以纳米球形聚电解质刷为载体原位还原制备贵金属纳米粒子的研究

以具有核壳结构的纳米球形聚电解质刷为载体,通过吸附不同种类的贵金属离子并将其原位还原,得到分布和粒径不同的贵金属纳米粒子。采用动态光散射(DLS)研究了金属离子浓度和pH对壳层聚电解质链长的影响,使用透射电镜(TEM)观察了贵金属粒子在纳米球形聚电解质刷中的分布,并测量了金属粒子的尺寸。结果表明:金属离子浓度增大,聚电解质链长减小;pH>5时,负载金属粒子之后的聚电解质链长度均大于负载前的长度。不同金属粒子的负载情况相差较大:相同温度下,纳米金属粒子的尺寸符合Ni>Ag>Co的顺序;较高温下制得的金属粒子尺寸要高于低温下制得的金属粒子尺寸;三种纳米金属粒子中,Co纳米粒子具有最好的分布和最小的尺寸。

Preparation of Noble Metal Nanoparticles by in-situ Reduction with Nano Spherical Polyelectrolye Brushes as Carrier

The noble metal nanoparticles with vary size and distribution were prepared by in-situ reduction reaction using the spherical polyelectrolyte brushes （SPB） as carrier. The effect of concentration of metal ion and pH on the length of polyelectrolyte chains was researched by DLS. And the distribution and size of nanoparticles was investigated by TEM. The results show that the length of polyelectrolyte chains reduce with the increase of the concentration of metal ion, and it is higher before loading metal nanoparticles than after when pH〉5. In addition, the distribution and size of nanoparticles exits remarkable differences for loading different noble metal nanoparticles. Under same reduction temperature, sequence of the size of obtained metal nanoparticles is Ni〉Ag〉Co. The size of metal nanoparticles is higher for reduction temperature of 25 ℃ than 5 ℃. Among three kind of metal nanoparticles, Co nanoparticle possesses the best distribution in SPB and smallest size.