纳米银墨水的液桥转印技术研究

本文利用液桥转印技术将填充于聚二甲基硅氧烷(PDMS)模板沟槽内的纳米银墨水经烧结固化后转印到玻璃基底表面形成微结构图形。研究了金属微结构在转印过程中的图形断裂和线条展宽等缺陷产生的原因。实验结果表明,液桥毛细作用力的存在可以大幅提高图形转印成功率;降低烧结温度和缩短烧结时间有利于提高银线微结构的连续性,而升高烧结温度和增加烧结时间有利于提高纳米银墨水的固化程度,从而抑制线条展宽进而提高透射率。综合考虑这两方面因素,优化了工艺参数,改善了银线微结构的断裂情况,并且使其具有较高的转印精度和透射率。     

纳米铝液的转移方式对图案自动成型效果的模拟

目的 研究利用选择性吸附原理实现纳米图案自动成型的可行性,以及转移方式对自动成型效果的影响。方法 通过分子动力学方法分别研究块体铝和两纳米铝团簇的加热升温过程,得到纳米铝液势能–温度变化曲线,并确定纳米铝液图案自动成型的模拟温度;利用LAMMPS软件建立图案自动成型所需的印版模型;分别以液膜转印和液滴喷印的方式,研究纳米铝液在石墨烯–铜基印版表面上润湿铺展情况。结果 纳米铝液能够在石墨烯–铜基印版表面实现图案自动成型;液膜模型和液滴模型的图案自动成型效果不同,液膜较薄时（双层铝原子）模拟时间为1 200 ps时,整个体系达到动态平衡状态,图案区的铝液厚度约为1.8 nm,图案自动成型效果较好;当液膜较厚时（三层铝原子）,模拟时间为1 200 ps时,整个体系达到动态平衡状态,但图案区的两线条间存在较多铝原子残留,自动成型效果较差;而2种液滴模型均实现了较好的图案成型效果,液滴数量为4滴时,模拟时间为3 000 ps时可形成厚度均匀的图案,当液滴数量为6滴时,模拟运行600 ps时图案区即可形成的稳定均匀的线条。结论 利用选择性吸附原理可实现纳米图案自动成型,成型效果受铝液转移方式的影响...     

镍包碳纤维填充导电橡胶薄膜的制备及性能

采用喷涂法制备了镍包碳纤维(CF@Ni)填充型柔性导电橡胶薄膜,探究了球形Ni粉颗粒对导电橡胶流动性及导电性的影响,研究了导电CF@Ni/橡胶薄膜的抗折叠性能以及薄膜与铝合金基体之间黏附强度。结果表明:以CF@Ni为主掺杂少量球形Ni的复合填料所制备的导电橡胶薄膜,电阻率在10-1Ω·cm级别;且随Ni粉增加,其电阻率不发生显著变化,但液态导电CF@Ni/橡胶流动性明显提高;喷涂获得的薄膜在0.2 MPa压力经100次折叠周期后,其导电性无明显下降;喷涂薄膜与铝合金基体之间的黏附强度约为0.219 MPa。所制备的导电CF@Ni/橡胶薄膜具有良好的导电性和抗折叠性能,导电橡胶薄膜中CF@Ni起主要导电作用,球形Ni粉不影响薄膜导电性,但在喷涂过程中有"润滑"作用,提高了喷涂效率。     

喷墨印刷工艺对导电墨水导电性能的影响

目的研究喷墨印刷工艺对导电墨水导电性能的影响。方法以EPSON 1390万能平板打印机为输出设备,选取塑料薄膜种类、打印分辨率、打印次数、电路形状为主要工艺指标,运用单因素实验法,测试不同指标作用下各印刷线路的单位电阻值。结果塑料薄膜的表面分子结构对墨水的导电性能有直接影响,表面张力高的塑料有利于获得较好的印刷效果,导电性会得到提高;较高的打印分辨率有利于提高墨层的连接精度,从而提高导电性;适当增加打印次数有利于形成清晰完整的印刷电路,可以降低平均电阻值;印刷电子线路形状不同,导电性能也不尽相同,导电性能顺序为直线型折线型矩形波型环型。结论喷墨印刷工艺对导电墨水的导电性能具有一定的影响,选择合适的印刷工艺有利于提高导电线路的导电性。     

消光型BOPP转移薄膜的研究

目前市场上转移膜基本上都是平膜型转移膜,通过在薄膜上采用涂布、加热、加压的方法将整版色彩完整转印到承印物表面,转移后的图案光泽度较高。但是近年来,越来越多的产品要求图案呈亚光,来降低图案的光泽度。目前采用的工艺是用平膜型转移膜转印后再处理,通过涂布消光剂或经过绒布辊来达到消光效果。     

金属网格柔性透明导电薄膜研究进展

随着柔性电子器件的发展，柔性显示器、柔性太阳能电池、柔性传感器等产品已经逐步从实验室走向市场。柔性透明导电薄膜作为柔性光电器件不可或缺的重要组成部分，今后其需求量只会不断增加。目前的光电子器件逐渐向大尺寸、轻薄、柔性、可拉伸、低成本等方面发展。氧化铟锡（Indium tin oxide,ITO）是目前使用最广泛的透明导电薄膜，但ITO制备工艺复杂，具有脆性，且铟是稀有金属，储量少，价格昂贵。因此，研制可替代ITO的高性能柔性透明导电薄膜越来越迫切。目前已有研究人员研制出多种可替代ITO的柔性透明导电薄膜，其中基于金属网格的柔性透明导电薄膜是替代ITO的有力竞争者。金属网格柔性透明导电薄膜展示了极好的光电性能和机械灵活性。它最吸引人的地方在于可以独立改变金属网格的线宽和间距，从而在调节薄膜方阻和透光率方面表现出更好的权衡性。目前，已有大量的研究人员研制出可与ITO媲美的金属网格柔性透明导电薄膜。多数研究者通过光刻技术制作出母版，再结合化学镀或电沉积技术进行导电薄膜制作。以光刻技术为基础制备的柔性透明导电薄膜性能良好，但光刻工艺复杂而且设备昂贵。还有研究人员通过其他技术进行研究，如印刷增材...     

喷墨热转印纸性能对油墨转移率的影响

目的研究喷墨热转印纸性能对油墨转移率的影响。方法选取4种纸张特性不同的喷墨热转印纸,分别测试其匀度、白度、灰分、透气度、吸收性和粗糙度等主要性能指标。用喷墨打印机对这些纸样打印相同的印刷图案,通过磁力烫画机将各样张的图案转印到同样材质的热转印T恤上,对比热转印纸转印前后质量的变化,探讨热转印纸张性能对油墨转移率的影响。结果匀度高的纸张,纤维分布规则,有利于获得较好的印刷适性,从而提高油墨转移率。纸张灰分含量低,纤维交织紧密,油墨转移良好。较低的粗糙度和吸收性及适中的透气度对提高油墨转移率具有显著作用。结论喷墨热转印纸的性能会直接影响油墨转移率,必须在热转印纸的生产及研发中加以控制。     

导电聚合物离子凝胶制备与电化学驱动性能研究

基于导电聚合物的电化学驱动器具有低工作电压、制备简单、易操控及低成本的优势，在软体机器人领域具有广阔的应用前景。目前多采用添加具有高电化学活性材料的方法提高其驱动性能，但纯导电聚合物电化学驱动器的驱动应变仍小于1%。通过添加剂调控导电聚合物的微观结构，获得了一种具有高导电性(1500S/cm)、高拉伸率(47%)的导电聚合物离子凝胶，其最大驱动应变达到1.4%,优于已经报道的导电聚合物电化学驱动器。这一结果表明，导电聚合物电极的微观结构对于电化学驱动器驱动性能具有重要作用，为后续研究提供了有益的借鉴。     

复合型导电纤维的制备及性能

选用实验室自制的白色导电Ti O_2熔融造粒制备导电母粒,然后通过复合熔融纺丝技术制备4种不同截面形貌的白色导电纤维,采用扫描电镜、X射线衍射仪和热重分析仪等对其结构和性能进行详细表征。通过与共混型导电纤维对比发现,4种复合型导电纤维的拉伸强度明显提高,同时纤维体积电阻率下降了3个数量级,复合纺丝能够有效提高纤维的综合性能;抗静电性能研究发现,织物抗静电性与纤维导电性不呈正比关系,但其与复合导电纤维中导电部分的尖锐程度和裸露表面积有一定关系:导电部分形貌越尖锐,裸露表面积越大,纤维抗静电性能越好;进一步研究表明,对称腰形复合型导电纤维综合性能最优,可应用于抗静电织物的制备。     

纳米银颗粒-银离子复合型导电墨水导电性研究

目的 为了减少纳米银颗粒墨水所制备图案的孔隙率，提高图案的导电性。方法 将多尺寸纳米银颗粒与银离子溶液混合制备得到纳米银颗粒-银离子复合型墨水，通过扫描电子显微镜（SEM）观察所制备图案的表面形貌，采用X-射线衍射仪（XRD）确定图案表面晶型，并对图案进行电阻率测试。结果 实验结果表明，纳米银颗粒-银离子的配比对该复合型导电墨水的导电性有重要影响。AgNPs与Ag⁺的体积比为2∶1的混合型墨水在干燥之后具有最佳导电性，电阻率为1.33×10^-3Ω·cm，该墨水中银的质量分数约为4.37%。经过热压之后，AgNPs与Ag⁺的体积比为5∶1的墨水所制备的图案导电性最好，电阻率为1.32×10^-4Ω·cm，该墨水中银的质量分数约为3.19%。结论 所制备的纳米银颗粒-银离子复合型墨水干燥后即可导电，经过热压处理之后导电性可进一步提高。该复合型墨水中银含量低，可大大降低其用于柔性器件的成本。     

Visually Imperceptible Liquid‐Metal Circuits for Transparent,Stretchable Electronics with Direct Laser Writing

A material architecture and laser‐based microfabrication technique is introduced to produce electrically conductive films (sheet resistance = 2.95 Ω sq^?1; resistivity = 1.77 × 10^?6 Ω m) that are soft, elastic (strain limit >100%), and optically transparent. The films are composed of a grid‐like array of visually imperceptible liquid‐metal (LM) lines on a clear elastomer. Unlike previous efforts in transparent LM circuitry, the current approach enables fully imperceptible electronics that have not only high optical transmittance (>85% at 550 nm) but are also invisible under typical lighting conditions and reading distances. This unique combination of properties is enabled with a laser writing technique that results in LM grid patterns with a line width and pitch as small as 4.5 and 100 µm, respectively—yielding grid‐like wiring that has adequate conductivity for digital functionality but is also well below the threshold for visual perception. The electrical, mechanical, electromechanical, and optomechanical properties of the films are characterized and it is found that high conductivity and transparency are preserved at tensile strains of ≈100%. To demonstrate their effectiveness for emerging applications in transparent displays and sensing electronics, the material architecture is incorporated into a couple of illustrative use cases related to chemical hazard warning.     

Patterning of micro-scale conductive networks using reel-to-reel flexographic printing

The flexographic printing process has been employed to print micro-scale conductive networks. These networks have been utilised to reduce the sheet resistance of a coated transparent conductive layer on a flexible substrate, while limiting the effect on the apparent transparency. The orientation and the width of the conductive tracks within the networks were varied to identify any effect on the resulting sheet resistance. The orientation was shown to a have minimal effect on the resulting sheet resistance. Track width affected the conductivity; thinner tracks resulted in networks with lower sheet resistance per area coverage. Conductive tracks within networks of 74.6 μm width and 0.74 μm height, resulting in a sheet resistance of 1.26 Ω/□ at 18.6% coverage have been achieved.     

导电混凝土的导电性能及影响因素研究进展

导电混凝土是具有导电、电热、电磁屏蔽等诸多特性或功能的复合材料,在道路融雪化冰、电气设备接地、结构健康监测以及电磁屏蔽等领域具有广阔的应用前景。导电混凝土应具有适宜的导电性能和电阻率稳定性,但是导电材料类型、形态和掺量以及导电混凝土含水率和环境温湿度等诸多因素都可能导致导电性能和电阻率稳定性降低,从而制约导电混凝土的工程应用。分类对比了常见导电材料的性能差异以及用不同导电材料制备的导电混凝土的导电性能差异,在此基础上,探讨了导电混凝土的导电性能和制备方法的研究现状,较为系统地分析了导电材料类型和掺量等因素对导电性能的影响,并提出了改善导电性能和电阻率稳定性的建议。     

Direct printing of silver nanoparticles by an agarose stamp on planar and patterned substrates

In this study, we have used an agarose stamp to conduct direct printing of silver nanoparticles, nanowires and nanoplates on both planar and structured substrates. Nanoparticle solution could be first coated on an agarose stamp, and then transferred to a planar substrate. Micro-patterns comprising metal nanoparticles could be printed on planar substrates without the formation of residual layers. Thus a three-dimensional metal microstructure could be easily fabricated. The patterning of electrodes by printing Ag nanowires directly on TiO(2) was also demonstrated to fabricate resistive random access memory (RRAM) devices by all-solution-processing methods. By using a flat agarose stamp, the patterns printed on the microstructured substrates were quite different from those on the nanostructured substrates. On the microstructured substrates, direct printing could print silver nanoparticles onto the protrusion surface, and could print silver layers as thick as several microns, useful for high conductivity electrodes. On the substrates with nanostructures such as photonic crystals or nano-gratings, direct printing could transfer nanoparticles into the grooves or cavities only due to the contact of the agarose stamp with the groove or concavity surface. A new approach to fabricate metal wire grid polarizers was further demonstrated. A nanoporous agarose stamp has a good potential for printing using nanoparticle suspension.     

Boron nitride stamp for ultra-violet nanoimprinting lithography fabricated by focused ion beam lithography

Cubic boron nitride (c-BN) is one of the hardest known materials (second after diamond). It has a high level of chemical resistance and high UV transmittance. In this study, a stamp for ultra-violet nanoimprint lithography (UV-NIL) was fabricated using a bi-layered BN film deposited on a quartz substrate. Deposition of the BN was done using RF magnetron sputtering. A hexagonal boron nitride (h-BN) layer was deposited for 30?min before c-BN was deposited for 30?min. The thickness of the film was measured as 160?nm. The phase of the c-BN layer was investigated using Fourier transform infrared (FTIR) spectrometry, and it was found that the c-BN layer has a 40% cubic phase. The deposited film was patterned using focused ion beam (FIB) lithography for use as a UV-NIL stamp. Line patterns were fabricated with the line width and line distance set at 150 and 150?nm, respectively. The patterning process was performed by applying different currents to observe the effect of the current value on the pattern profile. The fabricated patterns were investigated using AFM, and it was found that the pattern fabricated by applying a current value of 50?picoamperes (pA) has a better profile with a 65?nm line depth. The UV transmittance of the 160?nm thick film was measured to be 70-86%. The hardness and modulus of the BN was measured to be 12 and 150?GPa, respectively. The water contact angle of the stamp surface was measured at 75°. The stamp was applied to UV-NIL without coating with an anti-adhesion layer. Successful imprinting was proved via scanning electron microscope (SEM) images of the imprinted resin.     

聚苯胺/聚丙烯复合导电纤维的结构与性能

采用现场吸附聚合法(原位聚合法)制备了聚苯胺/聚丙烯复合导电纤维,讨论了掺杂酸浓度、氧化剂浓度、苯胺单体含量对纤维导电性能的影响。通过扫描电镜(SEM)、红外光谱分析(FT-IR)、纤维物理力学性能测定等,对导电纤维的结构与性能进行了研究。实验表明采用此法制得的复合纤维导电性能优良,电导率达到10-1数量级。     

新型导电胶的研究（Ⅰ）

通过对不同形状的铜粉导电性的研究，发现球状铜粉经过真空球磨后得到的，收片状和椭球状混合形状组成的铜粉具有良好的导电性，然后对这种球磨处理技术的条件进行了比较，并通过这种技术制得具有高导电性的银铜复合粉，百而对其导电胶的配方进行了研究。     

一种适用于铝合金的导电氧化工艺

铝件化学导电氧化后形成的膜需要有良好的耐蚀性和导电性。开发了一种铝件两步导电氧化工艺,先用以铬酐为主要成分的导电氧化液氧化,再用重铬酸钾封闭,并将此工艺投入生产应用。结果表明:该工艺稳定,氧化膜既有较好的耐蚀性,又保持了零件的导电性,适用于多种铝型材。     

导电沥青混凝土及其功能特性研究进展

为系统掌握国内外有关导电沥青混凝土的研究现状,通过调查现有导电沥青混凝土的添加材料、路用性能、功能特性、影响因素等,对比不同导电材料制备沥青混凝土的电导率特征,总结导电沥青混凝土的功能特性及其电导率影响因素。结果表明:国内外主要采用石墨、碳纤维、钢棉作为导电材料制备导电沥青混凝土,石墨对沥青混凝土的电导率提升效果最佳,碳纤维可提高沥青混凝土的路用性能;同时,导电沥青混凝土具有明显的压敏特性,感应加热可增强沥青混合料的抗疲劳性能,通电加热可快速提高沥青混凝土的温度,导电沥青混凝土的电导率主要受空隙率、环境温度、电极类型的影响。     

A new approach causing the patterns fabricated by silver nanoparticles to be conductive without sintering

Silver nanoparticles (Ag NPs) with a mean size of about 90?nm were synthesized by polyol reduction of silver nitrate with ethylene glycol (EG) in the presence of poly(vinyl pyrrolidone) (PVP). The Ag NPs undergo a spontaneous coalescence in the presence of chloride ions even without a traditional sintering process which occurs at a relatively high temperature. Such behavior can cause a rapid decrease in the resistivity of the patterns fabricated by Ag NPs. Conductive silver lines were successfully fabricated on FR-4 substrate using this method. The resulting conductivity of the silver lines reached about 16% of the bulk silver value, which enables fabrication of conductive patterns on some electronic devices.