【摘要】 采用化学还原法,在水相中,以硼氢化钠为还原剂,月桂酸为分散剂,通过还原银氨络合物溶液制备了纳米银胶体,之后通过调节胶体的pH值,分离出了纳米银颗粒。TEM和XRD分析表明,该纳米银颗粒的平均粒径大约为17 nm,集中分布于5～30 nm,且无明显的团聚现象;红外光谱分析表明该纳米银颗粒表面包覆有月桂酸,紫外光谱表明制得的纳米银胶体在397 nm处有较强的吸收峰。将分离出的"湿"纳米银颗粒作为功能相,加入预先配制的载体相中,运用机械搅拌和超声分散等手段,制得了纳米银导电浆料。热重分析表明该浆料含有约67%(质量分数)的金属银,在220℃下烧结2 h后,其电阻率为4.2×10-5Ω.cm。经微细笔直写后,其线条的分辨率可以达到60μm。更多还原

【Abstract】 In water phase,silver nano-colloid was prepared by chemical reduction method with sodium borohydride as reductant,lauric acid as dispersant,and silver-ammonia complex as main salt.Then,by adding phosphoric acid to adjust pH value of the colloidal system,silver nanoparticles were precipitated and separated.Transmission electron microscopy(TEM) and X-ray diffraction(XRD) analyses showed that the prepared Ag nanoparticles have an average diameter of about 17 nm with the distribution of 5~30 nm,and had no agglomeration.FT-IR spectrum indicated that the nanoparticles are capsulated by lauric acid,and UV-Vis spectrum revealed that the Ag nano-colloid has a strong absorption peak at 397 nm.Using the prepared wet Ag nanoparticles as functional phase,a conductive nano-silver paste was formulated with an organic vehicle by dispersion methods of mechanical stirring and ultrasonic vibration.Thermogravimetry analysis(TGA) showed that the paste contains 67 wt% Ag.Its electrical resistivity is up to 4.2×10-5 Ω·cm after sintering at 220℃ for 2 h.Upon direct-writing by micro-pen,an array pattern with the resolution of 60 μm is achieved.更多还原