【作者】 刘岩；

【导师】 刘惠玲；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2009， 硕士

【摘要】 膜载纳米钯/铁双金属颗粒对氯代有机物还原脱氯作用已经得到了认可,为了提高催化还原的效率,针对聚偏氟乙烯(PVDF)膜的疏水性进行改性,本文主要从PVDF膜的表面改性,到PVDF载体膜的基体改性和表面改性相结合,制备PVDF膜载纳米Pd/Fe双金属催化剂。采用扫描电子显微镜(SEM)、能谱分析(EDS)和红外光谱(FT-IR)对复合膜的颗粒膜表面形貌及表面基团组成进行了分析,以一氯乙酸(MCAA)为目标污染物考察复合膜的催化还原脱氯效果。在PVDF膜表面改性中,分别采用对PVDF膜载体亲水化处理后涂敷方法和直接原位聚合方法制备不同的PVDF膜载纳米Pd/Fe双金属催化剂,通过扫描电镜(SEM)对膜的表面形态进行表征结果表明,亲水化处理与交联处理影响了复合膜上纳米钯/铁双金属颗粒的分散状态,膜载铁量的测定进一步证明,经过亲水化处理涂敷方法比原位聚合方法在载铁量上更具有优势,不同膜对一氯乙酸脱氯研究表明,Pd/Fe还原膜对微量一氯乙酸均具有一定的降解能力,相比原位聚合工艺的脱氯率60.5%,涂敷方法脱氯率可达77%。就本实验条件对比发现,浸涂工艺具有一定的实际应用前景,经改性后的PVDF膜载纳米Pd/Fe双金属体系对于降解含氯有机物也具有一定的实用价值。在PVDF载体膜中,结合PVDF膜基体改性(主要是掺杂纳米颗粒,Al2O3)和表面涂覆改性寻求合适的PVDF复合膜制备过程。添加的纳米Al2O3有利于增强PVDF膜的亲水性,基体改性后的PVDF膜载铁量相对于商品膜有一定程度的提高,对一氯乙酸的降解也具有一定优势,加入纳米颗粒的复合膜还是相对稳定的。更多还原

【Abstract】 Membrane-immobilized Pd/Fe nanoparticles play an important role in reducing chlorinated organics for its efficiency and convenience. Polyvinylidene fluoride (PVDF) membrane was modified in order to improve membrane hydrophilicity to enhance dechlorination efficiency of iron. From the PVDF commodity membrane surface modification, to the self-made PVDF membrane the base and surface modification Membrane-immobilized Pd/Fe nanoparticles were prepared in this study.Particle shape and specific surface area of membrane-immobilized Pd/Fe nanoparticles were studied by Scanning Electron Microscope (SEM), Enengy Distribution Spectra (EDS) and Fourier Transform Infrared (FT-IR) spectrometer method. Membrane-immobilized Pd/Fe nanoparticles were used to dechlorinate monochloroacetic acid (MCAA) as the target pollutants.In the PVDF commodity membrane surface modification, two kinds of modified PVDF membrane-immobilized Pd/Fe nanoparticles by hydrophilization dip -coating method, in situ method respectively were prepared and characterized, two kinds of modified PVDF membrane-immobilized Pd/Fe nanoparticles were used to dechlorinate monochloroacetic acid, the morphology of membrane -immobilized Pd/Fe by scanning electron microscope (SEM) was characterized. Through compare research, we found that the distribution of Pd/Fe nanoparticles was best and the dechlorination effect of monochloracetic acid was highest in hydrophilization PVDF membrane-immobilized Pd/Fe nanoparticles. Compared to in situ process of the degradation rate of 60.5%, degradation rate of hydrophilization dip-coating method was up to 77%. Modified PVDF membrane-immobilized Pd/Fe nanoparticles by hydrophilization dip-coating method for the degradation of chlorine-containing organic compounds also have some practical value.In the self-made PVDF membrane, the combination of modified PVDF membrane-based (mainly doped nanoparticles, Al2O3) and dip-coating method to seek modification of the PVDF complex membrane preparation. Nanoparticles doped in the base of membrane were enhanced of the hydrophilicity of PVDF membrane.Through compare research, we found that the distribution of Pd/Fe nanoparticles was better and the dechlorination effect of monochloracetic acid was higher in modification PVDF membrane-immobilized Pd/Fe nanoparticles, adding the composite nanoparticles membrane was relatively stable.更多还原