离子注入PET薄膜导电性能及机理的研究

主要研究了Ar~+、As~+离子注入PET薄膜后对其导电性能的影响及其导电机理。在PET膜上分别注入了不同种类、不同剂量的离子,测定了其注入后的表面电阻率,研究了注入离子后薄膜表面电阻率与温度的关系,根据注入前后的FTIR-ATR谱图及有关理论对其导电机理进行了初步探讨。结果表明,随离子注入的种类不同、剂量的变化、温度的升降,PET膜的表面电阻率呈规律性变化。根据薄膜结构分析初步确认离子注入PET薄膜主要是离子导电。     

环保导电银浆的制备及其电子纸的性能研究

导电银浆是制备电子元器件的关键功能材料。以银和淀粉为做导电填料,按照淀粉/硝酸银质量比分别为2∶1,1∶1,1∶2和1∶3,用氧化还原法制备导电银浆。通过测量电阻研究物理因素(加热烧结、紫外光照照射、泡水、超声波等)对导电银浆导电性能的影响,用显微镜观察导电银浆的形貌。结果表明,淀粉/硝酸银为1∶3时,形成了均匀的淀粉为核、银粒子为壳的导电颗粒。比例为1∶2和1∶3时,在低温加热烧结过程中电阻率降低到初始值的60%～70%。所得银浆能耐受紫外光照、水泡和超声波。其中1∶3导电性最佳。最后,用淀粉/硝酸银比例为1∶3的银浆,分别与30%、45%和60%的墨水混合,涂布纸张,并经低温热烧结后,所得电子纸的电阻率为10 mΩ/cm。     

纳米导电纤维填充天然胶乳复合材料的电性能研究

用纳米导电纤维填充天然乳得复合材料,研究了复合材料的导电性、介电性以及温度对复合材料电阻率的影响。结果表明,随纳米导电纤维填充份数的增加,复合材料的电阻率下降,介常数增大;电阻率对温度的依赖性产大,并且当纳米导昵水在胶乳中形成导电网络时,电阻率和表面电阻率随温度同表现出不同的变化趋势。     

银粉性质对太阳能电池浆料的影响

作为传统化石能源的有效替代品,太阳能电池引起了学者们的广泛关注。导电银浆作为太阳能电池的重要原料,影响着太阳能电池的光电转换率和度电成本。银粉作为银浆中的导电相,其性能对银浆的电性能、流动性、粘附性等性质起着关键作用。近年来针对银粉的形态、尺寸、分散度、粒度分布和振实密度对导电银浆电性能的影响有较多研究。研究表明银粉的形态和粒径是决定银浆导电性、烧结质量等特性的主要因素;银粉的振实密度也是影响烧结厚膜的致密性以及电池的光电转化率的重要因素。在银粉制备过程中,不同种类的分散剂会影响银粉的分散性,从而影响银浆的细度、粘附性和电阻率。     

基于银纳米颗粒墨水在柔性基材表面制备导电薄膜及其电阻率

通过两相界面反应制备出小尺寸银纳米颗粒,用喷墨打印技术和热处理工艺在柔性PET基材表面制备导电薄膜。用紫外-可见光吸收光谱、透射电镜和能谱研究了银颗粒粒径、微结构和成分,结果表明所合成的颗粒为多晶结构,粒径为2～5nm。用扫描电镜和四探针薄膜电阻率测量法研究了热处理温度、时间与薄膜形貌、电阻率之间的关系,结果表明柔性PET塑料表面的银颗粒在150℃条件下处理30min,可获得表面平整、无明显裂纹、电阻率～6.4μΩ.cm的导电薄膜。     

花状氧化锌的制备及光电性能的研究

采用聚乙二醇(PEG(2000))辅助的水热合成法制备出了粒径较为均匀的花状氧化锌纳米团簇,并用SEM、XRD对其进行了表征.实验结果表明,表面活性剂(PEG-2000)和氨水的加入量对ZnO纳米团簇的形貌有直接的影响;将ZnO纳米团簇均匀涂在导电玻璃的导电面上,在一定温度下煅烧后制成纳米团簇膜电极,并进行了光电化学研究.     

微胶囊铜粉对铜复合浆料性能的影响

为提高铜浆料的导电性,利用微胶囊技术在铜粉表面包覆液体石蜡,增强铜粉的抗氧化性,并添加少量导电性能优异的碳纳米管作为导电增强相,制备碳纳米管-铜复合浆料.利用四探针测试仪、扫描电镜等测试方法研究了液体石蜡含量对包覆铜粉性能的影响以及微胶囊铜粉作为主导电相,碳纳米管作为导电增强相对浆料导电性能的影响.结果表明:液体石蜡包覆含量为4 wt%的微胶囊铜粉具有良好的导电性和抗氧化性,其电导率为44.32%IACS;微胶囊铜粉作为碳纳米管-铜浆料的主导电相,制备浆料膜层电阻率为22.59 mΩ·cm,相比于未包覆的铜粉为主导电相制备的浆料膜层电阻率降低了12.44%;碳纳米管作为导电增强相所制备的浆料相比于纯铜浆料,电阻率降低31.74%.     

液面沉积法制备透明柔性石墨烯导电薄膜

透明导电薄膜在现代电子领域有着非常广泛的应用。我们利用简单的液面沉积法在柔性基底PET上成功制备了氧化石墨烯薄膜,在室温下经过碘化氢(HI)蒸汽还原后得到石墨烯透明导电薄膜。利用各种表征手段(SEM、TEM、AFM、吸收光谱(UV-Vis)和电阻分析(四探针法))系统的研究了不同沉积层数的石墨烯薄膜的透光性和导电性之间的关系:随着石墨烯沉积层数的增加,导电薄膜的导电性上升,但薄膜的透光率下降。在透光率(λ=550nm)为82.22%时,导电薄膜的方块电阻为620Ω/□。     

导电银浆中纳米银团簇的分子动力学研究

目的 研究纳米银团簇的运动机理及连接料对团聚的影响。方法 以环氧树脂为导电银浆连接料,分别建立不同环氧树脂含量的纳米银团簇和环氧树脂模型,模拟不同环氧树脂含量下纳米银团簇的动力学平衡状况。结果 纳米银团簇在常温下极易发生团聚,加入环氧树脂后,系统能量虽然增大,但银团簇的运动活性明显降低;环氧树脂吸附于银团簇表面,阻止了银团簇间的团聚,银团簇的团聚倾向和银原子的运动活性随环氧树脂含量的升高逐渐降低;模拟结果显示,当环氧树脂质量分数增大至33%时,环氧树脂可起到防止银团簇团聚的效果。结论 在导电银浆中,纳米银团簇在常温下易团聚且受环氧树脂的影响较大。     

水性聚氨酯/丙烯酸酯基多维度导电银浆的制备及低温固化特性

采用醇热法制备了纳米银颗粒、纳米银线和微米银片，对其进行多维度配合作为复合导电填料，以水性聚氨酯/丙烯酸脂复合树脂(WPUA)为载体和黏结相，采用搅拌混合法制备了水性树脂基多维度低温固化导电银浆。利用透射电镜、扫描电镜、水接触角测试和电阻测试，研究了不同固化温度对导电银浆成膜后的力学性能、导电性能及亲疏水特性的影响。结果表明，随着固化温度的上升，银浆漆膜的硬度、附着力及耐水性逐渐增加，WPUA基银浆漆膜的硬度在120℃时可达到3H等级，附着力在100℃可达到1等级，水接触角在140℃时可以达到93°；而WPUA银浆漆膜的电阻率随着固化温度的上升，呈现先增加后减小的趋势，在固化温度为160℃时的电阻率为0.19×10^-3Ω·cm。文中制备的多维度复合导电银浆在柔性电子印刷领域有着很好的应用前景。     

The research of manufacture of flexible conductive tracks at room temperature

Nano silver is widely used in conductive lines for its advantages, nano size, low melt temperature and excellent conductivity. In general, nano silver of less than 50 nm need be sintered at 200 centigrade in order to acquire conductivity, but it limits the choice of the substrates, only high temperature resistant substrate can be used, for example, PI film and glass. In order to acquire flexible tracks with excellent conductivity at room temperature on paper and PET, nano silver emulsion of 2 percent silver content was prepared through liquid phase chemical reduction, and then the concentration of silver was improved to 17 percent by centrifuging at high speed. And the emulsion was adjusted to meet the demand of inkjet printing, such as surface tension, and viscosity, pH value, then was jetted onto photo paper and PET film. High conductivity was acquired after treated by 830 nm infrared laser, and the sheet resistance is less than 2 omega/(see symbol). After aging test, the conductivity was stable. The method can be used in solar cells, flexible LED, intelligent packaging and can replace the traditional screen printing method at low cost.     

纳米银导电油墨及其在柔性印刷电子中的应用

目的 探究纳米银导电油墨及其在柔性印刷电子中的应用。方法 通过总结国内外文献,从纳米银颗粒及其导电油墨的制备、印刷工艺、烧结工艺以及在柔性印刷电子技术中的应用几方面总结近年来的研究进展。结果 在油墨制备及使用中,简化制备工艺、降低生产成本、实现绿色环保、低温烧结,同时提高油墨的基材适应性是未来纳米银导电油墨的改进重点。直写技术具有精度高、速度快等优势,正逐渐替代丝网印刷技术成为主流。烧结工艺的研究重点在于实现低温烧结,其中化学烧结工艺简单,但提高导电性是研究重点。其他烧结方式则设备昂贵,环境要求高。结论 作为功能性电子材料,纳米银导电油墨因出色的电性能和印刷适性,正在被广泛应用于柔性印刷电子中。近年来通过对纳米银及其导电油墨的深入研究及技术改进,在纳米银颗粒的制备、低温烧结技术、节能环保加工工艺等方面获得了一定的进展。与此同时,将其作为功能材料应用于制备柔性传感器中,RFID标签天线、柔性电极、超级电容器、太阳能电池等正受到广泛研究与应用。     

Large scale, highly conductive and patterned transparent films of silver nanowires on arbitrary substrates and their application in touch screens

The application of silver nanowire films as transparent conductive electrodes has shown promising results recently. In this paper, we demonstrate the application of a simple spray coating technique to obtain large scale, highly uniform and conductive silver nanowire films on arbitrary substrates. We also integrated a polydimethylsiloxane (PDMS)-assisted contact transfer technique with spray coating, which allowed us to obtain large scale high quality patterned films of silver nanowires. The transparency and conductivity of the films was controlled by the volume of the dispersion used in spraying and the substrate area. We note that the optoelectrical property, σ(DC)/σ(Op), for various films fabricated was in the range 75-350, which is extremely high for transparent thin film compared to other candidate alternatives to doped metal oxide film. Using this method, we obtain silver nanowire films on a flexible polyethylene terephthalate (PET) substrate with a transparency of 85% and sheet resistance of 33 Ω/sq, which is comparable to that of tin-doped indium oxide (ITO) on flexible substrates. In-depth analysis of the film shows a high performance using another commonly used figure-of-merit, Φ(TE). Also, Ag nanowire film/PET shows good mechanical flexibility and the application of such a conductive silver nanowire film as an electrode in a touch panel has been demonstrated.     

气溶胶微喷射打印柔性应变传感器及性能研究

目的 研究气溶胶微喷射打印工艺在制备柔性应变传感器方面的可行性。方法 利用气溶胶微喷射打印工艺不受限于柔性基底且打印定位精度高的优势,通过等离子清洗技术增大PDMS表面附着力,使用纳米银墨水与PDMS基底制作用于人体运动检测的电阻式柔性应变传感器。结果 通过等离子清洗PDMS基底表面,解决了打印过程中柔性应变传感器因PDMS表面纳米银液滴凝聚而产生的不导电问题。探究了气溶胶微喷射打印工艺参数对打印银线宽度的影响规律,发现增大鞘气流量或缩小喷头内径能有效减小打印线宽。利用高精度万用表检测由气溶胶微喷射打印制备的传感器在受力时产生的电信号,测试传感器在无应力状态下导电性良好且稳定,计算出传感器应变在3.5%内且灵敏度可达163.84。将传感器用于人体手指部位的运动监测,证明其具有检测微小信号的能力。结论 气溶胶微喷射打印工艺可用于制备所需要的柔性应变传感器,该传感器在智能穿戴设备方面具有一定应用潜力。     

丝网印刷电子工艺参数对印刷质量的影响

目的研究丝网印刷过程中刮胶角度、刮胶速度、离网间距、刮胶压力对印刷品质量的影响规律,为丝网印刷电子的实际应用提供技术参考。方法利用现有丝网印刷试验台,对4个印刷参数进行正交试验;运用偏最小二乘法对实验中的数据进行影响因素主次判断。结果离网间距对印刷电子中导电线条宽度和导电线条表面粗糙度的影响最为明显,刮胶压力、刮胶角度和刮胶速度在确定范围内对导电线条表面粗糙度和宽度的影响并不明显;经由正交试验分析出丝网印刷的最优工艺条件为C3A1D1B3。结论通过偏最小二乘法对实验数据进行分析,验证了正交试验的合理性;在丝网印刷电子印制过程中,正确选用合理的离网间距是获得高品质印品的关键。     

Synthesis of monodisperse silver nanoparticles for ink-jet printed flexible electronics

In this study, monodisperse silver nanoparticles were synthesized with a new reduction system consisting of adipoyl hydrazide and dextrose at ambient temperature. By this facile and rapid approach, high concentration monodisperse silver nanoparticles were obtained on a large scale at low protectant/AgNO(3) mass ratio which was highly beneficial to low cost and high conductivity. Based on the synthesized monodisperse silver nanoparticles, conductive inks were prepared with water, ethanol and ethylene glycol as solvents, and were expected to be more environmentally friendly. A series of electrocircuits were fabricated by ink-jet printing silver nanoparticle ink on paper substrate with a commercial printer, and they had low resistivity in the range of 9.18 × 10( - 8)-8.76 × 10( - 8) Ω m after thermal treatment at 160?°C for 30 min, which was about five times that of bulk silver (1.586 × 10( - 8) Ω m). Moreover, a radio frequency identification (RFID) antenna was fabricated by ink-jet printing, and 6 m wireless identification was realized after an Alien higgs-3 chip was mounted on the printed antenna by the flip-chip method. These flexible electrocircuits produced by ink-jet printing would have enormous potential for low cost electrodes and sensor devices.     

银基填充复合材料电磁屏蔽效能研究

银基填充复合材料作为电磁屏蔽材料是电磁屏蔽领域研究热点之一。选用片状银粉、环氧树脂及固化剂制备导电银胶,使用涂抹棒将导电银胶均匀涂覆于聚酯基板上,固化后测试其各频率波段电磁屏蔽性能。研究了银基填充复合材料膜厚在不同波段电磁屏蔽性能的差别,测试其体积电阻率,通过扫描电镜观察横截面中片状银粉分散的均匀性,推导其电磁屏蔽机理。     

Thermal characterization of screen printed conductive pastes for RFID antennas

Thermal resistance is an essential aspect of electronic circuits designing. It leads to unexpected changes in electronic components during their work. In this study, new materials for screen printed RFID tag's antennas were characterized in terms of their resistance to thermal exposure. Polymer materials containing silver flakes, silver nanopowder, carbon nanotubes or conductive polymer PEDOT:PSS were elaborated and used for antenna printing on flexible materials. In order to verify their long term susceptibility to damages caused by the changing environmental conditions, the temperature cycling test was used in three different temperature ranges: +65 °C, −12 °C, −40 °C/+85 °C (3 h in each temp., dwell time 1 h). The highest durability to thermal exposure exhibited the paste with carbon nanotubes dispersed in poly(methyl methacrylate) PMMA and the lowest one – the paste with conductive polymer PEDOT:PSS.     

A simple, low-cost approach to prepare flexible highly conductive polymer composites by in situ reduction of silver carboxylate for flexible electronic applications

In recent years, efforts to prepare flexible highly conductive polymer composites at low temperatures for flexible electronic applications have increased significantly. Here, we describe a novel approach for the preparation of flexible highly conductive polymer composites (resistivity: 2.5 × 10⁻⁵ Ω cm) at a low temperature (150 °C), enabling the wide use of low cost, flexible substrates such as paper and polyethylene terephthalate (PET). The approach involves (i) in situ reduction of silver carboxylate on the surface of silver flakes by a flexible epoxy (diglycidyl ether of polypropylene glycol) to form highly surface reactive nano/submicron-sized particles; (ii) the in situ formed nano/submicron-sized particles facilitate the sintering between silver flakes during curing. Morphology and Raman studies indicated that the improved electrical conductivity was the result of sintering and direct metal-metal contacts between silver flakes. This approach developed for the preparation of flexible highly conductive polymer composites offers significant advantages, including simple low temperature processing, low cost, low viscosity, suitability for low-cost jet dispensing technologies, flexibility while maintaining high conductivity, and tunable mechanical properties. The developed flexible highly conductive materials with these advantages are attractive for current and emerging flexible electronic applications.     

导电油墨及其印刷技术的研究进展

目的 综述导电油墨及其印刷方式的研究进展,为开发价格低廉、性能稳定、导电性优良的导电油墨提供参考。方法 通过查阅文献归纳各类导电油墨的制备方式、印刷方式和应用领域,对导电油墨进行系统分类,比较各类导电油墨的性能和优缺点,并对其印刷技术进行分析,展望了导电油墨的发展前景。结果 目前关于导电油墨的研究集中在纳米银、纳米铜、石墨烯等导电填料的低温烧结油墨,主要采用丝网印刷、喷墨印刷等印刷方式,多用于制备传感器、柔性可穿戴设备等。未来的研究仍需关注如何低成本、低能耗、简单大量地制造导电油墨。结论 导电油墨的制备将与环境友好型的印刷方式相结合,向高导电性、高印刷适性发展,成为印刷电子领域的关键技术。