锗(Ⅳ)-8-羟基喹啉类印迹聚合物合成及其高选择性吸附机理研究

Based on the feature of high selectivity and recognizing of molecular imprinting technique for target molecules, the imprinted polymer has a specific adsorption properties and potential applications, which has the features of simplification and nano micro structure. The highly recognized and adsorptive, and particle size controlled 8- hydroxyquinoline imprinted polymers with germanium (Ⅳ) were prepared by using hybrid imprinting technique in this project, which using the germanium (Ⅳ) with 8- hydroxyquinoline and its derivatives as a template. And it was applied to directional, fast and effective separating the germanium ions from sulfuric acid system. The behavior of germanium ion on the interface of liquid and solid was explored between the sulphate solution and the imprinted polymer, and the extraction mechanism, adsorption thermodynamic and kinetic characteristics of germanium ion were studied, and the characteristics of adsorption physical and chemical were investigated by combining the advanced characterization methods such as EDX, FT-IR, XRD, etc, then the extraction equilibrium, kinetic and thermodynamic properties were explored in the process of hybridization, selective adsorption and separation. The feasibility, reliability and comparative advantage of extracting the germanium ion was researched by means of the selective adsorption of these polymers in zinc concentrate sulfuric acid pressure leaching solution.

基于分子印迹技术对模板分子具有高选择、高识别性的特点，印迹聚合物具有微结构简单化和纳米化的特征，因而具有特异的吸附性能和广阔的应用前景。本项目拟以锗(Ⅳ)与8-羟基喹啉及其衍生物为模板，采用杂化印迹技术，制备识别性强、粒度可控、吸附容量高的锗(Ⅳ)8-羟基喹啉类锗印迹聚合物，并引入硫酸体系中目标金属离子锗的靶向、快速和高效分离提取。探索锗离子在硫酸盐溶液与印记聚合物液固界面间的行为；研究印迹聚合物对锗离子的分离提取机理，研究聚合物的吸附热力学及动力学特征；结合EDX、FT-IR、XRD等先进的表征手段，研究8-羟基喹啉类锗印迹聚合物吸附的物理、化学特性，解释杂化印迹聚合、选择性吸附和分离提取过程中的平衡、动力学和热力学特性；研究该类印迹聚合物吸附选择性能力提取锌精矿硫酸氧压浸出液中锗离子的应用可行性、可靠性和比较优势。

本项目针对我国战略性金属锗的特点及其在锌精矿硫酸氧压浸出液中的赋存状态，以Ge(Ⅳ)与8-羟基喹啉的配合物为模板、烯酰胺为功能单体、二甲基丙烯酸乙二醇酯为交联剂、偶氮二异丁腈为引发剂、浓盐酸为调整剂、氯仿为溶剂，采用杂化沉淀聚合法制备对锗离子配合物有特异识别性能的印迹聚合物MIPs。系统研究了功能单体、交联剂、引发剂等浓度及用量因素与印迹聚合物MIPs对锗离子吸附性能的影响，得到了较佳的合成工艺参数：物料比Ge：8-羟基喹啉：AM：EGDMA=1:4:4:10，在50-55℃、pH为-0.5～-1.0条件下聚合反应24小时，MIPs对硫酸锌溶液中锗吸附率为96.84%、解吸率为96.50%，锗吸附容量为387.36mg/g。通过SEM、EDX、FT-IR、微机差热分析等手段检测和分析聚合物的化学/细观结构和热稳定性。MIPs的热分解温度为354.28℃，微观形貌为较规则球形，粒径分布较为均匀，平均粒径为50nm，具有明显空腔结构。微孔比表面积较大为170.32 m2•g-1，微孔体积为0.5138 cm2•g-1。锌精矿氧压浸出液吸附试验结果表明MIPs对Ge4+的吸附效果显著优于NIPs对Ge4+的吸附，且MIPs对其他杂质元素如镓、锌、铁、铜、锡、镍、镁等的吸附量也远低于其对锗的吸附量，其分离系数分别为Ge：Ga=30、Ge：Zn=45、Ge：Fe=45、Ge：Cu=30、Ge：Sn=45、Ge：Ni=90、Ge：Mg=45，表明以Ge4+为模板的印迹聚合物MIPs对Ge4+产生了显著的印迹效应。Ge(Ⅳ)-8-羟基喹啉类印迹聚合物的合成与应用为低品位锗资源湿法冶金过程中高选择性吸附分离提供了技术支撑和理论依据。