【摘要】： 超細(xì)粉末的用途與性能密切相關(guān),而性能很大程度上取決于其形貌和顆粒尺寸。作為微電子工業(yè)關(guān)鍵材料的銀粉,人們對(duì)其形貌有著特殊的要求。目前國(guó)內(nèi)外制備的銀粉大都為球狀,為了增加銀粉顆問(wèn)的接觸面以提高導(dǎo)電性能,通常需將球狀銀粉細(xì)磨成片狀。纖維狀的導(dǎo)電材料可以形成網(wǎng)狀導(dǎo)電回路,能有效提高導(dǎo)電材料的導(dǎo)電性能。因此,作者綜合分析了目前國(guó)內(nèi)外銀粉的制備方法,結(jié)合本課題組制備超細(xì)金屬或合金粉體材料的經(jīng)驗(yàn),提出了采用配位沉淀-熱分解法來(lái)制備纖維狀銀粉的新工藝,并研究了新工藝過(guò)程的理論基礎(chǔ)。 本文首先根據(jù)同時(shí)平衡原理和質(zhì)量守恒原理,推導(dǎo)出了常溫下Ag(Ⅰ)-C2O42--NH3-NH4+-H2O體系熱力學(xué)平衡的數(shù)學(xué)模型,計(jì)算并繪制了該體系的金屬離子濃度對(duì)數(shù)-pH圖,確定了配位沉淀法制備前驅(qū)體實(shí)驗(yàn)研究的pH值范圍。在此基礎(chǔ)上,實(shí)驗(yàn)研究了溶液體系各項(xiàng)物理化學(xué)條件對(duì)前驅(qū)體粒度和形貌的影響,結(jié)果表明：兩段式添加沉淀劑的反加料方式,反應(yīng)溫度為60℃,Ag+濃度為0.4mol/L,溶液的pH值為3.8～4.8,加料30min,陳化30min,攪拌速率600r/min,PVP的加入量為m(PVP)/m(AgNO3)=0.1時(shí)能制備得到棒狀前驅(qū)體。 本文還根據(jù)熱分解過(guò)程的熱力學(xué)理論分析了草酸銀鹽直接熱分解得到金屬銀粉的可行性和銀粉的熱穩(wěn)定性。系統(tǒng)研究了前驅(qū)體形貌、熱分解溫度、熱分解時(shí)間和氣氛對(duì)熱分解產(chǎn)物的影響。結(jié)果表明：在VN2：VCO2=3：1的氣氛中,熱分解溫度為140℃,升溫0.5h,保溫2.5h時(shí)可制備得到分散性良好的纖維狀銀粉,比表面積達(dá)1.054m2/g。
[Abstract]:The use of ultrafine powders is closely related to their properties, and their properties depend to a great extent on their morphology and particle size. As a key material in microelectronics industry, silver powder has special requirements for its morphology. At present, the silver powder prepared at home and abroad is mostly spherical. In order to increase the contact surface of silver powder to improve the electrical conductivity, it is usually necessary to fine grind the silver ball powder into flake shape. The fibrous conductive material can form a network conductive circuit, which can effectively improve the conductive properties of conductive materials. Therefore, the author synthetically analyzed the preparation methods of silver powder at home and abroad, combined with the experience of our group in the preparation of ultrafine metal or alloy powder materials, and put forward a new technology of preparing fibrous silver powder by coordination precipitation-thermal decomposition method. The theoretical basis of the new process is also studied. Based on the principle of simultaneous equilibrium and mass conservation, the mathematical model of thermodynamic equilibrium of Ag (鈪，

本文編號(hào)：2157007