analysis of TEM, SEM, XRD, EDS, and FT-IR. Post coating with ZnO nanoparticles, several surface and structural characteristics relating to the adsorption ability of the pistachio shell were significantly improved. The correlation of the kinetic data by a pseudo second-order model was successful for three antibiotics. High compatibility resulted between the TEC and CIP isotherm data and the Fruendlich model. However, the Langmuir model produced a better fit to the AMO isotherm curves. In addition, its spontaneous and exothermic nature was the main feature for the adsorption process of the three antibiotics onto CPS. Through the results, the chemical adsorption has been governed by the AMO, CIP, and TEC reaction onto the homogeneous and heterogeneous sites of CPS surfaces. The CPS exhibited a highest adsorption capacity for AMO (132.240 mg/g), then for TEC (98.717 mg/g), and CIP (92.450 mg/g). These results place CPS one among the highly efficient adsorbents that can be used to eradicate wastewater containing antibiotics.     

Preparation and Pb (II) adsorption in aqueous of 2D/2D g‐C3N4/MnO2 composite

A novel g‐C₃N₄/MnO₂ composite was prepared by in situ deposition of MnO₂ on graphitic carbon nitride (g‐C₃N₄) nanosheets, and its adsorption properties were evaluated for removal of Pb (II) in aqueous. Fourier transform‐infrared, spectrometer scanning electron microscopy and transmission electron microscopy characterization showed the g‐C₃N₄/MnO₂ composite had a two‐dimensional/two‐dimensional (2D/2D) structure with ample active sites. The Brunauer–Emmett–Teller specific surface area of g‐C₃N₄/MnO₂ composites (234.9 m²/g) was 13.5 times larger than that of g‐C₃N₄ (17.37 m²/g), providing better conditions for adsorption. The adsorption kinetic data were better fitted with the pseudo‐second‐order model. The Langmuir model was more suitable for describing the experimental equilibrium data of g‐C₃N₄/MnO₂, and the maximum adsorption capacity was 204.1 mg/g for Pb (II). The adsorption of g‐C₃N₄/MnO₂ composite for Pb (II) was an endothermic and spontaneous process, and reached adsorption equilibrium rapidly within initial 150 min. This composite was an excellent adsorbent because of its higher adsorption capacity and facile preparation progress.     

Nitrogen-rich carbon nitrogen polymers for enhancing the sorption of uranyl

Nitrogen enrichment and increased nitrogen content is an effective strategy for enhancing adsorption of uranium by carbon nitride polymers. Herein, we reported the uranium absorption by using a structurally well-defined and nitrogen-rich carbon nitride polymer with C₃N₅ stoichiometry for the first time. In comparison with the adsorption performance of g-C₃N₄ for U(VI), the conjugation system of the material was increased by connecting the heptazine unit through the azo bridge in the structure of C₃N₅, so that C₃N₅ exhibited several times higher adsorption performance than that of g-C₃N₄. The C₃N₅ has high kinetics for uranyl ions, which can adsorb 100 mg/g U(VI) in only 10 min and reach complete adsorption equilibrium in 60 min; the theoretical maximum adsorption capacity is 207 mg/g, meanwhile, the material exhibits high selectivity. The results of spectral analysis and theoretical calculations indicate that the process of uranyl ion capture by C₃N₅ is a combination of physical and chemical adsorption, and its higher density of electronic states makes the electrostatic binding ability enhanced, which is favorable to the adsorption of uranyl ions by C₃N₅. This work indicates that C₃N₅ has great promise and application in the separation and enrichment of uranyl ions, and also provides a reference for the systematic investigation of the adsorption ability of nitrogen-rich carbon nitrogen polymers on uranyl ions.     

Mixed phase Fe2O3/Mn3O4 magnetic nanocomposite for enhanced adsorption of methyl orange dye: Neural network modeling and response surface methodology optimization

In this research, a novel magnetic mesoporous adsorbent with mixed phase of Fe₂O₃/Mn₃O₄ nanocomposite was prepared by a facile precipitating method and characterized extensively. The prepared nanocomposite was used as adsorbent for toxic methyl orange (MO) dye removal from aqua matrix considering its high surface area (178.27 m²/g) with high saturation magnetization (23.07 emu/g). Maximum dye adsorption occurs at solution pH 2.0 and the electrostatic attraction between anionic form of MO dye molecules and the positively charged nanocomposite surface is the main driving force behind this adsorption. Response surface methodology (RSM) was used for optimizing the process variables and maximum MO removal of 97.67% is obtained at optimum experimental condition with contact time, adsorbent dose and initial MO dye concentration of 45 min, 0.87 g/l and 116 mg/l, respectively. Artificial neural network (ANN) model with optimum topology of 3–5–1 was developed for predicting the MO removal (%), which has shown higher predictive ability than RSM model. Maximum adsorption capacity of this nanocomposite was found to be 322.58 mg/g from Langmuir isotherm model. Kinetic studies reveal the applicability of second‐order kinetic model with contribution of intra‐particle diffusion in this process.     

Rapid removal of anionic organic dye from contaminated water using a poly(3-aminobenzoic acid/graphene oxide/cobalt ferrite) nanocomposite low-cost adsorbent via adsorption techniques

This research study aims to remove hazardous anionic azo dyes (Congo red (CR)) from aqueous solutions via a simple adsorption method using a poly(3-aminobenzoic acid/graphene oxide/cobalt ferrite) nanocomposite (P3ABA/GO/CoFe₂O₄) as a novel and low-cost nanoadsorbent, as synthesized by a simple and straightforward polymerization method. Typically, 3-aminobenzoic acid (3ABA), as monomer, was chemically polymerized with graphene oxide (GO) and cobalt ferrite (CoFe₂O₄) in an aqueous acidic medium containing an ammonium persulfate initiator. The adsorbent P3ABA/GO/CoFe₂O₄ nanocomposite was characterized using various techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, energy-dispersive analysis by X-ray and Brunauer–Emmett–Teller, vibrating sample magnetometer, and zeta potential techniques. These techniques confirmed the interaction between the poly(3-aminobenzoic acid) with GO and CoFe₂O₄ due to the presence of π-π interactions, hydrogen bonding, and electrostatic forces. Herein, the removal efficiency of dye from aqueous solution by the adsorbent was studied according to several parameters such as the pH of the solution, dye concentration, dosage of adsorbent, contact time, and temperature. The adsorption of the dye was fitted using a Langmuir model (R² between 0.9980 and 0.9995) at different temperatures, and a kinetic model that was pseudo-second order (R² = between 0.9993 and 0.9929) at various initial concentrations of CR dye. In addition, the data revealed that the P3ABA/GO/CoFe₂O₄ nanocomposite exhibited a high adsorption capacity (153.92 mg/g) and removal for CR dye (98 %) at pH 5. Thermodynamic results showed the adsorption process was an endothermic and spontaneous reaction. It was found that, in terms of reusability, the P3ABA/GO/CoFe₂O₄ adsorbent can be used for up to six cycles. In this study, P3ABA/GO/CoFe₂O₄ nanocomposites were found to be low cost, and have an excellent removal capability and fast adsorption rate for CR from wastewater via a simple adsorption method. Moreover, this adsorbent nanocomposite could be simply separated from the resultant solution and recycled.     

A DFT investigation of the interactions of Pd,Ag, Sn,and Cs with silicon carbide

With a view to understand the diffusion of radionuclides through the silicon carbide layers in tristructural isotropic coated fuel particles, density functional theory calculations are applied to assess the interaction of palladium, silver, tin, and caesium with silicon carbide. The silicon carbide molecule (Si₂C₂), crystalline cubic silicon carbide (β‐SiC), and the (120) ∑5 grain boundary of β‐SiC are investigated to elucidate the differences in the interactions of silicon carbide with these elements. The main stabilizing forces in the PdSi₂C₂ complex were found to be donor‐acceptor charge transfer (covalent) interactions, the Ag and Sn complexes involve significant contributions from both electrostatic and covalent interactions, while the Cs atom is bonded dominantly by electrostatic forces. For the unconstrained M? Si₂C₂ model, the following energetic ordering was obtained: Pd > Sn > Cs > Ag. The steric constraints in the bulk SiC and on the grain boundary change the order of binding energies to Pd > Ag > Sn > Cs in the interstitials and Pd > Sn > Ag > Cs in vacancies and at the grain boundary. By comparing the incorporation energies in the solid phases, it is possible to group these elements by similarities in the patterns of incorporation energies. Silver and palladium form a group with carbon, tin is grouped with silicon, and caesium is on its own. © 2014 European Commission. International Journal of Quantum Chemistry published by Wiley Periodicals, Inc.     

Adsorptive removal of phenol by bagasse fly ash and activated carbon: Equilibrium,kinetics and thermodynamics

Present study deals with the adsorption of phenol on carbon rich bagasse fly ash (BFA) and activated carbon-commercial grade (ACC) and laboratory grade (ACL). BFA is a solid waste obtained from the particulate collection equipment attached to the flue gas line of the bagasse-fired boilers of cane sugar mills. Batch studies were performed to evaluate the influences of various experimental parameters like initial pH (pH₀), contact time, adsorbent dose and initial concentration (C₀) on the removal of phenol. C₀ varied from 75 to 300 mg/l for the adsorption isotherm studies and the effect of temperature on adsorption. Optimum conditions for phenol removal were found to be pH₀ ≈ 6.5, adsorbent dose ≈10 g/l of solution and equilibrium time ≈5 h. Adsorption of phenol followed pseudo-second order kinetics with the initial sorption rate for adsorption on ACL being the highest followed by those on BFA and ACC. The effective diffusion coefficient of phenol is of the order of 10⁻¹⁰ m²/s. Equilibrium isotherms for the adsorption of phenol on BFA, ACC and ACL were analysed by Freundlich, Langmuir, Temkin, Redlich–Peterson, Radke–Prausnitz and Toth isotherm models using non-linear regression technique. Redlich–Peterson isotherm was found to best represent the data for phenol adsorption on all the adsorbents. The change in entropy (ΔS°) and heat of adsorption (ΔH°) for phenol adsorption on BFA were estimated as 1.8 MJ/kg K and 0.5 MJ/kg, respectively. The high negative value of change in Gibbs free energy (ΔG°) indicates the feasible and spontaneous adsorption of phenol on BFA. The values of isosteric heat of adsorption varied with the surface loading of phenol.     

Topological polymer chemistry by electrostatic self‐assembly

Recent developments in topological polymer chemistry are outlined. First, nonlinear polymer topologies are systematically classified on the basis of topological considerations of constitutional isomerism in a series of alkanes (C_nH_2n+2), monocycloalkanes (C_nH_2n), and polycycloalkanes (C_nH_2n?2, C_nH_2n?4, etc.). Various pairs of topological isomers are identified in randomly coiled, flexible polymer molecules with cyclic and branched structures. An electro‐ static self‐assembly and covalent fixation strategy has subsequently been developed for the efficient synthesis of a variety of topologically unique polymers, including monocyclic and polycyclic polymers, topological isomers, and topological block copolymers. In this process, new telechelics with moderately strained cyclic onium salt groups carrying multifunctional carboxylate counteranions have been designed as key polymeric precursors. Further extensions of topological polymer chem‐ istry have been achieved by the use of cyclic telechelics (kyklo‐telechelics) and cyclic macromonomers, obtainable also by means of the electrostatic self‐assembly and covalent fixation process. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2905–2917, 2003     

UV/TiO2 photodegradation of metronidazole,ciprofloxacin and sulfamethoxazole in aqueous solution: An optimization and kinetic study

Emerging pharmaceutical ingredients (APIs) like sulfamethoxazole (SMX), metronidazole (MNZ) and ciprofloxacin (CIP) are biopersistent and toxic to the environment and public health. In this study, UV/TiO₂ photodegradation was applied in the degradation of SMX, MNZ and CIP individually and in a mixture. For a 5 mg/L SMX solution, about 97% of SMX was degraded within 360 min, which was reduced to 80% for 80 mg/L of SMX solution at the same TiO₂ dosage and photodegradation time. The maximum removals of MNZ and CIP as individual components were 100% and 89%, respectively at 600 min of photodegradation reaction time. For binary mixtures, the highest removal (100%) was achieved for MNZ and CIP ([MNZ] = [CIP] = 40 mg/L) mixture at 120 min whereas the degradations were 97% and 96% for SMX and MNZ, and SMX and CIP binary mixtures, respectively, even after 600 min of experimental time at the same concentrations. For tertiary mixture, the maximum degradation 99% was observed for (SMX = CIP] = 20 mg/L and [MNZ] = [40 mg/L) at 600 min. The observed reaction rate was 0.01085 min^?1 when SMX concentration was 5 mg/L, which decreased to 0.00501 min^?1 for SMX concentration of 80 mg/L, indicating decreasing of reaction rate at higher concentration. The results indicate that the UV/TiO₂ process is promising to apply for the treatment of pharmaceutical wastewaters.     

Preparation and application of magnetic molecularly imprinted polymers for the isolation of chelerythrine from Macleaya cordata

A novel type of magnetic molecularly imprinted polymer was prepared for the selective enrichment and isolation of chelerythrine from Macleaya cordata (Willd) R. Br. The magnetic molecularly imprinted polymers were prepared using functional Fe₃O₄@SiO₂ as a magnetic support, chelerythrine as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross‐linker. Density functional theory at the B3LYP/6‐31G (d, p) level with Gaussian 09 software was applied to calculate the interaction energies of chelerythrine, methacrylic acid and the complexes formed from chelerythrine and methacrylic acid in different ratios. The structural features and morphology of the synthesized polymers were characterized by using Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, and vibration sample magnetometry. Adsorption experiments revealed that the magnetic molecularly imprinted polymers possessed rapid kinetics, high selectivity, and a higher binding capacity (7.96 mg/g) to chelerythrine than magnetic molecularly non‐imprinted polymers (2.36 mg/g). The adsorption process was in good agreement with the Langmuir adsorption isotherm and pseudo‐second‐order kinetics models. Furthermore, the magnetic molecularly imprinted polymers were successfully employed as adsorbents for the extraction and enrichment of chelerythrine from Macleaya cordata (Willd) R. Br. The results indicated that the magnetic molecularly imprinted polymers were suitable for the selective adsorption of chelerythrine from complex samples such as natural medical plants.     

Post Synthetic Modification of NH2-(Zr-MOF) via Rapid Microwave-promoted Synthesis for Effective Adsorption of Pb(II) and Cd(II)

Excessive heavy metals in the water constitute a health hazard to humans, yet it may be efficiently purified using adsorbents. Herein, for the first time, UiO-66-NH₂ was modified by Glycidyl methacrylate (GMA) via microwave heating method to investigate its potential for adsorption of Pb(II) and Cd(II) metal ions. Synthesized MOF was characterized by TGA, XRD, BET, FE-SEM-EDX, and FTIR. The MOF has a huge surface area of 1144 m²/g, a mean pore diameter of 2.84 nm, and a total pore volume of 0.37 cm³/g. The effect of UiO-66-GMA performance was evaluated by investigating the impact of pH (1–9), contact time (0–200 min), initial metal ions concentration (20–1000 mg/L), temperature (25–55 °C), adsorbent dosage (0.5–3 g/L), and co existences of other metals was investigated on Pb(II) and Cd(II) percentage removal. Following an analysis of the adsorption isotherms, kinetics, and thermodynamics, the Temkin isothermal model showed an excellent fit with the adsorption data (R² = 0.99). The adsorption process was a spontaneous endothermic reaction and kinetically followed the pseudo-second-order kinetics model. Microwave heating method produced highly crystalline small Zr-MOF nanoparticles with a short reaction time. It promoted the simple yet highly efficient synthesis of Zr-based MOFs, as shown by the reaction mass space-time yield. The adsorption capability of Pb to the presence of several polar functional groups, including as primary and secondary amines, ester, alkene, and hydroxyl groups. This adsorbent is a potential candidate for wastewater treatment due to its outstanding structural stability in acidic and basic solutions, high removal efficiency, and recyclability.     

层层组装微胶囊的制备及其智能响应与物质包埋释放性能

在胶体微粒模板上进行聚合物间或聚合物和小分子间的交替层层(LBL)组装, 得到核壳微粒, 然后去除胶体微粒得到层层组装微胶囊. 综述了层层组装微胶囊在组装驱动力、智能响应性能和物质包埋与释放等方面的最新研究进展. 首先从组装驱动力和微胶囊结构调控出发, 简述了基于静电和氢键作用的LBL微胶囊的交联方法及交联所引起的微胶囊结构和性能的变化, 介绍了基于新驱动力如共价键作用、 碱基对作用和主客体作用制备LBL微胶囊的技术. 讨论了LBL微胶囊的智能响应性, 包括pH、 温度、 电荷、 光电磁和化学物质响应等. 详细介绍了LBL微胶囊包埋与释放功能物质尤其是药物、 蛋白和酶的方法及其特色, 包括LBL直接包埋与释放、 预吸附或共沉淀包埋与释放、 电荷选择性自沉积包埋与释放及爆释等. 最后, 着眼于微胶囊的靶向传递和功能器件, 介绍了采用静电作用和生物识别作用制备得到的微胶囊阵列.