连续在线原位ATR-FTIR技术测定介孔CuAl_2O_4对黄药的吸附

Determination of the Adsorption of Xanthate on Mesoporous CuAl_2O_4 Using a Continuous Online In situ ATR-FTIR Technology

以丁胺和正十二醇为混合模板剂,采用共沉淀法制备了介孔纳米CuAl_2O_4.用X射线粉末衍射(XRD)、傅里叶变换红外(FTIR)光谱、N_2吸附-脱附对产物的结构进行了表征.采用连续在线原位衰减全反射傅里叶变换红外(ATR-FTIR)光谱技术研究了水溶液中丁基和辛基黄药在介孔CuA_l2O_4表面的吸附.随着吸附时间的延长,1200和1040 cm^(-1)两处黄药特征峰的高度逐渐增加,根据1200 cm^(-1)处C—O—C伸缩振动峰的变化来评价黄药在CuAl_2O_4表面的吸附动力学过程.结果表明,介孔纳米CuAl_2O_4对黄药有很强的吸附能力,在100 min的时间内,CuAl_2O_4样品对丁基和辛基黄药的吸附量分别达到了236和300 mg·g^(-1),且属于化学吸附.对实验数据进行理论模拟,发现吸附过程更接近于拟二级吸附动力学方程.

In this study, mesoporous nano CuAl2O4 was synthesized through a coprecipitation method using simple mixed templates consisting of butylamine and dodecanol. The sample was characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, and nitrogen adsorption- desorption techniques. The absorption of butyl and octyl xanthate from aqueous solution onto the synthesized mesoporous CuAl2O4 solid surfaces was studied by a continuous, online, in situ attenuated total reflection Fourier transform infrared spectroscopy （ATR-FTIR） technique. The CuAl2O4 membrane used in the adsorption experiments was prepared on a germanium internal reflection element using the chemical bath deposition method. During the adsorption process, the characteristic peak height of xanthate at 1200 and 1040 cm-1 emerged and gradually increased. By monitoring changes in the peak height at 1200 cm-1, which was assigned to the stretching vibration caused by C--O- C of the adsorbed xanthate molecules, the adsorption kinetics were studied. The adsorption results show that mesoporous CuAl2O4 has a high chemisorption capacity for xanthate, which reaches 236 and 300 mg·g-1 for butyl and octyl xanthate, respectively, within 100 min. The adsorption kinetics can be described by a pseudo-second-order reaction model.