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。     

激光辐射法用于聚酰亚胺/纳米Ag复合膜的制备

在涂覆有PVP/AgNO3胶体的聚酰亚胺(PI)薄膜上,采用激光辐射法将Ag+还原成Ag纳米粒子并嵌入到PI表面,从而制备出聚酰亚胺/纳米Ag复合膜。通过XPS、AFM、SEM等表征手段研究了复合膜表面的化学成分、以及激光通量和PVP/AgNO3配比对纳米银粒子形貌的影响。结果表明,激光通量的提高可使聚酰亚胺/纳米Ag复合膜上的纳米Ag粒子产生一定程度的定向排列;调节PVP/AgNO3的配比,可大致控制Ag粒子尺寸在25～160nm间变化。     

纳米银粒子/磺化聚苯乙烯复合微球的制备及其性能研究

以磺化聚苯乙烯微球(SPS)为载体,通过在其表面负载纳米银粒子的方法,合成了纳米银粒子/磺化聚苯乙烯(Ag/SPS)复合微球,并采用扫描电镜、红外光谱、XRD光谱、热重等方法进行表征,结果表明,在反应温度为70℃、反应时间8 h时,用化学还原法制备了Ag/SPS复合微球,单分散性较好,纳米银粒子包覆均匀。通过催化还原亚甲基蓝的实验发现,在一定范围内,催化反应速率随着复合微球纳米粒子的含量增加而升高;重复利用实验结果证明该复合微球有较高的重复利用性。     

银/聚苯胺纳米复合材料的制备及电化学性能

采用苯胺为分散剂合成纳米银胶溶液,并在此基础上引发苯胺的原位复合,制备出银/聚苯胺(Ag/PANI)纳米复合材料。通过傅里叶变换红外光谱仪、X射线衍射分析仪、扫描电镜、透射电镜和电化学分析仪对产物进行了分析与检测。研究结果表明,Ag/PANI纳米复合材料中形成了聚苯胺在外、银纳米粒子在内的包覆结构,纳米复合粒子为类球形状形貌。引入纳米银粒子后,制备的Ag/PANI纳米复合材料的电化学活性和比容量较PANI有了很大提高。Ag/PANI纳米复合材料的腐蚀电流密度为72.1μA/cm2,比PANI的腐蚀电流密度106μA/cm2降低了33.9μA/cm2,纳米复合材料防腐性能得到显著提高。     

氧化石墨烯纳米银复合材料的制备及对大肠杆菌抑菌性能的研究

以柠檬酸钠为还原剂,原位制备出氧化石墨烯/纳米银(GO/Ag)复合材料,并采用傅里叶红外光谱仪、纳米粒度分析仪和紫外分光光度计对GO/Ag复合材料进行表征,结果表明氧化石墨烯和纳米银稳定复合。以大肠杆菌为模型菌,通过抑菌圈及平板计数法实验评价了GO/Ag复合材料的抑菌性能,并通过对细胞膜完整性和通透性的影响研究了复合材料的抑菌机理,结果表明,GO/Ag复合材料对大肠杆菌有较强的抑菌效果,最小抑菌浓度(MIC)为0.005mg/mL;其优良的抑菌效果是通过破坏细菌细胞膜完整性,影响细胞膜通透性来完成的。     

纳米复合薄膜及其在果蔬保鲜中的应用

纳米复合包装薄膜一般为聚合物基纳米复合材料,可分为纳米材料/合成聚合物复合材料与纳米材料/天然聚合物复合材料。阐述了这2种复合材料的制备方法和性能特点,综述了纳米TiO2复合薄膜、纳米SiO2复合薄膜、纳米CaCO3复合薄膜、纳米银复合薄膜在果蔬保鲜中的应用研究,并展望了纳米复合薄膜在果蔬保鲜应用方面的研究方向。     

Ag掺杂对CrN薄膜结构、摩擦学性能和腐蚀性能的影响

为明确Ag含量对CrN-Ag纳米复合薄膜组织、摩擦学性能和耐腐蚀性能的影响规律,利用多靶反应磁控溅射技术制备CrN及CrN掺Ag纳米复合薄膜,并采用扫描电子显微镜结合能谱仪(SEM-EDS)、X射线衍射仪(XRD),球-盘摩擦试验机和电化学工作站对2种薄膜的微观组织、摩擦学行为和电化学腐蚀行为进行表征。结果表明：少量Ag元素(9.19%,原子分数,下同)的添加可以提高CrN-Ag纳米复合薄膜的致密度,而过量Ag元素的掺杂(29.58%)则会造成薄膜结构疏松,且引起Ag颗粒在表面富集。复合薄膜的摩擦系数随着Ag含量的增加而降低,高Ag含量(29.58%)薄膜的摩擦系数在摩擦时间为100 s内时低至0.40,而磨损率则随着Ag含量的增加表现出先降低后升高的趋势。CrN-Ag(L)复合薄膜的磨损率低至2.25×10^-6 mm³/(N·m),相比于未添加Ag的CrN薄膜,磨损率下降了64.9%。由电化学分析可知,低含量的Ag可增强CrN-Ag(L)复合薄膜的耐腐蚀性能,而过量的Ag则会造成CrN-Ag(H)薄膜耐腐蚀性的显著下降。     

Ag-SiO2复合纳米颗粒薄膜的制备及其光学特性研究

利用溶胶一凝胶法在玻璃基底上成功制备了Ag—SiO2复合纳米颗粒薄膜,SEM、TEM和XRD的表征分析表明Ag是以单晶纳米颗粒的形态均匀分散在SiO2基质中,形成了多孔状Ag—SiO2复合纳米颗粒薄膜。从Ag—SiO2复合纳米颗粒薄膜的光吸收谱发现,该复合薄膜中鲰纳米颗粒具有较强的等离子共振吸收峰,峰位在430nm附近,随着复合薄膜中Ag、Si摩尔比的逐渐增大,等离子共振吸收峰不断增强且发生蓝移,蓝移量可达30nm;研究Ag—SiO2复合纳米颗粒薄膜的光敛发光特性发现,当激发波长为220nm时,复合薄膜分别在330nm和375nm处出现了两个发光带,随着复合薄膜中Ag、Si摩尔比增大到0．11,两发光带均逐渐增强,继续增加Ag、Si摩尔比,两发光带又逐渐减弱,且375nm处的发光带变化尤为显著。     

TiO_2改性PVDF/PMMA复合薄膜的制备及其性能

以二氧化钛(TiO2)为填料,聚偏氟乙烯(PVDF)、聚甲基丙烯酸甲酯(PMMA)为基体,通过熔融共混制备PVDF/PMMA/TiO2复合薄膜,采用扫描电子显微镜、紫外/可见分光光度计、差示扫描量热仪和力学性能测试等方法表征了其各种性能。研究表明,PVDF与PMMA有良好的相容性,TiO2可以均匀的分散在基体中;TiO2的加入对材料的力学性能产生一定的影响,同时通过剥离实验对PVDF/PMMA/TiO2复合薄膜的粘结性能进行了表征。     

磁控溅射制备Ag/PEO-like生物功能材料及其性能研究

以乙二醇二甲基醚为单体,采用磁控溅射的方法制备Ag/PEO-like复合薄膜,探讨使用等离子体技术同时完成PEO-like聚合与Ag溅射的可行性,研究了溅射靶与基材的距离、单体与工作气体流量比等工艺参数对Ag/PEO-like复合薄膜的结构及性能影响.通过对薄膜结构及性能的表征红外光谱、紫外-可见光光谱、薄膜厚度等,发现磁控溅射的方法可以制备出Ag/PEO-like复合薄膜,材料的结构和成分随着等离子体工艺参数而改变.薄膜生物性能测试的结果表明Ag/PEO-like复合薄膜表现出良好的抗血小板吸附特性,并且具有优异的杀菌特性,对大肠杆菌和金黄色葡萄球菌的抗菌率均超过99%.     

Electrical transport behaviour of silver–PMMA nanocomposite films at low temperature

In this study, the silver nanoparticles, capped with oleylamine, were embedded in polymethylmethacrylate (PMMA) using sonication to fabricate Ag–PMMA nanocomposites. The well-dispersed nanocomposite samples are analysed using UV-Vis absorption spectroscopy, atomic force microscopy and small angle X-ray scattering. The interfacial interaction of Ag nanoparticles and PMMA polymer is investigated using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. It is concluded that a ligand-exchange process occurs when capped silver nanoparticles are incorporated in PMMA polymer. Electrical resistivity of nanocomposite samples was measured by a four-probe technique in the 70–300?K range. The nanocomposites showed a transition with onsets at ～230 and ～160?K. They exhibited a semiconductor-like conductivity at higher temperatures, a rapid metallic conductivity at middle range and nearly temperature independent conductivity at lower temperatures.     

基于超分子结构的光电子材料的制备与表征(英文)

为实现短波长光存储材料,提出一种基于金属纳米粒子与染料共掺杂的复合材料制备新方法.采用透射电子显微镜(TEM)、紫外-可见吸收光谱(UV-Vis)以及傅立叶变换红外光谱(FT-IR)对所制备的复合薄膜进行表征.实验发现,与未掺杂银的薄膜相比,掺杂银的复合薄膜中甲基橙的吸收蓝移了6nm.提出并利用超分子结构模型分析了该吸收蓝移的机理.研究结果显示,本研究所提出的这种新的材料制备方法具有制备吸收波长在400～500nm,且可望与GaN激光器在光存储技术中匹配的能力.     

纳米银粒子对聚合物激光离解方式的影响

采用激光飞行时间质谱研究了添加纳米银粒子的聚合物PS和PMMA的激光离解方式的变化,发现纳米银粒子导致聚合物炭化。在两相界面有诱导石墨化的作用;而且纳米银粒子的这种作用与两相的界面相互作用和结构有关,热处理导致纳米银粒子与PMMA的界面反应会改变激光能量的转化方式。从而减弱其激光炭化作用。     

Large-scale synthesis of single crystal silver nanowires by a sodium diphenylamine sulfonate reduction process

Silver nanowires with high aspect ratios of up to more than 60 were synthesized on a large scale by the redox reaction between silver nitrate and sodium diphenylamine sulfonate at room temperature and in the absence of surfactant and hard-template and seed. When the molar ratio of reductant sodium diphenylamine sulfonate and silver nitrate < or =1, most products were all the nanowires. When the molar ratio increases to 2:1, silver nanowires and nanobelts were concomitantly formed. The redox product N, N'-diphenylbenzidinedisulfonate and sodium diphenylamine sulfonate all play an important role in the formation of silver nanostructures. The structure, morphology, and composition of the silver nanowires were characterized by the X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray energy dispersive microanalysis (EDX), and UV-Vis spectroscopy respectively. High-resolution transmission microscopy (HRTEM) and selected area electron diffraction (SAED) reveal the single-crystal nature of the silver nanowires.     

氧化石墨烯/壳聚糖层层自组装复合膜的制备及其在环保领域中的应用

利用层层自组装技术将氧化石墨烯与壳聚糖进行自组装,制备出一种新型的氧化石墨烯/壳聚糖复合膜,并利用原位合成的方法引入纳米银粒子。采用紫外可见光谱(UV-Vis)、红外光谱(FTIR)、X射线衍射(XRD)和原子吸收等分析方法对复合膜的自组装行为和催化性能进行了研究。实验结果表明,氧化石墨烯与壳聚糖可通过层层自组装技术制备出新型复合膜,这种复合膜可包裹纳米银粒子,膜内纳米银粒子对4-硝基苯酚的催化活性较高,并且可实现循环使用。此外,在稳定性实验中,复合膜不会释放纳米银粒子或银离子,避免了给水体带来二次污染。因此,这种材料在水处理等环保领域中可能具有巨大的潜在实用价值。     

纳米银粒子的制备及其表征

采用聚乙烯吡咯烷酮、无水乙醇和去离子水混合溶液,利用水合肼还原硝酸银制备纳米银粒子.利用透射电子显微镜,紫外-可见吸收光谱和X射线衍射对纳米银粒子进行表征.结果表明,该法制备的纳米银粒子杂质含量低,粒度分布集中,颗粒均匀一致,形貌呈球形.     

Synthesis of uniform and stable silver nanoparticles by a gold seed-mediated growth approach in a buffer system

A seeding growth approach to the preparation of silver nanoparticles with a controllable size was developed. It contained a two-step reaction: the first step was gold seed clusters quickly generated by a chemical reaction using sodium borohydride as a reducing reagent; the second one was controllable silver nanoparticles were grown at the mild condition by using the mixed reducing reagents (hydroxylamine hydrochloride and sodium hydroxide) to form a buffer system. The gold core was beneficial for the crystalline of silver cations to form the nanoparticles and the buffer system which was composed of hydroxylamine hydrochloride and sodium hydroxide, and was helpful for controlling the size and shape of the as-prepared silver nanoparticles. These as-prepared nanoparticles were characterised by X-ray powder diffraction, UV-Vis spectroscopy (UV-Vis) and transmission electron microscopy along with energy dispersive X-ray spectroscopy. The results indicated that the obtained silver nanoparticles are highly crystallised with an average diameter around 10?nm. The content of gold seeds and the mild reaction rate controlled by the buffer system were considered to be key factors in the control of silver nanoparticles’ morphology and size. A possible mechanism of the silver nanoparticles formed was also proposed.     

Modeling of Silver Nanoparticle Synthesis in Ternary Reverse Microemulsion of Cyclohexane/Water/SDS

In the present study, a simple mathematical model has been developed for synthesis of silver nanoparticles. The silver nanoparticles have been synthesized in ternary reverse microemulsion of cyclohexane/water/sodium dodecyl sulfate (SDS). The silver nanoparticles were produced by reaction between silver nitrate in the water droplet core of one microemulsion and hydrazine as reducing agent in the water droplet core of another microemulsion. The dynamic behavior of process was modeled on mass balance equations which were solved using the finite difference method. The kinetic parameters of the critical number size (N _crit ), rate order of nucleation, and growth constants were estimated by minimizing the difference between the average particle size predicted by model and those obtained by experiments. The UV-Vis absorption spectra, transmission electron microscopy (TEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS) were used to analyze the structure and particle size distribution of silver nanoparticles.     

Biosynthesis and structural characterization of silver nanoparticles from bacterial isolates

This study aimed to develop a green process for biosynthesis of silver nanomaterials by some Egyptian bacterial isolates. This target was achieved by screening an in-house culture collection consists of 300 bacterial isolates for silver nanoparticle formation. Through screening process, it was observed that strains belonging to Escherichia coli (S30, S78), Bacillus megaterium (S52), Acinetobacter sp. (S7) and Stenotrophomonas maltophilia (S54) were potential candidates for synthesis of silver nanoparticles. The extracellular production of silver nanoparticles by positive isolates was investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results demonstrated that UV-visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy micrograph showed formation of silver nanoparticles in the range of 15-50 nm. XRD-spectrum of the silver nanoparticles exhibited 2θ values corresponding to the silver nanocrystal that produce in hexagonal and cubic crystal configurations with different plane of orientation. In addition, the signals of the silver atoms were observed by EDS-spectrum analysis that confirms the presence of silver nanoparticles (AgNPs) in all positive bacterial isolates.     

Facile synthesis of silver immobilized-poly(methyl methacrylate)/polyethyleneimine core–shell particle composites

A facile route to synthesize silver-embedded-poly(methyl methacrylate)/polyethyleneimine (PMMA/PEI-Ag) core–shell particle composites was illustrated in this present work. PMMA/PEI core–shell particle templates were first prepared by a surfactant-free emulsion polymerization. PEI on the templates' surface was further used to complex and reduce Ag⁺ ions (from silver nitrate solution) to silver nanoparticles (AgNPs) at ambient temperature, resulting in the PMMA/PEI-Ag particle composites. The formation of AgNPs was affected by the pHs of the reaction medium. The pH of reaction medium at 6.5 was optimal for the formation of PMMA/PEI-Ag with good colloidal stability, which was confirmed by size and size distribution, FTIR spectroscopy, UV–vis spectroscopy and X-ray diffraction. Moreover, the amount of AgNO₃ solution (4.17–12.50 g) was found to affect the formation of AgNPs. Transmission electron microscopy (TEM) indicated that the AgNPs were incorporated in the PMMA/PEI core–shell matrix, and had 6–10 nm in diameter. AgNPs immobilized on PMMA/PEI core–shell particles were also investigated by energy dispersive X-ray spectroscopy analysis mode extended from scanning electron microscopy (SEM/EDS). Furthermore, the presence of AgNPs was found to influence the thermal degradation behavior of PMMA/PEI particle composites as observed through thermogravimetric analysis (TGA).