Hits:

Indexed by:期刊论文

Date of Publication:2011-07-01

Journal:EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY

Included Journals:Scopus、SCIE

Volume:113

Issue:7

Page Number:841-847

ISSN No.:1438-7697

Key Words:Carbonylamine condensation; CO2; Reversible emulsion; Switchable amphipathic molecule

Abstract:Five long-chain alkyl amidines were synthesized by condensation of N,N-dimethylacetamide with octylamine, decylamine, dodecylamine, tetradecylamine, and hexadecylamine, respectively. Synthesis conditions including solvent, pH, temperature, and ratio of reactants were studied. The series of long-chain alkyl amidine compounds reacted with dry ice to produce amidinium bicarbonates cationic amphipathic molecules. The critical micelle concentration ( cmc) and surface tension at cmc ( gamma(cmc)) measured by drop volume method show that these amphipathic molecules have excellent surface activity. The changes of cationic content measured by two-phase titration and conductivity before and after bubbling CO2, show different properties between amidines and amidinium bicarbonates cationic amphipathic molecules. The switchable function of the amidinium bicarbonate cationic amphipathic molecule in emulsification and demulsification was studied.
   Practical applications: Our innovative work is synthesizing switchable amphipathic molecules, N'-alkyl-N,N-dimethylacetamidines, by carbonyl-amine condensation. Compared with a former way of synthesis, our work shows great potential advantages in industrial application. Our synthesis route is simpler with higher yield and is carried out at ambient temperature. Moreover, the products are environmentally friendly. Compared with traditional amphipathic molecules, our products, N'-alkyl-N,N-dimethylacetamidines, show good switchable properties, which can be switched on and off, trigged by CO2. This means these products can be reused for several times, which is significant for environmental protection.