期刊论文详细信息
Materials Research
Tailoring activated carbon by surface chemical modification with O, S, and N containing molecules
Rachel Ribeirovieira Azzi Rios1  Dênio Eduardo Alves1  Ilza Dalmázio1  Sílvio Fernando Vargas Bento1  Claudio Luis Donnici1  Rochel Monteiro Lago1 
[1] ,Universidade Federal de Minas Gerais ICEx Dep. Química
关键词: activated carbon;    surface modification;    functionalization;    cation exchange;    heavy metals;   
DOI  :  10.1590/S1516-14392003000200004
来源: SciELO
PDF
【 摘 要 】

In this work the surface of activated carbon was chemically modified in order to introduce O, S and N containing groups. The activated carbon surface was selectively oxidized with concentrated HNO3 under controlled conditions. Characterization by thermogravimetric analyses, infrared spectroscopy and NaOH titration suggested the formation of mainly -COOH and small amounts of -OH groups, with concentration of approximately 4.10(21) groups/g of carbon. These -COOH functionalized carbons showed high adsorption capacity for metal cations in aqueous solution in the following order: Pb+2>Cu+2>Ni+2 >Cd+2~Co+2>Ca+2 , suggesting a cation exchange mechanism via a surface complex [COO-M+2]. These -COOHsurf groups can be reacted with SOCl2 to produce a surface acylchloride group, -COCl. This surface -COCl group proved to be a very reactive and versatile intermediate for the grafting of different S and N containing molecules onto the carbon surface, such as 1,2-ethaneditiol (EDT-, HSCH2CH2SH) 1,7-dimercapto-4-thioheptane (DMTH-HSCH2CH2CH2SCH2CH 2CH2SH) or 1,2-ethylenediamine (EDA- NH2CH2CH2NH2 ) and triethyltetraamine, TEA (H2NCH2CH2NHCH2CH 2NHCH2CH2 NH2). The characterization of these materials was carried out by TG, IR and TPDMS (Temperature Programmed Decomposition Mass Spectrometry) experiments suggesting the formation of thioesther and amide surface groups, i.e. -COSR and -CONHR, with yields of approximately 50 and 75% for the reaction with DME and EDA, respectively. Preliminary adsorption experiments showed that these materials can efficiently remove metals such as Pb+2, Cu+2 and Ni+2 from aqueous medium.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License

【 预 览 】
附件列表
Files Size Format View
RO202005130151923ZK.pdf 650KB PDF download
  文献评价指标  
  下载次数:6次 浏览次数:3次