【作者】 刘燕；

【导师】 谢吉民；

【作者基本信息】 江苏大学 ， 清洁能源与环境保护， 2011， 博士

【摘要】 介孔材料是一类孔径在2-50nm之间、孔径分布窄且具有规则孔道结构的无机多孔材料。由于其具有比表面积大,传质均一,吸附容量高等特性,逐渐应用于分离科学,特别是其特有的长程有序介孔结构和孔道内外丰富的硅醇基为其功能化组装提供了有利条件。本课题采用对目标化合物具有特定识别功能的分子印迹技术合成具有介孔结构的高选择性、大吸附容量、优良再生性能的新型固相萃取吸附剂,建立针对目标污染物的靶向分离/富集体系,探讨其在环境金属污染物选择性分离/富集中的应用；同时通过制备金属掺杂改性的介孔材料并对酶进行固载,探讨改性介孔材料的电催化性质和固载酶的生物催化活性。主要研究结果如下：1.表面印迹改性介孔材料的制备及其表征应用接枝共聚法和溶胶凝胶法结合表面印迹技术合成了能选择性吸附模板离子Co(Ⅱ)、Pb(Ⅲ)和Cr(Ⅲ)的表面印迹改性介孔材料,运用FT-IR、SEM、XRD、TEM及N2吸附-脱附实验等手段对印迹聚合物进行了表征,证明合成的印迹聚合物具有高度有序的介孔结构。2.表面印迹改性介孔材料在环境金属污染物选择性分离/富集中的应用研究(1)Co(Ⅱ)在Co(Ⅱ)-IIP的吸附行为符合准二级反应动力学方程,吸附过程受粒子内扩散模型控制。Co(Ⅱ)-IIP对溶液中Co(Ⅱ)的吸附行为与Langmuir方程较为符合,室温下最大理论吸附容量为39.26mg/g。Co(Ⅱ)-IIP比非印迹聚合物对Co(Ⅱ)具有更好的亲和力和选择性。吸附的Co(Ⅱ)可定量洗脱,吸附剂可重复使用。(2)Pb(Ⅱ)-IIP对Pb(Ⅱ)的吸附表现出快的吸附速率、高选择性和令人满意的吸附容量。吸附行为符合准二级动力学方程和Langmuir等温吸附模型,吸附过程受内扩散和表面反应过程共同控制,孔扩散比膜扩散起更加主导的作用。该吸附剂用于水样和泥土样品中Pb(Ⅱ)的分离和测定,效果满意。(3)建立了以Cr(Ⅲ)-IIP为固相萃取吸附剂,ICP-AES和UV为检测手段,对Cr(Ⅲ)和Cr(Ⅳ)进行形态分析和分离/富集/测定的新方法。比较了Cr(Ⅲ)印迹离子在Cr(Ⅲ)-IIP和非印迹聚合物上的吸附动力学、热力学行为,研究了两者对印迹离子的选择性识别能力,表明Cr(Ⅲ)-IIP对Cr(Ⅲ)具有高的选择性和理想的吸附容量。用于实际样品测定,效果满意。3.金属掺杂改性介孔材料的制备及其在生物传感中的应用研究(1)采用聚合物物理包埋法制备了纳米CoMCM-41修饰玻碳电极并用SEM进行了表征。用循环伏安(CV)和差示脉冲电流法(DPV)研究了抗坏血酸(AA)和多巴胺(DA)在修饰电极上的电化学行为,得到了氧化电位完全分开的电位型传感器。传感器具有良好的选择性、重现性及高灵敏度,可用于实际样品中AA和DA的同时测定。(2)利用电沉积法制备了纳米NiMCM-41修饰电极膜并用于固定辣根过氧化物酶(HRP)。以对苯二酚为电子媒介体,HRP对过氧化氢响应的线性范围为3.52×10-61.31×10-3mol/L,检出限为1.17×10-6mol/L(S/N=3),米氏常数值为1.47mmol/L,说明固定化的HRP有较高的活性,且与H202有较强的亲和能力。(3)利用常压微波法合成了TiSBA-15改性介孔材料,通过一步电沉积法将TiSBA-15、CTS和乙酰胆碱酯酶(AChE)共固定于金电极表面。底物乙酰硫代胆碱在修饰电极上具有稳定的电化学响应,有机磷农药西维因对AChE抑制效率在0.005-0.1μg/mL和0.5-5μg/mL两段线性范围内与其浓度呈线性关系,检测限为0.003μg/mL,传感器具有良好的稳定性和重现性。(4)选择与葡萄糖氧化酶(GOD)分子尺寸相当的TiSBA-15介孔材料,一步电沉积法制备了GOD/TiSBA-15/CTS复合膜化学修饰电极。在复合膜上实现了GOD的直接电化学,GOD对葡萄糖有良好的电催化活性,线性范围0.02-10mmol/L,米氏常数值2.2mmol/L,建立了无试剂型葡萄糖生物传感器制备的新方法。更多还原

【Abstract】 Mesoporous materials are inorganic porous material with regular pore structure and narrow pore size distributions between 2 and 50 nm. Mesoporous materials have been gradually applied in separation due to their large surface area, homogeneous transfer and high adsorption capacity. Especially the long-range ordered mesoporous structure and well modified surface properties with abundant Si-OH active bonds inside and outside of the pore walls which provide advantageous conditions for functionalization assembling.In this study, mesoporous structure sorbents of high selectivity, large adsorption capacity and good regeneration capability were synthesized by molecular imprinted technology which has specified recognition capability towards target compound. New targeted separation/pre-enrichment system has been developed. Meanwhile, appropriate immobilization technology of protein by metal doping modification mesoporous materials has been studied. The electrocatalysis activity of metal containing mesoporous material and the immobilized enzyme were investigated. The main conclusion included the following items:1. The preparation of surface imprinting modified mesoporous materialsSurface imprinting modified mesoporous materials applied in selective adsorption of Co(II), Pb(II) and Cr(III) were prepared by graft polymerization and sol-gel reaction with the surface imprinting technique on the support of silica mesoporous material. The prepared polymer was characterized by FT-IR, SEM, XRD、TEM and N2 adsorption-desorption isotherm. The results showed that the polymer possessed high ordered mesoporous structure.2. The application of surface imprinting modified mesoporous materials in selective separation/enrichment of environmental metal pollutants(1) It was found that the pseudo-second-order model best correlated the kinetic data of Co(II) adsorption onto Co(II)-IIP. The adsorption process was controlled by the intraparticle diffusion mechanism. Langmuir model fitted the experiment data well and the maximum calculated capacity of Co(II) reached 39.26 mg/g. Co(II)-IIP showed high affinity and selectivity for template ion compared with NIP. Co(II) adsorbed to the adsorbent could be eluted quantitatively. Co(II)-IIP is a regenerable SPE adsorbent of good selectivity.(2) Pb(II)-IIP showed fast kinetics, high selectivity and satisfied adsorption capacity for adsorption of Pb(II). Pb(II) adsorption process over Pb(II)-IIP followed pseudo-second-order reaction kinetics and the Langmuir adsorption model. The adsorption process was controlled by intraparticle diffusion mechanism together with external mass transfer and the pore diffusion was more dominant than film diffusion. The sorbent was applied to the selective separation and determination of Pb(II) in water and sediment samples with satisfactory results.(3) A new SPE method for the speciation, separation, preconcentration and determination of Cr(III) and Cr(VI) by ICP-AES and UV on mesoporous imprinted polymer adsorbent was developed. The adsorption kinetics, thermodynamics behavior and recognizing ability towards Cr(III) on imprinted and non imprinted polymer were compared. The results showed that Cr(III)-IIP had higher selectivity and larger Langmuir adsorption capacity of 38.50 mg/g. The proposed method has been successfully applied in the determination and speciation of chromium in natural water samples with satisfactory results.3. The preparation of metal ion doping modified mesoporous materials and research of application in biosensing(1) Nano CoMCM-41 modified glassy carbon electrode has been fabricated by polymer imbedded method and characterized by SEM. The modified electrode exhibited significant sensitization and electro-separation effect towards AA and DA. With potential difference of 310 mV, it was possible to obtain potentiometric sensor for determination of AA and DA simultaneously.(2) Nano NiMCM-41 film modified electrode has been fabricated by coelectrodeposition method to immobilize horseradish peroxidase (HRP). HRP could maintain its bioactivity and showed linear response to hydrogen peroxide in the range of 3.52×10-6～1.31×10-3mol/L in the presence of hydroquinone with detection limit of 1.17×10-6mol/L (S/N=3). The Michaelis constant was 1.47 mmol/L. The biosensor showed good stability and reproducibility(3) TiSBA-15 was synthesized under normal pressure by microwave irradiation. Composites of TiSBA-15, CTS and AChE were immobilized on Au electrode by one-step electrodeposition method. Stable electrochemical response of acetylthiocholine was obtained on modified electrode which showed that AChE retained good catalytic activity. The carbaryl inhibition ratio was proportional to its concentration in two ranges from 0.005 to 0.1μg/mL and 0.5 to 5μg/mL with the detection limit of 0.003μg/mL. The biosensor showed good reproducibility and stability.(4) One-step electrodeposition method has been applied for preparation of TiSBA-15/CTS/GOD composites film modified electrode. The uniform pores of TiSBA-15 allowed to controlling the adsorption of enzyme molecules on the basis of size. Direct electrochemistry was investigated on the film and the immobilized GOD displayed an excellent electrochemical response towards the electrocatalytic oxidation of glucose in the presence of oxygen. The linear range was 0.02-10 mmol/L and the Michaelis constant was 2.2 mmol/L. A new method for fabricating reagentless glucose biosensor has been developed.更多还原