磁性铁氧化物晶面调控对铯离子吸附剂嫁接性能的影响研究

The resource of Cs in salt lake is difficult to efficiently extract and separate in comprehensive utilization because of low concentration. Using calix[4] arene-bis-crown-6 and derivatives as chelating molecules, grafted onto magnetic iron oxide surface and preparation of magnetic adsorbent is an effective approach to solve this problem. However, the application of this technology is restricted by the stability of calix[4] arene-bis-crown-6 or their derivatives grafted on magnetic iron oxide surface. This project will research the grafting abilities between the calix[4] arene-bis-crown-6 or derivatives and magnetic iron oxide particles which exposed by different facets. It is also investigate the factors that influence the stability and adsorption properties of prepared magnetic adsorbent. The detail of research contents as below: first of all, investigate the properties of different crystal planes on different magnetic iron oxide surface by computer simulation, and calculate the modified abilities of calix[4] arene-bis-crown-6 or their derivatives on different iron oxide surface. The factors affected the modified stability are also theoretical calculated. Secondly, we investigate the growth behavior of exposed planes on magnetic iron oxide under trace inorganic ions and organic compounds under the influence of adsorption effect. Design and prepare the magnetic iron oxides with different planes exposed, and research the surface properties of these particles. At last, investigate the adsorption stability of calix[4] arene-bis-crown-6 or their derivatives on different magnetic iron oxide planes. The abilities of adsorbent to Cs+ and the magnetic recycling properties are discussed, which guide us to prepare more stable and effective Cs+ adsorbent.

低浓度Cs资源清洁高效分离提取是盐湖资源综合开发利用的难题，利用杯[4]-双冠-6杯冠芳烃及衍生物作为螯合分子，嫁接到磁性铁氧化物表面而制成有效的磁性吸附剂是解决该问题的有效途径。然而，磁性铁氧化物表面嫁接杯[4]-双冠-6杯冠芳烃及衍生物的稳定性是影响该技术运用的主要瓶颈。本项目以不同暴露晶面的磁性铁氧化物颗粒嫁接不同杯冠芳烃及衍生物为研究对象，对晶体晶面特性影响嫁接稳定性及磁性吸附规律进行基础科学研究。具体内容包括：理论模拟计算磁性铁氧化物不同晶面的物理化学特性和对杯冠芳烃嫁接能力的影响；研究微量配体离子诱导作用下，不同磁性铁氧化物单晶颗粒暴露晶面的生长行为规律及暴露晶面的物理化学特性；研究磁性纳米颗粒暴露晶面对嫁接杯[4]-双冠-6杯冠芳烃及衍生物的影响以及杯冠芳烃表面官能团在磁性颗粒晶面上的作用关系；研究磁性吸附剂对Cs离子的吸附选择性能和磁性固液分离性能。

盐湖资源综合开发利用过程中，低溶度Cs+离子资源清洁高效分离是急需解决的问题，本项目在调控铁氧化物的基础上，利用冠醚衍生物嫁接到磁性铁氧化物表面制成有效的磁性吸附剂。首先利用单一有机物辛胺或甲酰胺作为配体，在制备颗粒过程中由于与氧化物颗粒表面羟基产生螯合作用，从而影响氧化铁颗粒在[110]方向的生长或（112）晶面的暴露。然后采用无机磷酸根离子和有机的尿素配体共同作用，研究其对氧化铁颗粒[001]方向和（001）晶面暴露的影响。最后为提高颗粒分散性，采用多羟基配体的丙三醇，探索配体对氧化铁颗粒[001]方向和（001）晶面暴露的影响。通过前期的铁氧化物的制备，结合文献和模拟计算后，对Fe3O4表面的羟基种类及羟基密度进行了分析。我们采用暴露面为（001）的Fe3O4 表面嫁接18-冠-6冠醚衍生物，所得磁性吸附剂的吸附行为进行考察，包括吸附热力学，动力学及循环利用性能进行了研究，为改进磁性吸附剂的性能提供部分理论依据。