聚苯胺對無電鍍銀微粒導電膠電阻效應之研究

Abstract

本實驗分成三個部分討論：第一部分為製備聚苯胺的研究，第二部分為製備導電粒子的研究，第三部份為製備導電膠的研究。藉由GPC與UV-Vis儀測量聚苯胺的分子量與特徵峰;藉由粒徑分析儀與SEM觀察顆粒尺寸與顆粒形貌；而藉由XRD及ICP觀察無電鍍銀後，銀是否有鍍著在微粒表面與銀鍍上去的量。第三部份為製備導電膠的研究 實驗結果發現在製備聚苯胺實驗方面，在0˚C下化學合成的聚苯胺，由GPC測量其平均分子量為3756; 由UV-vis儀觀察去摻雜態聚苯胺，其UV-vis光譜波長在320nm及640nm左右有吸收，這分別是由苯環的π-π*吸收的exciton吸收所造成的。製備得到的去摻雜態聚苯胺用不同的摻雜酸(HCl、HBr、HNO3、H3PO4、DBSA)摻雜，以DMSO做為溶劑，可得到最高導電度為硝酸摻雜態聚苯胺溶液，其值為164.33μs/cm；而以DBSA為摻雜酸的摻雜態聚苯胺在DMSO溶劑中有最大的溶解度6.43mg/ml。 製備導電粒子實驗方面先將平均粒徑為0.982 μm的扁平雪片狀石墨粉GS-75與平均粒徑為4.292 μm的扁平雪片狀石墨粉GP-44無電鍍銀；由XRD觀察無電鍍銀後的微粒可知鍍銀石墨粉GS-75/Ag與GP-44/Ag表面皆產生Ag與幫助電性導通的Ag2O。由ICP觀察石墨粉無電鍍銀十分鐘後，鍍上銀的量，而且比表面積較大的小顆粒石墨粉GS-75吸附銀的量會比大顆粒石墨粉GP-44吸附銀的量較多。 在製備導電膠實驗方面，發現石墨微粒在無電鍍銀之後，電阻係數ρ必定會下降；而且微粒在加入聚苯胺溶液之後，電阻係數ρ也必定會下降；而當再加入硫醇當分散劑之後，電阻係數ρ又稍微下降，故GS-75,GP-44在鍍銀且加入聚苯胺溶液與分散劑硫醇之後，電阻係數ρ會比原本不鍍銀且不加入分散劑硫醇下降約三個order。固化溫度在200°C之後，電阻係數便不會在下降。GS-75/Ag加入聚苯胺溶液之後且在200°C固化，其電阻係數ρ為0.000421ohm-cm，此值為本論文所作出來的最佳且最低的電阻係數值。

The thesis was divided into three parts. The first part of study was preparing polyaniline. The second part of study was preparing conductive particles. The third part of study was preparing electrically conductive adhesives (ECAs). In the experiments, we measured the molecular weight of polyaniline by GPC and polyaniline was characterized by ultraviolet-visible spectroscopy. We observed particle size and surface morphology by particle size instrument and SEM. We also analyzed if silver was electroless plated on particles surface and plated weight by XRD and ICP. In the study of preparing polyaniline, we synthesize it at 0°C. We find its molecular weight is 3756. UV–vis spectra of the emeraldine form of polyanoline shows two peaks, 320nm and 640nm.They are the characteristic peaks of he emeraldine form of PANI. After we synthesize the emeraldine form of polyaniline, we dope it by using different doping acids(HCl、HBr、HNO3、H3PO4、DBSA) and then we solve it in DMSO to measure its conductivity and solubility. In the study of preparing conductive particles, we take the 0.982 μm flake graphite(GS-75) and the 4.292 μm flake graphite(GP-44) to plate silver electroless. We can find there are Ag and Ag2O on GS-75/Ag and GP-44/Ag particles surface by XRD. We also find small particle graphite (GS-75) electroless plated more silver weight than big particle graphite (GP-44),because the specific surface area of small particle graphite (GS-75) was bigger. In the study of preparing electrically conductive adhesives, we can find resistivity ρ must decline after electroless plating silver. We also find resistivity ρ must decline after adding polyaniline solution, so resistivity ρ of ECAs of particles GS-75、 GP-44 decline about three order after plating silver and adding polyaniline solution. The best cruing temperature of ECAs was 200°C. In this thesis, the best resistivity ρ of ECAs was 0.000421 ohm-cm, and it was the ECAs of GS-75/Ag cured at 200°C.