【作者】 陈泳；

【导师】 康龙； 孔令斌；

【作者基本信息】 兰州理工大学 ， 材料学， 2018， 博士

【摘要】 随着人类的进步和社会的发展,一个古老而又无法回避的问题时时刻刻提醒着人们,那就是水污染。水污染带来的危害毋庸置疑,因此各国科学家开展了各种去除水中污染物的研究。其中,寻求高效吸附材料和解释吸附机理用来指导实践,成为吸附研究中的重点内容。高分子导电聚合物聚吡咯（PPy）通过不同掺杂剂对溶液中的离子有一定的选择性吸附作用,本论文利用两类不同掺杂剂,将聚吡咯与具有高比表面、低成本、吸附性能良好的凹凸棒（ATP）一起构建了具有选择吸附性能的新型复合材料,分别用来吸附溶液中的重金属离子及含氧酸根污染物,揭示影响复合材料选择性吸附的主次因素及对应的机理,阐明基于掺杂剂的选择性规律及吸附质结构对复合材料吸附性能的影响机理,为选择性吸附材料的构建和设计提供理论指导与依据。主要研究内容如下:（1）采用化学原位聚合法制备了掺杂小尺寸离子（Cl^-）的ATP/PPy/Cl复合材料,系统研究了外界因素对复合材料吸附性能的影响,得到复合材料对含氧酸根—阴离子污染物Cr（Ⅵ）(Cr₂O₇^2-)吸附的规律及机理。结果表明:小尺寸离子Cl^-掺杂的聚吡咯复合材料对阴离子污染物有着高效、快速的吸附效率。在100mg/L的Cr（Ⅵ）溶液中,当p H=3时,吸附10min即可达到平衡,吸附率为99.78%。吸附过程是氧化还原反应、表面络合、静电吸附及离子交换综合作用的结果。（2）通过研究掺杂剂的种类、结构等因素对复合材料吸附性能的影响,选定十二烷基磺酸根（SDS）作为大尺寸掺杂离子,采用化学原位聚合法制备ATP/PPy/SDS复合材料,系统研究外界因素对复合材料吸附能力的影响,得到复合材料对阳离子污染物—Ni（Ⅱ）(Ni²⁺)吸附的规律及机理。研究结果表明:大尺寸离子SDS掺杂的聚吡咯复合材料对重金属阳离子污染物具有高效吸附效率。在140mg/L的Ni（Ⅱ）溶液中,当p H=8时,45min时吸附率为86.2%,吸附容量达到120.68mg/g,远高于其他类型的吸附剂。吸附率高的原因是大尺寸掺杂离子使得复合材料与阳离子的交换能力得到了大幅度提高,此外复合材料表面带有大量负电荷,静电吸附作用发挥了同样重要的作用。（3）分别用ATP/PPy/Cl和ATP/PPy/SDS两种复合材料在Ni（Ⅱ）和Cr（Ⅵ）双离子污染物体系中进行吸附研究,探究了掺杂剂和复合材料选择性吸附污染物离子之间的对应关系,结果表明:掺杂离子尺寸不同决定了复合材料对阴离子污染物和阳离子污染物的响应不同。ATP/PPy/Cl优先吸附阴离子Cr（Ⅵ）,而ATP/PPy/SDS优先吸附阳离子Ni（Ⅱ）,研究显示两种材料对两种离子吸附的机理与单离子体系对应的机理是一致的,只不过由于掺杂离子的不同使得复合材料具备的静电吸附和离子交换能力出现了差异,从而导致复合材料对污染物离子的吸附选择性不同。（4）采用ATP/PPy/Cl复合材料在Cr（Ⅵ）和P（Ⅴ）双阴离子污染物体系中进行吸附研究,考察各种因素对复合材料吸附性能的影响,探讨了阴离子吸附质的性质对吸附材料性能的影响机制。结果表明:在0.5¹2h之间,100mg/L的Cr（Ⅵ）和P（Ⅴ）混合溶液中,复合材料对Cr（Ⅵ）的吸附始终高于P（Ⅴ）的,吸附剂用量为0.2g时,Cr（Ⅵ）的平衡吸附率为97.57%。当吸附Cr（Ⅵ）平衡后,P（Ⅴ）的吸附率会随着吸附剂用量的增加而增加,说明ATP/PPy/Cl优先选择吸附Cr（Ⅵ）。机理研究证实了Cr（Ⅵ）的吸附过程与单离子体系的是一致的,而P（Ⅴ）的吸附过程无法发生氧化还原反应,只能借助静电吸附和离子交换吸附。充分证明了吸附质性质的不同,导致其与吸附剂相互作用的机理不同,从而引起二者被吸附时出现了选择性的差异。（5）采用ATP/PPy/SDS复合材料在Ni（Ⅱ）和Cu（Ⅱ）双阳离子污染物体系中进行吸附研究。考察外界因素对复合材料吸附性能的影响,探讨了阳离子吸附质的性质对吸附材料性能的影响机制。结果表明:75mg/L的溶液中,当p H=6时,吸附25min,Cu（Ⅱ）的吸附率达到96.43%,Ni（Ⅱ）的吸附率达到69.75%,说明复合材料优先吸附Cu（Ⅱ）,这种差异与两种离子的水合半径及氧化还原特性相关。因为机理研究表明,吸附Cu（Ⅱ）的过程不但存在离子交换,而且吸附后的Cu（Ⅱ）与吸附剂表面能够形成表面络合物,同时吸附Cu（Ⅱ）的过程发生了氧化还原反应。而吸附Ni（Ⅱ）的过程仍然依靠了静电吸附和离子交换。复合材料吸附Cu（Ⅱ）的推动力要大得多,因此Cu（Ⅱ）的吸附率高于Ni（Ⅱ）的,这也是由吸附质自身性质所决定的。更多还原

【Abstract】 With the development of society and the progress of mankind,human beings are reminded by an ancient and unavoidable problem,which is water pollution.The harm caused by water pollution is very serious,thus many scientis ts begin to study how to remove various pollutants in water.The studies mainly focus on the explanations of mechanism and seeking adsorptive materials with high efficiency.Polypyrrole（PPy）,as a conductive polymer,has preferencial adsorption to ions in solution via doping with different dopants.Based on two dopants,the paper proposes to use attapulgite（ATP）which has high surface area,low-cost and good adsorption property and polypyrrole to fabricate the advanced composites with selective adsorption property.The composites are used to adsorb the heavy metal ions and oxygen acid radical,which aims to reveal the major and minor influence factors and corresponding mechanism.In order to provide therorical guide for designing and fabricating selective adsorption materials,the selective rules of dpants and the influence of adsorbates properties are illuminated.Major conent was shown as follow:（1）ATP/PPy/Cl composites doped by small size ion were prepared by in situ polymerization.The influence of various factors are systemically studied.Some adsorption laws and mechanism about anion ion-Cr（Ⅵ）or(Cr₂O₇^2-)were presented.The conclusion is that PPy composites own high efficient and quick adsorption efficiency after dopped by small size ion-Cl^-.After 10 min in 100mg/L Cr（Ⅵ）solution,adsorption efficiency reached 99.78%when p H is 3.The mainly mechanism is combined with redox reaction,surface complexation electrostatic attraction and ions exchange.（2）After studied the influence of species and structure of dopants on adsorption properties of composites,SDS are chosen as a large size dopant.ATP/PPy/SDS composites doped with SDS are synthesized by in situ polymerization.The influence of various factors are systemically studied.After 45 min in 140mg/L Ni（Ⅱ）solution,when p H is 8,adsorption efficiency reached 86.2%and adsorption capacity is 120.68mg/g,which is higher than other adsorbents.The high adsorption of Ni（Ⅱ）is facilitated through both electrostatic attraction and ions exchange process because of large size dopant and negative charge of surface.（3）ATP/PPy/Cl and ATP/PPy/SDS were employed to adsrob Ni（Ⅱ）and Cr（Ⅵ）for exploring the relationship between dpants and selective adsorption of composites.All results fully illustrate that there is different response between two composites and two kinds ions.ATP/PPy/Cl preferentially adsorb Cr（Ⅵ）,while ATP/PPy/SDS composites preferentially adsorb Ni（Ⅱ）.The mechanism is similar to that of single ion except that there are some differenc es about electrostatic attraction and ion exchange due to different doped ions,which lead to different preference of adsorbents.（4）ATP/PPy/Cl was used to adsorb Cr（Ⅵ）and P（V）.The influence of various factors are systemically studied.The influcnce of properties of anion ions on composites adsorption is discussed In 100 mg/L Cr（Ⅵ）and P（V）solution,the adsorption efficiency of Cr（Ⅵ）is always higher than that of P（V）during the contact time of 0.5¹2h.The equilibrium adsorption efficiency of Cr（V I）is 97.57%using0.2g adsorbent.The adsorption efficiency of Ni（Ⅱ）is increased with adsorbent dosage increase after completed adsorption of Cr（Ⅵ）,suggesting ATP/PPy/Cl composites prefer to remove Cr（Ⅵ）.The adsorption mechanism of Cr（Ⅵ）is similar to Cr（Ⅵ）single system,while the adsorption of P（V）completely depend on the electrostatic attraction and ions exchange process.Obviously,the differences derive from the influence of adsorbate properties.（5）ATP/PPy/SDS composites were employed to remove Ni（Ⅱ）and Cu（Ⅱ）.The influence of various factors are systemically studied.The influcnce of properties of cation ions on composites adsorption is discussed.The results show after 25min in75mg/L solution the adsorption efficiency of Cu（Ⅱ）and N i（Ⅱ）is 96.43%and69.75%when p H is 6.It is obvious that the composites prefer to adsorb Cu（Ⅱ）rather than Ni（Ⅱ）due to their hydrous radium and redox properties.The study of mechanism verifies that some surface complexes are formed between Cu（Ⅱ）an d adsorbents,and redox reactions occur at the same time.While the adsorption of Ni（Ⅱ）is facilitated through electrostatic attraction and ions exchange.Fortunately,the reason made the adsorption efficiency of Cu（Ⅱ）high is that the adsorption impetus of Cu（Ⅱ）is much larger than that of Ni（Ⅱ）,which relates to the properties of adsorbents.更多还原