Synthesis of amidoximated polyacrylonitrile nanoparticle/graphene composite hydrogel for selective uranium sorption from saline lake brine
Synthesis of amidoximated polyacrylonitrile nanoparticle/graphene composite hydrogel for selective uranium sorption from saline lake brine
复制标题
偕胺肟化聚丙烯腈纳米粒子/石墨烯复合水凝胶的合成用于选择性吸附盐湖卤水中的铀
DOI：
10.1016/j.cej.2019.123553
复制
发表时间：
2020-07-01
影响因子：
15.1
通讯作者：
Qin, Zhi
中科院分区：
文献类型：
--
作者：
Bai, Jing;Chu, Jian;Qin, Zhi
为了提高石墨烯水凝胶(GH)对铀的选择性，确保其在海水、盐湖卤水等复杂体系中提取铀的可能性，需要制备含胺肟基的GH。然而，在生长激素上接枝胺肟基并不是一件容易的事情。本工作采用一种创新的方法，通过在水凝胶形成过程中同时包裹聚丙烯腈(PAN)纳米粒子，然后再将其胺化，从而制备了酰胺化石墨烯水凝胶、聚芳腈纳米粒子/石墨烯复合水凝胶(PAO/GH)。用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)、X射线衍射仪(X射线衍射仪)和BET比表面积分析对所制备的吸附剂进行了表征。结果表明，成功地制备了含胺肟基的PAO/GH。系统研究了初始溶液pH、离子强度、时间和初始铀浓度对PAO/GH吸附铀的影响，并与空白石墨烯水凝胶(GH)进行了比较。引入胺肟基后，PAO/GH催化剂的铀选择性明显提高。此外，还用不同的表征方法探讨了PAO/GH对铀的吸附机理。氨基是PAO/GH吸附铀的主要官能团，也是电子供体。在此基础上，用PAO/GH从天然盐湖卤水中提取铀，证明PAO/GH是一种很有前途的从复杂体系中回收铀的吸附剂。
In order to increase the selectivity of graphene hydrogel (GH) for uranium and ensure its possible application in uranium extraction from complicated systems, such as seawater and saline lake brines, GH with amidoxime groups needs to be prepared. However, it is not an easy task to grafting amidoxime groups on GH. At present work, an innovative method is used to fabricate the amidoximated graphene hydrogel, polyarylonitrile nanoparticle/graphene composite hydrogel (PAO/GH), through simultaneously encapsulating polyacrylonitrile (PAN) nanoparticles in hydrogel formation process and then amidoximation. The prepared adsorbent is characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and BET specific surface area analyses. All the results prove that PAO/GH with amidoxime groups is successfully obtained. The effects of initial solution pH, ionic strength, time and initial uranium concentration on uranium sorption by PAO/GH are studied systematically and compared with the blank graphene hydrogel (GH). The uranium selectivity of PAO/GH increases obviously after introducing amidoxime groups. Moreover, the mechanism of uranium sorption by PAO/GH is also explored with different characterization methods. Amidoxime groups are revealed to be the main functional groups involved in uranium sorption by PAO/GH and served as electron donor. Basis on the above results, uranium extraction from natural saline lake brine by PAO/GH is also performed and PAO/GH is testified to be a promising adsorbent for recovering uranium from complicated systems.