本文選題：液相化學(xué)還原法 + 超細(xì)銀粉　； 參考：《長(zhǎng)沙理工大學(xué)》2015年碩士論文

【摘要】：為了制備球形高品質(zhì)超細(xì)銀粉,本文采用液相化學(xué)還原法制備形貌和粒徑可控的超細(xì)銀粉,對(duì)原料及工藝進(jìn)行了研究,主要內(nèi)容如下:1、比較了不同銀源、還原劑、分散劑對(duì)超細(xì)銀粉形貌和粒徑的影響。結(jié)果表明AgNO3、抗壞血酸和PVP(K30)更適合作原料制備高分散球形超細(xì)銀粉。2、考察了工藝條件對(duì)超細(xì)銀粉形貌和粒徑的影響。結(jié)果表明:隨著反應(yīng)體系中PVP加入比例的增加,銀粉形貌由不規(guī)則形狀到花瓣?duì)畹角蛐?粒徑逐漸減小;隨著體系反應(yīng)溫度的增加銀粉顆粒團(tuán)聚程度增加,粒徑增大,形貌基本無(wú)變化;隨著溶液pH值增大,顆粒團(tuán)聚程度增加,平均粒徑變大;隨著AgNO3濃度增加,銀顆粒平均粒徑變大;較快的滴液速度有利于得到粒徑分布范圍較窄且分散性良好的均一球形銀粉;有機(jī)溶劑作為洗滌過(guò)濾液有利于提高銀粉的分散性。3、結(jié)合實(shí)驗(yàn)和理論分析研究了影響超細(xì)銀粉形貌和粒徑的控制因素。結(jié)果表明銀粉成核作用主要影響銀粉顆粒的粒徑和粒徑的分布范圍;控制銀粉生長(zhǎng)過(guò)程可在一定程度上實(shí)現(xiàn)對(duì)銀粉形貌和粒徑的調(diào)控;銀原子濃度較快上升時(shí)的成核與生長(zhǎng)模式有利于得到粒徑均一的球形銀粉;銀顆粒的團(tuán)聚主要以顆�！奥�(lián)結(jié)”和“架橋”形式出現(xiàn)。4、以硝酸銀為原料,采用PVP(K30)為分散劑,抗壞血酸為還原劑,當(dāng)AgNO3濃度為0.2mol/L,m(PVP)/m(AgNO3)為0.6,pH值為7,反應(yīng)溫度為40℃,滴液速度為5ml/s,分離干燥環(huán)境為無(wú)水乙醇時(shí),可獲得表面光滑、球形度高、粒徑分布集中于0.45~1.3μm,平均粒徑為0.8μm的高分散超細(xì)銀粉。本文研究結(jié)果將為制備球形、花瓣?duì)詈推渌鼜?fù)雜形貌的高品質(zhì)超細(xì)微米/亞微米級(jí)銀粉提供一定的技術(shù)支撐和理論指導(dǎo)。
[Abstract]:In order to prepare spherical and high quality ultrafine silver powder, ultrafine silver powder with controllable morphology and particle size was prepared by liquid-phase chemical reduction method. The raw materials and technology were studied. The main contents were as follows: 1. The different silver sources and reductants were compared. Influence of dispersant on morphology and particle size of ultrafine silver powder. The results showed that Agno _ 3, ascorbic acid and PVP _ (K30) were more suitable for the preparation of highly dispersed spherical ultrafine silver powder. The effects of technological conditions on the morphology and particle size of ultrafine silver powder were investigated. The results showed that the morphology of silver powder decreased from irregular shape to petal shape to spherical shape with the increase of the proportion of PVP in the reaction system, and the particle size increased with the increase of reaction temperature, and the agglomeration degree of silver powder increased with the increase of reaction temperature. With the increase of pH value of the solution, the particle agglomeration degree increases, the average particle size becomes larger, and the average particle size increases with the increase of AgNO3 concentration. The higher the droplet velocity is, the more narrow the particle size distribution range is and the better the dispersion is, the uniform spherical silver powder can be obtained. Organic solvent was used as washing and filtering liquid to improve the dispersity of silver powder. Combined with experiments and theoretical analysis, the controlling factors affecting the morphology and particle size of ultrafine silver powder were studied. The results showed that the nucleation of silver powder mainly affected the particle size and distribution range of silver powder, and the control of the growth process of silver powder could realize the regulation of the morphology and particle size of silver powder to a certain extent. The nucleation and growth mode of silver atom concentration increases rapidly in favor of the spherical silver powder with uniform particle size, and the agglomeration of silver particles mainly occurs in the form of particle "bonding" and "bridging", with silver nitrate as the raw material and PVP K30 as dispersant, the agglomeration of silver particles is mainly in the form of "joining" and "bridging". When ascorbic acid was used as reducing agent, when the concentration of AgNO3 was 0.2 mol / L, the pH value of AgNO3 was 0.6 渭 mol / L, the reaction temperature was 40 鈩，

本文編號(hào)：1787745