title: Nano-diamond particles functionalized with single/double-arm amide-thiourea ligands for adsorption of metal ions.
abstract: Separation efficiency of solid-phase extractant is greatly subjected to the spatial configurations of functional ligands attached to the matrix, which has not been studied efficiently till now. In order to further understand the relationship between spatial configurations of the attached functional ligand and the adsorption ability of the extractant, two novel molecules (single-armed ligand, SA and double-armed ligand, DA) with identical coordination unit (amide-thiourea) but different spatial configurations (single/double arms) were designed and synthesized. The corresponding extractants, ND-SA and ND-DA were obtained by modification of nanodiamond (ND) with SA and DA and both the extractants displayed good chemical and thermal stabilities. The batch adsorption experiments showed that ND-SA and ND-DA possess large adsorption capacities (∼200 mg g(-1)), very fast adsorption kinetics (reaching equilibrium within 2 min) and excellent selectivities (up to 82% and 72%, respectively) for uranium. The study of the possible mechanism indicated that ND-DA tends to utilize its tweezer-like double arms to "clamp" metal ions and the stronger chelate interaction could to some extent weaken the coordination selectivity of attached DA ligand. In contrast, single-armed adsorbent ND-SA unexpectedly exhibited better adsorption selectivity for uranium than ND-DA owing to its more flexible spatial configuration and moderate complexing ability.
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Xiaosheng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Chiyao
authors.initials: C
authors.lastname: Bai
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wen
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
authors.forename: Meicheng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China. Electronic address: ma.lj@hotmail.com.
authors.forename: Lijian
authors.initials: L
authors.lastname: Ma
authors.affiliation: College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China. Electronic address: sjli000616@scu.edu.cn.
authors.forename: Shoujian
authors.initials: S
authors.lastname: Li
keywords: Adsorption; Amide–thiourea; Nanodiamond; Spatial configuration; Uranium