Role of chitin in montmorillonite fabric: Transmission electron microscope observations

Jin-Wook Kim, Yoko Furukawa, Kenneth J. Curry, Richard H. Bennett

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Particle concentration, charge, solution chemistry (i.e. ionic strength), and the nature of organic matter (OM) are the major factors controlling particle flocculation in aqueous environments. In the present study, the nature of clay fabric associated with clay-OM interaction at a range of ionic strengths was the focus. In the flocculation experiments, the aqueous suspension of montmorillonite and chitin was mixed with NaCl/MgSO 4 electrolyte solution. Advanced sample-preparation techniques and visualization methods using transmission electron microscopy were used to observe directly the micro- and nano-scale clay-OM fabric of the resulting flocs. Such direct observation elucidated the role of OM in clay flocculation; few attempts have been made in the past due to the technical difficulties in preserving the original structure. A comparison of clay fabric at two different ionic strengths of 0 and 0.14Mrevealed that the individual hexagonal clay particles settled slowly with little intra-aggregate void space (void ratio: 0.07) at 0 M while rapid flocculation and settling of clay particles at 0.14 M, with or without OM, resulted in a more open fabric with greater void space (void ratio: 0.33). The silver-staining technique demonstrated effectively the location of electron-transparent chitin in montmorillonite aggregates. Chitin appeared to link the face-to-face (FF) contacts of clay domains by bridging between negatively charged face surfaces. However, the resultant void ratio and the average hydrodynamic diameter (d H) values were lower than in the OM-free system after flocculation. The results indicated that the interplay between ionic strength and OM content affected the floc architecture and void ratio.

Original languageEnglish
Pages (from-to)89-98
Number of pages10
JournalClays and Clay Minerals
Volume60
Issue number1
DOIs
Publication statusPublished - 2012 Feb 1

Fingerprint

Bentonite
Chitin
transmission electron microscopes
chitin
montmorillonite
Biological materials
Electron microscopes
clay
flocculation
Flocculation
electron
organic matter
void ratio
ionic strength
Ionic strength
void
fabric
sample preparation
Silver
electrolyte

All Science Journal Classification (ASJC) codes

  • Soil Science
  • Earth and Planetary Sciences (miscellaneous)
  • Geochemistry and Petrology
  • Water Science and Technology

Cite this

Kim, Jin-Wook ; Furukawa, Yoko ; Curry, Kenneth J. ; Bennett, Richard H. / Role of chitin in montmorillonite fabric : Transmission electron microscope observations. In: Clays and Clay Minerals. 2012 ; Vol. 60, No. 1. pp. 89-98.
@article{0d1822d3d3414b5995972894e385a1f4,
title = "Role of chitin in montmorillonite fabric: Transmission electron microscope observations",
abstract = "Particle concentration, charge, solution chemistry (i.e. ionic strength), and the nature of organic matter (OM) are the major factors controlling particle flocculation in aqueous environments. In the present study, the nature of clay fabric associated with clay-OM interaction at a range of ionic strengths was the focus. In the flocculation experiments, the aqueous suspension of montmorillonite and chitin was mixed with NaCl/MgSO 4 electrolyte solution. Advanced sample-preparation techniques and visualization methods using transmission electron microscopy were used to observe directly the micro- and nano-scale clay-OM fabric of the resulting flocs. Such direct observation elucidated the role of OM in clay flocculation; few attempts have been made in the past due to the technical difficulties in preserving the original structure. A comparison of clay fabric at two different ionic strengths of 0 and 0.14Mrevealed that the individual hexagonal clay particles settled slowly with little intra-aggregate void space (void ratio: 0.07) at 0 M while rapid flocculation and settling of clay particles at 0.14 M, with or without OM, resulted in a more open fabric with greater void space (void ratio: 0.33). The silver-staining technique demonstrated effectively the location of electron-transparent chitin in montmorillonite aggregates. Chitin appeared to link the face-to-face (FF) contacts of clay domains by bridging between negatively charged face surfaces. However, the resultant void ratio and the average hydrodynamic diameter (d H) values were lower than in the OM-free system after flocculation. The results indicated that the interplay between ionic strength and OM content affected the floc architecture and void ratio.",
author = "Jin-Wook Kim and Yoko Furukawa and Curry, {Kenneth J.} and Bennett, {Richard H.}",
year = "2012",
month = "2",
day = "1",
doi = "10.1346/CCMN.2012.0600108",
language = "English",
volume = "60",
pages = "89--98",
journal = "Clays and Clay Minerals",
issn = "0009-8604",
publisher = "Clay Minerals Society",
number = "1",

}

Role of chitin in montmorillonite fabric : Transmission electron microscope observations. / Kim, Jin-Wook; Furukawa, Yoko; Curry, Kenneth J.; Bennett, Richard H.

In: Clays and Clay Minerals, Vol. 60, No. 1, 01.02.2012, p. 89-98.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Role of chitin in montmorillonite fabric

T2 - Transmission electron microscope observations

AU - Kim, Jin-Wook

AU - Furukawa, Yoko

AU - Curry, Kenneth J.

AU - Bennett, Richard H.

PY - 2012/2/1

Y1 - 2012/2/1

N2 - Particle concentration, charge, solution chemistry (i.e. ionic strength), and the nature of organic matter (OM) are the major factors controlling particle flocculation in aqueous environments. In the present study, the nature of clay fabric associated with clay-OM interaction at a range of ionic strengths was the focus. In the flocculation experiments, the aqueous suspension of montmorillonite and chitin was mixed with NaCl/MgSO 4 electrolyte solution. Advanced sample-preparation techniques and visualization methods using transmission electron microscopy were used to observe directly the micro- and nano-scale clay-OM fabric of the resulting flocs. Such direct observation elucidated the role of OM in clay flocculation; few attempts have been made in the past due to the technical difficulties in preserving the original structure. A comparison of clay fabric at two different ionic strengths of 0 and 0.14Mrevealed that the individual hexagonal clay particles settled slowly with little intra-aggregate void space (void ratio: 0.07) at 0 M while rapid flocculation and settling of clay particles at 0.14 M, with or without OM, resulted in a more open fabric with greater void space (void ratio: 0.33). The silver-staining technique demonstrated effectively the location of electron-transparent chitin in montmorillonite aggregates. Chitin appeared to link the face-to-face (FF) contacts of clay domains by bridging between negatively charged face surfaces. However, the resultant void ratio and the average hydrodynamic diameter (d H) values were lower than in the OM-free system after flocculation. The results indicated that the interplay between ionic strength and OM content affected the floc architecture and void ratio.

AB - Particle concentration, charge, solution chemistry (i.e. ionic strength), and the nature of organic matter (OM) are the major factors controlling particle flocculation in aqueous environments. In the present study, the nature of clay fabric associated with clay-OM interaction at a range of ionic strengths was the focus. In the flocculation experiments, the aqueous suspension of montmorillonite and chitin was mixed with NaCl/MgSO 4 electrolyte solution. Advanced sample-preparation techniques and visualization methods using transmission electron microscopy were used to observe directly the micro- and nano-scale clay-OM fabric of the resulting flocs. Such direct observation elucidated the role of OM in clay flocculation; few attempts have been made in the past due to the technical difficulties in preserving the original structure. A comparison of clay fabric at two different ionic strengths of 0 and 0.14Mrevealed that the individual hexagonal clay particles settled slowly with little intra-aggregate void space (void ratio: 0.07) at 0 M while rapid flocculation and settling of clay particles at 0.14 M, with or without OM, resulted in a more open fabric with greater void space (void ratio: 0.33). The silver-staining technique demonstrated effectively the location of electron-transparent chitin in montmorillonite aggregates. Chitin appeared to link the face-to-face (FF) contacts of clay domains by bridging between negatively charged face surfaces. However, the resultant void ratio and the average hydrodynamic diameter (d H) values were lower than in the OM-free system after flocculation. The results indicated that the interplay between ionic strength and OM content affected the floc architecture and void ratio.

UR - http://www.scopus.com/inward/record.url?scp=84859453060&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84859453060&partnerID=8YFLogxK

U2 - 10.1346/CCMN.2012.0600108

DO - 10.1346/CCMN.2012.0600108

M3 - Article

AN - SCOPUS:84859453060

VL - 60

SP - 89

EP - 98

JO - Clays and Clay Minerals

JF - Clays and Clay Minerals

SN - 0009-8604

IS - 1

ER -