纳米金属液滴的制备与其物性的实验研究

There are many changes in properties of solid materials with the dimension decreasing from 3 to 0. In order to fully and deeply understand the property changes with the change of dimension, it is necessary to study the properties of nanoscaled metal droplet. In this project, we first prepare nanoscaled metal droplets in continue matrix and then study the mechanic, optical properties.4 papers have been published in the international SCI journal. We have attended 1 international conference. There are some cooperation between our group and institute of nanotechnology, research center, Karlsruhe, Germany.In this research work, the following achievement has obtained..1, Nanoscaled Ga particles dispersed in polymer matrix has been prepared by means of ultrasonic vibration method.2, There is a relaxation internal friction peak located around 42°C in the sample with nanoscaled Ga particles dispersed in PS matrix. This internal friction peak is not the melting peak of Ga for the melting point of Ga is 29.8°C. It is suggested that this peak is related to the viscosity change of Ga with the change of measurement temperature.3, In normal condition, Ga is in stable a phase; however, there are other two metastable phases, b and g phases, of Ga existing under other conditions. For the bulk Ga sample, normally there is only a phase appearing on the DSC curve. In our experiment for the nanoscaled Ga particles dispersed in PMMA matrix, the b and g phases appear in the DSC curves with the decrease of particle size.4, The behaviour of nanoscaled Pb droplet dispersed in Al matrix has been studied by internal friction, DSC and TEM. The internal friction peak located at about the melting point of Pb was first observed. This peak can only be measured during the first heating measurement. It is suggest that this peak is related to the coarsening process of Pb droplets. When the size of the nanoscaled Pb droplets is less than 100nm, faceting occurs after cooling down from the liquid state, but big particles keep a spherical shape. .5, Nanoscaled monoclinic Ga oxide (b-Ga2O3) needles were prepared by ultrasonic vibration method. The b-Ga2O3 needles, with mean diameter about 10-20nm and length up to 100nm, are of onocrystalline mature. The b-Ga2O3 made by this method is very uniformity in size. It is suggested that the growth mechanism of b-Ga2O3 is not controlled by vapor-liquid-solid (VLS) and vapor-solid (VS) process, instead they are seemingly grown via surface oxide process of nanoscaled particles, in which the structural defects (porous) play an important role both during the nucleation and during growth of the needles..6, Ordered array of nanoscaled In particles has been prepared on the ordered Al2O3 template. In the following heating process, nanoscaled In particles become droplet, which makes the nanoscaled In particles more order. The experimental results indicated that the optical absorption peak position of nanoscaled In particles in ordered arrays has a explicit red-shift compared with that of disordered ones. It was also found that the peak position of nanoscaled In particles in ordered arrays after heat treatment had a blue-shift compared to that before heat treatment. The results are in qualitative agreement with theoretical calculation for Ag particles.

为了完整地把握维数的降低给材料物性所带来的影响，有必要研究纳米金属液滴的物性，这是纳米材料科学研究的深入和推广。本工作首先制备出分散于连续固体、液体基体中的分散性良好的纳米金属液滴，然后研究纳米金属液滴的物性（光学、力学、电学性能），以及这些物性与纳米固体颗粒、宏观液体的物性的异同和联系。.