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Title: Sorption kinetics of hexadecyltrimethylammonium on natural clinoptilolite

Abstract

Sorption kinetics of hexadecyltrimethylammonium (HDTMA) chloride on a natural clinoptilolite was studied in this research. The amount of HDTMA sorbed is a function of the initial HDTMA input and the sorption time. When the initial HDTMA input is less than the external cation-exchange capacity of the clinoptilolite, the HDTMA sorption is fast and equilibrium can be established in 1 h. As the initial HDTMA input is greater than the external cation-exchange capacity of clinoptilolite, which will result in more than a monolayer HDTMA surface coverage, the time for HDTMA sorption to reach equilibrium increases exponentially. The HDTMA sorption maximum on clinoptilolite increases logarithmically with mixing time. The counterion solution concentration data suggest that at the initial stage HDTMA molecules sorb on the zeolite via micelle forms, which is manifested by a decrease in chloride solution concentration with time. When HDTMA solution concentration is depleted to less than its critical micelle concentration, the adsorbed micelles (admicelles) rearrange themselves to a more stable monolayer or bilayer configuration, which is reflected by an increase in counterion solution concentration due to the desorption of chloride from admicelles. The time required for the surface rearrangement increases exponentially as the HDTMA input increases. The data ofmore » HDTMA sorption kinetics were fitted to different kinetic models, and the parabolic diffusion model fits the data best for the HDTMA sorption, counterion sorption at the initial stage and counterion desorption at the rearrangement stage. Thus, the sorption of HDTMA on clinoptilolite surfaces is diffusion controlled. The results also indicate that it is incomplete to discuss surfactant sorption without counterion concentration data.« less

Authors:
Publication Date:
Research Org.:
Univ. of Wisconsin-Parkside, Kenosha, WI (US)
Sponsoring Org.:
USDOE
OSTI Identifier:
20000008
DOE Contract Number:  
AR21-95MC32108
Resource Type:
Journal Article
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 15; Journal Issue: 19; Other Information: PBD: 14 Sep 1999; Journal ID: ISSN 0743-7463
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 54 ENVIRONMENTAL SCIENCES; INDUSTRIAL WASTES; SURFACTANTS; ADSORPTION; CLINOPTILOLITE; SORPTIVE PROPERTIES; MICELLAR SYSTEMS

Citation Formats

Li, Z. Sorption kinetics of hexadecyltrimethylammonium on natural clinoptilolite. United States: N. p., 1999. Web. doi:10.1021/la981535x.
Li, Z. Sorption kinetics of hexadecyltrimethylammonium on natural clinoptilolite. United States. doi:10.1021/la981535x.
Li, Z. Tue . "Sorption kinetics of hexadecyltrimethylammonium on natural clinoptilolite". United States. doi:10.1021/la981535x.
@article{osti_20000008,
title = {Sorption kinetics of hexadecyltrimethylammonium on natural clinoptilolite},
author = {Li, Z.},
abstractNote = {Sorption kinetics of hexadecyltrimethylammonium (HDTMA) chloride on a natural clinoptilolite was studied in this research. The amount of HDTMA sorbed is a function of the initial HDTMA input and the sorption time. When the initial HDTMA input is less than the external cation-exchange capacity of the clinoptilolite, the HDTMA sorption is fast and equilibrium can be established in 1 h. As the initial HDTMA input is greater than the external cation-exchange capacity of clinoptilolite, which will result in more than a monolayer HDTMA surface coverage, the time for HDTMA sorption to reach equilibrium increases exponentially. The HDTMA sorption maximum on clinoptilolite increases logarithmically with mixing time. The counterion solution concentration data suggest that at the initial stage HDTMA molecules sorb on the zeolite via micelle forms, which is manifested by a decrease in chloride solution concentration with time. When HDTMA solution concentration is depleted to less than its critical micelle concentration, the adsorbed micelles (admicelles) rearrange themselves to a more stable monolayer or bilayer configuration, which is reflected by an increase in counterion solution concentration due to the desorption of chloride from admicelles. The time required for the surface rearrangement increases exponentially as the HDTMA input increases. The data of HDTMA sorption kinetics were fitted to different kinetic models, and the parabolic diffusion model fits the data best for the HDTMA sorption, counterion sorption at the initial stage and counterion desorption at the rearrangement stage. Thus, the sorption of HDTMA on clinoptilolite surfaces is diffusion controlled. The results also indicate that it is incomplete to discuss surfactant sorption without counterion concentration data.},
doi = {10.1021/la981535x},
journal = {Langmuir},
issn = {0743-7463},
number = 19,
volume = 15,
place = {United States},
year = {1999},
month = {9}
}