Strong deaggregating effect of a novel polyamino resorcinarene surfactant on gold nanoaggregates under microwave irradiation.
Gold nanoparticles were prepared by ethylene glycol (EG) reducing gold chloride under microwave irradiation. The EG-stabilized gold colloids varied from red to blue with increasing amounts of EG, due to particle aggregation. Addition of the macrocyclic polyamine 2,8,14,20-tetranonyl-4,6,10,12,16,18,22,24-octa(1-aminoethylcarbamoyl)methoxyresorcinarene (TNMR) reversed nanoparticle aggregation under microwave irradiation and greatly improved their dispersion stability in aqueous solutions. These effects are likely due to the amphiphilic nature of TNMR, which has a large hydrophilic headgroup with eight amino groups and four hydrophobic chains. Moreover, the large and flexible hydrophilic groups containing more N and O atoms in the TNMR molecule has a strong stretching and penetrating ability in the aqueous solution, and TNMR molecules can easily form a bilayer protecting structure on the surface of gold nanoparticles, which plays a critical role in the color-change process of the EG-stabilized gold colloid.
College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou, China. shenming@yzu.edu.cn
Ming
M
Shen
Yan
Y
Sun
Ying
Y
Han
Rong
R
Yao
Chaoguo
C
Yan