Tailored aluminium oxide layers by bipolar current adjustment in the Plasma Electrolytic Oxidation (PEO) process

The plasma electrolytic oxidation process of aluminium alloys is investigated for two different current waveforms. It is shown that particular conditions may be established which strongly reduce the arcing that usually cause detrimental defects in the oxide layer for treatment time greater than typically 40-50 min. This results in a “softer” process. As a consequence thick homogenous layers may be grown with no large discharge channels. Through the presented results, the importance of the negative charge density relative to the positive one is evidenced thus pointing out the need of using a pulse bipolar current supply.     

Lithium Insertion in Poly(ethylene oxide)/MoO_3 Xerogel Nanocomposite Films

1　ＩｎｔｒｏｄｕｃｔｉｏｎＧｒｅａｔｅｆｆｏｒｔｓｈａｖｅｂｅｅｎｍａｄｅｉｎｒｅｃｅｎｔｙｅａｒｓｔｏｄｅ ｖｅｌｏｐｎｅｗｉｎｔｅｒｃａｌａｔｉｏｎｈｏｓｔ ｇｕｅｓｔｃｏｍｐｏｕｎｄｓｗｉｔｈｎｏｖｅｌｐｒｏｐｅｒｔｉｅｓａｓｍａｔｅｒｉａｌｓｆｏｒｅｌｅｃｔｒｏｃｈｒｏｍｉｃｄｅｖｉｃｅｓａｎｄｓｅｃ ｏｎｄａｒｙｌｉｔｈｉｕｍｂａｔｔｅｒｉｅｓ[1- 4] .ＣｏｍｐｏｕｎｄｓｂａｓｅｄｏｎＭｏＯ3 ｈａｖｅａｔｔｒａｃｔｅｄｍｏｒｅａｔｔｅｎｔｉｏｎｄｕｅｔｏｔｈｅｉｒｄｅｓｉｒａｂｌｅｃｈａｒ…     

生物功能材料PEO的制备及其发展方向

聚乙烯氧(PEO)因其高亲水性和抗细胞黏附的特性,被视为理想的生物功能材料.目前,PEO的制备主要是采用物理、化学方法.为了探求等离子体技术在PEO制备中的应用,采用电容耦合等离子体化学气相沉积法(CCPECVD)和离子源辅助等离子体化学气相沉积法(IB-PECVD),进行了PEO/PEG材料的制备实验.分析结果表明:采用等离子体化学方法可以制备出具有PEO结构的材料,不同的制备方法对材料的结构有一定的影响.     

暖通用6061铝合金表面Ni基等离子喷涂CoCrTaAlY/PEO涂层性能分析

利用冷喷涂技术在暖通用6061铝合金表面依次制备Ni基打底涂层,CoCrTaAlY和PEO涂层,并进行组织和耐热以及腐蚀性能测试分析,研究结果表明:CoCrTaAlY层形成了众多密实堆积颗粒,获得具有均匀分布结构的涂层;PEO层形成粗糙表面结构,表面形成了一些破碎颗粒以及不规则外形的颗粒,致密CoCrTaAlY层跟Ni基体形成了良好结合状态。试样都是在涂层和基体交界面部位发生断裂,涂层形成了比涂层和基体结合强度更大的内聚作用力。经过热震后,涂层表面并没有出现显著变化,同样存在粗糙区于光滑区两种类型的形貌,并且还有一些网状的微裂纹。经过热冲刷处理后,试样表面颜色只发生了轻度改变,涂层质量发生了先减小后增大的变化现象,涂层具备良好的耐高温氧化特性。     

聚氧化乙烯/凹凸棒土微粒助留助滤体系的研究

通过研究发现凹凸棒土能与PEO构成一种新的非离子型助留体系。当凹凸棒土用量为4%,PEO用量为0.01%时,PEO/凹凸棒土微粒助留体系有很好的助留助滤性能。该助留助滤体系对成纸的匀度没有影响,是一种微粒助留体系。凹凸棒土的添加对纸张的白度有一定的影响。并将该体系与CPAM/膨润土体系进行对比研究发现在相同的助留助滤效果的情况下,该体系比CPAM/膨润土的吨纸耗用成本低得多,是一种理想的经济实用型微粒助留体系。     

Preparation and characterization of polyethylene oxide (PEO)/gelatin blend for biomedical application: Effect of gamma radiation

polyethylene oxide (PEO)/gelatin blend membranes of four different compositions (w/w) (5/95, 10/90, 20/80, and 30/70) were prepared by solution casting. The films were irradiated by gamma radiation at a total dose of 250 krad (dose rate of 321 krad/h). The X‐ray diffractograms demonstrate both the PEO and radiation influences on the blend thus enhancing crystallinity of gelatin. X‐ray diffractograms of irradiated blend films containing 30% PEO showed highest integrated intensity. The DTA and TGA study showed that the irradiated blend films are more thermally stable than the non‐irradiated films. TMA study showed that the incorporation of PEO into gelatin increased melting point of the blend films. The melting point for irradiated gelatin film changes from 52.9°C to 75.6°C and the glass point changes from 60.3°C to 90.6°C. The phase separation and compatibility of the PEO/gelatin blend films were studied by scanning electron microscopy (SEM). The experimental results showed that the blend films exhibit higher thermal stability and improved mechanical properties in dry state, which suggests the occurrence of interaction detected by XRD and DTA among gelatin, PEO, and water molecules in the films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Advances in three-dimensional nanofibrous macrostructures via electrospinning

Compared with other nanofiber fabrication processes, electrospinning is versatile and superior in production and construction of ordered or more complex nanofibrous assemblies. Besides traditional two-dimensional (2D) nanofibrous structures, electrospinning is powerful in fabrication of three-dimensional (3D) fibrous macrostructures, especially for tissue engineering applications. This article summarizes and reviews recent advances in various promising and cutting-edge electrospinning techniques, including multilayering electrospinning, post-processing after electrospinning, liquid-assisted collection, template-assisted collection, porogen-added electrospinning, and self-assembly. And their formation mechanisms, features, and the challenges of electrospinning have also been discussed. Furthermore, these 3D nanofibrous macrostructures have been demonstrated to have potential applications in tissue engineering, energy harvesting and storage, and filtration.     

A review of the features and analyses of the solid electrolyte interphase in Li-ion batteries

The solid electrolyte interphase (SEI) is a protecting layer formed on the negative electrode of Li-ion batteries as a result of electrolyte decomposition, mainly during the first cycle. Battery performance, irreversible charge “loss”, rate capability, cyclability, exfoliation of graphite and safety are highly dependent on the quality of the SEI. Therefore, understanding the actual nature and composition of SEI is of prime interest. If the chemistry of the SEI formation and the manner in which each component affects battery performance are understood, SEI could be tuned to improve battery performance. In this paper key points related to the nature, formation, and features of the SEI formed on carbon negative electrodes are discussed. SEI has been analyzed by various analytical techniques amongst which FTIR and XPS are most widely used. FTIR and XPS data of SEI and its components as published by many research groups are compiled in tables for getting a global picture of what is known about the SEI. This article shall serve as a handy reference as well as a starting point for research related to SEI.     

Electrical,spectroscopic, and thermal properties of blends formed by PEDOT,PVC, and PEO

This study describes the preparation of blends between an amorphous polymer (PVC) and a crystalline polymer (PEO), with a third polymeric part that presents electronic conduction capacity (PEDOT‐PSS). Binary (PEO/PVC, PEO/PEDOT‐PSS, PVC/PEDOT‐PSS) and ternary (PVC/PEO/PEDOT‐PSS) blends were prepared by changing the concentrations of the constituents and were analyzed by electronic conductivity, Raman spatial resolution, infrared spectroscopies, and thermogravimetric analysis. The Raman and FTIR analyses showed the incorporation of PEDOT‐PSS within the blends. The higher conductivity presented by the ternary blend was 8.6 × 10^?6 Scm^?1, composed of 24% of PVC, 16% of PEO, and 60% of PEDOT‐PSS. For binary blends the conductivity was proportional to the PEDOT‐PSS content. The thermal stability could be observed through the TG curves of the blends that presented an increase of 19 K in the weight loss temperature at the 10% level when compared to the pure components. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1710–1715, 2005     

一种适用于机械浆的新型有效助留剂

介绍了一种适用于机械浆的新型有效助留剂的制备,影响其助留性能的因素及其助留过程和机理,并与线形聚氧化乙烯(PEO)体系对比,阐述了这种新助剂的潜在优点及其在未来造纸工业中的巨大应用潜力.