粉末冶金材料科学与工程
粉末冶金材料科學與工程
분말야금재료과학여공정
POWDER METALLURGY MATERIALS SCIENCE AND ENGINEERING
2013年
6期
874-881
,共8页
陈建波%李启厚%李玉虎%刘智勇%刘志宏
陳建波%李啟厚%李玉虎%劉智勇%劉誌宏
진건파%리계후%리옥호%류지용%류지굉
氧化银%丙三醇%沉淀转化法%超细银粉
氧化銀%丙三醇%沉澱轉化法%超細銀粉
양화은%병삼순%침정전화법%초세은분
silver oxide%glycerol%solid phase transformation%ultra-fine silver powder
在水-PVP体系中,以氧化银(Ag2O)为前驱体、丙三醇为还原剂,采用沉淀转化法制备超细银粉。借助扫描电镜(SEM)、X 射线衍射(XRD)、激光粒度分析等表征手段,研究氧化银转化生成银粉的机理及银粉的形貌与粒度控制规律。结果表明:银粉形成机理为Ag2O溶解和Ag+还原再结晶,为确保Ag2O完全还原,Ag2O/丙三醇摩尔比应小于或等于3:1;添加氨有利于制备粒度均匀、无团聚的类球形银粉,丙三醇浓度对银粉粒度的影响较大。在温度为80℃,Ag2O与丙三醇摩尔比为2:1,采用NH3·H2O为pH值调节剂,丙三醇浓度为2.4 mol/L,且其加料速度为6 mL/min,PVP添加量为Ag2O质量的1%的条件下,可以制备出平均粒度为0.52μm和粒度分布范围较窄的超细银粉。
在水-PVP體繫中,以氧化銀(Ag2O)為前驅體、丙三醇為還原劑,採用沉澱轉化法製備超細銀粉。藉助掃描電鏡(SEM)、X 射線衍射(XRD)、激光粒度分析等錶徵手段,研究氧化銀轉化生成銀粉的機理及銀粉的形貌與粒度控製規律。結果錶明:銀粉形成機理為Ag2O溶解和Ag+還原再結晶,為確保Ag2O完全還原,Ag2O/丙三醇摩爾比應小于或等于3:1;添加氨有利于製備粒度均勻、無糰聚的類毬形銀粉,丙三醇濃度對銀粉粒度的影響較大。在溫度為80℃,Ag2O與丙三醇摩爾比為2:1,採用NH3·H2O為pH值調節劑,丙三醇濃度為2.4 mol/L,且其加料速度為6 mL/min,PVP添加量為Ag2O質量的1%的條件下,可以製備齣平均粒度為0.52μm和粒度分佈範圍較窄的超細銀粉。
재수-PVP체계중,이양화은(Ag2O)위전구체、병삼순위환원제,채용침정전화법제비초세은분。차조소묘전경(SEM)、X 사선연사(XRD)、격광립도분석등표정수단,연구양화은전화생성은분적궤리급은분적형모여립도공제규률。결과표명:은분형성궤리위Ag2O용해화Ag+환원재결정,위학보Ag2O완전환원,Ag2O/병삼순마이비응소우혹등우3:1;첨가안유리우제비립도균균、무단취적류구형은분,병삼순농도대은분립도적영향교대。재온도위80℃,Ag2O여병삼순마이비위2:1,채용NH3·H2O위pH치조절제,병삼순농도위2.4 mol/L,차기가료속도위6 mL/min,PVP첨가량위Ag2O질량적1%적조건하,가이제비출평균립도위0.52μm화립도분포범위교착적초세은분。
The preparation of ultra-fine silver powders was investigated by precipitation-transformation method using Ag2O as precursor and glycerol as reductant in H2O-PVP system. The samples were characterized by XRD, SEM and laser size analyzer;the formation mechanism and the mechanism of controlling morphology and size of silver powders were studied experimentally. The results show that silver powders are formed by crystallization of Ag atom obtained from the reduction of Ag+ ions, which come from the dissolution of Ag2O. The molar ratios of Ag2O/glycerol should be obtained at less or equal to 3:1 in order to reduce Ag2O into silver completely in the preparation. Adding ammonia as pH modifier is beneficial to prepare silver powders with uniform morphology and size, and glycerol concentration affects the sizes of silver powders seriously. Adding ammonia as pH modifier, under the condition of temperature of 80 ℃, Ag2O/glycerol molar ratio of 2:1, glycerol concentration of 2.4 mol/L, reductant feeding rate of 6 mL/min and adding PVP of 1%Ag2O mass, the silver powders with a mean particle size of 0.52?m and narrow size distribution can be obtained.