电镀废液回收铜粉的化学镀银工艺及其电磁屏蔽性能

采用高频超声脉冲电解法从电镀铜废液中回收制备枝晶状的铜粉,并在铜粉表面进行化学镀银以制备电磁屏蔽用银包铜粉,采用SEM、EDS、XRD、TEM等对其进行形貌和组分分析,研究了银包铜粉复合涂层的导电性能和电磁屏蔽性能。结果表明,经过表面化学镀银可以有效地避免铜粉的氧化;涂层的电磁屏蔽性能与银包铜粉的添加量紧密相关,当涂层中银包铜粉质量分数为60%时,其电磁屏蔽效率高达52 dB。     

紫外光固化电磁屏蔽涂料的特性研究

以镀银铜粉为导电填料,以聚氨酯丙烯酸酯UV光固化树脂为基体材料,研制了UV光固化电磁屏蔽导电涂料。测试结果表明:该涂料的导电性能不但与填料含量、引发剂种类和含量有关,而且随涂层厚度的增强其电磁屏蔽效能增大。     

材料研究专题

题目：微波吸收材料和技术的新突破；题目：锰锌、镍锌铁氧体的研究现状及最新进展；题目：电磁屏蔽材料的研究现状及进展；题目：电磁屏蔽导电涂料用镀银铜粉的制备。     

导电相和固化剂对铜系导电涂料性能的影响

利用IR、SEM等手段,较详细地研究了铜粉–环氧树脂体系中固化剂与铜粉的相互作用,并探讨了铜粉用量、形状对涂料导电性能的影响规律。结果表明:固化剂(最佳用量为20%左右)可以通过形成配合物的反应,有效除去铜粉表面的氧化物,极大改善涂料导电性,使填充75%铜粉的体系具有约0.2×104Ω·m的体积电阻率。应用渗流模型和导电通道理论分析铜粉的用量、形状对涂料导电性能的影响规律。     

铜粉添加量对铜酚醛树脂导电油墨性能的影响

以微米级铜粉为导电填料、酚醛树脂为粘接剂制备了导电油墨,并将该油墨以聚酰亚胺薄膜为基底,采用丝网印刷技术制备导电涂层。研究了铜粉添加量对铜酚醛树脂导电油墨的黏度、固含量以及导电涂层的微观形貌、电阻率和附着力的影响。研究表明,当铜粉添加量质量分数为70%时,制备的铜酚醛树脂导电油墨具有良好的性能,该导电油墨经丝网印刷得到的导电铜膜经低温固化后具有良好的电性能,其电阻率最低可以达到53.865×10–3Ω·cm。     

聚氨酯乳液／纳米石墨微片复合导电涂料的制备及其电磁屏蔽性能

以纳米石墨微片为导电填料,聚氨酯乳液为基体,制备水性导电复合涂料,研究其导电性能和电磁屏蔽性能。结果表明,质量分数为35wt％纳米石墨微片,粘度区间160～180MPa·s,质量分数为2％的OP-10分散剂为最佳配方,最佳施工工艺为超声波分散30min后喷涂,涂层厚度控制在80um左右,在65℃的条件下固化。通过该法制备得到的导电涂料,其涂层表面电阻率降低至7．5Ω·cm^-2,平均的电磁屏蔽效能在27dB左右（300kHz～1．5GHz）。     

利用碱性蚀刻废液制备纳米铜导电浆料

利用液相还原的方法先在碱性蚀刻废液中制备成纳米级的铜粉,再通过对纳米铜粉表面的保护和真空干燥,然后将铜粉分散到聚氨基甲酸酯以及浆料助剂中得到纳米铜导电浆料。实验研究表明通过液相法制备出了的铜粉纯度比较高,大部分颗粒尺寸在100 nm以内,制备出来的导电浆料其体积电阻率可以达到18.35×10-3Ωcm。     

聚氨酯涂料红外发射率性能研究

文中主要通过对聚氨酯作为成膜物质时其红外性能和物理化学性能研究,通过加入纳米改性填料和改变涂装工艺的方法来降低其红外发射率,同时涂膜具有优良的物理化学性能.通过研究,用聚氨酯作为成膜物质,纳米NiO包覆片状铝粉和SiO2粉等为填料,得到了浅绿色涂层的红外发射率仅为0.39,具有一定的红外隐身与可见光隐身、雷达隐身相兼容效果,同时发现涂层的电导率、磁导率对涂层的红外发射率的影响也很大.     

玻璃微珠的表面化学镀银及红外辐射性能研究

采用化学镀方法在玻璃微珠表面镀银,考察了预处理条件、反应温度和反应时间等因素对玻璃微珠表面镀银的影响,并通过扫描电镜和X-射线衍射分析仪,对镀银后玻璃微珠的表面形貌和结构进行了观察和表征。将镀银玻璃微珠用于涂料中,考察了玻璃微珠在涂料中的应用及其红外辐射率的变化,探讨了化学镀条件对涂料红外辐射率的影响,结果表明,在控制反应温度和浓度的条件下,可使镀银玻璃微珠的红外辐射率由原来的1.02降为0.70,将其应用于涂料后,涂层的红外辐射率为0.80。     

高抗热震性红外辐射节能涂层的制备与性能研究

以堇青石、SiC、Cr2O3、TiO2、SiO2为原料,与磷酸盐胶粘结剂配料混匀后,经机械搅拌制备红外辐射涂料,采用刷涂的方式在高铝砖基体表面制备红外辐射节能涂层。采用TG-DSC研究分析红外辐射粉末的热稳定性,利用涂-4杯和漆膜附着力测定仪对涂料的流动性能和涂层与基体的结合强度进行表征,采用空冷和水淬方式研究涂层的抗热震性能,并探讨了碳化硅的含量对涂层红外发射率的影响。研究结果表明：胶粉比为2：1时,获得的涂料均匀,流动性最好;以磷酸盐胶粘结剂制备的红外辐射涂料经1100℃以上高温瓷化后,红外辐射涂层与基体的结合力增强,涂层抗热震性能良好;碳化硅含量为40%时,制备的复合红外辐射涂层具有最优的红外辐射性能。此外,在炭砖焙烧窑上使用该红外辐射涂料后,炉内温度提高了128℃,降低能耗8%左右。     

纳米SiO2对铝电解电容器闪火电压的影响研究

应用纳米材料改进铝电解电容器的性能将成为一条新途径。通过在工作电解液中添加纳米SiO2溶胶,研究了纳米SiO2对乙二醇体系工作电解液电导率和闪火电压的影响。结果表明,在研究体系中添加2%(质量分数)的纳米SiO2可以提高工作电解液的电导率10%、闪火电压提高20V,这与传统材料相比具有明显的优点。     

Effect of high voltage electric field on structure and property of PEDOT:PSS film

Low electrical conductivity of PEDOT:PSS film is to some extent a limit for its wide application. To solve this problem, the high voltage electric field was used to improve the film’s electrical conductivity and its effects on the film’s structure and properties were investigated. The PEDOT:PSS film was prepared on quartz substrate with spin coating. Visible light transmittance of the prepared film was tested with UV–Visible spectroscopy and chemical structure was measured with Fourier transform Raman spectroscopy (FIRM). The surface morphology was characterized with AFM, and electrical conductivity was measured with Hall effects measurement. The results showed that with the increase of the electric field, the electrical conductivity of PEDOT:PSS film was boosted rapidly at first, and then improved slowly when the electric field was above 200 kV/m. The film’s electrical conductivity improved more than 17 times in total from 0.51 × 10^–3 up to 8.92 × 10^–3 S/m. However, the film’s visible light transmittance decreased only a little with the increase of the electric field, not more than 3%. In addition, despite little change in the chemical structure of the PEDOT:PSS film, its surface roughness increased significantly with the increase of the electric field intensity.     

采用SiO2/SixNy双材料微桥测试结构测量PECVD富硅氮化硅薄膜的导热系数

In order to balance the compressive stress of a silicon dioxide film and compose a steady MEMS structure, a silicon-rich silicon nitride film with tensile stress is deposited by plasma enhanced chemical vapor deposition process. Accurately measuring the thermal conductivity of the film is highly desirable in order to design, simulate and optimize MEMS devices. In this paper, a Si02/SixNy bimaterial microbridge structure is presented to measure the thermal conductivity of the silicon-rich silicon nitride film by single steady-state measurement. The thermal conductivity is extracted as 3.25 W/（m-K）. Low thermal conductivity indicates that the silicon-rich silicon nitride film can still be utilized as thermally insulating material in thermal sensors although its thermal conductivity is slightly larger than the values reported in literature.     

Improvement of electrical conductivity of PEDOT:PSS films by 2-Methylimidazole post treatment

The electrical conductivity of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films was significantly improved without losing the optical transparency by treating the films with solution of 2-Methylimidazole in ethanol. The maximum electrical conductivity of such a thin film reached 930 S cm⁻¹, more than 1150 order of magnitude higher than that of pure PEDOT:PSS film. The mechanism of conductivity enhancement of treated thin PEDOT:PSS films was explored by atomic force microscopy (AFM) and UV/VIS spectrophotometer. The AFM scans show that the surface of the 2-Methylimidazole treated PEDOT:PSS layer is smoother than that of the pristine PEDOT:PSS thin film. Improvement in the morphology, electrical and optical properties of PEDOT:PSS films makes them highly suitable for numerous applications in optoelectronic devices.     

Properties of PAn/PVA Conducting Composite Film by Electrochemical Polymerization

The polyaniline(PAn)poly(vinyl alcohol)(PVA)conductive composite film is synthesized with perchloric acid(HClO4)as the dopant and oxidant in reaction system by electrochemical polymerization.The results shows that this composite film has very high conductive properties,the maximum value of conductivity reaches 0.173 S/cm at the concentration 0.75mol.The influences of HClO4 on the conductivity of the composite film are investigated .In addition,the electrode reaction progress is discussed with the results that obtained from SEM and FTIR analyzing.     

Increase in thermoelectric power factor of carbon-nanotube films after addition of polystyrene

We report the enhancement of the thermoelectric power factors of single-walled carbon-nanotube (SWCNT) films caused by the addition of polystyrene to the films as a binder. The Seebeck coefficient of the SWCNT films was increased by addition of polystyrene. On the other hand, the electrical conductivity gradually decreased with increasing amount of polystyrene. The power factor was maximum for a polystyrene concentration of 20 wt%; it was approximately 1.7 times higher than that of a pure SWCNT film. These results indicate that polystyrene is a superior binder polymer for synthesizing CNT/polymer thermoelectric composites.     

Effect of Chemical Doping and Ion Implantation on Conductivity of Poly （p-phenylene vinylene） Derivatives

The surface conductivity of poly [2-methoxy-5-(3 '-methyl)butoxy]-p-phenylene vinylene (PMOMBOPV) films doped with FeCl3 and H2 SO4 by chemical method and implanted by N ions was studied and the comparison of environmental stability of conductive behavior was also investigated. The energy and dose of N ions were in the rang 15～35 kev and 3. 8× 1015 ～9. 6× 1016 ions/cm2, respectively. The conductivity of PMOMBOPV film was enhanced remarkably with the increases of the energy and dose of N ions. For example, the conductivity of PMOMBOPV film was 3.2 × 10-2 S/cm when ion implantation was performed with an energy of 35 kev at a dose of 9. 6 × 1016 ions/cm2 , which was almost seven orders of magnitude higher than that of film unimplanted. The environmental stability of conductive behavior for ionimplanted film was much better than that of chemical doped films. Moreover, the conductive activation energy of ion-implanted films was measured to be about 0.17 eV.     

溶胶–凝胶法制备ATO-SiO_2抗静电复合薄膜的特性研究

采用两步溶胶–凝胶法制备出 ATO(掺锑氧化锡)-SiO_2复合抗静电薄膜。通过 DTA-TG、XRD、SEM 对 薄膜的结构和形貌进行了表征,结果表明:抗静电复合薄膜表面均匀致密。薄膜中 SiO_2为无定形结构,ATO 的衍射峰 与 SnO_2一致。研究了 SnO_2的含量对薄膜导电性能、结合强度和透过率的影响,发现随 SnO_2含量增加 ?(SnO_2/ SiO_2)从 5 至 12.5,薄膜的表面电阻降低(从 1010ù/□降低到 108ù/□),薄膜的结合强度下降,薄膜的透过率降低(从 89.0%降至 84.2%),结合三方面性能,得出最佳 SnO_2的配比为:?(SnO_2/ SiO_2)=10。     

N掺杂MgZnO薄膜的p型导电稳定性研究

利用磁控溅射技术,以Mg0.06Zn0.94O为陶瓷靶材,制备了N掺杂p型Mg0.1 3Zn0.8 7O薄膜,薄膜的电阻率为42.45Ω·cm,载流子浓度为3.70×1017/cm3,迁移率为0.40cm2·V-1·s-1。研究了该薄膜p型导电性质在室温空气下随时间的变化情况。实验结果表明,薄膜的电阻率逐渐升高,载流子浓度降低,五个月以后,薄膜转变为n型导电,电阻率为85.58Ω·cm,载流子浓度为4.53×1016/cm3,迁移率为1.61cm2·V-1·s-1。真空热退火后重新转变为p型。结果显示,其p型导电类型的转变与在空气中吸附H2O或H2等形成浅施主有关。     

Thermal conductivity of AlN thin films deposited by RF magnetron sputtering

Aluminum nitride (AlN) film, which is being investigated as a possible passivation layer in inkjet printheads, was deposited on a Si (1 0 0) substrate at 400 °C by radio frequency (RF) magnetron sputtering using an AlN ceramic target. Dependence on various reactive gas compositions (Ar, Ar:H₂, Ar:N₂) during sputtering was investigated to determine thermal conductivity. The crystallinity, grain size, and Al–N bonding changes by the gas compositions were examined and are discussed in relation to thermal conductivity. Using an Ar and 4% H₂, the deposited AlN films were crystalline with larger grains. Using a higher nitrogen concentration of 10%, a near amorphous phase, finer morphology, and an enhanced Al–N bonding ratio were achieved. A high thermal conductivity of 134 W/mk, which is nine times higher than that of the conventional Si₃N₄ passivation film, was obtained with a 10% N₂ reactive gas mixture. A high Al–N bonding ratio in AlN film is considered the most important factor for higher thermal conductivity.