PVA-based activated carbon fibers with lotus root-like axially porous structure

A novel method was developed for the fabrication of activated carbon fiber (ACF) with wet spinning polyvinyl alcohol (PVA) fibers as the precursors. Through a combination of preoxidation, dehydration, carbonization and activation under a certain tension, PVA-based ACFs (PVA-ACFs) with high yields and good mechanical properties were obtained. The surface and cross-section morphologies, pore structures, surface geometries, surface functional groups and crystal structures of the PVA-ACFs were characterized using field emission scanning electron microscopy, low temperature nitrogen adsorption, Fourier transformed infrared spectrophotometry, X-ray photoelectron spectroscopy and X-ray power diffraction. All the PVA-ACF samples prepared had lotus root-like axially meso- and macroporous structures with the domination of micropores. Fractal geometries of PVA-ACFs deduced from nitrogen adsorption isotherms indicates that capillary force dominated in the interactions between nitrogen and the PVA-ACFs. The surface functional groups of the PVA-ACFs depend on the activating agents. Graphitoidal crystal structures were observed for the PVA-ACFs. The small crystal size and short range ordering between the crystallites ensured a high specific surface area of the PVA-ACFs.     

Paving the way for CRM success: The mediating role of knowledge management and organizational commitment

Customer relationship management (CRM) has become one of the most influential technologies in the world, and companies are increasingly implementing it to create value. However, despite significant investment in CRM technology infrastructure, empirical research offers inconsistent support for its positive impact on performance. This study develops and tests a research model analyzing the process through which CRM technology infrastructure translates into organizational performance, drawing on the resource-based view (RBV) and the knowledge-based view (KBV) of the firm. Based on an international sample of 125 hotels, the results suggest that organizational commitment and knowledge management fully mediate this process.     

过磷酸钙含氟尾气处理的新方法

对动态泡沫床处理过磷酸钙含氟尾气的有关技术及费用作了说明 ,指出该方法费用高 ;提出一种新方法 ,该方法不加任何化学助剂 ,采用水作吸收剂 ,只需改变动态泡沫床一些设计参数和选用一种特殊的喷头 (喷头周围设计 1个圆锥形死角区 ,使含氟气体不可能进入该区 )避免了硅胶堵塞。该方法已在湖南浦市化工总厂运行 1年多未发现堵塞 ,同时该法投资少、能耗低、排放尾气达标     

Effect of particle size on the surface oxidation and flotation behavior of galena particles in lime system

ABSTRACT

In this research, the effect of particle size on the surface oxidation and flotation behavior of galena in the lime system was studied. Coarse (?0.074 + 0.038 mm), intermediate (?0.038 + 0.025 mm) and fine (?0.025 mm) galena particles were used in the experiment. The dissolution tests, flotation tests, and sorption tests were accomplished. Through further analysis by XPS, the effect of particle size and lime was observed. The decrease of mineral particle sizes increased the adsorption ratio of collector and the dissolution of galena, while the hydrophilic product OH^?/Ca(OH)⁺ produced by dissolution occupied the dominant position, which led to the minerals hydrophilic.     

碳纤维经氧等离子/KH550处理后的表面形态和结构

碳纤维(CF)表面经氧等离子、KH550和 LiAlH_4处理后,其物理和化学性能得以改善.由于提高了 CF 和树脂间的联结,使 CF 复合材料的层间剪切强度提高50%以上,在湿热下的强度保留率达94%以上.使用纤维接触角测定仪,SEM 和 XPS 等对 CF 表面的浸润性、形态和化学组成进行了研究.实验指出:CF 经等离子和 KH550处理后,其临界表面能有了提高;CF 本身仅受氧离子刻蚀,故其拉伸强度的损失小于其他处理方法.     

聚丙烯纤维母粒着色生产技术

概述了聚丙烯母粒色纺的生产技术,提出了色母粒制备的质量要求:颜料粒径≤1.0μm,细且丝颜料粒径≤0.5μm;压力过滤值≤0.15MPa·cm~2/g;色母粒热稳定性280～300℃.色母粒的加入对纺丝工艺与产品质量指标有影响,喷丝板换板周期色纺丝约为本色纺的一半,纤维强力约降低10%.依据有关配色定律可优化配方工艺,降低成本,增加效益.     

纳米碳酸钙的表面活化改性研究

本文主要介绍通过加入特定的表面改性剂,制得了表面改性的活性碳酸钙.并对活化过程中的一系列影响因素,如活化温度、活化时间、碳酸钙悬浊液浓度、表面改性剂用量进行了研究.     

Effect of Twin-Plane Reentrant Edge on the Coarsening Behavior of Barium Titanate Grains

When BaTiO₃ ceramics were sintered at relatively low temperatures (≤1250°C), the grains with reentrant edges caused by a (111) double twin grew exclusively. As a result, a microstructure with a bimodal grain-size distribution composed of platelike large grains and fine matrix grains was obtained. In contrast, at the usual sintering temperature between 1250° and 1350°C, grains containing a (111) double twin did not exhibit any growth advantage. In this case, a coarse and uniform microstructure was obtained. When this coarse-grained specimen was further heat-treated at 1365°C, the grains possessing a double twin were observed to grow exclusively again. The results were explained in terms of a coarsening process controlled by two-dimensional nucleation.     

改性活性炭的表面特性及其对苯酚的吸附性能

研究了表面改性对活性炭吸附苯酚性能的影响。研究发现,硫酸氧化可增加活性炭表面酸性基团的含量,提高了活性炭的表面亲水性,降低pHPZC值,因而对吸附水中的苯酚的性能产生明显影响,降低了对苯酚的吸附。     

阻燃增塑剂溴化及溴氯化石蜡的合成工艺

综述了阻燃增塑剂溴化及溴氯化石蜡的各种合成工艺路线，讨论了相应的合成反应机理．包括反应历程和有关化学热力学计算，简要介绍了安徽省化工研究院已工业化的溴化及溴氯化石蜡合成工艺的特点。