介孔氧化硅交联壳聚糖复合材料的制备及其对重金属吸附性能研究

Preparation and its adsorption performance of heavy metal ions on mesoporous silica crosslinked chitosan composite

利用γ-氨基丙基-三乙氧基硅烷偶联剂与活化的介孔氧化硅表面的羟基反应制备硅烷化介孔氧化硅,然后以乙二醛为活化剂与壳聚糖反应,制备一种新型的介孔氧化硅交联壳聚糖复合材料。采用小角度X射线衍射仪(SAXRD)、红外光谱(IR)、透射电子显微镜(TEM)和比表面测试仪(BET)等表征产物的结构、形貌和孔径分布等,并使用原子吸收分光光度计(AAS)评价该复合物对Pb^(2+)的吸附去除性能。研究结果表明:介孔氧化硅交联壳聚糖复合材料对Pb^(2+)的去除率比单一的介孔氧化硅或壳聚糖有明显的提高,它对Pb^(2+)的等温吸附线符合Langmuir模型,在温度25℃和p H=4.5时,它对Pb^(2+)的饱和吸附量为97.8 mg·g^(-1),高于纯壳聚糖的饱和吸附量(87.6 mg·g^(-1))。

The reaction between y-aminopropyl triethoxysilane coupling agent and the surfaced hydroxide radical of the activated mesoporous silica was utilized to prepare silanization smesoporous silica,which then reacted with chitosan to prepare a new kind of mesoporous silica crosslinked chitosan composite using glyoxal as activator. Phase structure,morphology and pore size distribution, etc. of corresponding products were characterized by small angle X-ray diffraction（ SAXRD） , Fourier transform infrared spectroscopy （FT-IR） ,high-resolution transmission electron microscopy（ TEM） , and Brunauer-Emmett-Teller（ BET） test, etc. Moreover, its ad-sorption property of Pb2＋ ions was investigated by atomic absorption spectrometry （ AAS）. The results showed that the removal rate for Pb2＋ ions on the composite was improved rapidly than the single mesoporous silica or chitosan adsorbent. The adsorption data of the composite obeyed the Langmuir equation, and its maximum adsorption capacity of Pb2＋ ions at 25 and pH =4. 5 was 97. 8 mg ·g-1 , which was higher than 87. 6 mg·g-1 of the maximum adsorption capacity of Pb2＋ions on single chitosan adsorbent.