納米銅及多孔銅的制備及其性能研究
發(fā)布時間:2018-04-30 04:39
本文選題:片狀納米銅 + 低共熔溶劑; 參考:《南昌航空大學》2015年碩士論文
【摘要】:納米銅粉在電子封裝材料、多孔散熱材料、高級潤滑油、催化劑等諸多領(lǐng)域具有廣泛的用途。而多孔金屬銅可望在催化、傳感、驅(qū)動和CPU散熱等領(lǐng)域獲得廣泛應(yīng)用。本文以不同種類的離子液體為反應(yīng)介質(zhì),在不同反應(yīng)溫度下,以Cu(NO3)2為銅源,水合肼為還原劑,采用離子熱法合成了納米銅粉。研究了反應(yīng)介質(zhì)種類和溶液的PH值等因素對納米銅顆粒形貌的影響。采用XRD、SEM、XPS和紫外-可見光光譜對所制備的納米銅粉進行了表征。同時以納米銅顆粒為原料,g-C3N4為造孔劑,采用微波燒結(jié)法制備了多孔銅散熱材料,并對多孔銅散熱材料性能的影響因素進行了研究。主要概括如下:1.當反應(yīng)溫度在120℃-160℃時,所制備的樣品只有銅物相,而當反應(yīng)溫度達到180℃時,所制備的樣品除了銅物相,還有Cu2O生成。2.當反應(yīng)介質(zhì)為四乙基溴化銨/丁二酸離子液體體系時,所制備的納米銅呈三角狀,而當反應(yīng)介質(zhì)為尿素/氯化膽堿離子液體體系時,所制備的納米銅呈不規(guī)則球形。3.所制備的三角形納米銅在200-900 nm波長范圍有兩個吸收峰,分別在525 nm和605 nm處。4.通過多孔銅孔隙率的對比研究發(fā)現(xiàn):多孔銅散熱材料的孔隙率隨著C3N4體積分數(shù)增加而增加;溫度從750℃升到800℃時,孔隙率變化不大,當溫度超過825℃時,孔隙率突降;但保溫時間從10min增至40min,孔隙率變化很小。5.通過多孔銅力學性能的對比研究發(fā)現(xiàn):隨著孔隙率的增大,多孔銅抗彈性變形能力極劇降低,彈性區(qū)間變形范圍明顯減小;發(fā)泡劑C3N4含量保持70%不變,多孔銅的力學性能隨燒結(jié)溫度的升高而變好。6.通過多孔銅熱導率的研究發(fā)現(xiàn):多孔銅導熱系數(shù)皆隨著多孔銅孔隙率的增大而降低。銅在775℃以下燒結(jié)時,導熱系數(shù)較低,燒結(jié)溫度在800℃和825℃時,導熱系數(shù)顯著提高。7.通過多孔銅膨脹系數(shù)的研究發(fā)現(xiàn):在30℃~150℃溫度范圍內(nèi),相同溫度下,不同C3N4體積分數(shù)的多孔銅線膨脹系數(shù)相差不大,在溫度超過80℃后,不同C3N4體積分數(shù)多孔銅試樣的線膨脹系數(shù)近似相同,都穩(wěn)定在一個固定值。
[Abstract]:Nano-copper powder has been widely used in many fields such as electronic packaging materials, porous heat dissipation materials, high-grade lubricating oils, catalysts and so on. The porous metal copper is expected to be widely used in the fields of catalysis, sensing, driving and CPU heat dissipation. In this paper, nanocrystalline copper powder was synthesized with different kinds of ionic liquids as reaction medium, Cu(NO3)2 as copper source and hydrazine hydrate as reducing agent at different reaction temperature. The effects of reaction medium and pH value of solution on the morphology of copper nanoparticles were studied. The prepared nano copper powders were characterized by XRDX SEMX XPS and UV-vis spectra. At the same time, the porous copper heat dissipation material was prepared by microwave sintering with nano-copper particles as raw material and g-C _ 3N _ 4 as pore-forming agent, and the factors affecting the properties of porous copper heat dissipation materials were studied. The main generalizations are as follows: 1. When the reaction temperature is between 120 鈩,
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