Surface charging of layered double hydroxides during dynamic interactions of anions at the interfaces

Xu, Z. P., Jin, Y., Liu, S., Hao, Z. P. and Lu, G. Q. (2008) Surface charging of layered double hydroxides during dynamic interactions of anions at the interfaces. Journal of Colloid and Interface Science, 326 2: 522-529. doi:10.1016/j.jcis.2008.06.062

Author Xu, Z. P.
Jin, Y.
Liu, S.
Hao, Z. P.
Lu, G. Q.
Title Surface charging of layered double hydroxides during dynamic interactions of anions at the interfaces
Journal name Journal of Colloid and Interface Science   Check publisher's open access policy
ISSN 0021-9797
Publication date 2008-10-15
Year available 2008
Sub-type Article (original research)
DOI 10.1016/j.jcis.2008.06.062
Open Access Status DOI
Volume 326
Issue 2
Start page 522
End page 529
Total pages 8
Editor Darsh T. Wasan
Place of publication USA
Publisher Academic Press
Language eng
Subject C1
860899 Human Pharmaceutical Products not elsewhere classified
100708 Nanomaterials
Abstract In this research, we investigated the effect of dynamic anion adsorption/exchange on the surface charging property Of Mg2Al-Cl-LDH and Mg2Al-CO3-LDH particles that show the average zeta potential of 41 and 34 mV in the as-prepared suspension, respectively. The addition of NaCl up to 3 x 10(-3) M in the suspension does not obviously affect the zeta potential of both LDHs, which can be attributed to the less affinity of Cl- to LDH. The introduction of Na2CO3 severely reduces the zeta potential at the CO32- concentration higher than 1 x 10(-4) M, and to the negative value in both LDH systems at ca. 2 x 10(-3) M, which is presumably resulted from the exchange and the re-orientation of CO32- in a tilt/vertical style on the surface. All four organic anions (dodecyl sulfate, folate, citrate and polyacrylate) also significantly affect the zeta potential of the LDH particles. At the lower concentrations of organic anionic groups (<1 x 10(-4) M), the zeta potential was slightly affected, i.e. limited exchange/adsorption. However, the concentration increasing to some point suddenly decreases and reverses the zeta potential of the LDH Particles, which is presumably caused by the hydrophobic interactions that bind the hydrophobic hydrocarbon chains (especially in dodecyl sulfate) into the micelle-like bilayer bunches on the LDH Surface. in addition, the effect of pH in 5.5-11.0 on the LDH particle surface charging is mainly reflected through the conversion of CO32- to HCO3-/H2CO3 when pH decreases from ca. 11 to 6, with limited contribution from protonation/depprotonation and exchange/adsorption.
Keyword Chemistry, Physical
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID DP0879769
Institutional Status UQ
Additional Notes DOI: 10.1016/j.jcis.2008.06.062

Document type: Journal Article
Sub-type: Article (original research)
Collection: 2009 Higher Education Research Data Collection
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Created: Fri, 17 Apr 2009, 01:38:46 EST by Vicki Thompson on behalf of School of Chemical Engineering