无毒低表面能防污涂料

简介了无毒低表面能防污涂料的发展现状及机理，指出了日前存在的主要问题及国内外存在的主要差距。     

磁控溅射偏压对Cr薄膜密度以及表面形貌的影响

利用磁控溅射技术,在不同偏压条件下在Si(001)基底上沉积了金属Cr薄膜样品。用同步辐射装置对样品进行了X-射线反射率测试,采用X-射线反射率分析法研究了不同偏压下Cr薄膜密度的变化。发现当偏压小于300 V时,偏压对所沉积的薄膜起到紧致的效果,偏压为300 V时薄膜密度最大;当偏压大于300 V时,薄膜密度减小。另外,为了探究偏压对薄膜表面形貌的影响,用扫描电子显微镜对各样品进行了表面分析,发现在偏压较小时薄膜表面较为平整;随着偏压增大,表面呈现界面分明的岛状分布。     

铜板表面溅射MgF2在池沸腾条件下抗CaCO3污垢性能

污垢的沉积导致换热器的效率降低。采用磁控溅射技术在铜板基底上溅射MgF2,在池式沸腾装置中对CaCO3溶液的结垢过程进行了试验研究。利用扫描电镜（SEM）分析不同基底的表面形貌和计算了相应的表面能。研究表明,溅射MgF2的铜板其表面能较低,可提高其抗垢性能。     

Substrate Temperature Dependent Surface Morphology and Photoluminescence of Germanium Quantum Dots Grown by Radio Frequency Magnetron Sputtering

The visible luminescence from Ge nanoparticles and nanocrystallites has generated interest due to the feasibility of tuning band gap by controlling the sizes. Germanium (Ge) quantum dots (QDs) with average diameter ~16 to 8 nm are synthesized by radio frequency magnetron sputtering under different growth conditions. These QDs with narrow size distribution and high density, characterized using atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) are obtained under the optimal growth conditions of 400 °C substrate temperature, 100 W radio frequency powers and 10 Sccm Argon flow. The possibility of surface passivation and configuration of these dots are confirmed by elemental energy dispersive X-ray (EDX) analysis. The room temperature strong visible photoluminescence (PL) from such QDs suggests their potential application in optoelectronics. The sample grown at 400 °C in particular, shows three PL peaks at around ~2.95 eV, 3.34 eV and 4.36 eV attributed to the interaction between Ge, GeO_x manifesting the possibility of the formation of core-shell structures. A red shift of ~0.11 eV in the PL peak is observed with decreasing substrate temperature. We assert that our easy and economic method is suitable for the large-scale production of Ge QDs useful in optoelectronic devices.     

磁控溅射法制备纳米Cu薄膜及其微结构的研究

采用磁控溅射法制备出以ITO为基底的纯Cu薄膜,考察溅射时间和基底温度等工艺条件对生长Cu薄膜的影响.用电子扫描显微镜(SEM)、X射线衍射仪(XRD)对薄膜的形貌、厚度和结构进行表征.实验结果表明:在一定范围内调控衬底温度和溅射时间,可获得不同形貌、尺寸和厚度的Cu薄膜,所得薄膜的晶体结构为面心立方结构,均沿(111...     

Temperature dependent optical properties of single, hierarchically self-assembled GaAs/AlGaAs quantum dots

We report on the experimental observation of bright photoluminescence emission at room temperature from single unstrained GaAs quantum dots (QDs). The linewidth of a single-QD ground-state emission (≈ 8.5 meV) is comparable to the ensemble inhomogeneous broadening (≈ 12.4 meV). At low temperature (T  ≤  40 K) photon correlation measurements under continuous wave excitation show nearly perfect single-photon emission from a single GaAs QD and reveal the single photon nature of the emitted light up to 77 K. The QD emission energies, homogeneous linewidths and the thermally activated behavior as a function of temperature are discussed.     

干污泥表面形貌及孔隙分布规律

污泥干燥焚烧以回收其热能的资源化利用正受到越来越多的关注。污泥干燥过程中,孔隙的大小及其分布直接影响污泥中液体及气体的传递过程．进而影响干燥速率。为研究干污泥表面形貌及孔隙分布规律,采用扫描电子显微镜观测了干污泥表面形貌。利用动态氮吸附法测量了干污泥的孔隙大小。利用数理统计方法研究了孔隙分布规律,研究结果表明干污泥的孔隙分布服从对数正态分布。建立了孔隙分布模型,求解了5种干污泥的孔隙分布特征参数,模型计算值与实际测量值吻合较好,均方根误差小于18．2％,所建立的干污泥孔隙分布模型具有一定的通用性及准确性。     

低温氧等离子体对PET薄膜的表面改性研究

采用氧气低温等离子体,在工作压力为20 Pa,功率为60 W的条件下对聚对苯二甲酸乙二醇酯(PET)薄膜进行了表面改性,借助接触角、X射线光电子能谱仪、扫描探针显微镜、差示扫描量热仪对薄膜改性前后的性能进行了分析和表征。结果表明,处理后的薄膜表面引入了C—N、N—C=O、C=O等新的极性官能团,接触角显著减小;薄膜表面出现了圆锥状或圆球状的突起,粗糙度增加;薄膜的热性能(主要是结晶度)发生了改变。     

Morphology and chemical composition of Si-ion-irradiated zirconolite glass-ceramic

Evaluation of the radiation resistance of zirconolite glass-ceramic is significant to it serves as the first barrier for high-level waste (HLW). The evolutions in the morphology and chemical composition of a Ce-bearing zirconolite glass-ceramic induced by 15 MeV Si-ion-irradiation were studied in this paper. The swelling of the glass matrix, amorphization, and shape change of the zirconolite phase were identified after irradiation. The chemical compositions of both zirconolite and glass matrix were changed and more Ce was incorporated into the glass. These modifications induced by ion irradiation were discussed in detail combined with thermal-spike model calculations, suggesting that the electronic energy deposition also can play a dominant role in the evolutions of both the morphology and the chemical composition of the ion irradiated zirconolite glass-ceramic. These results are extremely important for understanding the microstructural evolutions of zirconolite glass-ceramic in a strong radiation environment.     

Energy transfer process and temperature-dependent photoluminescence of PbS quantum dot-doped glasses

PbS quantum dot (QD)-doped glasses were fabricated through melt-quenching method. After heat treatment schedule, uniform QDs were precipitated in the glasses and near-infrared emission covering 900-1700 nm was obtained under excitation. From photoluminescence (PL) spectra and lifetime decay curves, the whole emission band of QD-doped glasses consisted of emission from the 1S-1S state and the trap state. While using excitation with higher energy, the full width at half maximum (FWHM) of QD-doped glasses broadened because smaller QDs were excited. Energy transfer process among QDs was revealed by measuring the lifetime of different emission bands in PL spectrum and the energy transferred from smaller QDs with broader bandgap to bigger QDs with narrow bandgap. Temperature-dependent PL and the corresponding lifetime decay curves of PbS QD-doped glasses were analyzed. Temperature-dependent bandgap structure of PbS QDs was obtained by using density functional theory (DFT) calculations. The results here give deep insight into optical properties of PbS QD-doped glasses and it is beneficial to design and develop high-performance QD-based optoelectronic devices in theory.     

Growth of Inclined GaAs Nanowires by Molecular Beam Epitaxy: Theory and Experiment

The growth of inclined GaAs nanowires (NWs) during molecular beam epitaxy (MBE) on the rotating substrates is studied. The growth model provides explicitly the NW length as a function of radius, supersaturations, diffusion lengths and the tilt angle. Growth experiments are carried out on the GaAs(211)A and GaAs(111)B substrates. It is found that 20° inclined NWs are two times longer in average, which is explained by a larger impingement rate on their sidewalls. We find that the effective diffusion length at 550°C amounts to 12 nm for the surface adatoms and is more than 5,000 nm for the sidewall adatoms. Supersaturations of surface and sidewall adatoms are also estimated. The obtained results show the importance of sidewall adatoms in the MBE growth of NWs, neglected in a number of earlier studies.     

基于量子点的荧光共振能量转移的应用

介绍了基于量子点(QDs)的FRET原理,综述了基于QDs的FRET在生物传感器、蛋白质相互作用、生物分子构像变化和癌症治疗的光敏剂研究中的应用.     

光聚合法快速制备低表面能涂层

以硅烷偶联剂为基础利用光聚合技术,快速将含氟单体以共价键的方式固定在玻璃表面,同时通过模板进行局部曝光,对涂层表面进行了图案化修饰;采用衰减全反射红外光谱、偏光显微镜、X射线光电子能谱分析以及水接触角对涂层性能进行了测试。实验结果表明:在玻璃表面得到了低表面能涂层,经图案化修饰后,涂层的疏水性可以进一步得到提升。     

Investigation of Fouling Mechanisms Using Surface Morphology and Physicochemical Membrane Features

The influences of membrane composition and surface morphology for membranes composed of polyethersulfone (PES) and fumarate alumoxane (Fum‐A) on fouling were investigated. Membrane fouling and blocking mechanisms were analyzed using the Hermia and combined pore blocking models. According to the Hermia fitted parameters, nanocomposite membranes revealed better antifouling properties. The lowest fouling coefficient belonged to the 2 wt % Fum‐A/PES membrane. In whey filtration, membrane surface morphology did not seem to have an important impact on the blocking mechanism as hydrophilicity. However, results clearly indicated a strong correlation between the surface morphology and the contribution of each individual fouling mechanism in the combined pore blocking/cake formation models.     

石墨烯量子点－VB2荧光能量转移法测定 VB2

以氧化石墨烯为单一碳源,通过简单的超声－水热法制备了形貌均一、单分散性好、尺寸约为5 nm的石墨烯量子点（ GQD）。所制备的GQD不仅具有强的蓝色荧光发射,而且具有激发波长依赖性荧光。以GQD作为能量供体,以维生素B2（ VB2）为能量受体,建立了一种荧光能量转移体系检测VB2含量的方法。在优化条件下,本方法的检测范围为1．0×10^－6～3．0×10^－5 mol· L^－1,相关系数为0．9978,检出限为3．3×10^－7 mol· L^－1。     

能源微藻表面特性对其气浮采收效率的影响

选取小球藻与鱼腥藻为代表藻种,结合微藻的表面特性与XDLVO理论,研究了影响微藻浮选采收的关键因素,根据微藻表面的电负性,用阳离子表面活性剂C16TAB浮选两种藻.结果表明,pH为4~10时,两种藻的Zeta电位在-6.72~-15.01 m V之间,均显电负性;小球藻的黏附自由能为1.21 m J/m2,显亲水性,鱼腥藻的黏附自由能为-55.85 m J/m2,显疏水性.相同条件下,疏水性的鱼腥藻回收率始终高于亲水性的小球藻.小球藻和鱼腥藻在Zeta电位最大的pH处(分别为7和8)富集比最高(分别为12.45和1.3),而回收率在pH=10时最高,表明由于液膜的排液行为,回收率和富集比无法同时达到最大值.C16TAB对微藻表面疏水性有修饰作用,加入80 mg/L C16TAB后,小球藻疏水率从19%提高到64%,回收率提高了67.38%.     

Surface Composition and Morphology of Particles Dried Individually and by Spray Drying

This study investigates how the morphology of spray-dried particles is related to the formulation and properties of the components in the formulation. Further, the scale effects in comparisons of levitation-dried single particles and spray-dried particles in a lab-scale spray dryer have been addressed. The Drying Kinetics Analyzer^TM generates single particles from a levitated drop under simulated spray-drying conditions. A set of surface-active polymers (bovine serum albumin, hydroxypropyl methyl cellulose, and triblock co-polymer Poloxamer), in combination with lactose, were analyzed for their dynamic surface properties in solution, and their effect on particle morphology and surface composition were determined by low-vacuum SEM and XPS analyses. The morphology obtained in spray drying was reproduced in the single-particle drying. The surface compositions were also similar, but higher levels of surface-active materials were found at the surface of the single particles as compared to the spray-dried particles. Further, the adsorption rate of surface-active compounds at the drop surface estimated by dynamic surface tension was found to be an important parameter to estimate the surface composition at different drying scales. The particle morphology was primarily determined by the surface rheological properties of the feed solution and, to a lesser extent, by the surface composition.     

关于低表面能无毒防污涂料的应用研究

本文综述了低表面能无毒防污涂料的国内外研究现状及应用前景，全氟丙烯酸酯低表而能防污涂料由于无毒、环保且性能优越，将成为该类涂料的发展方向。     

有机氟低表面能涂料的研究进展

简要介绍了新型、环保的有机氟低表面能涂层的现状及国内外的最新研究进展;同时,结合有机氟低表面能涂层优良的环保特性,分析、讨论了在舰船上使用的可行性;最后,展望了有机氟低表面能涂料应用前景及发展动向。     

低表面能树脂的性能及固化研究

通过化学改性,合成了环氧树脂/有机硅复合树脂。探讨了不同固化剂及其复配方式对其固化性能的影响,并得到最佳的固化剂配方。通过红外光谱（IR）、扫描电子显微镜（SEM）、动态力学分析（DMA）以及接触角测试,研究并比较了改性前后有机硅树脂涂层的微观结构形貌、体系混溶性、表面性能（接触角）等的变化。研究结果表明：环氧树脂与有机硅树脂之间具有较好的微观混溶性;改性后,树脂表面的粗糙度增加,接触角增大,形成低表面能树脂。