离子印迹荧光传感器选择性检测镉离子

该文运用离子印迹技术,结合表面修饰方法以2-萘基丙烯酸酯为荧光配体,聚偏氟乙烯(PVDF)膜为支撑介质,在二甲基亚砜中于65℃下热引发聚合得到镉离子荧光印迹传感器.该荧光印迹传感器在中性条件下对镉离子表现出良好的选择性和抗干扰能力,检出限为5.5×10-7mol/L,与ICP - MS法无显著性差异.循环使用10次的相...     

铅离子印迹聚合物选择性吸附特性的研究与应用

利用离子印迹技术以铅离子为模板,甲基丙烯酸为功能单体,偶氮二异丁腈为引发剂,乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合法制备铅离子印迹聚合物。通过红外光谱和紫外光谱对该离子印迹聚合物进行表征,采用静态平衡吸附实验分析铅离子印迹聚合物的吸附性能和吸附选择性。实验结果表明:与非印迹聚合物相比较,Pb(II)印迹聚合物对Pb(II)具有较强的吸附能力和较好的吸附选择性,饱和吸附量为19.44mg/g,pH=6时吸附效果最好,达到吸附平衡的时间是7h;静态分配系数Kd和选择性系数k分别为1381ml/g和20.3。将该离子印迹聚合物应用于环境水样中铅离子测定时的预富集,结果满意。     

离子液体作为功能单体制备溶菌酶分子印迹复合膜的研究

以1-乙烯基-3-乙酸乙酯咪唑氯离子液体为功能单体,以再生纤维素膜为基膜,采用温和的表面ATRP接枝聚合技术在水溶液中制备了溶菌酶分子印迹膜.通过紫外-可见光谱分析了离子液体与模板分子的作用力,讨论了功能单体1-乙烯基-3-乙酸乙酯咪唑氯用量对印迹复合膜性能的影响,研究了分子印迹复合膜对溶菌酶模板分子及其结构类似物的吸附行为和选择性识别特性.结果表明,以1-乙烯基-3-乙酸乙酯咪唑氯离子液体作为功能单体的溶菌酶分子印迹膜能够从结构类似物混合体系中选择性分离富集溶菌酶,且具有很好的稳定性和可再生性能.     

硅胶表面铜离子印迹聚合物的制备和性能研究

以Cu2+为模板,1,4-二羟基蒽醌为单体,硅胶为载体,γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH-570)为偶联剂,利用表面离子印迹技术制备了Cu2+印迹聚合物。采用紫外光谱法、傅里叶变换红外光谱法(FT-IR)、扫描电镜对Cu2+印迹聚合物进行结构和表面形貌表征,并用原子吸收光谱法考察了吸附时间、吸附酸度、吸附温度、吸附浓度等对聚合物吸附性能的影响,研究了印迹聚合物在混合溶液中对Cu2+的选择性,将该聚合物重复利用6次,吸附量达到第一次的82%,并将该印迹聚合物应用到河水和自来水中,能够有效地测出水中铜离子的浓度,回收率分别为95.5%和107.2%。     

微波辅助合成镍离子表面印迹聚合物及其性能

本研究以镍离子为模板离子,水杨醛缩乙二胺席夫碱为功能单体,乙二醇二甲基丙烯酸酯为交联剂,以烷基化硅胶为载体,通过表面印迹法在微波条件下制备了镍离子印迹聚合物(IIP)。用傅里叶红外光谱(FITR)和扫描电子显微镜(SEM)对离子印迹聚合物进行了表征。通过研究吸附过程中pH值、温度和初始浓度等因素对IIP吸附性能的影响,确定最佳吸附条件为:pH=8,温度为30℃,吸附时间为40 min,浓度为30 mg·L~(-1)。结果表明,Langmuir等温线可以较好地描述IIP吸附过程,最大吸附量为24.23 mg·g~(-1),与饱和吸附量24.97mg·g~(-1)基本相符,符合准二级动力学模型。此外,对IIP进行了镍离子的选择吸附性能研究,其选择性系数远大于1,表明该聚合物有良好的选择性吸附性能。     

镉(Ⅱ)离子印迹聚合物的制备及性能研究

将量子点技术和离子印迹技术相结合,以镉(Ⅱ)为模板离子,CdSe/CdS量子点为荧光成分,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,采用本体聚合法制备了镉(Ⅱ)离子印迹聚合物。利用X射线衍射仪(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱仪(IR)、综合热分析仪(TG)等仪器对印迹聚合物进行表征,通过吸附实验和荧光猝灭实验考察其聚合物的吸附性能和荧光性能。结果表明:离子印迹聚合物内部存在大量的印迹空穴,并且具有良好的吸附性能和荧光性能。此聚合物有望作为固相萃取剂在分离富集领域获得应用。     

基于离子液体辅助氯霉素分子印迹聚合物的制备及应用

以氯霉素(CAP)为模板,2-乙烯基吡啶(2-Vp)为功能单体,四氢呋喃和离子液体1-丁基-3-甲基咪唑四氟硼酸盐[BMIm]BF4的混合溶液为反应溶剂,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,合成了氯霉素的分子印迹及非印迹聚合物。优化功能单体、不同溶剂对印迹聚合物吸附性能的影响,结果表明,以2-乙烯基吡啶为功能单体,四氢呋喃和离子液体[BMIm]BF4(体积比1∶1)作为反应溶剂合成的分子印迹聚合物对氯霉素具有高的吸附容量,良好的特异性识别性能。氯霉素分子印迹聚合物的印迹因子为2.6,进行吸附-解吸附循环5次后,氯霉素印迹聚合物的性能稳定,可重复使用。将制备的氯霉素分子印迹聚合物作为富集材料,应用于鸡蛋样品中氯霉素的检测,回收率可达62.3%~81.1%,准确性好。     

铅离子印迹聚合物的制备表征及其吸附性能研究

以铅离子为模板,壳聚糖为功能单体,采用分子印迹技术,加入交联剂环氧氯丙烷,合成了铅离子印迹的交联壳聚糖。通过红外光谱对铅离子交联壳聚糖进行了结构表征,通过扫描电镜对其形态结构进行表征。研究了不同条件下交联壳聚糖对铅离子的吸附性能,结果表明,当溶液p H=4.5时,交联壳聚糖对溶液中铅离子的吸附效率较高。吸附在交联壳聚糖上的铅离子可用0.1mol·L的EDTA溶液洗脱,洗脱率达82.73%。利用原子吸收分光光度法对印迹聚合物的最大吸附量进行了研究,结果表明,所合成的模板交联壳聚糖分子印迹聚合物对铅离子具有良好的吸附性;对印迹聚合物的选择性吸收进行研究,研究表明,印迹聚合物对铅离子的选择性好,能用于水溶液中除去铅离子。     

铅(Ⅱ)离子印迹复合膜的制备及其性能研究

以聚丙烯微孔膜(MPPM)为支撑,采用共价表面修饰和离子印迹技术,制备了Pb(Ⅱ)离子印迹复合膜.首先通过紫外光引发丙烯酸接枝聚合,在MPPM表面引入羧基;然后基于羧基和氨基的反应,将壳聚糖共价接枝到MPPM表面;再以Pb(Ⅱ)为模板离子、环氧氯丙烷为交联剂,通过配位键作用形成离子印迹位点.制备过程通过ATR-FTIR和XPS分析得到了证实.利用扫描电子显微镜(SEM)-能量色散X射线光谱仪(EDX)对膜表面及截面的形貌及元素分布进行了分析.静态水接触角和纯水通量实验结果显示,印迹复合膜具有良好的表面亲水性和渗透性,在离子印迹聚合物接枝率为174.4μg/cm2时,水通量高达2659±58 L/(m2.h).印迹复合膜对Pb(Ⅱ)离子的吸附亲和性和渗透选择性分别通过平衡结合实验和竞争渗透实验进行评价.与非印迹复合膜相比,印迹复合膜对Pb(Ⅱ)离子展现出更强的吸附亲和性,更快的吸附速率及更好的渗透选择性,以Cu(Ⅱ)和Zn(Ⅱ)作为竞争离子,其渗透选择性因子分别为3.43和3.93.     

铅离子印迹固相萃取原子吸收光谱分析

以Pb2+为模板,丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合技术,制备了对Pb2+具有特异性识别作用的离子印迹材料。通过红外光谱,吸附容量,干扰实验等讨论了该离子印迹材料的相关性质。结果表明,该离子印迹材料对Pb2+的结合能力明显强于非印迹材料,能够很好的排除其他金属离子的干扰。通过制备该离子印迹材料,能够富集水体中的痕量铅,结合原子吸收光谱法对其进行定量分析,为测定复杂环境样品中痕量铅离子提供一个高选择性,高预富集效率的固相萃取材料和分析方法。     

Mimicking receptor for methylmercury preconcentration based on ion-imprinting

Solid-phase extraction (SPE) based on molecularly imprinted polymers (MIPs) were used to develop selective separation and preconcentration for methylmercury ion from complex matrixes. In this study, an ion-imprinting polymer was prepared to make artificial organomercury lyase preorganizing three methacryloyl-(l)-cysteine methylester (MAC) monomers and one methylmercury ion in a three-coordinate form by template polymerization, with the goal preparing a solid-phase which has the high selectivity for methylmercury ions.Methylmercury-imprinted beads were produced by a dispersion polymerization technique with use methylmercury-methacryloyl-(l)-cysteine (MM-MAC) complex monomer and ethylene glycoldimethacrylate (EDMA). After removal of methylmercury ions, methylmercury-imprinted beads were used for solid-phase extraction and determination of mercury compounds. Methylmercury adsorption and selectivity studies of methylmercury versus other metal ions which Hg(II), Zn(II), Pb(II) and Cd(II) were reported and distribution and selectivity coefficients of these ions with respect to methylmercury were calculated here.ICP-OES and HPLC-DAD determinations of methylmercury and mercury ions in the certified reference, LUTS-1 from the National Research Council of Canada and synthetic sea water showed that the interfering matrix had been almost removed during preconcentration. The methylmercury-imprinted solid-phase as mimic receptor was good enough for methylmercury determination in complex matrixes.     

A new specific polymeric material for mercury speciation: Application to environmental and food samples

A new polymeric material (Patent: P201400535) highly specific for mercury is presented. Its great capability to pre-concentrate and selectively elute inorganic mercury and methylmercury are the main figures of merit. The polymer can be reused several times. To our knowledge, this is the only polymer proposed in the literature for direct inorganic mercury and methylmercury speciation without need of chromatography or quantification by difference. The polymer formation is based on the reaction of a vinyl derivative of 8-hydroxiquinoline as monomer, and 2-(Methacryloylamino) ethyl 2-Methyl Acrylate (NOBE) as co-monomer. Random radical polymerization by the precipitation method was carried out using Azobisisobutyronitrile (AIBN) as initiator. The polymer was characterized by SEM and FTIR. Adsorption binding isotherms were evaluated using Langmuir and Freundlich models, showing high adsorption capacity for both inorganic and organic mercury species. The polymer was employed to sequentially determine inorganic mercury and methylmercury, using a solid phase extraction (SPE) scheme. Cross reactivity of several ions, as well as matrix effects from a high saline matrix like seawater was irrelevant as the retained fractions mostly eluted during the washing step. The procedure was first validated by analyzing a certified reference material (BCR 464) and finally applied to commercial fish samples. The speciation proposed procedure is cheap, fast, and easy to use and minimizes reagents waste.     

A Highly Efficient Chelating Polymer for the Adsorption of Uranyl and Vanadyl Ions at Low Concentrations

A new polymer containing double amidoxime groups per repeating unit was synthesized to enhance the metal ion uptake capacity. The adsorption properties of this new polymeric adsorbent, amidoximated poly(N,N-dipropionitrile acrylamide), for U(VI), V(V), Cu(II), Co(II) and Ni(II) ions were investigated by batch and flow-through processes at very low concentration levels (ppb). The chelating polymer showed high adsorption capacity for uranyl as well as vanadyl ions. In selectivity studies from a mixture of metal ions in aqueous solutions, the adsorbent showed high selectivity for uranyl and vanadyl ions in the following order: U(VI) > V(V) Co(II) = Cu(II) Ni(II) as determined by calculating the distribution coefficients D, of corresponding ions. The adsorption of uranyl and vanadyl ions from natural seawater by the new adsorbent was also examined in flow through mode.     

Investigation of Metal Ion Removal Selectivity Properties of the Modified Polyacrylamide Hydrogels Prepared by Transamidation and Hofmann Reactions

Modified crosslinked polyacrylamides having different functional groups prepared by transamidation reaction in aqueous and non‐aqueous medium and by Hofmann reaction were used as chelating agents for removal of Cu(II), Cd(II) and Pb(II) ions from aqueous solutions at different pH values. Under non‐competitive conditions, polymers adsorbed different amounts of metal ions, depending on their functional groups and swelling abilities. The metal ion adsorption capacities of polymers changed between 0.11–1.71 mmol/g polymer. Under competitive conditions, while the polymers having mainly secondary amine groups were highly selective for Cu(II) ions (99.4%), those having mainly secondary amide and carboxylate groups have shown high selectivity towards Pb(II) ions (99.5%). The selectivity towards Cu(II) ion decreased and Pb(II) ion selectivity increased by the decrease of the pH of the solutions. The high initial adsorption rate (<10 min) suggests that the adsorption occurs mainly on the polymer surface. A regeneration procedure by treatment with dilute HCl solution showed that the modified polymers could be used several times without loss of their adsorption capacities.     

Polymer Supported Schiff Base Complexes of Iron(III), Cobalt(II) and Nickel(II) Ions and their Catalytic Activity in Oxidation of Phenol and Cyclohexene

The polymer supported transition metal complexes of N,N′‐bis (o‐hydroxy acetophenone) hydrazine (HPHZ) Schiff base were prepared by immobilization of N,N′‐bis(4‐amino‐o‐hydroxyacetophenone)hydrazine (AHPHZ) Schiff base on chloromethylated polystyrene beads of a constant degree of crosslinking and then loading iron(III), cobalt(II) and nickel(II) ions in methanol. The complexation of polymer anchored HPHZ Schiff base with iron(III), cobalt(II) and nickel(II) ions was 83.30%, 84.20% and 87.80%, respectively, whereas with unsupported HPHZ Schiff base, the complexation of these metal ions was 80.3%, 79.90% and 85.63%. The unsupported and polymer supported metal complexes were characterized for their structures using I.R, UV and elemental analysis. The iron(III) complexes of HPHZ Schiff base were octahedral in geometry, whereas cobalt(II) and nickel(II) complexes showed square planar structures as supported by UV and magnetic measurements. The thermogravimetric analysis (TGA) of HPHZ Schiff base and its metal complexes was used to analyze the variation in thermal stability of HPHZ Schiff base on complexation with metal ions. The HPHZ Schiff base showed a weight loss of 58% at 500°C, but its iron(III), cobalt(II) and nickel(II) ions complexes have shown a weight loss of 30%, 52% and 45% at same temperature. The catalytic activity of metal complexes was tested by studying the oxidation of phenol and epoxidation of cyclohexene in presence of hydrogen peroxide as an oxidant. The supported HPHZ Schiff base complexes of iron(III) ions showed 64.0% conversion for phenol and 81.3% conversion for cyclohexene at a molar ratio of 1∶1∶1 of substrate to catalyst and hydrogen peroxide, but unsupported complexes of iron(III) ions showed 55.5% conversion for phenol and 66.4% conversion for cyclohexene at 1∶1∶1 molar ratio of substrate to catalyst and hydrogen peroxide. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 90.5% and 96.5% with supported HPHZ Schiff base complexes of iron(III) ions, but was found to be low with cobalt(II) and nickel(II) ions complexes of Schiff base. The selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was different with studied metal ions and varied with molar ratio of metal ions in the reaction mixture. The selectivity was constant on varying the molar ratio of hydrogen peroxide and substrate. The energy of activation for epoxidation of cyclohexene and phenol conversion in presence of polymer supported HPHZ Schiff base complexes of iron(III) ions was 8.9 kJ mol^?1 and 22.8 kJ mol^?1, respectively, but was high with Schiff base complexes of cobalt(II) and nickel(II) ions and with unsupported Schiff base complexes.     

基于MCM-41分子筛表面的镱离子印迹聚合物的制备及其性能

运用离子印迹技术,以3-氯丙基三乙氧基硅烷为锚定剂,将功能单体直链聚乙烯亚胺(PEI)接枝在MCM-41分子筛表面,选择镱离子作为模板离子,以环氧氯丙烷交联制备出基于MCM-41表面的镱离子印迹聚合物Yb(Ⅲ)-IIP-PEI/MCM-41,并以同样的方法制备非离子印迹聚合物(NIP-PEI/MCM-41)。 利用傅里叶变换红外光谱仪和扫描电子显微镜等技术手段对Yb³⁺印迹聚合物进行表征,采用静态吸附法确定了Yb(Ⅲ)-IIP-PEI/MCM-41对Yb³⁺的最佳吸附条件及选择性吸附性能。 结果表明,Yb(Ⅲ)-IIP-PEI/MCM-41和NIP-PEI/MCM-41的最大吸附量分别为229.93和99.27 mg/g;印迹材料对Yb³⁺的吸附符合Langmuir模型;吸附平衡在40 min的时候基本可以达到,可以利用准二级动力学模型来描述其吸附过程;Yb(Ⅲ)-IIP-PEI/MCM-41对Yb³⁺具有较强的选择性,同时也具有很好的重复使用性能。 成功地将MCM-41和离子印迹聚合物的优点结合起来,制备出一种对稀土Yb离子既有高吸附量又有高选择性的吸附材料,为进一步将其应用在处理实际废水,分离回收低浓度稀土废水中的稀土元素等方面打下了基础。     

An examination of some active organometallic substances for ion-selective electrodes

Examinations of a number of possible electroactive substances for use in both liquid membrane and solid-state ion-selective electrodes were carried out. Liquid membrane electrodes incorporating organometallic salts of lead and thallium were considered as constituents of sulphate, chromate, carbonate and nitrate responsive sensors. No practically useful device was, however, found. Several electrically semiconducting metal-phthalocyanines, metal-tetracyanoethylene (TCNE) polymers and metal-coordination polymers were also synthesized and investigated with solid-state electrode constructional techniques. Metal-phthalocyanine electrodes were found to be responsive to anions rather than to cations and some anion selectivity was observed. Metal-TCNE polymer electrodes showed response to metal ions identical with those contained in the polymer, and some good selectivities, operational activity ranges and response times were found. Electrodes made from coordination polymers incorporating copper showed a limited response to copper ions whilst inclusion of cadmium and iron(III) in the polymer matrix produced an electrode with anion reponse and slight anion selectivity.     

A Novel Conjugated Polymer Consists of Benzimidazole and Benzothiadiazole: Synthesis,Photophysics Properties,and Sensing Properties for Pd2+

A conjugated polymer PPBIBTE based on benzimidazole and benzothiadiazole was synthesized through palladium-catalyzed sonogashira cross-coupling reaction. The chemical structures of the monomers and the polymer were indicated by ¹H NMR, and investigation of photophysics properties and sensing optical properties for metal ions were observed by ultraviolet–visible and photoluminescence spectroscopy. PPBIBTE showed remarkable selectivity for Pd²⁺ by “turn-off” fluorescence sensing progress. In addition, the Stern–Volmer and Benesi-Hildebrand plots were used to reveal the interaction between the polymer and Pd²⁺, while job's method was applied to calculate the determination of stoichiometry. The results demonstrate that PPBIBTE can utilize static quenching for Pd²⁺ by forming a 1:1 complex. And it is a potential sensing material as fluorescence chemosensor for Pd²⁺ with high selectivity and sensitivity. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 831-842     

Synthesis and characterization of 2, 4-dihydroxy-benzaldehydeoxime-formaldehyde polymers and their application as ion-exchangers

Polymers were prepared by the condensation of 2, 4-dihydroxybenzaldehydeoxime (2, 4-DBO) and formaldehyde (F) in the presence of oxalic acid as catalyst with varying molar ratios of reacting monomers. Polymers were characterized by their IR spectra, elemental analyses, TGA and M_n as determined by vapour pressure osmometry as well as by non-aqueous conductometric titrations. Viscosity measurements of the solutions of polymer samples were carried out in dimethylformamide. Chelation ion-exchange properties have also been studied employing the batch equilibration method. This method involved the measurement of distribution of a given metal between the polymer sample and a solution containing metal ions. The study was carried out over a wide pH range and in media of various ionic strengths. The polymer showed a higher selectivity for UO ₂ ²⁺ and Fe³⁺ ions than for Cu²⁺, Ni²⁺, Co²⁺ and Mn²⁺ ions.