Synthesis and characterization of partially hydrolyzed polyacrylamide nanocomposite weak gels with high molecular weights

High‐molecular‐weight partially hydrolyzed polyacrylamide nanocomposite (HPAMNC) weak gels were synthesized and evaluated for their flooding behaviors in oil‐recovery applications. The structure, morphology, and properties of the obtained HPAMNC samples and their weak gels were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). XRD patterns clearly proved the exfoliation of the montmorillonite (MMT) layers in the polymer matrix; this was consistent with TEM analysis. The morphology of the HPAMNC was proven to be in a cross‐wire aggregated form by SEM analysis. The viscosity‐average molecular mass of the obtained HPAMNC was approximately 8.51 × 10⁶ under the optimized MMT load at 1.0 wt %. The flooding experiments showed that the oil‐recovery rates in sand pack tubes with low and high permeability were enhanced by approximately 35.1 and 46.2%, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42626.     

Numerical simulation study of the T‐peel behavior of coated fabric films used in inflatable structures

A simple and reliable finite element method was developed to analyze the T‐peel behavior of fabric coated with thin films. The material model was constructed simply by a tensile test of the coating and the coated fabric. In addition, the influence of the welding parameters on the mechanical properties of the welded zone was considered. Although some material characters were neglected, the material model was found to be convenient for engineering applications. The reliability was examined by a comparison of the numerical results with the experiments. A T‐peel test was conducted, and a camera configured with an optical microscope lens was used to observe the material flow from the thickness view. The load–displacement curve predicted by the simulation agreed well with the experimental results. Small voids were detected when the sample was near fracture. These places were consistent with the simulation results and showed where the maximum stress–strain was located. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41299.     

电压间谐波对紧凑型荧光灯光闪变效应的实验研究

为进行实验研究,对IEC闪变仪模型中的加权滤波器进行分解,提出闪变仪的分解模型,该模型可直接导入实验获得的光通量信号以进行光闪变强度Pst计算,实验验证了该模型的可行性和有效性;设计并建立了实验装置,利用高准确度照度计采集紧凑型荧光灯在含有特定间谐波频率和幅值的电压下的光通量输出,使用闪变仪分解模型,对其在间谐波电压下的光闪变效应进行实验研究,获得了紧凑型荧光灯在不同间谐波频率和含量下的光闪变强度Pst,并据此提出了针对紧凑型荧光灯光闪变的间谐波限制曲线。     

配电网三相不平衡过电压有源抑制方法研究

分析三相不平衡电压的产生机理,提出有源抑制方法,设计了有源逆变装置,等效为可控电流源,安装在中性点与地之间,优化控制注入电流的大小和相位,能强迫电网三相电压平衡。仿真分析和样机实验测试结果表明,该方法不需要测量线路对地参数,抑制三相不平衡过电压速度快、准确度高,甚至能将中性点位移电压抑制到零。     

The flame‐retardant properties and mechanisms of poly(ethylene terephthalate)/hexakis (para‐allyloxyphenoxy) cyclotriphosphazene systems

Para‐allyl ether phenol derivative of cyclophosphazene (PACP) was prepared and used as a filler to modify the flame‐retardant properties of poly(ethylene terephthalate) (PET) by melting‐blending. The mechanism of flame‐retardant was discussed and the influences of flame‐retardant contents to the mechanical properties were studied. The results revealed that the incorporation of only 5 phpp PACP (0.37 wt % phosphorus containing) into PET matrix can distinctly increase the flame retardancy of PET/PACP composition, and it has a little effect on the mechanical properties of PET. The high flame‐retardant performance of PET/PACP composite was attributed to the combination of condensed‐phase flame retardant and gas‐phase flame retardant. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42711.     

Simultaneous detection and removal of metal ions based on a chemosensor composed of a rhodamine derivative and cyclodextrin-modified magnetic nanoparticles

A variety of chemosensors have been reported for detection of metal ions. However, the metal ions could not be separated and removed at the same time for the goal of water purification. This paper presents to detect and remove metal ions from aqueous solution simultaneously by a fluorescence chemosensor and functional magnetic nanoparticles. A novel probe adamantyl (AD)–maleic anhydride (MAH)–rhodamine B (RhB) was designed and synthesized from RhB, ethylene diamine, MAH, and AD. AD–MAH–RhB showed high selectivity and sensitivity to metal ions in aqueous solution. The sensing mechanism was explored by FTIR and mass spectra. The results suggested that AD–MAH–RhB could conjugate with metal ions and form the binding complexes with various stoichiometries of probe and metal ions. Moreover, β-cyclodextrin-modified magnetic nanoparticles (CD-MNP) were fabricated and used as host materials to form inclusion complex of CD-MNP and AD–MAH–RhB-metal ions. Then, the metal ions could be removed by an outer magnet, which were confirmed by fluorescent spectrum. The probe and CD-MNP had the great potential application for sewage treatment.