湿法玻璃粉体表面改性的研究

通过分级选取不同粒径的玻璃粉体,研究湿法对玻璃粉体表面改性的最佳条件,通过IR与TG-DSC分析,表明含20%水的乙醇溶液作为分散剂在70℃下进行实验得到的粉体表面改性效果较好,失重转变点出现在303℃(280～500目)与323℃(小于500目),较纯酒精243℃(280～500目)更高,终止点的温度也较高,其有机出峰也更为明显。同时研究表明粉体粒径粗细与表面改性结果成反比,随着粒径变小改性效果也更好,改性后的玻璃粉体在有机物质中分散比未改性玻璃粉体更为均匀,将改性后玻璃粉调配成浆料后的流动性下降,改性后的浆料流动时间均超过10 min。     

超细粉体表面包覆技术综述

通过超细粉体的表面包覆以改善粉体的分散性及其表面性质,已经成为超细粉体制备和应用的关键技术。综述了超细粉体的表面包覆方法,包括机械化学法、气相沉积法、聚合物包裹法、液相化学法及微胶囊化法等,主要介绍了每种方法的基本原理及应用。     

Densification Energy during Nanoindentation of Silica Glass

Load/unload displacement curves at room temperature (humidity 49%) for silica glass have been measured in the penetration range of 0.5–1.2 μm using a Vickers nanoindentation technique (load/unload speed 50 mN/s). Deformation energies have been estimated for the first time. The universal (dynamic) hardness, H _u, and elastic recovery, E _R, at the penetration depth, h _t, of 1.0 μm are H _u= 4.1 GPa and E _R= 0.7. The following energies for total deformation, U _t, elastic deformation, U _e, and plastic deformation (i.e., densification during loading), U _p, are obtained: U _t=190, U _e=135 and U _p= 55 kJ/mol at h _t= 0.5 μm and U _t= 139, U _e= 96 and U _p= 43 kJ/mol at h _t=1.0 μm. All these deformation energies increase with decreasing penetration depth. It is found that plastic deformation energies of 38–55 kJ/mol for 0.5 < h _t < 1.2 μm are very close to the activation energy (46–54 kJ/mol) for the recovery of densification in silica glass, but are very small compared with the single bond strength (443 kJ/mol for Si—O bond) of SiO₂.     

氧等离子体对聚丙烯粉体的表面处理研究

用氧等离子体对聚丙烯（PP）粉体进行表面处理,采用水接触角（WCA）、红外光谱（IR）对处理前后PP粉体的水接触角、表面组分的变化进行了分析。实验结果表明,随着等离子体处理时间延长,水接触角减小。IR分析表明,在氧等离子体处理中,PP粉体表面有含氧极性官能团生成,导致粉体表面水接触角减小。     

玻璃表面的金和白金装饰

综述了玻璃表面金和白金的各种装饰方法,指出这些方法存在的问题以及发展方向。     

Effect of Sodium on Crystallite Size and Surface Area of Zirconia Powders at Elevated Temperatures

Fine ZrO₂ powders were synthesized by an aqueous precipitation method using zirconyl nitrate. By adding the precursor salt to NaOH, single-phase ZrO₂ powders were formed, and the monoclinic phase did not appear upon heat treatment up to 1000°C. The samples were digested in NaOH for different amounts of time. Different levels of washing of digested samples produced surface area at 900°C for 4 h ranging from 8 to 100 m²/g. It was found that the properties of the powders at elevated temperatures were sensitive to the sodium content. The surface area decreased while the crystallite size and pore size of the samples increased with increased sodium content. Our results indicated that sodium is detrimental to the stabilization of surface area at elevated temperatures.     

Relative Colloidal Stability in Ethanol of Powders with Si-O Surface Species

The relative colloidal stability in ethanol of ceramic powders with Si-O surface groups (Si₃N₄, SiC, and MoSi₂) is reported. SiO₂/EtOH suspensions are also examined as a reference. The comparative relationships between pH, particle-surface charge, zeta potential, stability, and suspension rheology are discussed. The nature and influence of the surface species are determined, and the similarities and differences are compared. DLVO theory was used to define suspension stability, and it was found that non-oxide particles in EtOH are charge-stabilized and have viscosity and flow curves that agree with the electrokinetic measurements.     

高硅氧玻璃纤维制品烧结工艺可节能性探讨

为减少高硅氧玻璃纤维后处理过程中消耗的大量热能,对传统烧结工艺进行改良,研究烧结工艺的可节能性。研究发现原烧结过程是在敞开体系里进行,易损失大量热能;在封闭体系进行高硅氧玻璃纤维烧结处理,则可减少能量损失。经综合分析,最终确定新工艺至少可节能约25％。     

Estimation of the Surface Energy of Polymer Solids

The methods to estimate the surface tension of polymer solids using contact angles have been reviewed in the first part. They are classified into the following three groups depending on the theories or the equations applied: (1) the methods using the Young's equation alone, (2) the methods using the combined equation of Young and Good-Girifalco, and (3) the methods using the equations of work of adhesion. Some notes and comments are given for each method and results are compared with each other. The two-liquids method for rather high energy surface is also introduced.

Next, some new possibilities to evaluate the surface tension of polymer solids are presented by our new contact angle theory in consideration of the friction between a liquid drop and a solid surface. The advancing and receding angles of contact (θ _a and θ _r ) are explained by the frictional tension γ_F and accordingly two kinds of the critical surface tension γ_C (γ_Ca and γ_Cr ) are given.

This work has shown that one of the recommendable ways to evaluate γ_S is either the maximum γ_LV cos θ_a or the maximum γ_C using the advancing contact angle θ_a alone, and another way is the arithmetic or the harmonic mean of the γ_Ca and γ_Cr . A depiction to determine the γ_C such as ln(1 + cos θ₀ ) vs. γ_LV with cos θ₀ = (cos θ₀ + cos θ_r )/2 has also been proposed.     

复杂曲面玻璃制品的逆向设计研究

针对玻璃制品的特点,以某玻璃工艺品鼠标的曲面造型设计为研究对象。通过三坐标测量机的非接触测量获取零件表面的点云数据,并利用Imageware软件对测量数据进行处理,采用基于NURBS曲面重构理论进行鼠标造型覆盖面重构,最终实现了鼠标的曲面重构。与传统的玻璃造型设计方法相比,该方法对缩短产品研发周期、快速响应市场有显著效果。     

Effect of Surface Forces on Subcritical Crack Growth in Glass

Data on the growth of cracks tested in aqueous solutions were interpreted in terms of surface force theory. For applied stress intensity factors greater than 0.25 MPa · m½, the position and the slope of the curves and their dependence on pH and ion concentration can be explained in terms of surface force theory, provided these forces are of a magnitude and range that are representative of those involved in the cohensive bonding of solids. Weaker forces, such as structural, double-layer, or dispersion forces, have little effect on crack growth in silica glass for K _I > 0.25 MPa · m½.     

玻璃表面化学增强技术

玻璃的理论强度很高,但由于原料组成、熔化、成形和退火等各工艺过程的影响,玻璃的实际强度比理论值要低很多。采用表面化学增强技术,能够降低玻璃的表面缺陷,提升玻璃的力学强度、表面硬度、耐划伤等性能。玻璃表面化学增强技术有离子交换法、表面化学抛光、脱碱增强法、表面涂层增强、表面微晶化增强技术等方法,通过对上述方法的研究和对比分析,每种方法都有各自相应的特点和应用范围,这些方法拓宽了玻璃表面化学增强技术的研究和发展。     

电子级玻璃纤维布表面处理研究

采用正交试验的方法研究了电子布表面处理过程中生产车速、开纤压力、布面烘干温度和处理剂配方对电子布性能的影响程度,确定影响试验结果的各个因子的主次顺序,通过调整主要的影响因子来提高电子布的含浸性和减少板材干花比例,并成功解决了高粘度酚醛环氧树脂胶系板材的干花问题。     

增强树脂用玻璃纤维表面处理技术的研究进展

玻璃纤维表面处理是获得优良性能的玻璃纤维复合材料的关键技术,从增强聚合物基复合材料的角度,综述了玻璃纤维表面处理的研究情况,提出了研究中亟待解决的问题,认为开发大分子偶联剂以及表面二次接枝处理是表面处理技术未来的发展方向。     

我国玻璃表面装饰的现状及发展方向

将高技术与传统艺术相融合对21世纪玻璃表面装饰是颇具吸引力的;同时玻璃表面装饰应与多功能材料、复合材料、智能材料相结合。     

Mechanism and Simulation of Removal Rate and Surface Roughness During Optical Polishing of Glasses

Glass optics with ultra‐low roughness surfaces (<2 Å rms) are strongly desired for high‐end optical applications (e.g., lasers, spectroscopy, etc.). The complex microscopic interactions that occur between slurry particles and the glass workpiece during optical polishing ultimately determine the removal rate and resulting surface roughness of the workpiece. In this study, a comprehensive set of 100 mm diameter glass samples (fused silica, phosphate, and borosilicate) were polished using various slurry particle size distributions (PSD), slurry concentrations, and pad treatments. The removal rate and surface roughness of the glasses were characterized using white light interferometry and atomic force microscopy. The material removal mechanism for a given slurry particle is proposed to occur via nano‐plastic deformation (plastic removal) or via chemical reaction (molecular removal) depending on the slurry particle load on the glass surface. Using an expanded Hertzian contact model, called the Ensemble Hertzian Multi‐gap (EHMG) model, a platform has been developed to understand the microscopic interface interactions and to predict trends of the removal rate and surface roughness for a variety of polishing parameters. The EHMG model is based on multiple Hertzian contacts of slurry particles at the workpiece–pad interface in which the pad deflection and the effective interface gap at each pad asperity height are determined. Using this, the interface contact area and each particle's penetration, load, and contact zone are determined which are used to calculate the material removal rate and simulate the surface roughness. Each of the key polishing variables investigated is shown to affect the material removal rate, whose changes are dominated by very different microscopic interactions. Slurry PSD impacts the load per particle distribution and the fraction of particles removing material by plastic removal. The slurry concentration impacts the areal number density of particles and fraction of load on particles versus pad. The pad topography impacts the fraction of pad area making contact with the workpiece. The glass composition predominantly impacts the depth of plastic removal. Also, the results show that the dominant factor controlling surface roughness is the slurry PSD followed by the glass material's removal function and the pad topography. The model compares well with the experimental data over a variety of polishing conditions for both removal rate and roughness and can be extended to provide insights and strategies to develop practical, economic processes for obtaining ultra‐low roughness surfaces while simultaneously maintaining high material removal rates.     

玻璃表面功能化纳米改性技术研究进展新动态

对目前常用的气相沉积法、磁控溅射法、离子交换法、溶胶一凝胶法等玻璃表面功能化纳米改性技术的方法进行了介绍。     

浮法玻璃表面的理化特征

从浮法玻璃成形工艺的特点出发,论述了浮法玻璃表面渗锡以及渗锡分布特征,浮法玻璃表面化学成分的变化特征,浮法玻璃表面物理性质的变化特征。     

玻璃瓶罐表面冷热端喷涂增强优化

玻璃瓶罐是一种绿色环保的食品包装容器,由于玻璃化学组成设计及玻璃熔制、成型、退火和使用等环节中的某些原因,导致玻璃表面存在微观缺陷,从而影响使用。采用扫描电子显微镜分析玻璃瓶罐表面的微观形貌,研究玻璃瓶罐表面喷涂增强的方法,改善使用性能,制定玻璃瓶罐生产过程中的冷热端喷涂技术工艺。研究结果表明,采用新研制的冷端喷涂液喷涂的玻璃瓶的滑动角小于10°。