Abstract: Ag coated composite microspheres were synthesized on fly ash microspheres matrix by chemical plating with Tollens’ reagent and formaldehyde. The properties of composite microspheres，including size distribution，chemical composition，surface morphology and structure of coating layer were characterized by laser particle size analyzer，SEM，XRD，and EDS. Testing on insulation properties showed that the temperature of Ag coated composite microspheres coating was lower by four degrees than original fly-ash microspheres coating. Fly-ash microspheres-Ag composite particles with thermal insulation properties could be produced according to the proposed process，and the composite particles could reduce building energy consumption if it was used for building surface.

Key words: fly-ash microspheres, chemical silver plating, composite particles

摘要： 采用化学镀的方法，以银氨溶液为镀液，甲醛为还原剂，按照一定的工艺过程对粉煤灰微珠进行表面镀银处理，得到了粉煤灰微珠-Ag复合颗粒。同时借助激光粒径分析仪、X射线衍射仪、场发射扫描电子显微镜、X射线能谱仪等检测设备对复合颗粒的粒径分布、化学成分、镀层表面形貌和结构进行了分析。对复合微珠进行保温隔热性能测试，掺镀银微珠的涂料比原微珠的涂料温度低约4℃。结果表明，按照设定的工艺过程，可以成功制备出具有保温隔热低辐射功能的粉煤灰微珠-Ag复合颗粒，作为一种功能性骨料有望用于建筑物外围护结构表面的砂浆或涂料中以降低对远红外热的辐射能力。

关键词: 粉煤灰微珠, 化学镀银, 复合颗粒