Liquid chromatography used to size-separate the amphiphilic-molecules stabilized nano-particles of CdS in the 1-10 nm range

The making of nano-particles in the 1-10 nm range in micro-emulsions, the surface coating of these by the amphiphilic-molecules in the same microemulsion and the subsequent treatment of the oil-phase based particles in the liquid chromatography (HPLC) is the focus of this work. A HPLC column with Silica (5 μm diameter, 120 angstrom pore size) with C₁₈ (ODS) bonded phase was used. Toluene is used as the mobile phase. The CdS nanoparticles in the mobile phase were continuously monitored by ultra-violet spectroscopy. The CdS products were collected at different time intervals. For a relatively coarse feed, in 5.7 nm range, a rich product with a sharp size distribution can be obtained. High resolution transmission electron micrograph shows that the product is well crystallized. The eluted products from the HPLC were treated separately in a Size Exclusion Chromatography. Elution times for size-exclusion-chromatography show that the different HPLC products come out in different time intervals suggesting the possibility of nanoparticle size separation by this method.