Performance Relationships in Surfactants - American

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Surface Properties of Zwitterionic Surfactants 1. Synthesis and Properties of Some Betaines and Sulfobetaines M . D A H A N A Y A K E and M I L T O N J . R O S E N Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, NY 11210

+

Zwitterionic surfactants of structure RN (CH C H )(CH)CHCOO-, where R is an alkyl chain of 10 or 12 carbon atoms, and RN (CH C H )(CH )CH CH SO -, where R is 8, 10, or 12 carbon atoms, have been synthesized. From surface tension-concentration curves in aqueous solution at 10°, 25°, and 40°C, surface excess concentrations and areas/molecule at surface saturation, critical micelle concentrations, efficiency and effectiveness of surface tension reduction, and thermodynamic parameters of adsorption and micellization have been calculated. The areas/molecule indicate that the entire ionic head group in each series is lying flat in the aqueous solution/air interface. For the glycines, the standard free energies of micellization and of adsorption per methylene group at the aqueous solution/air interface are -2.80 kJ and -3.05 kJ, respectively; for the taurines, the standard free energy of adsorption per methylene is -3.15 kJ, all at 25°C. 2

3

6

5

2

+

2

6

5

3

2

2

3

The use of zwitterionic surfactants commercially has increased dramatically in recent years (1J because of their unique properties, such as compatibility and synergism when used in conjunction with most other types of surfactants. This type of surfactant is used in textile processing aids, cosmetic products, cleaning agents, and as antistatic agents. The sulfobetaines have been found to be very good lime soap disperants (2). In spite of this wide applicability, a survey of the literature reveals that, compared to ionic and nonionic surfactants, there have been relatively few investigations of their surface and thermodynamic properties. Investigation has been hampered by the nonavailability of pure compounds and proper analytical techniques to determine their concentration in solution. 0097-6156/ 84/ 0253-0049506.00/ 0 © 1984 American Chemical Society

In Structure/Performance Relationships in Surfactants; Rosen, M.; ACS Symposium Series; American Chemical Society: Washington, DC, 1984.

50

S T R U C T U R E / P E R F O R M A N C E R E L A T I O N S H I P S IN S U R F A C T A N T S

T o r i and Nakagawa ( 3 - 7 ) , in a s e r i e s o f papers, d e s c r i b e d the m i c e l l a r p r o p e r t i e s o f C , C i > and C12 C - a l k y l b e t a i n e s o f the type (CH ) N-CH(R)C00~, and N - o c t y l b e t a i n e , C H i N ( C H ) 2 C H C 0 0 - . From s t u d i e s o f the temperature dependence o f the cmc, they were able to c a l c u l a t e Δ Η ^ . Herrmann (8) s t u d i e d C i > C i , and C i N - a l k y l 8

3

3

0

+

7

8

+

2

3

0

2

6

s u l f o b e t a i n e s of the t y p e , R - N ( C H ) ( C H ) S 0 ~ with regard to the chain length and i o n i c s t r e n g t h v a r i a t i o n on the cmc. He c a l c u l a t e d the standard f r e e energy c o n t r i b u t i o n to m i c e l l i z a t i o n o f a methylene group to be 0.61 kcal mol" and, t h e r e b y , concluded t h a t the i n t e r n a l s t r u c t u r e o f the m i c e l l e s o f these z w i t t e r i o n i c s i s s i m i l a r to a l l other i o n i c and n o n i o n i c s u r f a c t a n t s s t u d i e d . Thermodynamic parameters o f m i c e l l i z a t i o n have a l s o been i n v e s t i g a t e d by Molyneux ( 9 ) , and Swarbrick ( 1 0 ) . They were able to estimate the standard f r e e energy c o n t r i b u t i o n to m i c e l l i z a t i o n of the head group o f N - a l k y l and C-al kyl betaines to be +3.3 and +2.7 Kcal mol"" , r e s p e c t i v e l y . Molyneux e t a l . found the p l o t of l o g cmc vs. 1/T f o r dodecyl N-methylbetaines to be l i n e a r , whereas Swarbrick e t a l . observed a minimum i n the curve f o r the corresponding decyl and undecyl b e t a i n e s . From these d a t a , these workers were able to estimate the standard e n t h a l p i e s and e n t r o p i e s of m i c e l l i z a t i o n and to compare these r e s u l t s with o t h e r n o n e l e c t r o l y t e amphophiles. In c o n t r a s t to t h i s , there i s l i t t l e i n f o r m a t i o n a v a i l a b l e (11) on the thermodynamics o f a d s o r p t i o n o f a l k y l b e t a i n e s and no data on the thermodynamic parameters o f a d s o r p t i o n o r m i c e l l i z a t i o n f o r sulfobetaines. In the present work, we have s y n t h e s i z e d two betaines and three s u l f o b e t a i n e s i n very pure form and have determined t h e i r s u r f a c e and thermodynamic p r o p e r t i e s o f m i c e l l i z a t i o n and a d s o r p t i o n . From these data on the two c l a s s e s o f z w i t t e r i o n i c s , e n e r g e t i c s of m i c e l l i z a t i o n and a d s o r p t i o n of the h y d r o p h i l i c head groups have been estimated and compared to those o f n o n i o n i c s u r f a c t a n t s . +

3

2

2

3

3

Downloaded by UCSF LIB CKM RSCS MGMT on November 23, 2014 | http://pubs.acs.org Publication Date: May 21, 1984 | doi: 10.1021/bk-1984-0253.ch003

1

1

Experimental S e c t i o n N - a l k y l N-benzyl N - m e t h y l g l y c i n e s ,

C H n

2n+1

N (CH C H )(CH )CH C00". +

2

6

5

3

2

Two homologues, i n which η = 10 (Ci BMG) and 12 ( C i B M G ) , were s y n t h e s i z e d by r e a c t i n g N-methylbenzyl amine (3 moles) and sodium c h l o r o a c e t a t e (1 mole) i n 95% ethanol overnight at 40°C. The r e s u l t i n g s o l u t i o n was t r e a t e d w i t h 0.5 moles o f N a C 0 and steam d i s t i l l e d to remove the excess N-methylbenzyl ami ne. Water was removed by r o t a r y evaporator and the crude residue N-methylbenzyl g l y c i n e was r e c r y s t a l l i z e d from i s o p r o p y l a l c o h o l . The t e r t i a r y amine thus obtained was d i s s o l v e d i n absolute ethanol and was r e f l u x e d f o r two days with f i v e molar percent excess of the a p p r o p r i a t e bromoalkane (97% Humphrey Chemical, North Haven, Conn.). Solvent was removed and the residue i n aqueous N a C 0 s o l u t i o n was e x t r a c t e d w i t h hexane to remove any unreacted bromo a l k a n e . Next, the N - a l k y l N-benzyl N-methylglycine was e x t r a c t e d i n t o chloroform from the aqueous l a y e r . Solvent was s t r i p p e d o f f and the crude m a t e r i a l was r e c r y s t a l l i z e d t h r i c e from carbon t e t r a c h l o r i d e and twice from THF/CHC1 (60:40 v/v) m i x t u r e . The y i e l d s o f the p u r i f i e d betaines were about 75% o f the t h e o r e t i c a l . A n a l y t i c a l data f o r the compounds were as f o l l o w s : 0

2

2

3

2

3

3


3.

DAHANAYAKE A N D ROSEN

Betaine, Sulfobetaine: Synthesis, Properties

calculated H

~~C

N~

C

found Η

Ν

CioBMG

75.19

10.41

4.38

74.48

10.82

4.32

CioBMG

76.03

10.73

4.03

75.70

10.76

3.92

N-alkyl

N-benzyl N - m e t h y l t a u r i n e s ,

C H n

2 n + 1

N (CH C H )(CH )CH CH S0 \ +

2

6

5

3

2

2

Three homologues i n which η = 8 (C BMT), 10 (CioBMT), and 12 (Ci BMT) were s y n t h e s i z e d by a procedure s i m i l a r to t h a t f o r the N - a l k y l b e t a i n e s . Here, the N-methylbenzyl amine and sodium s a l t of 2 - c h l o r o e t h a n e s u l f o n i c a c i d were r e f l u x e d i n 95% methanol f o r two days. A f t e r treatment w i t h 0.5 M N a C 0 , the r e s u l t i n g s o l u t i o n was steam d i s t i l l e d to remove the excess N-methylbenzyl amine. Water was removed and the crude residue was r e c r y s t a l l i z e d from e t h a n o l . The t e r t i a r y amine thus obtained was d i s s o l v e d i n absolute ethanol and r e f l u x e d f o r f i v e days w i t h f i v e molar percent excess of the a p p r o p r i a t e bromoalkane. T h e r e a f t e r , the procedure was s i m i l a r to t h a t f o r the N - a l k y l g l y c i n e s . Crude product was r e c r y s t a l l i z e d t h r i c e from water and then from THF/CHC1 (50:50 v/v) m i x t u r e . A n a l y t i c a l data f o r the compounds were: 8


3

2

2

3

3

calculated

found

c

Π

CioBMT

64.99

9.55

3.79

65.20

9.92

3.74

C BMT

66.45

9.89

3.52

66.31

10.01

3.48

i2

IT

—

C

Η

F~

The molar a b s o r p t i v i t i e s f o r the two betaines and the three s u l f o b e t a i n e s i n aqueous s o l u t i o n are l i s t e d i n Table I. Before being used f o r s u r f a c e t e n s i o n measurements, aqueous s o l u t i o n o f s u r f a c t a n t s were f u r t h e r p u r i f i e d by repeated passage (12) through minicolumns (SEP-PAK C i C a r t r i d g e , Waters A s s o c . , M i l f o r d Mass.) o f o c t a d e c y l s i l a n i z e d s i l i c a g e l . The c o n c e n t r a t i o n of s u r f a c t a n t i n the e f f l u e n t from these columns was determined by u l t r a v i o l e t absorbance, using the molar a b s o r p t i v i t i e s l i s t e d i n Table I. 8

l a b l e I.

Molar A b s o r p t i v i t i e s f o r R-N (CH C H )(CH )CH C00~ and R-N (CH C H )(CH )CH CH S0 +

+

Compound

2

6

5

3

2

\nax

2

2

6

5

3

2

3

eidm'mol^cnf

CioBMG

263

3.80

Ci BMG

263

3.55

C BMT

263

3.88

CIOBMT

263

3.80

C BMT

210

12.12

2

8

I 2

1

χ 10" ) 3


51

52


Surface t e n s i o n measurements. S o l u t i o n s o f the betaines were prepared w i t h quartz-condensed, d i s t i l l e d w a t e r , s p e c i f i c conduct ance, 1.1 χ 10* mho cm" a t 25°C. A l l s u r f a c e t e n s i o n measurements were made by Wilhelmy v e r t i c a l p l a t e t e c h n i q u e . S o l u t i o n s to be t e s t e d were immersed i n a constant-temperature bath a t the d e s i r e d temperature ±0.02°C and aged f o r a t l e a s t 0.5 h before measurements were made. The pH of a l l s o l u t i o n s was > 5.0 ( u s u a l l y , i n the range 5 . 5 - 5 . 9 ) , where s u r f a c e p r o p e r t i e s show no change w i t h pH. 6

1


R e s u l t s and D i s c u s s i o n s P l o t s o f s u r f a c e t e n s i o n , γ , vs. the l o g of the molar c o n c e n t r a t i o n , C, o f the s u r f a c t a n t i n the bulk phase a t 1 0 ° , 2 5 ° , and 40°C f o r the N - a l k y l g l y c i n e s and the N - a l k y l t a u r i n e s are shown i n Figures 1 and 2 respectively. Surface excess c o n c e n t r a t i o n , Γ, i n mol cm" , and area/molecule, A, i n nm , at the l i q u i d / a i r i n t e r f a c e were c a l c u l a t e d from the relationships: 2

2

Γ

οίιτ(π|τ)

=

τ

a n d

A =

^r

:!

where ( 3 γ / 8 l o g C)-j- i s the slope o f the γ - l o g C curve at constant temperature, T, R = 8.31 J m o l " ^ , and Ν = Avogadro's number. Values o f the c r i t i c a l m i c e l l e c o n c e n t r a t i o n (cmc), minimum area per molecules ( A „ . ) , ττ . the e f f e c t i v e n e s s o f s u r f a c e t e n s i o n reducππη' ' cmc t i o n ( 1 3 ) , and p C , the e f f i c i e n c y o f s u r f a c e t e n s i o n r e d u c t i o n (14), are l i s t e d i n Table I I . The CioBMG and C12BMG were found to have high s o l u b i l i t y i n w a t e r , whereas the corresponding N - a l k y l t a u r i n e s were s p a r i n g l y s o l u b l e i n water. As a r e s u l t o f the poor s o l u b i l i t y , the o n l y cmc determined i n t h i s s e r i e s was f o r CioBMT at 4 0 C . The cmc o f C BMT was not determined due to i t s high cmc and i n s u f f i c i e n t m a t e r i a l . The areas per molecule f o r the g l y c i n e s and f o r the t a u r i n e s , when compared to the cross s e c t i o n a l areas o f the compounds as obtained from m o l e c u l a r models, suggest t h a t , a t the aqueous s o l u t i o n / a i r i n t e r f a c e , the i o n i c head groups, - N ( C H C H ) ( C H ) C H C H S 0 " ( i n the case o f the t a u r i n e s ) and - N ( C H C H ) ( C H ) C H C 0 0 ~ ( i n the case o f the g l y c i n e s ) , are l y i n g f l a t i n the i n t e r f a c e . Although the e f f i c i e n c i e s o f s u r f a c e t e n s i o n r e d u c t i o n , p C , f o r the betaines and t h e i r corresponding s u l f o b e t a i n e s are almost the same, the former appear to show g r e a t e r e f f e c t i v e n e s s i n s u r f a c e t e n i o n r e d u c t i o n , as i n d i c a t e d by the -n values. T h i s may be due 1

1

2 0

e

8

+

+

2

2

6

5

6

5

3

3

2

2

3

2

2 0

cm

to the s m a l l e r areas per molecule o f the betaines as compared to the corresponding s u l f o b e t a i n e s . Standard Thermodynamic Parameters o f M i c e l l i z a t i o n . Standard f r e e energies of m i c e l l i z a t i o n were c a l c u l a t e d by the r e l a t i o n s h i p : AGm-iη

A H

=

RT In CMC

Standard e n t r o p i e s and e n t h a l p i e s o f m i c e l l i z a t i o n , A S ° . and mi c mic» d from the r e l a t i o n s h i p s ' : c

a

n

b

e

c

a

l

c

u

1

a

t

e




53


3.

4.5

3.5

2.5

-log C Figure 1.

Surface t e n s i o n vs. l o g c o n c e n t r a t i o n o f CioBMG i n

aqueous s o l u t i o n at 1 0 ° ^ r , 2 5 ° ^ , and 4 0 ° p ' ; o f C12BMG at 1 0 ° Δ , 2 5 ° G , and 40° • .


1.5



54


DAHANAYAKE A N D ROSEN Table

II.


Surface P r o p e r t i e s of R - N ^ C H Z C G H S M C H S J C H Z C O O " and R-N (CH2C H5)(CH )CH2CH2S03+

3

G

Compound

T(°C) 10°

6.31 χ 1 0 "

25°

5.25 χ 1 0 "

40°

4.36 χ 1 0 "

10°

6.026 χ 10""*

25° 40°

CioBMG


Δ miη nm χ 100

cmc _ mole dm""

C12BMG

C BMT 8

3

2

54.8

3.34

38.7

56.9

3.36

38.0

59.7

3.30

36.3

56.2

4.42

39.7

5.49 χ 10" *

57.6

4.42

39.0

5.25 χ 1 0 "

59.7

4.32

37.6

10°

54.0

2.26

—

25°

60.9

2.23

--

63.4

2.17

—

10°

55.8

3.4

—

25°

60.9

3.34

64.0

3.22

10°

58.5

4.52

—

25°

61.2

4.44

—

64.0

4.32

—

3

1

4

4.57 χ 1 0 "

3

40° d(AG /dt)

=

e

and

ΔΗ° = The A S °

cmc mN m'

3

40° C12BMT

PC20

3

40° CioBMT

π

i c

1

—

33.8

-AS°

AG + TAS°

values i n Table I I I

0

are a l l p o s i t i v e , i n d i c a t i n g

i n c r e a s e d randomness i n the system upon t r a n s f o r m a t i o n of the z w i t t e r i o n i c s u r f a c t a n t molecules i n t o m i c e l l e s . The values, t o o , are p o s i t i v e , due to the endothermic d e s o l v a t i o n a s s o c i a t e d w i t h m i c e l l i z a t i o n . S m a l l e r Δ Η ° . and A S ° . values at 25-40°C than mic mic a t 10-25° are due to the s m a l l e r h y d r a t i o n of the monomers at the higher temperatures. In the temperature range s t u d i e d , no minimum i n the v a r i a t i o n o f A H ° w i t h temperature was observed, i n a g r e e ment with the work of Swarbrick e t a l . ( 1 0 ) . From the v a r i a t i o n o f the Δ Η ° . values f o r the two a l k y l mic b e t a i n e s , i t i s seen t h a t , f o r the s h o r t e r a l k y l c h a i n compounds, the enthalpy change i s a s i g n i f i c a n t f a c t o r i n the process o f m i c e l l i z a t i o n w h i l e , f o r the l o n g e r c h a i n compounds, the f r e e energy change i s due almost e n t i r e l y t o the entropy change. From the standard f r e e energy o f m i c e l l i z a t i o n o f the N - a l k y l g l y c i n e s , the AG°^ per methylene group at 25°C i s - 2 . 8 0 k J . This i c


56


Table I I I .

Standard Thermodynamic Parameters o f M i c e ! 1 i z a t i o n f o r R-N (CH C H )(CH )CH C00+

Compound


CioBMG

C12BMG

T(°C)

2

6

5

(kJ

3

2

ΔΗ° (kJ m o l ' )

moT )

10

-11.5

25

-13.0

40

-13.9

10

-17.4

25

-18.6

40

-19.6

(kJ π ι ο Γ ' Κ " ) 1

1

1

+8.5

+0.070

+4.7

+0.044

+4.6

+0.078

+0.9

+0.067

i s i n c l o s e agreement w i t h the corresponding value o f - 2 . 8 5 kJ at 20°C obtained by Molyneux e t a l . ( 9 ) . Standard Thermodynamic Parameters o f A d s o r p t i o n . standard thermodynamic parameters of a d s o r p t i o n . Table IV.

Standard Thermodynamic Parameters of A d s o r p t i o n f o r R-N (CH2C H )(CH3)CH C00- and R-N (CH C H )(CH3)CH CH S03~ +

6

Compound C10BMG

Ci BMG 2

C BMT 8

C10BMT

C BMT i2

Table IV l i s t s the Values have been

5

+

2

T(°C)

AG° (kJ mol" )

10

-24.7

25

-26.0

40

-27.2

10

-30.9

25

-32.1

40

-33.2

10

-18.7

25

-20.0

40

-20.6

10

-25.1

25

-26.3

40

-27.0

1

10

-31.5

25

-32.6

40

-33.5

ΔΗ° (kJ mol" ) 1

2

6

5

2

Δ5° (kJ m o l - ' K " ) 1

+0.2

+0.087

-2.6

+0.078

-7.1

+0.082

-10.9

+0.071

+5.9

+0.083

-9.2

+0.036

-2.7

+0.079

-12.9

+0.045

-10.6

+0.074

-14.8

+0.060


2

3.



c a l c u l a t e d by the r e l a t i o n s h i p ( 1 5 ) : AG! ad H

=

From the d a t a , A G °

RT In CMC - π · Α , cmc min η

per methylene group at 25°C i s - 3 . 0 5 kJ f o r the

d

g l y c i n e s and - 3 . 1 5 kJ f o r the t a u r i n e s . These are i n agreement with values of - 3 . 1 5 kJ f o r l o n g - c h a i n a l c h o l s and 1 , 3 - d i o l s 0 5 ) . The ΔΗ® . values are l e s s p o s i t i v e than the Δ Η ° . values f o r the aa mic same a l k y l g l y c i n e s . This shows l e s s dehydration o f the s u r f a c t a n t r e q u i r e d f o r adsorption a t the aqueous s o l u t i o n / a i r i n t e r f a c e than f o r the process o f mi c e l l i z a t i o n . This i s c o n s i s t e n t w i t h previous observations on polyoxyethylenated n o n i o n i c s and a l k y l p y r i d i n i u m halides (16,17). The A S ° values are a l l s l i g h t l y more p o s i t i v e than the A S °


r

d

i c

values f o r the same compound, r e f l e c t i n g the g r e a t e r r e s t r i c t i o n o f space i n the m i c e l l e than at the aqueous s o l u t i o n / a i r i n t e r f a c e . The A S ° values and A H ° values are both more p o s i t i v e f o r the d

d

betaines than f o r the corresponding s u l f o b e t a i n e s . This shows t h a t the s u l f o b e t a i n e s r e q u i r e l e s s dehydration f o r a d s o r p t i o n at the aqueous s o l u t i o n / a i r i n t e r f a c e . Using A G ( - C H ) = A G ° ( - C H - ) - 5.56 kJ m o l " , on the b a s i s o f s o l u b i l i t y data (9,18) f o r l i q u i d N-alkanes i n water at 25°C, standard f r e e energies o f a d s o r p t i o n and m i c e l l i z a t i o n , A G ° ( - W ) and e

3

1

2

d

A G ° - ( - W ) r e s p e c t i v e l y , f o r the h y d r o p h i l i c head groups, C

-N (CH )(CH2C H5)CH2CH S03" and - N ( C H C H ) ( C H ) C H C 0 0 ~ , were c a l c u l a t e d . These values are l i s t e d i n Table V t o g e t h e r w i t h the standard f r e e energy values f o r the head groups -CH0HCH -CH 0H and -0CH CH 0H ( 1 9 ) . The AG6T^W) values f o r the two z w i t t e r i o n i c s are comparable to each o t h e r . Both the A G ° . ( - W ) and A G ° . (-W) values f o r the two ad ' rmc nonionics are l e s s p o s i t i v e than f o r the two z w i t t e r i o n s , p o s s i b l y due to the g r e a t e r h y d r a t i o n o f the z w i t t e r i o n s than o f the e t h e r oxygen and/or -OH groups. From the s o l u b i l i t y data of n-decane i n w a t e r , the enthalpy f o r the process n-decane (H 0) •> n-decane (pure) at 25°C has been estimated by Boddard e t a l . (20) to be - 5 . 8 5 kJ m o l " . S u b s t r a c t i n g t h i s value from the c a l c u l a t e d AH°(25°c) values f o r CioBMG and Ci BMT, i n Tables I I I and IV, the AH (-W) values f o r m i c e l 1 i z a t i o n and f o r adsorption at the aqueous s o l u t i o n / a i r i n t e r f a c e a t 25°C can be e s t i m a t e d . Values are shown i n Table V. From the A H ° ( - W ) term f o r the two types of h y d r o p h i l i c groups, i t i s e v i d e n t t h a t there i s an exothermic e f f e c t i n the t r a n s f e r o f the -N (CH C H )(CH )CH2CH2S0 " from aqueous medium to the i n t e r f a c e . This exothermic enthalpy term, together w i t h a l a r g e r negative entropy term f o r the N - a l k y l t a u r i n e head group, i s p o s s i b l y due to the p a r t i a l n e u t r a l i z a t i o n of the o p p o s i t e l y charged groups i n the h y d r o p h i l i c heads due to t h e i r arrangement i n checkerboard f a s h i o n aqeuous s o l u t i o n / a i r i n t e r f a c e s suggested by Beckett and Woodward (21). In the case o f the N - a l k y l g l y c i n e s , endothermic dehydration of the h y d r o p h i l i c head may outweigh the n e u t r a l i z a t i o n e f f e c t , thus making Δ° ,(-W) p o s i t i v e . 3

6

+

2

2

6

5

3

2

2

2

2

2

v

v

2

1

2

e

d

+

2

6

5

3

3


57

In Structure/Performance Relationships in Surfactants; Rosen, M.; ACS Symposium Series; American Chemical Society: Washington, DC, 1984. —

+16.3

—

2

+8.8

2

-0CH CH 0H

2

—

2

—

—

+10.0

3

+7.4

2

-CH(0H)CH CH 0H

2

—

5

3

—

6

-0.042

2

-1.9

+

1

+12.4

+10.6

2

•N (CH C H )(CH )CH CH S0 "

3

+20.5

5

-0.018

6

1

ΔΗ°. mic (kJ mol" )

1

mi c (kJ mol" )

A S

ads (kJ η ι ο Γ ' Κ ' )

+4.6

2

1

ads (kJ m o l ' ) A H

+10.0

+

1

ad (kJ mol" )

A G

e

Standard Thermodynamic Parameters of Adsorption and M i c e l l i z a t i o n o f Various Head Groups (-W) at 25 C

-N (CH C H )(CH )CH C00"

(-W)

Table V.


—

—

—

1

mi c mol^K" ) -0.027

(kJ

3.



59

Literature Cited 1. 2.

Ernst, R.; Miller, E. J., Jr. "Amphoteric Surfactants"; Bluestein, B. R.; Hilton, C. L., Ed.; Marcel Dekker: New York, 1982; pp. 137-150. Kaminiski, M.; Linfield, W. M. J. Am. Oil Chem. Soc. 1979, 56,


771.

3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

Tori, K.; Nakagawa, T. Kolloid - Ζ. Z. Polym. 1963, 50, 187. Tori, K.; Nakagawa, T. Kolloid - Ζ. Z. Polym. 1963, 188, 47. Tori, K.; Nakagawa, T. Kolloid - Ζ. Z. Polym. 1963, 189, 50. Tori, K.; Nakagawa, T. Kolloid - Ζ. Z. Polym. 1963, 191, 42. Tori, K.; Nakagawa, T. Kolloid - Ζ. Z. Polym. 1963, 191, 48. Herrmann, K. W. Colloid Interface Sci. 1966, 22, 352. Molyneux, P.; Rhodes, C. T . ; Swarbrick, J. Trans. Faraday Soc. 1965, 61, 1043. Swarbrick, J.; Daruwala, J. J. Phys. Chem. 1969, 73, 2627. Swarbrick, J., J. Pharm. Sci. 1969, 58, 147. Rosen, M. J. J. Colloid Interface Sci. 1981, 79, 587. Rosen, M. J. J. Colloid Interface Sci. 1976, 56, 32. Rosen, M. J. J. Am. Oil Chem. Soc. 1974, 51, 461. Rosen, M. J.; Aronson, M. Colloids Surfaces 1981, 3, 201. Rosen, M. J.; Cohen, A. W.; Dahanayake, M.; Hua, X. J. Phys. Chem. 1982, 86, 541. Rosen, M. J., Dahanayake, M.; Cohen, A. Colloids Surfaces 1983, 5, 159. McAuliffe, C. Nature (London) 1963, 200, 1092. Kwan, C.; Rosen, M. J. J. Phys. Chem. 1980, 84, 547. Goddard, E. D.; Hoeve, C. Α.; Benson, G. C. J. Phys. Chem. 1957, 61, 593. Beckett, A. H.; Woodward, R. J. J. Pharm. Pharmcol. 1963, 15, 422.

RECEIVED January 20, 1984


Performance Relationships in Surfactants - American

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