Facile synthesis and anti-icing performance of superhydrophobic flower-like OTS-SiO2 with tunable size

The superhydrophobic flower-like OTS-SiO₂ particles with tunable size were synthesized for application in anti-icing technology, in which the nanosilica fibers were grown on surface of SiO₂ sphere. Furthermore, the anti-icing process of flower-like OTS-SiO₂ particles was investigated by a high speed video and thermal infrared imaging equipment. It was found that the flower-like OTS-SiO₂ particles with a diameter of 300.0 nm showed best anti-icing ability, in which the frozen time of water droplets could be prolonged to 564.0 s at −25.0℃. The good anti-icing ability was attributed to micro-nano hierarchical structure and surface modification of flower-like OTS-SiO₂ particles. The work has an important guiding implication for the subsequent design and preparation of superhydrophobic particles for application in anti-icing technology.     

Facile synthesis of Ag/ZnO microstructures with enhanced photocatalytic activity

In this paper, we developed a facile low-temperature solution route to prepare radical-shaped ZnO microprisms and to deposit metal silver on the surface of ZnO to form Ag/ZnO microstructures. The samples were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Experimental results show that the deposition of metal Ag nanospecies can be achieved successfully by simply aging the solution at 75 °C, and the radical-shaped microstructures of ZnO are well maintained. The Ag/ZnO microstructures exhibit much lower PL emission intensity and much higher photocatalytic activity than those of radical-shaped ZnO microprisms.     

超疏水叠杯状碳纳米管薄膜的制备(英文)

采用化学气相沉积法制备了高纯度的叠杯状碳纳米管薄膜。生长15 min后,薄膜厚度可达～300μm。热重分析表明薄膜的纯度高达99.9%。透射电镜表征表明碳纳米管中石墨烯片层与轴向存在一定偏角呈叠杯状排列,其直径为80 nm～230 nm。通过对催化剂与叠杯状碳纳米管的结构分析,提出其根部生长机制。该叠杯状碳纳米管薄膜易于转移且具有良好的柔性。疏水性测试表明其具有超疏水表面,接触角约为155°,因而有望作为防水和自清洁保护层。     

A facile solution-immersion process for the fabrication of superhydrophobic surfaces with high water adhesion

The present work reports a simple and effective way to produce copper compound films on zinc substrate via solution-immersion process. The surfaces were characterized by field-emission scanning electron microscopy, Fourier transform IR, X-ray photoelectron spectrum and X-ray powder diffraction. The wettability of the surfaces is also investigated. The as-prepared superhydrophobic surfaces exhibit high adhesion to water and scratches on the surfaces could be repaired by immersing the damaged samples into the solution again.     

Facile synthesis of Ag/ZnO nanorods using Ag/C cables as templates and their gas-sensing properties

A solid-state chemical reaction with the assistance of Ag/C nanocables was implemented for the preparation of Ag/ZnO nanorods. This is the first time Ag/ZnO nanorods are fabricated by using Ag/C cables as template. Compared with the traditional organic surfactant, Ag/C cable is a new and effective template to control the shape of precursors in the solid-state reaction under ambient conditions. The results of systematical gas-sensing studies demonstrate that the sensor based on Ag/ZnO nanorod materials has high sensitivity, good selectivity and short response and reversion time to ethanol. It demonstrates that Ag/ZnO nanorods can be used as gas-sensing material.     

Nonlocal free vibration of orthotropic non-prismatic skew nanoplates

The free vibration of orthotropic non-prismatic skew nanoplate based on the first-order shear deformation theory (FSDT) in conjunction with Eringen’s nonlocal elasticity theory is presented. As a simple, accurate and low computational effort numerical method, the differential quadrature method (DQM) is employed to solve the related differential equations. For this purpose, after deriving the equations of motion and the related boundary conditions, they are transformed from skewed physical domain to rectangular computational domain of DQM and accordingly discretized. After validating the formulation and method of solution, the effects of nonlocal parameter in combination with geometrical parameters and boundary conditions on the natural frequencies of the orthotropic skew nanoplates are investigated.     

Surfactantless synthesis of silver nanoplates and their application in SERS

Silver nanoplates with thicknesses of 50-70 nm and edge lengths ranging from 200 nm to 1 mum have been grown on semiconductor wafers at room temperature through a simple galvanic reaction between an aqueous solution of AgNO(3) and n-type GaAs. The as-grown Ag structures have chemically clean surfaces due to no surfactant or coordinating molecules being involved in the synthesis. Electron microscopy characterizations indicate that each Ag plate has rough surfaces and a half-moon morphology with one straight edge and one arclike edge. Systematic studies on varying reaction conditions reveal that the oxide (i.e., Ga(2)O(3) and As(2)O(3)) layers of GaAs, generated in situ in the reactions, play an important role in assisting the growth of anisotropic nanoplates. The cleanliness of the surfaces of the Ag nanoplates is beneficial to attachment of interesting molecules on their surfaces for various applications, such as plasmonic-enhanced photophysical and photochemical processes and surface-enhanced spectroscopies.     

非光照条件下三角形银纳米片形成的两种方式

报道了非光照条件下三角形银纳米片形成的两种方式,应用TEM和紫外-可见光谱仪对银纳米颗粒的生长过程进行了研究.硝酸银分步还原首先形成尺寸小于10 nm的银颗粒,在60℃时,银颗粒在表面活性剂BRIJ35分子的作用下先形成三角形银纳米框架,然后再填补不断密实,最终形成规则的三角形银纳米片.在80℃先形成小尺寸的三角形银纳米颗粒,然后直接长大形成三角形银纳米片.     

钛酸锶薄膜的液相自组装制备与表征

采用自组装单层膜技术在玻璃基板上成功制备了钛酸锶薄膜,利用接触角仪对前期处理后的基片润湿角进行表征,利用X射线衍射(XRD),扫描电镜(SEM)等手段表征了薄膜的物相和微观结构。实验结果表明:采用自组装单层膜技术制备的钛酸锶薄膜结晶良好,样品表面均匀,颗粒尺寸大约在300nm～500nm之间。     

Double layered superhydrophobic PDMS-Candle soot coating with durable corrosion resistance and thermal-mechanical robustness

Nature-inspired superhydrophobic coatings with typical Cassie-Baxter contacts garner numerous interests for multifunctional applications.However,undesirable poor mechanical and thermal stability are still crucial bottlenecks for real-world employment.This work introduces a cost-effective,fluorine free and versatile strategy to achieve double-layered PDMS agglutinated candle soot coating with superior water-repellent superhydrophobicity.The surface morphologies,chemical compositions and wettability behaviors were investigated in detail.The mechanical stability,chemical stability and durable corrosion resistance of the fabricated PDMS-CS coating were evaluated through friction,calcination and electrochemical impedance spectroscopy.The results demonstrate a remarkably enhanced mechanical robustness and corrosion resistance,indicating PDMS units can act as an effective agglutinating agent between candle soot and underlying substrate.The synergistic effect of PDMS agglutination,porous network nanostructures and extremely low surface energy of incomplete combustion induced candle soot deposition contribute to the eventually robust corrosion resisting coating,which greatly increases the possibility for practical applications.     

Fabrication of superhydrophobic copper by wet chemical reaction

A wet chemical reaction was employed herein to fabricate a stable superhydrophobic surface on a polished copper substrate at ambient temperature. The resulting surface showed superhydrophobic properties as evidenced by a water contact angle (CA) of about 154° and a water sliding angle (SA) of about 4°, which may be attributed to the combination of the roughened surface morphology by means of wet chemical reaction and the formed low surface free energy per chemical modification with poly (dimethysiloxane) vinyl terminated (PDMSVT). Scanning electron microscopy (SEM) images of the resulting surface reveal the resulted copper oxalate microscopic sizes with average diameter of about 0.5 μm and circular submicroscopic structures with diameter of about 100 nm, constructing a hierarchical structure consisted by micro- and nano-scale elements similar to that of lotus leaf in some extent. The elemental and chemical compositions of the resulting surface were also identified by Powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. This work provides improved understanding of the effect of surface roughness and surface energy on superhydrophobicity.     

L-赖氨酸自组装膜对铜的缓蚀性能研究

用电化学测量法研究不同组装时间和不同组装浓度时L-赖氨酸自组装单分子膜在0.5mol·L-1 HCl溶液中对铜的缓蚀作用,进行了吸附等温线拟合,并通过分子模拟探讨L-赖氨酸在铜表面的吸附模型。结果表明,L-赖氨酸自组装膜的最佳组装条件是在10mmol·L-1组装液中组装8h,缓蚀率达87%。等温吸附线拟合表明L-赖氨酸在Cu表面的吸附遵循Langmuir等温吸附方程。分子模拟表明,L-赖氨酸分子通过末端-NH2上的N原子与Cu原子结合,并且以近似垂直的方式吸附在Cu(111)表面。     

石墨烯纳米片/(酚酞聚芳醚酮-环氧树脂)双逾渗导热复合材料的制备和性能

为在较低的导热填料含量下提高环氧树脂(EP)的热导率,通过溶液法制备了石墨烯纳米片/(酚酞聚芳醚酮-EP) (GNP/(PEK-C-EP))复合材料.基于接触角测量计算并预测了GNP的选择性分布,并通过SEM和激光闪光法研究了GNP和PEK-C含量对GNP/(PEK-C-EP)复合材料的微观结构和热导率的影响.结果 表...     

Microwave-assisted green synthesis of MnO2 nanoplates with environmental catalytic activity

In this paper, MnO₂ nanoplates were synthesized in aqueous solution under the microwave irradiation, without using any templates, catalysts, and organic reagents. The as-prepared MnO₂ nanoplates were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and thermo-gravimetric (TG) analysis, and nitrogen sorption measurements. Microwave irradiation could produce MnO₂ with uniform size and well-defined shape as well as high crystallinity. On the basis of experimental results, a possible formation mechanism of MnO₂ nanoplates was proposed. Furthermore, the resulting MnO₂ nanoplates were found to exhibit remarkable environmental catalytic performance in degradation of Rhodamine B (RhB) in aqueous solution, indicating these MnO₂ nanoplates is very promising for wastewater treatment.     

Size- and shape-controlled conversion of tungstate-based inorganic-organic hybrid belts to WO3 nanoplates with high specific surface areas

Two-dimensional monoclinic WO(3) nanoplates with high specific surface areas are synthesized through a novel conversion process using tungstate-based inorganic-organic hybrid micro/nanobelts as precursors. The process developed involves a topochemical transformation of tungstate-based inorganic-organic hybrid belts into WO(3) nanoplates via an intermediate product of H(2)WO(4) nanoplates, utilizing the similarity of the W-O octahedral layers in both H(2)WO(4) and WO(3). The as-obtained WO(3) nanoplates show a single-crystalline nanostructure with the smallest side along the [001] direction. The WO(3) nanoplates are 200-500 nm x 200-500 nm x 10-30 nm in size, and their specific surface areas are up to 180 m(2) g(-1). Photocatalytic measurements of visible-light-driven oxidation of water for O(2) generation in the presence of Ag(+) ions indicate that the activity of the as-obtained WO(3) nanoplates is one order of magnitude higher than that of commercially available WO(3) powders.     

Fabrication of superhydrophobic TPU film for oil-water separation based on electrospinning route

In this work, we described an electrospinning process for creating superhydrophobic thermoplastic polyurethanes (TPU) mat with bead-on-string morphologies. The initially hydrophobic TPU electrospun film presented superhydrophobic trait after treatment with hydrophobic nanosilicas, which was pre-fabricated by refluxing nanosilicas in a toluene solution of hexadecyltrimethoxysilane (HDTMS). The relationship between the microstructures and wettability was also discussed. This superhydrophobic TPU film turned out to be benign materials for separating oil and water mixture. The development of the electrospun process described in this paper, as well as the extension of our method, will no doubt facilitate the achievement of other functional superhydrophobic films for various applications.     

Small scale effect on the free vibration of orthotropic arbitrary straight-sided quadrilateral nanoplates

As a first endeavor, the free vibration of orthotropic arbitrary straight-sided quadrilateral nanoplates is investigated using the nonlocal elasticity theory. The formulation is derived based on the first order shear deformation theory (FSDT). The solution procedure is based on the transformation of the governing equations from physical domain to computational domain and then discretization of the spatial derivatives by employing the differential quadrature method (DQM) as an efficient and accurate numerical tool. The formulation and the method of the solution are firstly validated by carrying out the comparison studies for the isotropic and orthotropic rectangular plates against existing results in literature. Then, the effects of nonlocal parameter in combination with the geometrical shape parameters, thickness-to-length ratio and the boundary conditions on the frequency parameters of the nanoplates are investigated.     

硅基底上图形化自组装膜的构筑

为在硅基底上得到不同化学基团修饰的图形,采用传统的光刻技术与自组装相结合的方法,成功地制备了由甲基与氨基末端官能团组成的图形化自组装膜。将图形化自组装膜泡入碳纳米管DMF(N,N-二甲基甲酰胺)分散液中,图形化自组装膜的氨基区域能均匀吸附一层分散液中碳纳米管,而甲基没有,表明图形化自组装膜的不同自组装膜区域的不同表面性质,证实了该方法的可行性。     

One-step synthesis of unique silica particles for the fabrication of bionic and stably superhydrophobic coatings on wood surface

The silica particles with unique morphology and hydrophobicity have been synthesized via a drop-coating method. After this one-step sol–gel process, silica particles as well as polystyrene were employed in the bionic and stably superhydrophobic coatings on wood surface (with water contact angle of 153 ± 1° and sliding angle less than 5 ± 0.5°). Scanning electron microscopic (SEM) studies revealed that the composite coatings possess two dimensional hierarchical structures comprising of micron scale papilla and submicron scale granules. The synergistic effect of micron/submicron binary structure and low surface energy layer was responsible for the superhydrophobicity of wood surface. Moreover, the chemical and mechanical stabilities of treated wood have been investigated as well, and the results show that the product possesses superhydrophobic property in a wide extent, such as pure water, corrosive water under both acidic and basic conditions, and some common organic solvents. More importantly, it will offer an opportunity to extend the range of practical applications for wood resources.