巯基化复合微球的合成及其对Ag^+吸附性能的研究

Adsorption behavior of silver by thiol-functionalized composite microspheres

以2-巯基丙酸、β-环糊精、可溶性淀粉为原料,采用反相乳液聚合法合成了一种巯基化β-环糊精-淀粉复合微球吸附剂。利用傅里叶红外光谱仪、场发射扫描电镜、X-射线衍射仪和X-射线能谱仪对巯基化复合微球及其吸附产物进行表征,研究了其对Ag^+的吸附行为,考察了不同吸附时间、Ag^+初始浓度和初始p H对吸附量影响。并在最佳吸附条件下,对比研究了淀粉微球、β-环糊精交联淀粉复合微球及巯基化复合微球这三种不同吸附剂对Ag^+的吸附能力。结果表明:2-巯基丙酸和β-环糊精包合物与可溶性淀粉发生了交联,巯基化复合微球球形比较规整,结晶度相对复合微球的结晶度有所降低。巯基化复合微球对Ag^+的最佳吸附条件为:吸附时间40 min,初始p H=5,Ag^+初始浓度0.14 mol/L。吸附能力:Qe(巯基化复合微球)>Qe(淀粉微球)>Qe(复合微球)。

A kind of sulfhydrylation beta- cyclodextrin- starch composite microsphere adsorbent was synthesized by inverse emulsion polymerization,using 2- thiohydracrylic acid,beta- cyclodextrin and soluble starch as raw materials. Using Fourier transform infrared spectroscopy,field emission scanning electron microscopy,X- ray diffraction and X- ray spectrometer to characterize the composite microspheres and their adsorption products,the adsorption behavior of Ag^＋was studied and the effects of different adsorption time,initial Ag^＋concentration and initial p H value on the adsorption capacity were investigated. Under the optimum conditions,the adsorption capacity on Ag^＋of the three adsorbents,which were starch microspheres,beta cyclodextrin cross- linked starch composite microspheres and sulfhydrylation composite microspheres,was studied.The results showed that the complex of 2- thiohydracrylic acid and beta- cyclodextrin was crosslinked with soluble starch,compared with composite microspheres,the crystallinity of the sulfhydrylation composite microspheres decreased,and the spherical shape was more regular.The optimal adsorption conditions of the sulfhydrylation composite microspheres to Ag^＋were as follows： the adsorption time was 40 min,the initial p H was 5,the initial concentration of Ag^＋was0.14 mol / L. Adsorption capacity was Qe（ sulfhydrylation composite microspheres） Qe（ starch microspheres） Qe（ composite microspheres）.