基于辐射接枝基底的宏尺寸UiO-66-S膜制备及其对代血浆中汞离子的清除

Preparation of large-size UiO-66-S films based on radiation grafted substrates and its mercury ion-removal performance in artificial plasma

为开发高效吸附材料,以提高重金属中毒的治愈率,设计制备了基于辐射接枝基底的宏尺寸金属有机框架UiO-66-S膜,并研究了其在代血浆中对重金属离子的选择清除特性。通过酸碱滴定法定量测定了基底上马来酸酐(MAH)接枝面密度,研究了辐照参数对接枝面密度的影响,实现了在0.10~75.80 nmol/cm2范围内对接枝面密度的调控。对MAH接枝膜表面浸润性和力学性能的研究证明辐射接枝过程会改变材料表面浸润性,而不会对材料力学性能造成影响。在接枝面密度为14.94 nmol/cm2的基底上,通过原位生长和合成后修饰制备了UiO-66-S膜,并用傅里叶变换衰减全反射红外光谱、X射线衍射、X射线光电子能谱和扫描电镜等手段对其进行了表征。结果表明得到了纳米厚度的连续UiO-66-S膜。UiO-66-S膜在代血浆中多离子共存的条件下,表现出对汞离子的优异选择性,其清除率可达到50%以上。吸附过程符合伪二阶动力学方程,且与纯水体系相比,UiO-66-S膜对代血浆中汞离子的清除速率更快。

To develop efficient adsorption materials to improve the cure rate of heavy metal poisoning,we designed and prepared large size metal-organic framework(MOF)UiO-66-S films based on irradiation-grafting pretreated substrate,and investigated the selectivity of these films with multi-heavy metal ions in artificial plasma.The grafting density of maleic anhydride on a substrate was quantitatively measured by chemical titration and the effects of the radiation parameters on the grafting density were studied.The grafting density could be tuned from 0.10 to 75.80 nmol/cm2 by changing the radiation parameters.The investigation of surface wettability and mechanical property proved that the irradiation-grafting process changed the surface wettability of maleic anhydride grafting substrate but did not affect its mechanical property.We prepared UiO-66-S films by in-situ growth and postsynthesis modification on the substrate with the grafting density of 14.94 nmol/cm2 and characterized the film by attenuated total reflection flourier transformed infrared spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and scanning electron microscope,which showed how the nanothickness continuous MOF film was obtained.The UiO-66-S films exhibited high selectivity to mercury ions in the artificial plasma with multi-ions coexisting;the removal ratio reached more than 50%.The adsorption process followed the pseudo-second-order kinetic equation.Moreover,the mercury ion-removal rate of the UiO-66-S films in the artificial plasma was faster than that in pure water.