Hybrid ZnO/polymer thin films prepared by RF magnetron sputtering

Zinc oxide/poly(acrylic acid) (ZnO/PAA) multilayered hybrid films with different layer thicknesses were prepared by radio frequency magnetron sputtering. Zinc peroxide was used as precursor materials for the preparation of ZnO layers, since the zinc peroxide decomposes to ZnO during the film deposition. The films have a high transmittance in the visible region and exhibit visible photoluminescence emission. The band gap energy of the films—determined by the Tauc relationship—decreases with increasing layer thickness (3.40–3.36 eV) due to the increasing crystalline size of the ZnO particles. The morphological investigations showed that a real layered hybrid film structure formed.     

Complex aggregates of silica microspheres by the use of a polymer template

Evaporation of a droplet of silica microsphere suspension on a polystyrene and poly(methyl methacrylate) blend film with isolated holes in its surface has been exploited as a means of particles self-assembly. During the retraction of the contact line of the droplet, spontaneous dewetting combined with the strong capillary force pack the silica microspheres into the holes in the polymer surface. Complex aggregates of colloids are formed after being exposed to acetone vapor. The morphology evolution of the underlying polymer film by exposure to acetone solvent vapor is responsible for the complex aggregates of colloids formation.     

Monitoring morphological and optical properties on hybrid porous polymer films

This work focuses on an optical and morphological comparative study of hybrid functional polymer porous films on glass substrates using the spin coating technique. The covering of these membranes, by a predeposited Zn²⁺ seed layer, was done applying the dip casting technique, which allows the synthesis of a large area and the control of the orientation of ZnO nanoparticles. It was possible to observe changes on the optical properties and surface morphology, which were attributed to both the spatial structure of the macromolecule and their interaction with the inorganic nanoparticles. It was also clear that hybrid porous matrices exhibit a blueshift with decreasing particle size.     

Flame retardancy of carbon nanofibre/intumescent hybrid paper based fibre reinforced polymer composites

A hybrid nanopaper consisting of carbon nanofibre (CNF) and/or clay, polyhedral oligomeric silsesquioxane (POSS), ammonium polyphosphate (APP), has been fabricated through the papermaking process. The as-prepared hybrid nanopaper was then incorporated onto the surface of glass fibre (GF) reinforced polymer matrix composites through injection moulding. The morphologies of hybrid nanopapers with and without the polymer resin were characterized with scanning electron microscopy (SEM). The polymer resin penetrated the entire nanopaper under a high-pressure compressed air system. The thermal decomposition behaviour of hybrid nanopapers infused with resin was studied with real-time thermogravimetric analysis/Fourier transform infrared spectrometry (TGA/FTIR). The test results indicate that the addition of clay in the hybrid paper increased the char residues of the nanocomposites. The fire retardant performance of composite laminates incorporating hybrid nanopaper was evaluated by cone calorimeter testing using a radiant heat flux of 50 kW/m². The cone test results indicated that the peak heat release rate (PHRR) decreased dramatically in the case of laminate composites incorporating CNF/clay/APP hybrid paper. However, the extent of reduction of PHRR of the composite laminates incorporated with CNF/POSS/APP hybrid paper was lower. The formation of compact char materials was observed on the surface of the residues and analyzed by SEM and X-ray photoelectron spectroscopy (XPS). The flame retardant mechanisms of hybrid nanopapers in composite laminates are discussed.     

Preparation of zinc oxide nanorods using pulsed laser ablation in water media at high temperature

ZnO columnar single crystals were formed by pulsed laser ablation in deionized water and surfactant aqueous solutions of lauryl dimethylaminoacetic acid (LDA) and cetyltrimethylammonium bromide (CTAB) at 80 degrees C. ZnO particles produced by laser ablation were dissolved at a higher temperature than 60 degrees C, and then crystalline growth to columnar structure proceeded. While large ZnO columnar crystals were obtained in deionized water, the crystals prepared in surfactant solution were smaller than those in deionized water due to inhibition of crystalline growth by surfactant adsorption on ZnO surfaces. The size of ZnO nanorods depended on how surfactant molecules adsorb on ZnO surface.     

Redox-responsive polymer prodrug/AgNPs hybrid nanoparticles for drug delivery

The redox-responsive hybrid nanoparticles of P(MACPTS-co-MAGP)@AgNPs is developed for drug delivery and fluorescence monitoring of the drug release by applying the NSET-based strategy.     

ZnO/eosin-Y混合薄膜的生长机理和形态

Thin hybrid films of ZnO/eosin-Y were prepared by electrodeposition at-0.8 and-0.9 V in aqueous and non-aqueous baths at temperatures ranging from 40 to 90 ℃ with dye concentrations of 100 and 400 μmol·L-1.The films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),energy-dispersive X-ray analysis (EDX),and absorption spectroscopy.The films prepared in a non-aqueous bath were non-porous and did not adsorb dye molecules on their surface.However,the films grown in aqueous media were porous in nature and adsorbed dye during the deposition of ZnO.Preferential growth of the film along the (002) face was observed,and the highest crystallinity was achieved when the film was deposited at 60 ℃.The maximum absorption was achieved for the films grown at 60 to 70 ℃,a deposition potential of-0.9 V,and a dye concentration of 100 μmol·L-1.     

Synthesis and property study of UV-curable hyperbranched polyurethane acrylate/ZnO hybrid coatings

In the present work, the third generation hyperbranched polyester (HBPE-3G) based polyurethane acrylate (HBPUA-32)/ZnO hybrid coatings are prepared, by modifying 16 hydroxyl groups of HBPE-3G with an acrylic adduct. The HBPE-32 is prepared from the di-trimethylol propane and 2,2-bis(hydroxymethyl) propionic acid, converted into hybrid coatings by incorporating 1%, 3% and 5% nano ZnO powder into the polymer matrix. The ¹H, ¹³C NMR and FT-IR spectroscopy methods are used for structural characterization, degree of branching calculation and structure to property correlation study and various hybrid film properties are analyzed by TGA, DMTA, XRD and SEM instruments.     

Pd/ZnO和Ag/ZnO复合纳米粒子的SPS和XPS研究

用焙烧前驱物碱式碳酸锌的方法制备了ZnO纳米粒子，采用光还原沉积贵金属的方法分别得到了质量分数为0.5％的Pd/ZnO和Ag/ZnO复合纳米粒子，并利用XRD、TEM、XPS和SPS等测试技术对样品进行表征.初步探讨了贵金属在ZnO纳米粒子表面形成原子簇的原因及沉积贵金属对ZnO纳米粒子表面光电压信号的影响.以光催化氧化气相正庚烷为模型反应，考察了沉积贵金属对ZnO纳米粒子光催化活性的影响，并探讨了光催化活性有所提高的内在原因.结果表明， ZnO纳米粒子沉积贵金属后，其表面光电压信号明显下降，而光催化活性却大大地提高，这说明可以通过表面光电压谱的测试来初步的评估纳米粒子的光催化活性，即粒子的表面光电压信号越弱，其光催化活性越高.     

Influence of rapid thermal annealing on structure and interfacial characteristic of ZnO thin films

Highly C‐axis oriented ZnO thin film was manufactured by radio‐frequency magnetron sputtering technique on Si (111) substrate. The main objective was to study the influence of rapid thermal annealing (RTA) temperature on the structure and interfacial characteristic of ZnO thin films. X‐ray diffraction results showed that the ZnO thin films annealed at 600 °C by RTA technique had a perfect C‐axis preferred orientation compared to the other ZnO thin films, and the full width at half maximum of ZnO (002) rocking curve measurements indicted that the RTA‐annealed ZnO thin films possessed better crystal structure. Atom force microscopy displayed that the grain size of RTA‐annealed ZnO thin films was fine and uniform compared with the as‐deposited ZnO thin films, although the grains grew in RTA process and the root meant square roughness was smaller than that of as‐deposited films. High‐resolution transmission electron microscopy showed that there was an obvious amorphous layer between ZnO thin films and Si substrate, but the RTA‐annealed ZnO thin films exhibited larger and denser columnar structure and a preferred orientation with highly c axis perpendicular to the amorphous layer. Copyright © 2012 John Wiley & Sons, Ltd.     

Stable ZnO/ionic liquid hybrid materials: novel dual-responsive superhydrophobic layers to light and anions

Novel dual-responsive superhydrophobic hybrid materials,ZnO/SAMs(self-assembled monolayers)of ionic liquids(ILs)with different counter-anions(I-,BF4-,PF6-and Tf2N-),were synthesized and characterized.ZnO nanoparticles were first deposited on glass surfaces to produce roughness.Next,SAMs of fluorinated-alkyl-3-(3-triethoxysilylpropyl)-4,5-dihydro-imidazoliumiodide(abb.[C8Ftespim]I)were grafted onto these surfaces via-Si-O-covalent bonds using self-assembly technique.The Iion could be subsequently exchanged with BF4-,PF6-or Tf2N-through a simple aqueous anion-exchange reaction.The ZnO/ILs hybrid layers were characterized by atomic-force microscopy(AFM),scanning-electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).Their wettability was estimated through the measurements of static and dynamic contact angles(CAs).Compared to corresponding films of ZnO/[C8Ftespim]I with CAs 140.7°±2.0°,films of ZnO/[C8Ftespim]PF6 and ZnO/[C8Ftespim]Tf2N showed CAs with 154.0°±2.0°and 152.0°±2.0°,respectively that remained for a long time.This result suggests that anion-exchange can afford superhydrophobic materials.In addition,the wettability of ZnO/[C8Ftespim]X hybrid layers can be reversibly switched by altering ultraviolet(UV)irradiation and dark storage,which shows a photo-induced reversible switch of wettability.The synergistic action of ZnO nanoparticles and SAMs of ILs produced light-anion dual-responsive superhydrophobic materials with ideal stability.     

ZnO/Ag复合纳米粒子的制备与表征

以乙酸锌为前驱物,乙醇为溶剂,油酸钠为表面修饰剂,采用溶液化学法,在乙醇体系中制得纳米Zn O。然后缓慢加入一定量的硝酸银乙醇溶液,在乙醇的还原作用下将Ag+还原为Ag纳米粒子,制得Zn O/Ag复合纳米粒子。通过紫外-可见吸收光谱(UV-Vis)、荧光光谱(FL)、透射电子显微镜(TEM)和X射线衍射(XRD)等方法对所制备的氧化锌-银复合纳米粒子样品进行表征。结果表明,所合成的Zn O/Ag复合纳米粒子为球形,尺寸为20-30nm且粒径分布较窄。Ag纳米粒子附着于Zn O纳米粒子表面,并起到良好的表面修饰作用。对制备Zn O/Ag复合纳米粒子的机理进行了初步探究。     

Preparation of ZnO Nanoparticles: Structural Study of the Molecular Precursor

The structure of zinc acetate derived precursor currently used in the sol-gel synthesis of ZnO nanoparticles is described. The reaction products obtained before and after reflux of ethanolic zinc acetate solution have been studied by UV-Vis, photoluminescence, FTIR and EXAFS at the Zn K edge. EXAFS results evidence for both precursor solutions a change from the octahedral coordination sphere of oxygen atoms characteristic of the solid zinc acetate dihydrate compound into a four-fold environment. The EXAFS spectra of precursor solutions can be satisfactorily reproduced using the molecular structure reported for Zn₄O(Ac)₆ (Ac = COOCH₃). UV-Vis and FTIR measurements are also in agreement with the formation of this oligomeric precursor. The structural modification is more pronounced after reflux at 80°C, because the increase of the Zn₄O(Ac)₆ amount and the formation of nearly 3.0 nm sized ZnO nanoparticle.     

Influence of vacuum on the formation of porous polymer films via water droplets templating

We report on the formation of ordered arrays of micron-sized holes on the surface of polymer films cast from volatile solvents in the presence of humidity in vacuum. A lower pressure in a vacuum chamber can accelerate the evaporation of solvent in the same way as the accelerating action of the air flowing across the solvent surface and results in the formation of porous films via the “breath figure” templating method. This vacuum technique has a good reproductiveness for the fabrication of the well-ordered porous films in a large area. It is very controllable to prepare the porous films in a vacuum chamber via controlling the vacuum level. The pore sizes can be easily tuned from 5.6 to 17.1 μm by changing the vacuum level. The mechanism for the formation of the porous films in vacuum was also discussed. The polymer films with ordered porous structure and tunable pore sizes have potential applications in many areas such as microarrays and as scaffolds for tissue engineering. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

纳米结构ZnO/染料/聚吡咯光阳极的光电化学性质

用光电化学方法研究了染料RuL2 (NCS) 2 (L =2 ,2′ bipydine 4,4′ dicarboxylicacid) (简写为Dye)、聚吡咯 (PPy)敏化氧化锌 (ZnO)纳米晶电极以及用RuL2 (NCS) 2 和PPy复合敏化ZnO纳米晶膜电极的光电化学行为 .实验表明 ,ZnO/PPy纳米多孔膜电极为双层n 型半导体结构 .PPy和RuL2(NCS) 2 都可对ZnO纳米晶膜产生敏化作用 ,ZnO/RuL2 (NCS) 2 /PPy复合多孔膜电极产生的光电流远大于ZnO/PPy纳米多孔膜电极和ZnO/Dye多孔膜电极产生的光电流 .讨论了该电极的光生电子的机理 ,初步测定了ZnO/RuL2 (NCS) 2 /PPy电极作为光阳极的光电化学电池的工作特性曲线 ,测得该电池的光电转换效率为 1 .3% ,填充因子为 0 .75 .     

Synthesis and luminescence properties of hybrid organic-inorganic transparent titania thin film activated by in-situ formed lanthanide complexes

Stable transparent titania thin films were fabricated at room temperature by combining thenoyltrifluoroacetone (TTFA)-modified titanium precursors with amphiphilic triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO, P123) copolymers. The obtained transparent titania thin films were systematically investigated by IR spectroscopy, PL emission and excitation spectroscopy and transmission electron microscopy. IR spectroscopy indicates that TTFA coordinates the titanium center during the process of hydrolysis and condensation. Luminescence spectroscopy confirms the in-situ formation of lanthanide complexes in the transparent titania thin film. TEM image shows that the in-situ formed lanthanide complexes were homogeneously distributed throughout the whole thin film. The quantum yield and the number of water coordinated to lanthanide metal center have been theoretically determined based on the luminescence data.     

Functional polymer/inorganic hybrid nanoparticles for macrophage targeting delivery of oligodeoxynucleotides in cancer immunotherapy

To efficiently deliver CpG oligodeoxynucleotides (ODN) in cancer immunotherapy, a multifunctional macrophage targeting delivery system was designed and prepared. Mannosylated carboxymethyl chitosan/protamine sulfate/CaCO₃/ODN (MCMC/PS/CaCO₃/ODN) nanoparticles were prepared using a facile self-assembly method. The functional components, including MCMC to endow the nanoparticles with macrophage targeting ability, PS to improve the ODN loading capacity and enhance the cell uptake, and CaCO₃ to encapsulate ODN and induce the favorable pH sensitivity, were introduced to the delivery systems by self-assembly. Due to the mannose mediated endocytosis and the favorable effects of PS in overcoming delivery barriers, MCMC/PS/CaCO₃/ODN nanoparticles exhibit a much higher ODN delivery efficiency and a significantly enhanced immune stimulation capacity as compared with Lipofectamine 2000/ODN complexes. The regulation of NF-κB activity by our ODN delivery system results in dramatically increased production of proinflammatory cytokines including IL-12, IL-6, and TNF-α in RAW264.7 cells. The significantly increased CD80 expression after stimulation by the ODN delivery systems indicates the successful modulation of the macrophage polarity to the anti-tumor M1 phenotype. The multifunctional macrophage targeting delivery system developed has promising applications in delivery of CpG ODN in cancer immunotherapy.     

Preparation, morphology and properties of nano-sized Al2O3/polyimide hybrid films

Nano-sized Al₂O₃/polyimide (PI) hybrid films based on 4,4′-oxydianiline (ODA) and pyromellitic dianhydride (PMDA) were prepared by incorporation with different content of nano-sized Al₂O₃ via in situ polymerization. The TEM and SEM micrographs indicated that the Al₂O₃ particles were homogenously dispersed in the polyimide matrix by means of the ultrasonic treatment and the addition of coupling agent. The mechanical properties and thermal stability of the pure PI film can be improved by adequate addition of Al₂O₃. The PI hybrid film was strengthened and toughened simultaneously by the introduction of the well-dispersed Al₂O₃ particles. The PI hybrid films showed improved electrical aging performance as compared with pure PI film. Especially, the PI hybrid films with 10 wt.% of Al₂O₃ content exhibited obviously enhanced electrical aging performance with the time to failure of 3.4 times longer than that of pure PI film. The improved electrical aging performance of the hybrid film was attributed to the nano-sized Al₂O₃ particles highly dispersed in the hybrid film, which confirmed by the investigation of the morphology and the surface composition of PI hybrid film before and after electrical aging.     

纳米金属铜与纳米氧化锌之间相互作用的EPR和XPS研究

由于纳米材料独特的表面效应、电子效应及量子尺寸效应 ,已被广泛应用于各个领域 .有关纳米材料研究的报道很多 [1～ 7] ,大部分是关于纳米材料的制备[1～ 4 ] 及其特性研究 .对于纳米金属及纳米氧化物之间相互作用的研究迄今尚未见报道 .本文采用超声分散和机械研磨法物理混合纳米金属铜粉和纳米氧化锌 ,借助 EPR和 XPS技术对样品进行了表征 ,发现混合体系出现了 Cu2 + 的顺磁信号 ,Zn L3M4 5M4 5俄歇动能和 O1s的电子结合能亦发生了变化 ,表明纳米 Cu0 和纳米 Zn O之间存在相互作用 ,作用形式为 Cu— O—Zn.1　实验部分1 .1　样品…     

ZnO nanoparticles as chain elasticity reducer and structural elasticity enhancer: Correlating the degradating role and localization of ZnO with the morphological and mechanical properties of PLA/PP/ZnO nanocomposite

The main purpose of this study was to investigate the effect of zinc oxide (ZnO) nanoparticles on the morphological, mechanical, thermal, and rheological properties of PLA/PP blend. In this regard, nanocomposites containing 1, 3, and 5 wt% of ZnO nanoparticles were prepared by melt mixing. In addition, three different mixing procedures were adopted to study their effects on the microstructure of nanocomposites. The rheological behaviors demonstrated a higher elasticity and less compatibility for two phases in the case of nanocomposites containing nanoparticles in harmony with the morphological observations. Accordingly, it was correlated to the elasticity originating from the interphase, anticipated coalescence of dispersed particles as a result of degradation of PLA chains triggered by ZnO nanoparticles (ZnO‐NPs) and also agglomeration of ZnO‐NPs depending on the content of nanoparticles and chosen mixing procedure. It was also found that mixing method puts a remarkable influence on the microstructure and rheological behavior of nanocomposites. Results of mechanical characterizations and thermogravimetric analysis (TGA) also confirmed the degradation induced by ZnO nanoparticles.