A simple and fast plasma reduction method is developed for synthesis of Au and Pd metal nanoparticles. The scanning electron microscopy(SEM) analysis indicates a formation of aggregates of Au and Pd nanoparticles with branched structure. The transmission electron microscopy(TEM) image shows that the inclusive nanoparticles are all about 5 nm in size. Compared to conventional hydrogen reduction method, plasma method inhibits the agglomeration of metal particles. The room temperature operation is very helpful to limit the nanoparticle size. Most interestingly, plasma reduction produces more flattened metal particles. This plasma reduction does not require the use of any hazardous reducing chemicals, showing the great potential for the fabrication of noble metal nanoparticles.
The solubility, metastable zone width, and induction time of analgin for unseeded batch cooling crystallization in ethanol–aqueous system were experimentally determined. The solubility data could be well described by the van't Hoff equation model. The metastable zone width at various cooling rates was measured, and some parameters of nucleation kinetic were calculated using the Ny'vlt theory. Furthermore, the induction period of various temperatures and supersaturation ratios was also measured. According to classical nucleation theory, some nucleation parameters and interfacial energy was calculated through the induction time(t_(ind)) data. Homogeneous nucleation tended to occur when the supersaturation is high, whereas heterogeneous nucleation was more likely to occur when the supersaturation is low.
The thermodynamic properties of metamizol monohydrate in pure solvents(methanol,ethanol,n-propanol and isopropanol) and two binary mixed solvent systems including(methanol+ethanol) and(methanol+isopropanol) were measured from 283.15 K to 313.15 K by gravimetric method under atmospheric pressure thought as 0.1 MPa.The modi fied Apelblat equation,the CNIBS/R-K equation,the Hybrid model and the NRTL model were used to correlate the solubility of metamizol monohydrate,respectively.The results show that the solubility of metamizol monohydrate in all the tested solvents increases with the rising temperature which means that it has temperature dependence.What's more,the effects of solvent components of the binary solvent mixtures on solubility were discussed,it illustrates that the increasing of the molar fraction of methanol gives the system a greater dissolving power.Furthermore,according to the NRTL model,the enthalpy,the Gibbs energy and the entropy of the mixing process were also obtained and discussed.
