Abstract:
A method for preparing hydrophobic gold nanoparticles includes adding 1,2-dichlorobenzene as a solvent to gold precursor and using oleylamine and oleic acid with volume ratio of 7.5:2.5 to 5:5 as surfactants. The size of the prepared gold nanoparticles can be controlled over a broad range and may be utilized in various fields such as bio-imaging, photonic crystallization, sensors, organic catalysts, surface enhanced raman spectrum, electronic devices, etc. Further, a method for colorimetric detection of a strong acid uses hydrophilic nanoparticles that are phase transited from the prepared hydrophobic gold nanoparticles. Up to 5 ppm of low content hydrochloric acid can be detected utilizing phase transited hydrophilic nanoparticles in the colorimetric detection method, and the gold nanoparticles that were used in the detection of strong acid can be reused without loss of activity through neutralization with bases.
Abstract:
Provided is a preparing method of an Ag nano-particle for mass-producing Ag nano-particles, the method including: performing a first reaction of a reaction solution containing an Ag precursor and oleylamine at a set first temperature T1; performing a second reaction of the reaction solution at a second temperature T2 set so as to be higher than the first temperature; and obtaining a reactant from the reaction solution, wherein at least one of the first and second reactions is performed in a state in which the reaction solution is not stirred.