Abstract
A series of nonionic surfactants containing different chains of polyethylene oxide monomethyl ether [‒O(CH
2
CH
2
O)
x
CH
3
, x = 7, 12, 16, 44, and 112] based castor oil were synthesized. Their structures were confirmed using FTIR, H
1
-NMR, and C
13
-NMR spectra. Structural effects of the synthesized surfactants on surface tension γ, critical micelle concentration (CMC), and hydrophile lipophile balance (HLB) were investigated. The effect of structural features on their surface behavior is analyzed through changes in surface properties, including the surface excess concentration (Γ
max
), the effectiveness of adsorption, the area per surfactant molecule at the air/water interface at surface saturation (A
min
). Thermodynamic properties; adsorption and micellezation were also investigated. Biodegradation of these nonionic surfactants were studied.