Role of Cloud Point of the Capping Agent (Nonionic Surfactant, Triton X-100) on the Synthesis of Silver Nanoparticles

Abstract

The solution behavior of the nonionic surfactants below and above the cloud point (CP) is quite different. At below CP, a single phase of molecular or micellar solution exists, whereas above the CP, the solution separates into two phases: the first one is denser and smaller phase contains most of the surfactant and the other one is relatively voluminous aqueous phase has surfactant concentration close to the critical micelle concentration (cmc). There are many reports are available where nonionic surfactant used as capping agent. But, to the best of our knowledge, there is no report on the CP's role on the synthesis of nanoparticles (NPs). Therefore, it is very important to understand role of the CP on the synthesis of NPs. In the present work, we report the role of clouding of nonionic surfactant, Triton X-100 (using as capping agent) on the synthesis of AgNPs below and above the CP. The morphology of AgNPs was studied by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-Vis absorption, etc., techniques. Below the CP spherical polydisperse particles of 12 ± 5 nm mean diameter were found whereas above the CP the aggregated particles with higher diameter were found.

Bactericidal and Cytotoxic Properties of Silver Nanoparticles

“…The size, geometry, morphology and homogeneity of AgNPs can also be manipulated by means of microemulsion technique. Several surfactants can be used to form microemulsion, including cationic cetyltrimethylammonium bromide (CTAB), anionic sodium dodecyl benzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS), and nonionic Triton X-100 [83,84]. Water-in-oil (W/O) microemulsions or reverse micelles are often employed to prepare metallic nanoparticles [85,86,87].…”