
J. Jpn. Soc. Soil Phys.
#C%
No. +*1, p. -1 .- ,**1   *ῌ**E#ects of Imogolite Addition on Colloidal Stability ofMontmorillonite and Kaolinite
Yu Lu MA* and Jutaro KARUBE*** United Graduate School of Agricultural Science, Tokyo University of Agriculture andTechnology, -ῌ,+ῌ+ Chuo, Ami-machi, Ibaraki-ken, -**ῌ*-3-, Japan** Faculty of Agriculture, Ibaraki University, -ῌ,+ῌ+ Chuo, Ami-machi,Ibaraki-ken, -**ῌ*-3-, JapanAbstract
E#ects of imogolite addition on colloidal stability of montmorillonite and kaolinite were examined to clarify the colloidal properties of imogolite which coagulates in alkaline condition.
One to one mixture of montmorillonite and imogolite coagulated at any pH. Observation throughtransmission electron microscope revealed that montmorillonite and imogolite, including themixture with lower imogolite concentration, mutually ﬂocculated (formed a domain) at any pH.
Non-deferrated kaolinite coagulated below pH /.3 and dispersed above pH 0.*, whereas /῍ imogolite added sample showed the opposite stability. Deferrated kaolinite dispersed above pH ..,,
whereas +*῍ imogolite added sample coagulated at any pH.

All the imogolite added samples

microscopically ﬂocculated both under acidic and alkaline conditions. In acidic conditions, it
was attributed to the electrostatic attraction between permanent negative charge of crystalline
clay minerals and variable positive charge of imogolite. In alkaline conditions, it was considered
to be resulted by the neutralized surface charge of imogolite.
Key words : imogolite, montmorillonite, kaolinite, colloidal stability, charge characteristics

Harsh et al. ',**,( b7c Tsuchida et al. ',**/( d+    ef/JKLM2ghI:*+Vijkl

 !"#$%& 'Horikawa, +31/ ; Harsh etal., +33, ; Karube, +332()

*+,-.

/&_mnI9)@ '+332( -opf2

V +*῍ qr_C-opfC/st'PZNC( / pH 0.* 012&34 567389 pH B_VuvX) 564:*+/;< 'Clark and McBride, +32. ; 4wC"#$%VxyzlV{HB_V|}),**-() 562=>>?@A) BCDE!C5B4 BB f -SFG2H9I4 Horikawa '+31/( /
_eS

2V~I4 5C2Z[VnC:*+/JKLCMNO2PQ4 RSTOUVWIB_273

XYNO5CZ[/\]X^_`aX) ]X4X)* r -**ῌ*-3- i -ῌ,+ῌ+**  -**ῌ*-3- i -ῌ,+ῌ+
4 f -S
4 eS
4 D4 +*D :CV@>27 _»  d +*1 ¼ ,**138
0./ 
Karube, +332   pH Ahmad and ($ G(7 w7f, E"H9 ," 4/!" pH #$ %&'   892($,,, ()*+,-." /0 12 7- +332 *+ bc"%&

3 45 6 ,**- (7 89%Clk  :*;< #$ =( pHsUtu5 A + g f, x?

 >*  )?@A2B<)$ C*.*, M;D  *%&)

NaOH  pH

E**4  89% #*DI I.
);DNa\ *KNO- J2($ /* cm-*.. M  NaCl

M2( KL" ,. {|*D f,w7

KL

, cm- p, HCl *.* cm-2($ I2xl" pH892FG*H E$ IC C.-E($ H2 8l"OL f,  2"J FG K 2(*L #@ANO" TPjM- FGH !($x2( $%j$ f,KLH2 NO &l(=, =892( + M KNO-Pj/* cm- sUtu5p," Q2 IT+** cm- sUtu5 *C*- ?>,+ 2( Jj$ C$%j*Jj Na\ FG*2"N O;P ,ῌ !QR

+ Clk 6&8QR + ῌ 9#22($ 922( Na\ * Clk S2M-{¡Ry($ *2"UVW8 F UVXYZ[&2 ¢2£" &02 CEC * AEC

SN2("TFG Karube, +332

Na\ $%2( Ahmad#($ %&*2"&and Karube, +332

'%& ] J^ (_`+., mm a>
Na\ $%2(4 #($ )O %& E¤7($,,- !"#$%&#@A 892(f,*3c4
kg mk-2"TA *.*.

¥U2 <VW2(%u¦X" %) ,**+ *+ bc"N O;Pd§¨&YZ©t A + mm ª Ie /ῌ !QRSN «[-¬­\®¯°2($2(f,4#($ g + mS mk+ a>.f,4-.2"hij- '()*&)l(4 #($,, -+ ++,)+-./0,,+ k-*., kg m/j-++ 12 *FGm#n2 01o+ : * + : *.+ + : *./ + : +* : +K 2($ K o H2o *3c5$pH %&12FG@A2(%&dk-2* g m FG K 2(f,#@A ±῍+*2 %&²$ !"

#2($  FG + : *.+ K f, pH ,.1 a>@A2 pH -.* aT #2($ (q2#]³K^/ *FGH2o + : * + : *.*/ + : *.+ * : +;? <)? 0´_7 µgM NO*);D FG 4p2($ FGq¶-.($ + : *./ K f, pH -.- a>@A2 pHr Kf,

 2 g mk- *2($/* cm sUtu5-./ aT]³K-*? 12 HCl=( NaOH  pH

,($ I.aivHw6p,)Ml($ f,w7 xl" pHf, z +~P +{;<|l"M- +/892 y{:}; Mr{;<|l" ,. {<=C*- ?

>2($ pH 92"M- ,. {<=2(f,j?
@7WA +* cm- x?

#BT/  CD MODEL TY-.D EM-#F892($ / 89 f, pH892#2($ C  + : *.+ K f,*^!*^/  < `<NO¶-.($+ : + K f,!" pH @A2($ QFG


:(7  *a·£b ;?@A2(*+,-.

$ 89%@A2( c ¸2" -. ,. , =*7"+°$-+, !"#$%&'(FG + : *./ Kf,­\®¹º ¹º῍+²$ Q pH ...

 : DA #$%&N0h$&,-1"_`ῌ+#$%&DATU,-1 "N c*., kg m-M : #$%& I : ~B TU  + " ,-* "uv

Fig. +Colloidal stability of montmorillonite, imogolite, and their mixtures. (measured using
scattered light, c*., kg m-)M : montmorillonite, I : imogolite
Relative turbidity approaches + when dispersed and * when coagulated.
ῌ+   Karube, +332  M : I+ : *./pH ...

M : I+ : *./pH 3..

39

#$%&DATUH IJK

Photo +Transmission electron micrographs ofmontmorillonite-imogolite mixtures.

!"  #$%&'(")*+,- ./0$1 pH 3.. 
23 4#$%&'(")*+-, 

-,+   5,- #$0h$&ijkTUB pH /.3 lm,-8%&,-"6789:;<= >pH 0.* ln83 Sῌ, pH 0.* ln

8 #$%&'"67?")*

B pH+3@A B2;<=

"uv3aC Sῌ- pH /.3 lm,-CopHq r]8 sHq t%

B 0h$&pHq wx?"yz8 sHqDAEAFG<3H IJKLM"N{|3aC 3}8 sHqBpHq~==O #$%&B DAEA"Oz 0h$&ijkTU"F

PQR1>./0$1>,-83 Sῌ+ /ῌ DA R18./0$1B,-83+ : *./ + : *.+ DATU VWX"83B YZ%

Sῌ, R183B sHq

"B,-8>,-[ \]^@A #3a;<= " + : *.+ DATUB R1

$%&_` ]^3a bc!de"fg8

 ./0$10h$& =N*>o"N;<=3 @A <3B8^ rBµ¶ ·eJ ¸ +*1 ¹ 9,**1:40

ῌῌ, 9RNO:
FG`a.
/ bc¬J 9+, :K :  I : FG+,-  ./M ®¯ FGIJM `a°
±*+,- ²³_#80¯

Fig. ,Colloidal stability of kaolinite (non-deferrated) and kaolinite-imogolite mixtures(measured using scattered light).
K : kaolinite, I : imogolite
Scattered light intensity increases whendispersed. Although imogolite disperses inacidic conditions, scattered light was imperceptible due to low concentration.

 9RNO9*.*, M NaCl ´:Fig. -%

NO:

WV¬J

Charge characteristics of kaolinite (nondeferrated and deferrated) (measured with*.*, M NaCl).

E FG ZVWh ijkl

mn 0 !"#$ KLJbcM
op

C*'PqVrstuvw<=!wM

$-,, 

RNO./ xMFG + : *./`a./ Vrstuyzyzῌ,{M$ pH ... 9|}:  pH +*.. 9bc|}: FG
     !"#$% %&' (ῌ, )*+,- ./0'12&3 "*% 4" ~E*'*$ %%8  FG

bcM !"#$ pH ...   ~ *UVWM !"#x FGZ VWC8"4$ 56,- )*'% &378 9(ῌ.:$ ;pH +*.. bcMe ' FG ~<= 56,- >?@ AB<= % V@ J E rh ῌLῌLCDE FGH +*῍  IJKLJ EM

% 78"#$klmn  !"#$ FGZVWCJM

9Gustafsson,,**+: 4 KLJFGA¡bcNO./ pH .., PQ 9(ῌM% !¢M#] V@ J  !

pH UV£¤ ¥¦#$ KLJFG WXY4 9(ῌ-:$ IJZVW[~ ZVW §¨4 M#] FG©/:$ NO./RNO./ ST'MT'\M UVWST#]^_*$ %# FGH +*῍ `aM MT'pH bc 9(ῌ/:$IJbc  NOdefg UVW ª « ¬ UVWCFF
 ~ E !"#$­

pH ... $ %# (ῌ0tu : BC<=+>vwZ[=>@Ac8xy z{ῒῌ.

Z[=> \]^_` #BCab@Ac8 \def`K : Z[=> I : fdeg0 ab@A #EFhi j῍,#kl :mno iFig. .

Colloidal stability of kaolinite (non-deferrated) and kaolinite-imogolite mixtures(measured using transmitted light).
K : kaolinite, I : imogolite
Transmitted light intensity decreases whendispersed. Ordinate was inverted for comparison with Fig. ,.

K : Iq+ : *.+pH ... (dispersed)

K : Iq+ : *.*/

pH +*.. (coagulated)

41

ῐῑῌ,

Z[=>#BCab KLMrs

Photo ,Transmission electron micrographs ofkaolinite-imogolite mixtures.

   !"#$%"&

' pH +*.. ()*+,- ./0  12 

345678(9 :  ;##$%"&'.ῌ ῎ ῍ ῏ῌ <=+>0 ? pH (@A 
ῒῌ/Fig. /Z[=> \^_` #BCab@Ac8 \Apf` + : + (BC<=+>0

Colloidal stability of kaolinite (deferrated)and kaolinite-imogolite mixtures (measuredusing scattered light).

FGHI@A JC-  KLMNO&P? pH ( ' BCDCE
<=+>#0 ? pH (Q ' R8( 0 <=+>
STU#VWXY :#$%"& '_«'aS ¬ +*1 ­ y,**1z42

::Z[   '()*+,%\]^_`a'bcJ+,'WX'2dD   'eB-+fgh0$2%3#45ῌ ῐ ῏ ῍
Ahmad, M.M. and Karube, J. (+332) : E#ects of salts
and pH on the critical coagulation concentrationof montmorillonite. Trans. Jpn. Soc. Irrig. Drain.
Reclam. Eng., +3/ : 3-῏33.
Clark, C. J. and McBride, M.B. (+32.) : Cation and anion retention by natural and synthetic allophane
and imogolite. Clays and Clay Minerals, -, : ,3+῏,33.
Gustafsson, J.P. (,**+) : The surface chemistry of imogolite. Clays and Clay Minerals, .3 : 1-῏2*.
Harsh, J.B., Chorover, J. and Nizeyimana, E. (,**,) :Allophane and imogolite. pp. ,3+῏-,,. ln J.B. Dixon
and D.G. Schulze (ed.) Soil mineralogy with environmental applications. SSSA Book Series No. 1.
῎ῌ0% Y9'+ ¡¢£¤¥'¦§¨
yO :  ; ;<=  ©<= P$z
yª :  ; ;<=:©<=:P$z

Fig. 0Illustrations explaining the transmission
electron micrographs of kaolinite-imogolite
mixtures.
(upper : acidic ; ﬂocculated in microscopic
and dispersed in macroscopic observation)(lower : alkaline ; ﬂocculated both in microscopic and macroscopic observation)

SSSA, Madison, WI.
Harsh, J.B., Traina, S. J., Boyle, J. and Yang, Y. (+33,) :Adsorption of cations on imogolite and their effect on surface charge characteristics. Clays andClay Minerals, .* : 1**῏1*0.
Horikawa, Y. (+31/) : Electrokinetic phenomena of
aqueous suspensions of allophane and imogolite.
Clay Science, . : ,//῏,0-.
Karube, J. (+332) : Hysteresis of the colloidal stabilityof imogolite. Clays and clay minerals, .0 : /2-῏/2/.

ijklm ῌ nopq ῌ rstu ῌ hvwx y+332z :ῌ pH /.3  !

/῍ "#$% &

' '()*+,-./

012%3#45 6 7'89:;<=>$% pH ??@4A

'BCDEF῍ 

={|}% '%,+~_  +30 : +*-῏++*.
ijklm y,**-z : ',+~%

 _ ,20῏,21.
h y,**-z : _'= } p -..
Tsuchida, H., Ooi, S., Nakaishi, K. and Adachi, Y.

GDHIJ(,**/) : E#ects of pH and ionic strength on elec-+,-KLM0D pH .., NO 75

trokinetic properties of imogolite. Colloids and

Surfaces A : Physicochemical and Eng. Aspects,

! +*῍ "#$%PQ' pH 

' RSG1'J+,-TTU"7%GD  '()*+,%'V'WX-./012%3#45
῎ ;<=>$% PQ' Y9,0/ : +-+῏+-..

m y,**+z : v?4'={|}' ^_ . : ,.,῏,.2.

pq : *+:   r6s  !tu %&῍ !"43ῌ 

 #$%&'()     + : + *+,   - (. pH ,) /012345678    - *+9+:;<=+>. (. pH ?@,) ABC - pH/.3 DE, pH 0.* DF ,: G /ῌ KL 
-(. #$ !:HI,) J *+MN-OPP,) QRS- O TUV/WXYZ[\]^_`/Wab -cd:/efgh ij7)klmno : ,**1 m . n ,* okRmno : ,**1 m 3 n 1 o