聚苯胺-木质素纳米复合物的制备及对银离子的吸附还原性能

PREPARATION OF POLYANILINE-LIGNIN NANOCOMPOSITES AND THEIR REDUCING ADSORPTION FOR SILVER IONS

以酶解木质素为分散剂、苯胺为单体,采用原位聚合法制备聚苯胺-酶解木质素(PANI-Lignin)纳米复合物.采用红外光谱、紫外-可见光谱、场发射扫描电子显微镜、透射电子显微镜、热重分析和宽角X射线衍射研究了PANI-Lignin纳米复合物的结构和性能.同时,采用静态吸附法研究了PANI-Lignin纳米复合物对银离子的吸附性能.研究结果表明,酶解木质素的添加量对PANI-Lignin纳米复合物的结构和性能有很大影响.酶解木质素添加量为10 wt%时,PANI-Lignin复合物为粒径约为70 nm的纳米粒子.随着酶解木质素添加量由0增加到30 wt%,PANI-Lignin纳米复合物对银离子的吸附容量和吸附率是先增加后减少.当酶解木质素添加量为10 wt%时,PANI-Lignin纳米复合物的银离子吸附容量达到最大值,为565.4 mg/g.对吸附后产物的分析可知,吸附后有长达1 cm,宽为0.220～4.38μm,厚为219～311 nm的纳米带状单质银生成,说明该PANI-Lignin复合物具有较强的反应性银离子吸附能力.

Polyaniline-（enzyme-hydrolyzed lignin） （PANI-Lignin） nanocomposites were prepared via an in situ polymerization from aniline by using enzyme-hydrolyzed lignin （EHL） as a dispersant. The EHL content ranging from 0 to 30 wt% was used to optimize the structure and properties of the PANI-Lignin nanocomposites. The PANI-Lignin nanocomposites were characterized by using FTIR, UV-Vis spectra, field emission scanning electron microscopy （ FE-SEM ）, transmission electron microscopy （ TEM ）, thermogravimetric analysis （TGA） and wide angle X-ray diffraction. Meanwhile,the silver ions adsorbability of the PANI-Lignin nanocomposites was examined by a static sorption technique. It was found that the EHL content affected greatly on the structure and properties of the PANI-Lignin nanocomposites. The typical FE- SEM and TEM images of the PANI-Lignin nanoeomposite with the EHL content of 10 wt% showed that nanoparticles with an average diameter of 70 nm were obtained. The adsorption capacity of silver ions onto the PANI-Lignin nanoeomposites with the EHL content of 0 wt% -30 wt% increased first,and then decreased. The maximal adsorption capacity was up to 565.4 mg/g for the PANI-Lignin nanocomposite with the EHL content of 10 wt% and the initial silver ions concentration of 0.05 mol/L. The product of PANI-Lignin composite with the EHL content of 10 wt% after adsorption was investigated by transmission electron microscopy and wide angle X-ray diffraction. The results showed that silver nanobehs with length up to 1 cm, width of 0. 220 -4.38 p^m and thickness of 219 ~ 311 nm were achieved after adsorption of silver ions onto the PANI-Lignin nanoeomposite with the EHL content of 10 wt%. This result indicates that the PANI-Lignin nanoeomposite possesses a strongly reactive adsorbability of silver ions. Therefore,the successful preparation of the PANI-Lignin nanocomposites can provide an effective method to the removal and recovery of silver ions from wastewater.