New thiol adsorbent grafted on silica gel: synthesis, characterization and employment for heavy metal adsorptions.
Silica gel surface has been modified in two reaction steps: (i) the silylating agent 3-mercaptopropyltrimetoxysilane was firstly immobilized to give a surface Sil-SH and (ii) this precursor incorporated an ethylene sulfide molecule to obtain the surface denoted Sil-SSH. This material was characterized by elemental analysis, IR spectroscopy, thermogravimetry, solid state 13C and 29Si NMR, and surface area measurement. These materials were employed as adsorbents for divalent heavy cations from aqueous solutions at room temperature and the isotherms were adjusted to a modified Langmuir equation. The maxima number of moles adsorbed were 1.0, 1.5, 1.6, 2.2, 2.4 and 3.3 mmol g(-1) for Co, Cu, Ni, Cd, Pb, and Hg, respectively.
Departamento de Química, Universidade Federal da Paraíba, CCEN, João Pessoa, Brazil. arakaki@labpesq.quimica.ufpb.br
Luiza N H
LN
Arakaki
Vera L S
VL
Augusto Filha
José G P
JG
Espínola
Maria G
MG
da Fonseca
Severino F
SF
de Oliveira
Tomaz
T
Arakaki
Claudio
C
Airoldi
D000327:Adsorption; D004784:Environmental Monitoring / Q000379:methods; D005782:Gels / Q000737:chemistry; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry*; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
D005782:Gels; D019216:Metals, Heavy; D013438:Sulfhydryl Compounds; D058428:Silica Gel; D012822:Silicon Dioxide