Environmental Engineering Reference
In-Depth Information
Cationic surfactants
(a) Alkyltrimethylammonium halide (b) Alkylpyridinium halide
CH 3
X
H 3 C
N
(CH 2 )nCH 3
N
(CH 2 )nCH 3
CH 3 X
Anionic surfactants
(a) Sodium alkylsulfate (b) Sodium alkylsulfonate (c) Sodium alkylpolyethoxysulfate
C m H 2m+1 (OCH 2 CH 2 ) n OSO 3
Na
C n H 2n+1 OSO 3
C n H 2n+1 SO 3
Na
Na
(d) Sodium alkylbenzenesulfonate
C n H 2n+1
SO 3
Na
Nonionic surfactants
(a) Alcohol ethoxylate (b) Octylphenoxy ethoxylate
CH 3
CH 3
CH 3 (CH 2 ) m O(CH 2 CH 2 O) n H
H 3 C
C
CH 2
C
O(CH 2 CH 2 O) n H
CH 3
CH 3
(c) Alkylphenoxy ethoxylate (d) Sorbitan alkylate
H(OCH 2 CH 2 ) w O
O(CH 2 CH 2 O) x H
CH 3 (CH 2 ) m
O(CH 2 CH 2 O) n H
O(CH 2 CH 2 O) y H
CH
O
(e) Silicone derivative
CH 2 O(CH 2 CH 2 O) z C(=O)R
OSi(CH 3 ) 3
H 3 C
Si
(CH 2 ) 3 (OCH 2 CH 2 ) n OCH 3
OSi(CH 3 ) 3
Miscellaneous
(a) Zwitterionic surfactant (b) Biosurfactant (Monorhamnolipid)
O
H
C
H 2
H
C
R
H
C
CH 3
2
OH
O
O
O
(CH 2 ) 6 CH 3
C
C
COOH
CH 3 (CH 2 ) 11
N
(CH 2 ) 3 SO 3
H 3 C
CH 3
OH
OH
Fig. 2 Chemical structures of typical surfactants
alkylbenzene. Recently, silicone derivatives such as Silwet L-77 showing a higher
surface activity have been developed for formulations (Stevens 1993). As other
categories, a zwitterionic surfactant having both cationic and anionic parts in a
molecule and many kinds of biosurfactants including rhamnolipids produced by
 
Search WWH ::




Custom Search