Cu(II)/Zn(II)-assisted assembly approach to prepare highly porous diamine/triamine-bridged polysilsesquioxanes with desirable adsorption properties

Abstract In this paper, a series of diamine/triamine-bridged polysilsesquioxanes were prepared by the sol-gel method from diethylenetriamine (DETA) and ethylenediamine (EDA) based precursor containing trimethoxysilane groups. Cu(II) and Zn(II) were used to assist the construction of the highly porous materials. A fully hydrolyzable silane tetraethylorthosilicate (TEOS) and a template PEO-PPO-PEO (P123) were also used in the co-condensation process. It was proven in the characterization of porous structures that the presence of Cu(II) or Zn(II) significantly improved the porosity of the adsorbent materials. These materials showed a positive correlation between the porosity and the degree of utilization of N-containing groups in the adsorption experiments for Au(III) and Cu(II). They also showed some imprinting effect of selectively binding to the same metal ion which was used in the synthesis. Interestingly, these materials showed excellent selectivity for Au(III) in some instances. Potential applications of these materials may include selective enrichment of Au(III), Cu(II) and Zn(II) in environmental samples.