Image Analysis and Modeling of the Orientation of Pores in a Constrained Film on a Rigid Substrate

The nature of porosity in functional materials is often a critical parameter in determining their functionality, for example, in structure materials and fuel cell electrodes. Here, we study the development of the anisotropy of porous yttria‐stabilized zirconia (YSZ), focusing particularly upon the contribution of pore orientation to this anisotropy. Simulation from when the ink is deposited on the surface of a rigid substrate shows that platelike pores are found tend to align along the transverse direction of the substrate. Cross‐sectional image analysis of the pores from the attendant pores of YSZ particles or pore‐forming agent (PFA) matches with the simulated modeling when materials transport is insignificant in determining the shape of pores. The anisotropy created in the densification stage is separated from that in the green body by analyzing the image of porous structures formed with spherical glassy carbon which is unable to contribute to anisotropy during green‐state processing.     

Influence of GaAs Substrate Orientation on InAs Quantum Dots: Surface Morphology, Critical Thickness, and Optical Properties

InAs/GaAs heterostructures have been simultaneously grown by molecular beam epitaxy on GaAs (100), GaAs (100) with a 2° misorientation angle towards [01−1], and GaAs (n11)B (n = 9, 7, 5) substrates. While the substrate misorientation angle increased from 0° to 15.8°, a clear evolution from quantum dots to quantum well was evident by the surface morphology, the photoluminescence, and the time-resolved photoluminescence, respectively. This evolution revealed an increased critical thickness and a delayed formation of InAs quantum dots as the surface orientation departed from GaAs (100), which was explained by the thermal-equilibrium model due to the less efficient of strain relaxation on misoriented substrate surfaces.     

桉木浆纳/微米和脱脂棉纳米纤维素的形貌分析

用环境扫描电子显微镜和透射电子显微镜表征了桉木浆纳/微米和脱脂棉纳米纤维素的形貌。环境扫描电子显微镜观察桉木浆纳/微米和脱脂棉纳米纤维素表面形貌不同,桉木浆纳/微米纤维素主要呈棒状,长度小于20 μm,直径可达0.377 μm;脱脂棉纳米纤维素主要呈球状,长度小于0.5 μm。利用环境扫描电子显微镜,脱脂棉纳米纤维素超声波破碎后直接观察和再经冷冻干燥后观察表面形貌有一定的差异。透射电子显微镜观察桉木浆纳/微米纤维素和脱脂棉纳米纤维素的长度可达到纳米级。     

塑料部件紫外光固化涂层起泡问题研究

以紫外光固化涂料涂装塑料部件后其涂层产生的起泡现象为研究对象,通过显微镜观察和元素分析方法对产生气泡的涂层进行表征和分析,总结了气泡的类型和产生的原因,并提出了相关的建议及解决办法。     

新型纤维素薄膜的NMMO生产工艺

介绍了新型纤维素薄膜的 NMMO制造工艺 ,并指出和传统的粘胶工艺相比新工艺具有无污染、能耗小、产品性能好的优点。     

Effect of Substrate Orientation, Roughness, and Film Deposition Mode on the Tensile Strength and Toughness of Niobium–Sapphire Interfaces

The strength and toughness of interfaces between sputter-deposited polycrystalline niobium films and sapphire substrates with basal and prismatic orientations were measured. The effect of deposition parameters and substrate roughness on these interface properties also was investigated. Substrates of polycrystalline alumina with two different surface morphologies were chosen for studying the effect of interface roughness. The interface strength was measured using a previously developed laser spallation experiment in which a laser-generated compressive stress pulse in the substrate, upon reflection into a tensile stress pulse from the coating's free surface, pulls the interface apart. The interface toughness was obtained using a controlled delamination technique, in which a residually stressed loading layer was used to buckle the underlying test layer from its substrate. The energy balance in the prebuckeled and postbuckled states provided a direct measure of the interface toughness. These values were independently obtained by another experiment in which well-characterized, artificially generated, interfacial flaws were loaded using a stress pulse in the laser spallation assembly. The coating's free surface velocity upon crack initiation was related to the critical energy release rate via a numerical simulation. The results of the two toughness experiments conformed to each other and related fairly well to the independently obtained strength measurements.     

成膜温度对漆膜表面形态的影响

采用种子乳液法合成了核壳结构苯丙乳液，用原子力显微镜(AFM)对不同成膜温度漆膜表面形态，尤其是乳化剂在漆膜表面的分布进行了研究。发现控制乳液的成膜温度略高于Tg，可以得到粒子排列整齐的均一膜，膜的耐水性等性能更好。     

Effect of Cellulose Characteristic and Hydrolyze Conditions on Morphology and Size of Nanocrystal Cellulose Extracted from Wheat Straw

In this paper, preparation and characterization of cellulose and nanocrystalline celluloses (NCC) and the effect of cellulose characteristic and hydrolyze conditions on the morphology and size of the obtained NCC will be discussed. Two different celluloses were prepared by two procedures, A and B, then the cellulose obtained was hydrolyzed under the same conditions. The result showed that the morphology and size of the nanocrystals obtained are not only attributed to the cellulose sources, but also to the hydrolyze conditions.     

降香黄檀/纤维素抗菌复合膜的疏水改性

为改善纤维素薄膜易吸潮的缺点,并保持其生物可降解性,利用安全无毒、可食用的单硬脂酸甘油酯、大豆卵磷脂,对降香黄檀/纤维素抗菌共混膜表面进行疏水改性。将两种小分子溶液用旋涂法涂覆于薄膜表面,并对改性后复合膜的分子结构、疏水性能、力学性能、透光性能以及阻隔性能进行系统研究。实验结果表明,单硬脂酸甘油酯改性后的复合膜具有优异的疏水性,接触角为103.8°,具有良好的力学性能,拉伸强度为154.57MPa,良好的阻气阻水性能,优于市场上商用聚偏氯乙烯(PVDC)纤维素复合膜,而复合膜透光性较差,透光率仅在30%。而大豆磷脂改性后的复合膜疏水性能稍差。因此,单硬脂酸甘油酯改性后的纤维素复合膜不易吸潮,且具有优良的性能和商业价值。     

再生细菌纤维素薄膜的制备工艺

详细介绍了利用N-甲基吗啉-N-氧化物(NMMO)为溶剂溶解细菌纤维素以及制备再生细菌纤维素薄膜的工艺流程,并对NMMO溶解细菌纤维素机理进行了简要的分析。