由于巯基与重金属离子（如：银、铅）具有较强的极化作用，所以巯基化改性后的材料可用于制备表面包银的复合粒子及作为去除铅离子的吸附剂。针对现有制备技术得到的银包石墨（NG@Ag）复合粒子存在壳层不致密、散银、密度大、银含量高以及铅吸附剂吸附慢、难分离等问题，本论文发展了一种在低羟基密度的石墨粒子表面接枝高密度巯基的制备方法，以此来制备薄而致密银壳层包覆的石墨@Ag复合粒子及获得了一种高吸收、快去除且易分离的铅吸附剂。探究了这种复合粒子的形成机理及其导电胶的性能；研究了接枝不同巯基密度的石墨粒子对Pb(Ⅱ)的等温吸附行为及吸附动力学；并研究了水溶液pH值和循环次数对巯基化石墨粒子的吸附能力的影响规律。取得的主要研究结果如下：

首先，在低羟基密度的石墨粒子表面实现了高巯基密度的修饰。重点研究了反应参数（如：MPTMS、H 2O及催化剂氨的浓度）对石墨粒子表面巯基密度的影响规律。研究表明，水和氨既能促使MPTMS分子与石墨粒子表面上的羟基发生缩合，也能促进MPTMS分子在石墨粒子表面的自缩聚。这有利于在石墨粒子表面形成高密度的巯基；控制水和MPTMS的体积比还能调控石墨粒子表面巯基的密度。

其次，运用调控石墨粒子表面巯基密度的方法制备了壳层厚度可控的NG@Ag核壳复合粒子。阐明了巯基密度与形成致密壳层时的最小壳厚之间的关系；揭示了复合粒子的壳层厚度对其电性能的影响规律。研究表明，高密度巯基修饰的石墨粒子表面能得到高密度的银晶核，利于制备薄而致密的银壳层；本文制备的NG@Ag复合粒子不仅具有更低的银含量（32 wt%）和更小的密度（3.06 g/cm^~3），而且具有更优异的导电率（高达 1.7×10^~6 S/m）。此外，其填充的环氧树脂导电胶导电性能高，成本低且填充比小。这种轻质、高性能的导电填料有望广泛应用于导电与电磁屏蔽复合材料中。

最后，选用比表面积更大的石墨粒子进行高密度巯基化修饰，研究了接枝不同巯基密度的石墨粒子对铅离子的吸附性能。结果表明，该类吸附剂符合Langmuir等温吸附模型，具有较高的吸附量，可达55.67 mg/g。其中MNG-2吸附剂能在短时间内（20 min）将浓度为 1.0 mg/L的Pb(Ⅱ)降低到0.012 mg/L（< 0.015 mg/L，即：饮用水中Pb(Ⅱ)的最高浓度）其吸附过程的速率常数k 2高达3.07 g·mg^~-1·min^~-1，进一步证实了该吸附剂对溶液中残留铅离子去除快的能力。这主要是因为吸附剂表面接枝了高密度巯基的缘故。而且，MNG吸附剂的粒径为微米级，易分离回收。此外，该吸附剂在中性溶液中的吸附能力最佳；经过3次循环后，其吸附效率仍然保持在90%以上，具有良好的使用寿命。这类铅吸附剂不仅价格低廉、合成简单，还具有高吸收、快去除且易回收的特点，有望广泛用于去除水中的Pb(Ⅱ)。

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