氧等离子体预处理对涤纶基纳米铜膜性能影响

利用射频磁控溅射法,在涤纶织物表面沉积纳米铜薄膜,研究氧等离子体预处理对涤纶基纳米铜膜形貌、润湿性能、拉伸性能影响。借助扫描电子显微镜(SEM)和原子力显微镜(AFM)观察氧等离子体处理前后纤维表面粗糙度、纳米铜颗粒大小变化,同时对表面沉积纳米铜织物导电性能、润湿性能进行测试。结果表明,氧等离子体处理对涤纶基材表面刻蚀明显,纳米铜颗粒分布均匀致密,纤维表面粗糙度、纳米铜颗粒大小均显著增加,镀铜织物经向拉伸性能也得到提高,液滴在样品表面接触角较小,样品亲水性能得到明显改善。     

等离子体表面处理对柔性导电纤维传感性能的影响

研究了具有PPy(聚吡咯)微纳米尺度涂层的XLA导电纤维的研制与应变传感性能。但由于XLA纤维的表面十分光滑,因此在用传统的化学气相沉积法进行涂层之前需要对纤维进行特殊处理。等离子体处理可以改变纤维表面粗糙度,使PPy更易于附着于纤维表面且增加其与纤维的接触强度。比较了经过不同等离子体处理时间(5和15min)的导电XLA纤维的力学及应变传感性能。实验结果表明,等离子体处理对纤维的力学性能几乎没有影响,但对导电纤维的应变传感性能影响很大。     

氩等离子体预处理对纳米结构银非织造布抗菌性能的影响

采用磁控溅射技术,在丙纶非织造布(PP)基材表面沉积厚度为0.5～3 nm的纳米结构银薄膜,重点研究了PP基材经氩等离子体预处理前后对纳米结构银薄膜抗菌性能的影响.采用振荡烧瓶法测试样品的抗菌性能,利用原子力显微镜(AFM)观察氩等离子处理前后PP基材表面的形态变化,同时应用EDX对纳米结构银薄膜进行元素分布及定量分析.实验结果表明:在纳米结构银薄膜厚度相同的条件下,经氩等离子预处理的丙纶非织造布具有更好的抗菌性能;AFM分析表明,经氩等离子处理后的纤维表面有明显的刻蚀痕迹,纤维表面凹凸不平,形成很多微小的空隙,溅射出的银粒子不易团聚,活性增加,抗菌性能因此提高;而EDX结果分析表明,抗菌性能提高是由于经氩等离子处理后,银离子溶出总量增加的缘故.     

非织造布表面处理对纳米纤维分布及成型的影响

采用磁控溅射和等离子体技术处理非织造布,可以明显地改善纳米纤维分布的均匀性;进一步探讨了等离子体处理后对基材表面基团及导电性的影响,结果显示为基材表面产生很多极性基团、导电性增强,相同纺丝条件及纺丝时间下,使其表面沉积的纤维直径变小、沉积的纤维数量增加,也进一步减小了复合膜的孔径、孔径分布更加集中,有利于制得高效率、高精度的复合过滤膜。     

整体中空复合材料预制件等离子体处理的效果表征

采用空气介质阻挡放电(DBD)常压等离子体对整体中空复合材料玻纤预制件的表面进行处理.利用FTIR-ATR、SEM、毛效实验表征处理后的预制件表层纤维及芯材纤维,并利用LRXPlus电子材料试验机测试整体中空复合材料的平压性能.结果表明,等离子体可通过预制件孔径渗透到织物芯材,表层纤维和芯材表面反应活性点增多;两者表面粗糙度均增加;纤维浸润性分别提高了20.9%和19.4%;整体中空复合材料的平压强度提高了28.79%.     

丝织物基溅射纳米银薄膜的界面性能研究

采用RF磁控溅射技术,通过改变溅射时间的方式在丝织物基材上沉积纳米银薄膜.采用SEM和AFM对丝纤维表面银薄膜进行表征.采用剥离试验讨论薄膜与丝织物基材间的界面结合.结果表明,随溅射时间的延长,丝纤维表面纳米银逐渐增加,纳米银粒径呈增大趋势,薄膜逐渐向连续结构过渡.在实验范围内,溅射时间延长,薄膜与基材间的结合牢度得到提高.     

PET基纳米Ag薄膜导电性能及AFM分析

为了研究在PET基非织造布上沉积纳米Ag薄膜厚度对薄膜表面形貌及导电性能的影响，采用磁控溅射法，在PET非织造布上制备了不同厚度的纳米结构Ag薄膜，采用原子力显微镜（AFM）分析不同厚度纳米结构Ag薄膜形貌及粒径的变化；研究了纳米Ag薄膜厚度与薄膜导电性能的关系。实验结果表明：随着膜厚的增加，膜表面逐渐形成连续结构；同时PET非织造布基银薄膜存在一个临界膜厚，在临界膜厚处，薄膜致密度更高，生长更为均匀，薄膜缺陷较少；同时，随着膜厚增加，导电性能提高，在临界膜厚处，电阻率达到最小。     

纳米银-聚合物薄膜的制备及力电性能测试

聚合物基底上纳米银颗粒薄膜的制备工艺相对简单,成本较低,且该薄膜具有成为高敏感性压阻应力/应变传感材料的潜力。本文采用银镜制备法在聚酰亚胺(PI)和聚乙烯(PE)上合成了纳米银颗粒薄膜,系统研究了该薄膜制备工艺、结构特性、材料性能之间的关系。实验考察了材料“浸泡”时间及聚合物材料前处理等因素对材料表面吸附纳米颗粒含量的影响,研究了 “浸泡”时间对纳米银颗粒粒径大小、颗粒含量及分布的影响,并探讨了不同聚合物基体的颗粒特性对薄膜二维导电渗滤,压阻特性及拉伸性能的影响。研究表明,增加“浸泡”时间能够增加纳米银颗粒粒径大小,提高银颗粒的含量及分布均匀性；在相同的制备条件下,PI基底较PE基底对纳米银颗粒具有更加优异的吸附效果；在PI 和PE基底上的纳米银颗粒薄膜均表现出显著的压阻性能,且电阻对应变的敏感性随应变的增大及银颗粒含量的减少而显著提高。     

层状复合电磁屏蔽材料的制备及性能研究

采用磁控溅射法在涤纶水刺非织造布表面沉积纳米结构单层膜、双层膜及层状复合薄膜(在织物两面分别沉积薄膜),利用原子力显微镜(AFM)对薄膜的表面形貌进行分析,并利用四探针测试仪和矢量网络分析仪对样品的电学性能进行了测试。结果表明,在总镀膜时间不变的情况下,层状复合薄膜的电学性能明显优于单层膜和双层膜电学性能,Cu层状复合薄膜电学性能要好于Al层状复合薄膜的电学性能;随着Cu镀膜时间的增加,复合薄膜的颗粒均匀性和电学性能都有所提高,当织物两面镀膜时间各为60min时,屏蔽效能达到80dB。     

基于磁控溅射的聚丙烯/纳米银复合非织造功能材料的制备及性能研究

采用磁控溅射法,在聚丙烯非织造布表面沉积纳米银膜,制备纺粘聚丙烯/纳米银复合非织造功能材料,对其表面形貌SEM、表面元素能谱、抗紫外性以及电磁屏蔽性等进行表征分析及测试研究。结果表明:以聚丙烯非织造布基材、Ag靶为靶材,经过磁控溅射制成聚丙烯/纳米银复合非织造功能材料;聚丙烯非织造布原样基本不具有抗紫外及电磁屏蔽性;相比之下,随着溅射时间由5min增加到15min,功能材料表面所沉积的纳米Ag颗粒薄膜越致密,表面Ag元素的含量由10.09%增加到32.07%,抗紫外线功能及电磁屏蔽性大幅度增强,具有良好的电磁屏蔽性;而溅射时间分为10min、15min的功能材料达到了防紫外线产品的要求。     

氩等离子体预处理对纳米结构银非织造布抗菌性能的影响

采用磁控溅射技术，在丙纶非织造布（PP）基材表面沉积厚度为0．5-3nm的纳米结构银薄膜，重点研究了PP基材经氩等离子体预处理前后对纳米结构银薄膜抗菌性能的影响。采用振荡烧瓶法测试样品的抗菌性能，利用原子力显微镜（AFM）观察氩等离子处理前后PP基材表面的形态变化，同时应用EDX对纳米结构银薄膜进行元素分布及定量分析。实验结果表明：在纳米结构银薄膜厚度相同的条件下，经氩等离子预处理的丙纶非织造布具有更好的抗菌性能；AFM分析表明，经氩等离子处理后的纤维表面有明显的刻蚀痕迹，纤维表面凹凸不平，形成很多微小的空隙，溅射出的银粒子不易团聚，活性增加，抗菌性能因此提高；而EDX结果分析表明，抗菌性能提高是由于经氩等离子处理后，银离子溶出总量增加的缘故。     

Kevlar织物化学镀掺钨镀银层

应用“非刻蚀-无钯活化”法对Kevlar织物进行表面改性,化学镀制备掺钨镀银层。采用多种表征方法测试掺钨镀银层的结构、形貌和成分,分别用四探针法、Na₂S全浸及超声实验研究掺钨镀银层Kevlar织物的导电性能、抗硫变色性能以及银层/纤维结合性能。研究结果表明:纳米尺寸银颗粒均匀镶嵌在Kevlar纤维表层,形成活化中心;随后,均匀且致密的掺钨镀银层被制备,该镀层显示晶态结构,W以WO₃和Ag₂WO₄的形式存在,该镀层呈现优异的导电性能和结合力。与纯银镀层相比,掺钨镀银层具有更优异的抗硫变色性能。     

Electrical percolation threshold in Ag–DLC nanocomposite films prepared by RF-sputtering and RF-PECVD in acetylene plasma

Silver–diamond like carbon (Ag–DLC) nanocomposite films were deposited on glass and silicon substrates by co-deposition of RF-sputtering and RF-PECVD method in acetylene plasma. The effects of deposition time on creation of conductive percolation pathway in Ag–DLC nanocomposite films were investigated. The films were characterized by XRD pattern, AFM images, UV–Vis and FTIR spectra. Pressure of chamber’s variation over time was illustrated the rate of carbon and silver deposition changing. The results showed that nanoparticles’ size and surface roughness was increased by increasing deposition time. Surface plasmon resonance peak’s red shift in optical absorption spectra of samples could be depends on silver nanoparticles’ scale up. Based on electrical measurements, electrical percolation threshold was observed only in the film with 35 min deposition time. Pathway was created for electric current by Ag nanoparticles’ moving in carbon matrix due to sp³ bonds and silver content in the films. The aging effect was studied for sample #2 in the threshold of percolation, where obtained Ag nanoparticles memorize its previous pathway. This investigation provides a better understanding for electric properties of Ag–DLC nanocomposite based on the percolation theory.     

Electrical,morphological and structural properties of RF magnetron sputtered Mo thin films for application in thin film photovoltaic solar cells

Molybdenum (Mo) thin films were deposited using radio frequency magnetron sputtering, for application as a metal back contact material in “substrate configuration” thin film solar cells. The variations of the electrical, morphological, and structural properties of the deposited films with sputtering pressure, sputtering power and post-deposition annealing were determined. The electrical conductivity of the Mo films was found to increase with decreasing sputtering pressure and increasing sputtering power. X-ray diffraction data showed that all the films had a (110) preferred orientation that became less pronounced at higher sputtering power while being relatively insensitive to process pressure. The lattice stress within the films changed from tensile to compressive with increasing sputtering power and the tensile stress increased with increasing sputtering pressure. The surface morphology of the films changed from pyramids to cigar-shaped grains for a sputtering power between 100 and 200 W, remaining largely unchanged at higher power. These grains were also observed to decrease in size with increasing sputtering pressure. Annealing the films was found to affect the resistivity and stress of the films. The resistivity increased due to the presence of residual oxygen and the stress changed from tensile to compressive. The annealing step was not found to affect the crystallisation and grain growth of the Mo films.     

Microtexture and electrical properties of PAN-ACF

Microstructure and electric conductivity of PAN-based activated carbon fibers (PAN-ACF) were investigated using tension and KOH activation. The application of tension during stabilization decreased pore volume as well as specific surface area. Increase of KOH solution concentration caused serious damage to the surface of PAN-ACF. This surface damage of PAN-ACF resulted in increase of specific surface, pore volume and wider pore size distribution. PAN-ACF with higher tension showed higher electric conductivity. However, the electric conductivity was decreased by the increased BET surface area.     

基于胶体晶体构筑银纳米薄膜及其抑制微放电性能研究

近年来,微放电效应的抑制研究在加速器、大功率微波器件等领域得到了广泛的关注。采用聚苯乙烯(PS)胶体晶体模板辅助磁控溅射法制备了类空心球结构的银薄膜,通过调节PS模板尺寸及溅射时间(镀银层厚度),得到具有抑制微放电效应的银薄膜。采用SEM表征银薄膜的形貌与结构,并用二次电子发射系数(SEY)测试平台表征银薄膜的SEY。结果表明,PS模板尺寸及溅射时间对银薄膜形貌及其二次电子抑制作用有显著的影响,当溅射时间为600s,模板尺寸为1 000nm时,银薄膜的SEY较小,即对二次电子的抑制作用较为显著,与初始镀银铝合金样品相比,其SEY值降低了48%。     

Influence of annealing on thermoelectric properties of bismuth telluride films grown via radio frequency magnetron sputtering

Bismuth telluride films were prepared via radio frequency magnetron sputtering. Mixed powders with different composition were used as sputtering targets. Influence of the annealing temperature on surface topography, crystal structure and thermoelectric properties of the films has been investigated. It was found that the grain size increased and the surface roughness decreased with a rising annealing temperature. X-ray diffraction analysis revealed an improved crystallization after the annealing, and that crystal planes perpendicular to c-axis became prominent. High temperature treatments resulted in a decrease of Seebeck coefficient and an increase of electrical conductivity. The highest power factor was obtained after being annealed at 300 °C.     

Influence of plasma treatment on CNT absorption of cotton fabric and its electrical conductivity and antibacterial activity

In this study, effect of plasma pretreatment on the absorption of carboxilated carbon nanotubes (CNTs) on the surface of cotton fabrics was investigated. Treated samples were characterised using a Raman spectrophotometer. Also, the morphological properties of samples were studied using a scanning electron microscope. Electrical resistance and interactions between CNTs and plasma-treated cotton functional groups at the surface were also evaluated. Antibacterial activity of cotton fabric when modified by low temperature plasma and stabilised with CNTs was also investigated. Results showed a uniform coating of CNTs on the plasma-treated cotton fabric and it was found that the plasma treatment is effective on improving CNTs absorption by cotton fabric. Generally, cotton fabric characterisation, such as antibacterial activity and electrical conductivity, after plasma treatment and loading CNT are improved.     

Grating-coupled surface plasmon enhanced short-circuit current in organic thin-film photovoltaic cells

In this study, we demonstrate the fabrication of grating-coupled surface plasmon resonance (SPR) enhanced organic thin-film photovoltaic cells and their improved photocurrent properties. The cell consists of a grating substrate/silver/P3HT:PCBM/PEDOT:PSS structure. Blu-ray disk recordable substrates are used as the diffraction grating substrates on which silver films are deposited by vacuum evaporation. P3HT:PCBM films are spin-coated on silver/grating substrates. Low conductivity PEDOT:PSS/PDADMAC layer-by-layer ultrathin films deposited on P3HT:PCBM films act as the hole transport layer, whereas high conductivity PEDOT:PSS films deposited by spin-coating act as the anode. SPR excitations are observed in the fabricated cells upon irradiation with white light. Up to a 2-fold increase in the short-circuit photocurrent is observed when the surface plasmon (SP) is excited on the silver gratings as compared to that without SP excitation. The finite-difference time-domain simulation indicates that the electric field in the P3HT:PCBM layer can be increased using the grating-coupled SP technique.     

Effect of Ar pressure on grain size of magnetron sputter-deposited Cu thin films

Copper (Cu) thin films with thicknesses ranging from 300 to 425 nm were prepared at various argon (Ar) pressures on p-type silicon substrates by direct current magnetron sputtering deposition. X-ray diffraction (XRD) and Karl Suss four-point probe were employed to study the film crystallinity and conductivity, respectively, as a function of Ar pressure in the deposition process. Detailed analysis on the XRD patterns shows that low Ar pressure enhances the Cu film crystallinity with larger grain size, which was deduced using Scherrer's formula. The behaviour of the electrical property of the Cu films complies with the trend of the grain size with Ar pressure, in which the film conductivity decreases with increasing Ar pressure. The authors attribute these phenomena to the degraded surface diffusion mechanism of the adatom on the growing surface, with increasing Ar pressure during the sputtering deposition process