离子印迹技术及其在重金属污染治理和回收中的应用

综述了国内外离子印迹技术在金属离子污染治理和回收利用方面的研究现状和进展。对本体聚合、原位聚合、沉淀聚合、表面分子印迹技术、膜技术、微乳液聚合、原子转移自由基聚合等离子印迹聚合物的制备方法进行了比较、分析和总结,重点对离子印迹技术在重金属污染治理和回收利用方面进行述评。除了报道离子印迹技术在Cu^(2+)、Fe^(3+)、Hg^(2+)、Zn^(2+)、Cd^(2+)、U^(6+)等金属离子污染治理的成功案例外,还特别介绍了几种表面离子印迹聚合物制备采用的材料,如壳聚糖、硅胶、菌丝体。研究表明,与传统方法制备的聚合物相比,离子印迹聚合物的吸附容量和吸附速率大幅提高,尤其是离子印迹聚合物微球和表面印迹聚合物,对目标离子有突出的选择性。离子印迹聚合物因其可靠的机械稳定性、识别能力、易解吸和再生等性能,在离子分离、净化和回收领域已广为人们所接受,并为金属离子污染治理和回收的工业应用提供了技术基础。最后探讨了离子印迹技术研究领域面临的问题和趋势。

Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-(2'-hydroxy)benzylideneaminonaphthothiazole as potential antimicrobial agents

Objective： A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Methods： Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-（2＇-Hydroxy）ben- zylideneaminonaphthothiazole was converted to its Co（Ⅱ）, Ni（Ⅱ） and Cu（Ⅱ） metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results： All the compounds moderately inhibited the growth of Cram positive and Gram negative bacteria. In the present study among all Schiff bases 2-（2＇-hydroxy）benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu（Ⅱ） metal complex was found to be most potent. Conclusion： The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.

Thermodynamics, kinetics and mechanism analysis of Cu(Ⅱ) adsorption by in-situ synthesized struvite crystal

Synthesized struvite was innovatively applied to removing Cu（II） from aqueous solution. The Cu（II） adsorption behavior and relative mechanisms were studied and analyzed. The maximum Cu（II） adsorption under pH=4.0 and 318 K calculated from adsorption thermodynamic analysis was 145.1 mg/g. The sorption kinetics can be favorably described by pseudo-second order model. The activation energy （Ea） of 17.5 kJ/mol suggested that the adsorption process was a chemical adsorption. The calculated thermodynamic parameters indicated that the adsorption was a spontaneous and endothermic one. On the basis of characterization upon struvite before and after adsorption, it was found that the electrostatic attraction and coordination bonding supported the ion sorption on struvite surface, and the transformation of copper ion into copper hydroxide occurred on struvite surface and within its crevices.

A series of 3d-4f heterometallic frameworks comprising 2D lanthanide-organic layers and diverse Cu-complex pillars

Six novel 3D layer-pillared lanthanide-transition metal coordination polymers,LnCuX(IN)2(Ac)(H2O)(Ln = Tb,X = Br(1);Ln = Er,X = Cl(2)),[LnCuCl(IN)2(Ac)].H2O(Ln = Gd(3);Ln = Eu(4)),and [LnCu2Br2(IN)2(Ac)(H2O)].nH2O(Ln = Dy,n =0(5);Ln = Gd,n = 0.5(6))(IN = isonicotinate,Ac = acetate),have been obtained by linking Ln-organic layers and diverse Cu-complex pillars under hydrothermal conditions.1 and 2 are isostructural and formed by 2D Ln-IN-Ac layers and CuX(IN)2 pillars(X = Br(1),X= Cl(2));3 and 4 are isomorphic and comprised of 2D Ln-IN-Ac layers and dimeric Cu2Cl(IN)4 pillars;while 5 and 6 are isostructural and built from 2D Ln-IN-Ac layers and tetrameric Cu4Br4(IN)4 pillars.The magnetic susceptibility investigation of 3 and 6 shows the presence of weak antiferromagnetic exchange interactions between the Ln3+ ions.Compounds 1-6 represent good examples of using 2D Ln-organic layers and diverse Cu-complex pillars as building units to construct intriguing 3D Ln-TM-organic frameworks.

Ferromagnetic interactions in EO-azido-bridged binuclear transition metal(Ⅱ) systems: Syntheses, crystal structures and magnetostructural correlations

Three new isostructural binuclear transition metal complexes with azido ion and 1,2-bis（3-（pyridin-2-yl）-lH-pyrazol-1- yl）ethane （bppe）, formulated as [M2（N3）2（bppe）2]（C104）2 （M = Co, 1; Ni, 2; Cu, 3）, were successfully synthesized. They were structurally and magnetically characterized. In 1-3, the double azido ions link two adjacent octahedral metal centers together in the end-to-on mode （EO）, with the M-NEo-M angles of 99.41°, 100.24° and 99.80°, respectively. The co-ligand bppe acts as terminal ligand to saturate the remaining coordination sites. The magnetic properties of 1-3 have been investigated in the tem- perature range of 2-300 K. Fitting of the magnetic susceptibility data revealed the occurrence of the strong ferromagnetic in- teractions [J = 26.32 cm-1 （1）, J = 38.23 cm-1 （2） and J = 139.83 cm-1 （3）]. Density functional theory calculations have been performed on 1-3 to provide a magneto-structural correlation of the ferromagnetic behavior.