Synthesis, Properities And Applications Of Janus Nanoparticles

Janus nanoparticles comprising of two components of different chemistry, functionality have attracted attentions in a wide range of applications, e.g.in catalysis, building blocks, optics, and drug delivery. The interesting features of Janus nanoparticles are attributed to their tunable and controllable asymmetric structure, which allows controlling their physicochemical properties. In this paper, we synthesized three different type of Janus nanoparticles with varying ligand combinations and characterized them using Scanning Probe Microscope(SPM), Transmission Electron Microscope (TEM), Ultraviolet-visible Spectrophotometry(UV-vis), Fourier Translation Infrared Spectroscopy(FT-IR), contact angle meter. All of these techniques confirm the presence of Janus nanoparticles and studied the application of Janus nanoparticles.Au nanoparticles with different length of Alkane-thiols are synthesized using modified-Stucky method. Using Dodecyl mercaptan (DDT) and Hexane mercaptan (HT) at ratio of1:1,2:1,4:1to study the relationship of the composition ratio of binary mixtures of different length and surface morphology of the resultant NP. The results shows that different ratio of DDT and HT can observed the phase separation on the surface. Increasing the ratio of DDT can move the middle separation line. Later, we established dipole theory to reveal the interactions between Janus nanoparticles.Based on the above experiment, we use DDT as hydrophobic ligand and use11-Mercaptoundecanoic acid (MUA) as hydrophilic ligand to synthesis immiscible amphiphilic Janus nanoparticles. The IR result shows that the dual ligands are on the same particle. The interface modification and emulsifying properties confirmed that the result are Janus-type nanoparticles. and then, changing the ratio of DDT/HT of Au@DDT/MUA nanoparticles can also effect the catalytic reaction rate to p-nitrophenol, and modulate the catalytic reaction rate.AuAg bimetallic Janus nanoparticles are synthesis using strong and weak ligand-coated gold nanoparticles. In this paper, we study the growth mechanism of AuAg at the conditions of weak coated and strong ligand, particle structure，optical properties and catalytic properties. The result shows that modulating the ratio of weak and strong ligand can synthesis AuAg Janus nanoparticles under strong reducing agent, And can also improve the catalytic activity of Au nanoparticles.