TY - JOUR
T1 - Effect of surfactant molecular structure on perchlorate removal by various organo-montmorillonites
AU - Luo, Wuhui
AU - Sasaki, Keiko
AU - Hirajima, Tsuyoshi
N1 - Funding Information:
Financial support was provided to KS by the funding program “Progress 100” (World Premier International Researcher Invitation Program) through operating expense grants of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) . FESEM observation and XPS measurement were conducted on the Advanced Analytical Center in Kyushu University.
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/9/1
Y1 - 2015/9/1
N2 - A series of organo-montmorillonites (organo-Mt) was synthesized using various cationic surfactants with different alkyl-chain lengths, head groups, and alkyl-chain numbers, which were systematically examined for perchlorate adsorption. The products were characterized by the specific surface area, field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. In addition, the surfactant loadings and surface charges were investigated by CHN analysis and zeta potential measurements. The greatest adsorption capacity of 0.95. mmol/g-composite was obtained on benzyloctadecyldimethylammonium-modified Mt. Increasing the alkyl-chain length significantly enhanced the capacity and selectivity for perchlorate adsorption, but resulted in decrease of adsorption rate. Compared with trimethylammonium and pyridinium with the same alkyl-chain length, the benzyldimethylammonium as a head group showed better performance in terms of adsorption capacity and selectivity of perchlorate because of higher hydrophobicity. Moreover, increasing the alkyl-chain number decreased adsorption rate, but enhanced adsorption capacity, because of dense packing of alkyl chains and high driving force for entrapment of counter ion-accompanying surfactant. The perchlorate adsorption performance of organo-Mt was synergistically influenced by the alkyl-chain length, head group and alkyl-chain number of the surfactants used for modification.
AB - A series of organo-montmorillonites (organo-Mt) was synthesized using various cationic surfactants with different alkyl-chain lengths, head groups, and alkyl-chain numbers, which were systematically examined for perchlorate adsorption. The products were characterized by the specific surface area, field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. In addition, the surfactant loadings and surface charges were investigated by CHN analysis and zeta potential measurements. The greatest adsorption capacity of 0.95. mmol/g-composite was obtained on benzyloctadecyldimethylammonium-modified Mt. Increasing the alkyl-chain length significantly enhanced the capacity and selectivity for perchlorate adsorption, but resulted in decrease of adsorption rate. Compared with trimethylammonium and pyridinium with the same alkyl-chain length, the benzyldimethylammonium as a head group showed better performance in terms of adsorption capacity and selectivity of perchlorate because of higher hydrophobicity. Moreover, increasing the alkyl-chain number decreased adsorption rate, but enhanced adsorption capacity, because of dense packing of alkyl chains and high driving force for entrapment of counter ion-accompanying surfactant. The perchlorate adsorption performance of organo-Mt was synergistically influenced by the alkyl-chain length, head group and alkyl-chain number of the surfactants used for modification.
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U2 - 10.1016/j.clay.2015.06.003
DO - 10.1016/j.clay.2015.06.003
M3 - Article
AN - SCOPUS:84934954033
VL - 114
SP - 212
EP - 220
JO - Applied Clay Science
JF - Applied Clay Science
SN - 0169-1317
ER -