Effect of Polyoxyethylene Chain Length on the Physicochemical Properties of N,N‐Dimethyl‐N‐dodecyl Polyoxyethylene Amine Oxide Hybrid Surfactants (C12EOnAO,with n = 1–4) |
| |
| Authors: | Hui Cheng Huinian Zhang Xuefeng Liu Mengchu Lin Zhirong Qin Yun Fang |
| |
| Affiliation: | 1. , School of Chemical and Material Engineering, Jiangnan University, Wuxi, People's Republic of China;2. , The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, People's Republic of China;3. , Zhejiang Zanyu Technology Co. Ltd., Hangzhou, People's Republic of China |
| |
| Abstract: | In order to determine the structure‐performance relationship of nonionic‐zwitterionic hybrid surfactants, N,N‐dimethyl‐N‐dodecyl polyoxyethylene (n) amine oxides (C12EOnAO) with different polyoxyethylene lengths (EOn, n = 1–4) were synthesized. For homologous C12EOnAO, it was observed that the critical micelle concentration (CMC), the maximum surface excess (Γm), CMC/C20, and the critical micelle aggregation number (Nm,c) decreased on going from 1 to 4 in EOn. However, there were concomitant increases in surface tension at the CMC (γCMC), minimum molecular cross‐sectional area (Amin), adsorption efficiency (pC20), and the polarity (I1/I3]m) based on the locus of solubilization for pyrene. The values of log CMC and Nm,c decreased linearly with EOn lengthening from 1 to 4, although the impact of each EO unit on the CMC of C12EOnAO (n = 1–4) was much smaller than that typically seen for methylene units in the hydrophobic main chains of traditional surfactants. Compared to the structurally related conventional surfactant N,N‐dimethyl‐N‐dodecyl amine oxide (C12AO), C12EOnAO (n = 1–4) have smaller CMC, Amin, and CMC/C20, but larger pC20, Γm, and Nm,c with a higher I1/I3]m. This may be attributed to the moderately amphiphilic EOn (n = 1–4) between the hydrophobic C12 tail and the hydrophilic AO head group. |
| |
| Keywords: | Hybrid surfactant N N‐dimethyl‐N‐dodecyl polyoxyethylene (n) amine oxide Structure‐performance relationship |
|
|
