Preparation of Magnetic Molecularly Imprinted Polymer Nanoparticles for Selective Adsorption and Separation of β-Estradiol

In this study, we report the synthesis of MIP-coated hybrid NPs by “semi-covalent” imprinting technique throught a thermally reversible covalent bond and application for biochemical separation of β-estradiol (E₂). A moleculary imprinted polymer (MIP) were synthesized using 3-(triethoxysilyl) propyl isocyanate and dibutyltin dilanurate as a functional monomer and cross-linking agent and β-estradiol as template. The removal of the template by a simple thermal reaction produced specific β-estradiol recognition sites on the surface of silica shell. Meanwhile, a solid-phase extraction (SPE) based on E₂- MMIPs has been established for efficient separation and fast enrichment of E₂ from the plasma. Recoveries of E₂ from two kinds of plasma spiked at different concentration levels ranged from 86.9 to 103.3 with RSD <1.76 %.In this manner LOD was 0.0019 and LOQ was 0.0057 (µmol L^?1), capacity factor and selectivity factor were 3.05 and 1.099 respectively. Also E₂- MMIPs was used for selective separation of E₂ from drugs mixture.     

Syntheses,Crystal Structures,Magnetic and Luminescent Properties of Ni(Ⅱ), Cd(Ⅱ) and Pb(Ⅱ) Coordination Compounds Constructed from 5-Fluoronicotinic Acid

Five coordination compounds, namely [Ni_2(5-Fnic)_2(H_2 O)_4](1), [Ni(5-Fnic)(μ-5-Fnic)(H_2 biim)]n(2), {[Cd((μ-5-Fnic)2(H2 O)2]×4,4'-bipy}n(3), [Pb_2(μ-5-Fnic)_2(μ3-5-Fnic)_2(H_2 O)_2]n(4), and [Pb(5-Fnic)_2(4,4'-bipy)(H_2 O)](5), have been constructed hydrothermally using 5-FnicH(5-FnicH = 5-fluoronicotinic acid), H_2 biim(H_2 biim = 2,2'-biimidazole), 4,4'-bipy(4,4'-bipy = 4,4'-bipyridine), NiCl_2×6 H_2 O, CdCl_2×H_2 O and PbCl_2. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses(TGA), and single-crystal X-ray diffraction analyses. Structures of 1～5 range from discrete 0 D monomers(1 and 5) to 1 D coordination polymers(2 and 4) and 2 D metal-organic network(3). A broad structural diversity of 1～5 is guided by the type of the metal(Ⅱ) node and the introduction of auxiliary ligands. The magnetic(for 2) and luminescent(for 3～5) properties were also investigated and discussed.     

Synthesis and Characterization of Novel Magnetic Poly(urethane-imide)/Fe3O4@SiO2–NH2 Nanocomposites

Russian Journal of Applied Chemistry - Poly(urethane-imide)/Fe3O4@SiO2–NH2 nanocomposites were synthesized by the reaction of 4,4′-diphenylmethane diisocyanate (MDI), polypropylene...     

Crystal structure and quantum chemical investigation of [Cd(NTO)_4Cd(H_2O)_6]·4H_2O

The common explosives, RDX (1,3,5-trinitro-1,3,5-triazacyclohexane), HMX (1,3,5,7- tetranitro-1,3,5,7-tetraazacyclooctane) and TNT (trinitrotoluene), were considered adequately for all weapons applications. Due to many catastrophic explosions resulting from unintentional initia-tion of impact, friction or shock, these explosives have become less attractive. TATB (1,3,5-tria- mino-2,4,6-trinitrobenzene) is noted for its insensitivity, however, it does not have the energetic performance of e…     

Syntheses and structures of seven-coordinate K3[Cd(Dtpa)], K2[Cd(H2O)4][Cd(Edta)(H2O)]2 · 2H2O, and Na2[Cd(H2O)4][Cd(Edta)(H2O)]2 · 2H2O complexes

The title complexes, K₃[Cd(Dtpa)] (H₅Dtpa = diethylenetriamine-N,N,N,N′,N′-pentaacetic acid, (I)), K₂[Cd(H₂O)₄][Cd(Edta)(H₂O)]₂ · 2H₂O (H₄Edta = ethylenediamine-N,N,N′,N′-tetraacetic acid, (II)), and Na₂[Cd(H₂O)₄][Cd(Edta)(H₂O)]₂ · 2H₂O (III), were prepared, and their compositions and structures were determined by elemental analyses, IR spectra, and single-crystal X-ray diffraction techniques, respectively. In complex I, the Cd is seven-coordinated by one Dtpa ligand yielding a pseudo-monocapped trigonal prism conformation, and the complex crystallizes in the triclinic crystal system with the Pi space group. The crystal data are as follows: a = 8.7300(17), b = 9.1200(18), c = 15.110(3) Å, α = 95.52(3)°, β = 96.59(3)°, γ = 99.63(3)°, V = 1170.0(4) ų, Z = 2, ρ = 1.754 g/cm³, μ = 1.519 mm^?1, F(000) = 616, R = 0.0644 and wR = 0.1712 for 3842 observed reflections with I ≥ 2σ(I). For complex II, in the [Cd(Edta)(H₂O)]^2? complex anion the Cd²⁺ ion is seven-coordinated by one Edta ligand and one water molecule, yielding a pseudo-pentagonal bipyramid conformation. In the [Cd(H₂O)₄]²⁺ cation, the bridged Cd is six-coordinated, yielding an almost standard octahedral conformation. The complex crystallizes in the monoclinic system with P2₁/n space group. The crystal data are as follows: a = 9.098(3), b = 16.442(6), c = 12.023(4) Å, β = 91.053(6)°, V = 1798.3(12) ų, Z = 2, ρ = 2.098 g/cm³, μ = 2.086 mm^?1, F(000) =1124, R = 0.0406 and wR = 0.1152 for 3680 observed reflections with I ≥ 2σ(I). In complex III, the conformations of Cd²⁺ ions are similar to those of the potassium salt complex, and the complex also crystallizes in the monoclinic crystal system with the P2₁/n space group. The crystal data are as follows: a = 9.134(7), b = 16.500(13), c = 12.075(10) Å, β = 91.054(12)°, V = 1820(2) ų, Z = 2, ρ = 2.015 g/cm³, μ = 1.856 mm^?1, F(000) = 1092, R = 0.0363 and wR = 0.0879 for 3707 observed reflections with I ≥ 2σ(I).     

Preparation of new spongy adsorbent for removal of EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ) from water

A new spongy adsorbent (PU-DTC) was prepared with a polyurethane (PU) adsorbent for removal of EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ) from water. This new spongy adsorbent was characterized by using SEM and 13C NMR and FT-IR spectroscopy. Adsorption kinetic curve indicated that this new spongy adsorbent could quickly remove EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ) from water, and adsorption isotherm also indicated that PU-DTC had high equilibrium adsorption capacity for EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ).     

Construction and Photoluminescence Properties of Zn(Ⅱ)/Cd(Ⅱ) Complexes with 4-Amino-3,5-propyl-1,2,4-triazole Ligand

Reaction of ZnCl2 and 4-amino-3,5-propyl-1,2,4-triazole(dpatrz) or CdCl2, NaN3 and dpatrz, in aqueous solution at room temperature yields two neutral clusters: a dinuclear complex [Zn2(dpatrz)2Cl4](I) and a linear trinuclear complex, [Cd3(dpatrz)4(N3)2Cl4](Ⅱ). Both complexes have been characterized by X-ray single-crystal diffraction, powder XRD, IR, elemental analysis, TG and fluorescence analysis. Complex I crystallizes in orthorhombic, space group Pbca with a = 11.865(2), b = 14.464(3), c = 15.985(3) , V = 2743.4(9) 3, Z = 4, C16H32N8Cl4Zn2, Mr = 609.4, Dc = 1.475 g·cm3, μ = 2.16 mm-1, F(000) = 1248, GOOF = 1.091, the final R = 0.0295 and wR = 0.0665 for 1999 observed reflections(I 2σ(I)). Complex Ⅱ crystallizes in monoclinic, space group P21/c with a = 11.408(2), b = 15.211(3), c = 18.152(6) , β = 123.75(2)o, V = 2619.1(1) 3, Z = 2, C32H64N22Cl4Cd3, Mr = 1236.05, Dc = 1.567 g·cm3, μ = 1.46 mm-1, F(000) = 1244, GOOF = 1.042, the final R = 0.0444 and wR = 0.0913 for 3466 observed reflections(I 2σ(I)). The analysis of X-ray revealed that both structures lie about the inversion centers: complex I adopts two μ1,2-triazole bridges linking two Zn(Ⅱ) ions and Ⅱ forms a linear trinuclear structure with four μ1,2-triazoles and two μ1,1-N3- bridging modes. There are different coordinated geometries for three Cd(Ⅱ) ions in Ⅱ: one is coordinated with an octahedral environment, and the other two are distorted tetragonal pyramids(τ = 0.34). The hydrogen bonds of C–H···Cl and N–H···Cl lead to the discretes into a 3D supramolecular network in both compounds. The thermal stabilities and photoluminescence behaviors of them were also studied.     

Polymers for the Extraction of Chromium—Role of Polymers in the Removal and Recovery of Chromium from Wastewater

The present review discusses different possible routes of removal and recovery of chromium from industry and laboratory wastewater with special emphasis on the role of polymers in this context. Polymers can play a vital role in the easy, rapid and cost effective separation of chromium from aqueous solutions. Such studies of separation are important from the standpoint of identifying selective hosts and extractors for chromium. The use of suitable polymers in the removal and recovery of chromium from solutions is discussed.     

New crystalline forms of thorium arsenate: Preparation and characterisation of Th(HAsO4)2·4H2O and Th(HAsO4)2·2.5H2O

Two new forms of microcrystalline thorium arsenate have been synthesised. They have been characterised as Th(HAsO₄)₂·4H₂O and Th(HAsO₄)·2.5H₂O by chemical analysis and thermal, X-ray, IR and ion exchange studies. The interlayer distances are: Th(HAsO₄)₂·4H₂O: 8.23 Å and Th(HAsO₄)₂·2.5H₂O: 8.59 Å. However, thermally and chemically, both these exchangers are less stable than Th(HAsO₄)₂·H₂O; Th(HAsO₄)₂·2.5H₂O being more stable than Th(HAsO₄)·4H₂O. The maximum lithium ion uptake and the corresponding arsenate released, respectively are: 1.75 and 1.20 mmol/g for Th(HAsO₄)₂·4H₂O at pH 9.0 and 3.42 and 0.28 mmol/g for Th(HAsO₄)₂·2.5H₂O at pH 11.8. For both exchangers, the loss of zeolitic water as well as that released on formation of thorium pyroarsenate takes place in one step between 383 and 773 K.     

A Study on the Preparation of Konjac Glucomannansilk Fibroin Composite Aerogels and Its Adsorption of Water Pollutant Cr(Ⅲ)

It is emergent to develop a green waste water adsorbent with high efficiency.Therefore,a type of low-cost,green and environmentally friendly konjac glucomannan(KGM)-silk fibroin(SF)composite aerogels were compounded via simple chemical grafting and vacuum freeze drying,and a study on its adsorption capacity was also conducted.The characterizations of FT-IR,SEM,XRD and DSC indicate that the modified aerogels show a porous network space structure and there is a strong hydrogen bond effect between the KGM and SF molecules,which improves the density,compressive strength and thermal stability of aerogel materials.The adsorption experiments show that KGM-SF aerogels can effectively adsorb the water pollutants Cr(Ⅲ)with a maximal adsorption capacity of 82 mg·g^-1.In addition,the adsorption isotherm and dynamic model analysis are used to elaborate the adsorption mechanism of KGM-SF aerogels and explain that the composite aerogels can be single molecule chemisorption.KGM-SF aerogels have potential adsorption capacity.     

Preparation and Catalytic Activity of SO_4~(2-)/TiO_2-La_2O_3 in Synthesis of Butyl Butyrate

Butyl butyrate is a very important compound, which is transparent liquid and has the pear, apple flavor. Natural exist is in the fruit, such as apple, pear, banana, grape and strawberry, etc. Primarily used for to prepare the edible spice and is also widely used in industrial intermediate product, solvent and synthetic perfumery. Until now, there are many methods to synthesize it. Conventionally H2SO4 was reported, but it causes many problems, such as the erosion of equipment, easily causes …     

Thermal decomposition and kinetic data of Cd(BF4)2·6H2O

The thermal dehydration and decomposition of Cd(BF₄)₂·6H₂O were studied by means of DTA, TG, DSC and X-ray diffraction methods and the end products of the thermal decomposition were identified. The results of thermal analysis show that the compound is fused first, then it is dehydrated until Cd(BF₄)₂·3H₂O is obtained, which has not been described in the literature so far. The enthalpy of phase transition is H _ph.tr.=115.6 kJ mol^–1 Separation of the compound is difficult since it is highly hygroscopic. Then, dehydration and decomposition take place simultaneously until CdF₂ is obtained which is proved by X-ray diffraction. On further increasing the temperature, CdF₂ is oxidized to CdO and the characteristic curve assumes a linear character.Based on TG data, kinetic analyses were carried out separately for both parts of the curve: first until formation of the trihydrate and then — until formation of CdF₂. The formal kinetic parameters are as follows:for the first phase:E ^*=45.3 kJ mol^–1; rate equationF=^2/3; correlation coefficient 0.9858 for the second phase:E ^*=230.1 kJ mol^–1; rate equationF=(1–)^2/3[1-(1–)^1/3]^–1; correlation coefficient 0.9982.     

Preparation and Characterization of Nano-ZnFe2O4/TiO2 Films

The nano-ZnFe2O4/TiO2 films possess the functions of desulfurization and degradation for organic pollutants. The sols of ZnFe2O4/TiO2 were prepared by sol-gel method and coated on glass and porous ceramic by vertical coating and dipping-lift processes, respectively, and the samples were obtained after drying and sintering. The composition, appearance, absorption spectrum of the films, and the influence of the film on porous ceramic performances were analyzed using SEM, AFM, UV-Vis spectrometer, and mercury porosimeter, respectively, to determine the operation parameters of the multifunction porous ceramic elements for gas-purification.     

Thermochemistry of two lead borates; Pb(BO2)2·H2O and PbB4O7·4H2O

Two pure hydrated lead borates, Pb(BO₂)₂·H₂O and PbB₄O₇·4H₂O, have been characterized by XRD, FT-IR, DTA-TG techniques and chemical analysis. The molar enthalpies of solution of Pb(BO₂)₂·H₂O and PbB₄O₇·4H₂O in 1 mol dm^?3 HNO₃(aq) were measured to be (?35.00 ± 0.18) kJ mol^?1 and (35.37 ± 0.14) kJ mol^?1, respectively. The molar enthalpy of solution of H₃BO₃(s) in 1 mol dm^?3 HNO₃(aq) was measured to be (21.19 ± 0.18) kJ mol^?1. The molar enthalpy of solution of PbO(s) in (HNO₃ + H₃BO₃)(aq) was measured to be ?(61.84 ± 0.10) kJ mol^?1. From these data and with incorporation of the enthalpies of formation of PbO(s), H₃BO₃(s) and H₂O(l), the standard molar enthalpies of formation of ?(1820.5 ± 1.8) kJ mol^?1 for Pb(BO₂)₂·H₂O and ?(4038.1 ± 3.4) kJ mol^?1 for PbB₄O₇·4H₂O were obtained on the basis of the appropriate thermochemical cycles.     

Syntheses and crystal structures of two Cd(II) coordination polymers: one-dimensional chain [Cd(C4H6N2)2(C4H2O4)(H2O)2] n and two-dimensional sheet [Cd(C4H6N2)(H2O)(C4H4O4)] n · n H2O

Two new Cd(II) coordination polymers, [Cd(C₄H₆N₂)₂(C₄H₂O₄)(H₂O)₂] _n (1) (where C₄H₆N₂?=?2-methylimidazole, C₄H₂O₄?=?fumarate), and [Cd(C₄H₆N₂)(H₂O)(C₄H₄O₄)] _n ?·?nH₂O (2), (where C₄H₄O₄?=?succinates), have been prepared and structurally characterized by single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1 in a one-dimensional chain structure, in which carboxy is monodentate; a three-dimensional supermolecular network structure was formed through hydrogen bonding. In complex 2, the coordination geometry of the Cd atoms is a pentagonal bipyramid, and a two-dimensional sheet is formed though carboxyl group bridging. In 1 and 2, IR spectra indicate the presence of bridging carboxyl groups, confirmed by structure analyses.     

Adsorption of chiral aromatic amino acids onto carboxymethyl-β-cyclodextrin bonded Fe(3)O(4)/SiO(2) core-shell nanoparticles

Surface of magnetic silica nanoparticles is modified by grafting with carboxymethyl-β-cyclodextrin (CM-β-CD) via carbodiimide activation. The functionalized magnetic core-shell nanoparticles (MNPs) are characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infra Red (FTIR) spectroscopy, X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Vibrating Sample Magnetometer (VSM). These nano-sized particles are scrutinized for adsorption of certain chiral aromatic amino acid enantiomers namely, d- and l-tryptophan (Trp), d- and l-phenylalanine (Phe) and d- and l-tyrosine (Tyr) from phosphate buffer solutions. Adsorption capacities of the coated magnetic nanoparticles toward amino acid enantiomers are in the order: l-Trp>l-Phe>l-Tyr and under the same condition, adsorption capacities are higher for l-enantiomers than the corresponding d-enantiomers. All the equilibrium adsorption isotherms are fitted well to Freundlich model. FTIR studies depict significant changes after adsorption of amino acids onto nanoparticles. The stretching vibration frequencies of NH bonds of the amino acid molecules are changed with complex formation through host-guest interaction. The structure and hydrophobicity of amino acid molecules emphasize the interactions between amino acid molecules and the nano-adsorbents bearing cyclodextrin, thus play important roles in the difference of their adsorption behaviors.     

Removal of Cd(Ⅱ) from Aqueous Solutions by Natural Freshwater Surface Coatings

Natural freshwater surface coatings(biofilms and associated minerals), which were developed in the Nanhu Lake, Changchun, P. R. China, were used as an efficient biosorbent for the removal of Cd(Ⅱ) from aqueous solutions. The batch experiments were carried out to determine the adsorption properties of Cd(Ⅱ) onto the natural surface coatings. The classical Langmuir adsorption isotherm was applied to estimating the equilibrium coefficients of Cd(Ⅱ) adsorbed on the surface coatings. The results show that the maximum adsorption capacity of the surface coatings is 434.78 μmol Cd/m2(being equal to 0.17 mmol Cd/g of surface coatings or 10.38 mmol Cd/g Fe) and the Cd(Ⅱ) removal from solution media by the natural surface coatings was shown to be strongly affected by solution pH and ion strength. The resulted information also indicates that the maximum Cd removal efficiency(CRE) was determined to be approximately 90% at initial Cd mass concentration of 0.1 mg/L(the concentration limit of Cd (Ⅱ) in wastewaters for discharge in aquatic media in Chinese legislation), and the kinetic adsorption of Cd(Ⅱ) onto the surface coatings is fast with around 70% of the total adsorption-taking place in 150 min in solution under the controlled laboratory conditions (mineral salts solution with defined speciation, ionic strength 0.05 mol/L, and 25 ℃). With the advantage of high Cd adsorption capacity, the natural surface coatings appear to be a potentially effective biosorbent for the removal and recovery of Cd (Ⅱ) from polluted water.     

Synthesis and structures of Pb3O2(CH3COO)2·0.5H2O and Pb2O(HCOO)2: two corrosion products revisited

Reactions of carboxylic acids with lead play an important role in the atmospheric corrosion of lead and lead-tin alloys. This is of particular concern for the preservation of lead-based cultural objects, including historic lead-tin alloy organ pipes. Two initial corrosion products, Pb(3)O(2)(CH(3)COO)(2)·0.5H(2)O (1) and Pb(2)O(HCOO)(2) (2), had been identified through powder diffraction fingerprints in the Powder Diffraction File, but their structures had never been determined. We have crystallized both compounds using hydrothermal solution conditions, and structures were determined using laboratory and synchrotron single-crystal X-ray diffraction data. Compound 1 crystallizes in P1, and 2 in Cccm. These compounds may be viewed as inorganic-organic networks containing single and double chains of edge-sharing Pb(4)O tetrahedra and have structural similarities to inorganic basic lead compounds. Bond valence sum analysis has been applied to the hemidirected lead coordination environments in each compound. Atmospheric exposure experiments contribute to understanding of the potential for conversion of these short-term corrosion products to hydrocerussite, Pb(3)(CO(3))(2)(OH)(2), previously identified as a long-term corrosion product on lead-rich objects. Each compound was also characterized by elemental analysis, thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), and Raman spectroscopy.