Embossing of organic thin films using a surfactant assisted lift-off technique

A simple technique for patterning organic materials using a surfactant assisted lift-off method is proposed. Thin films of various organic materials are prepared, and areas in contact with a surfactant coated poly(dimethylsiloxane) (PDMS) stamp are selectively removed. The general applicability of this technique is shown for materials containing nitrate, amine, and carboxylic acid functional groups. This technique provides a new methodology for fabricating patterns with vertical dimensions ranging from 30 nm up to 3 μm on organic thin films with specific functional groups.     

Finite element simulation of Love wave sensor for the detection of volatile organic gases

The three-dimensional (3D) finite element (FE) simulation and analysis of Love wave sensors based on polyisobutylene (PIB) layers/SiO$_{2}$/ST-90$^\circ$X quartz structure are presented in this paper, as well as the investigation of coupled resonance effect on the acoustic properties of the devices. The mass sensitivity of the basic Love wave device with SiO$_{2}$ guiding layers is solved analytically. And the highest mass sensitivity of 128 m$^{2}$/kg is obtained as $h_{\rm s}/\lambda =0.175$. The sensitivity of the Love wave sensors for sensing volatile organic compounds (VOCs) is greatly improved due to the presence of coupled resonance induced by the PIB nanorods on the device surface. The frequency shifts of the sensor corresponding to CH$_{2}$Cl$_{2}$, CHCl$_{3}$, CCl$_{4}$, C$_{2}$Cl$_{4}$, CH$_{3}$Cl and C$_{2}$HCl$_{3}$ with the concentration of 100 ppm are 1.431 kHz, 5.507 kHz, 13.437 kHz, 85.948 kHz, 0.127 kHz and 17.879 kHz, respectively. The viscoelasticity influence of the sensitive material on the characteristics of SAW sensors is also studied. By taking account of the viscoelasticity of the PIB layers, the sensitivities of the SAW sensors with the PIB film and PIB nanorods decay in different degree. The gas sensing property of the Love wave sensor with PIB nanorods is superior to that of the PIB films. Meanwhile, the Love wave sensors with PIB sensitive layers show good selectivity to C$_{2}$Cl$_{4}$, making it an ideal selection for gas sensing applications.     

新一代太阳电池概述

文章对新一代太阳电池的基本概念、研究现状和研究目标进行了详细的介绍.从“充分吸收光能,减少能量转换损失”的角度,分析了新一代太阳电池的结构设计特征.以纳米技术与叠层电池结构为基础,就高能光子的利用,介绍了宽带隙吸收层窗口电池、量子点热载流子电池和多重激子激发（MEG）的量子点电池;为解决低能光子损失,介绍了窄带隙光伏材料和中间带光伏器件包括量子点中间带和高失配构建的中间带电池;探讨了利用光-光转换的模式,对上转换和下转换的电池体系以及可能的极限效率进行了阐述.     

纳米结构泡沫金冲击响应的分子动力学模拟

采用分子动力学计算程序对纳米结构泡沫金(Au)的冲击响应进行了模拟,得到了不同疏松度条件下泡沫Au的冲击压缩特性。通过获取不同势函数条件下实密Au的冲击Hugoniot关系以及泡沫结构稳定性测试选取适合描述Au泡沫冲击过程中原子的相互作用势。采用密堆积球壳的方式建立泡沫Au的初始构型。通过改变空心球壳的尺寸得到不同疏松度的稳定的泡沫Au结构。对泡沫Au的冲击过程进行分子动力学模拟,获得了不同疏松度泡沫Au在不同冲击压缩强度下的热力学状态参数。将模拟结果与已有的状态方程数据库以及疏松物质冲击压缩模型进行比较,结果表明,计算和理论模型给出的结果仍然存在明显的差异性,亟需通过进一步实验研究来验证模拟计算和理论模型结果的可靠性。     

Nanoconfined heliconical structure of twist-bend nematic liquid crystal phase

We produced controlled heliconical structures of a twist-bend nematic (N_TB) liquid-crystal (LC) phase in nanoconfinement in a porous anodic aluminium oxide (AAO) film. The structural parameters of the N_TB phase such as conical angle and helical pitch can be modulated by varying the surface energy of the inner surface of the porous AAO film, done by using different self-assembled monolayers (SAMs). The LC molecules tend to be more freely packed, thus forming a larger conical angle, when placed on the tri-deca-fluoro-1,1,2,2-tetrahydrooctyl-trichlorosilane (FOTS)-treated substrate, which has a relatively low surface energy. In contrast, the molecules form a more tightly packed structure, and thus a smaller conical angle, when placed on the 2-(methoxy(polyethyleneoxy)-propyl)trimethoxysilane (PEG 6/9)-treated substrate, which has higher surface energy. This work improves our collective understanding of self-assembled heliconical structures in the N_TB phase.     

A multi-functional polymer coating that is heat-resistant,hydrophobic and transparent

A multi-functional polymer film with high hydrophobicity and transparency was formed by simple casting of a polycarbonate solution onto a substrate having micro-scale roughness.The high hydrophobicity was heat-resistant,which can be retained up to 390 ℃.The polymer film may have potentially wide-ranging applications in industry and high technology.     

Auto-organized nano-structure of collagen on Gemini surfactant monolayer

Two kinds of Gemini surfactant monolayer, which showed different hydrophobic property, were selected as adsorption substrates for collagen. The topographic images of collagen were investigated by using an atomic force microscopy (AFM). Their auto-organized nano-structures were influenced by the property of substrate and the process of sample preparation, such as concentration of collagen solution, adsorption time and drying condition. Network-like structures formed on the both Gemini monolayers. With increasing concentration of collagen solution and adsorption time, the density of the network-like structure increased and their strands became wider and the mesh sizes decreased apparently. Contrary to the reference, the network-like structures of collagen also formed on the less hydrophobic Gemini surfactant monolayer even after very short adsorption time, which was considered to result from the more hydrophobic patch on it.     

新兴的纳米结构亚波长光学器件及其发展

介绍了新颖的纳米结构亚波长光学器件的特点,从器件的基本功能特性和工作机理两个方面详细讨论了其应用状况,并阐述了纳米制造技术对亚波长光学器件发展的重要推动作用及这一领域今后的研究热点。     

退火温度对纳米氧化铜湿敏性能的影响

湿度传感器在生产和生活中扮演着不容小觑的角色,越来越受到人们的广泛关注.本文利用低温液相法以氢氧化钠、过硫酸铵和铜粉为原料,成功制备出氧化铜纳米结构.运用扫描电子显微镜(SEM)、X-射线衍射仪(XRD)等技术对材料的结构与形貌进行表征,发现可以通过退火温度来调控氧化铜纳米结构的表面形貌,进一步比较研究了不同退火温度下制备的纳米氧化铜的湿敏性能.并将CuO纳米材料涂敷在电极表面制成了湿敏元件.研究结果表明,元件的湿敏特性明显与材料的退火温度密切相关,在500℃退火获得的氧化铜纳米线灵敏度最高,达到1.93×10~5;湿滞最小,几乎为零;感湿频率特性曲线的线性度好.分析认为这主要是由于,退火温度500℃时,氧化铜呈现纳米线状结构,具有更大的表面积,增加了与水分子的接触面积,进而具有更佳的湿敏特性.