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81.
Polymeric composites with conductivities ranging from 10–4 to 1 S cm–1 were prepared by electrochemically polymerizing pyrrole in a matrix of polyurethane. The polypyrrole/polyurethane alloy films obtained were characterized by element analysis, electron microscopy and electrical conductivity measurements. The morphology of the films depended on the solvent, the electrolyte and the current density. The mechanism of the electrochemical polymerization showed that PPy grew in a treelike structure, with molecular chains extending from the electrode surface into the solution. The transition temperature of the PPy/PU increased with the PPy content.  相似文献   
82.
New novel fire‐resistant and heat‐resistant cyclotriphosphazene‐containing polyimide resins were prepared in situ by the polymerization of (p‐aminophenoxy)(phenoxy)cyclotriphosphazenes with 3,3′,4,4′‐benzophenonetetracarboxylic acid or 3,3′,4,4′‐diphenylsulfonetetracarboxylic acid and a crosslink agent, 5‐norbornene‐2,3‐dicarboxylic acid and were used as polymer matrix compositing with a woven carbon fiber to prepare nadic‐end‐capped cyclotriphosphazene‐containing polyimide/carbon fiber composites. The thermal stability, flame retardance, morphology of the surface fracture, and some physical properties of the composites were investigated by thermogravimetric analysis, scanning electron microscopy, and a material testing system, respectively. The composites had good thermal stability, flame retardance, and mechanical properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 810–818, 2003  相似文献   
83.
This study aims to understand the different photocuring behaviors of acrylated polyester by adding different photoinitiators and monomers. Differential photo calorimeter (DPC) is used to understand the exothermal effects during photocuring. The self-catalyst model of dynamic analysis software was then used to obtain the relationships between reaction speed, reaction extent, and rate of reaction. In addition, this study also tried to understand the formation of photocuring resin from the rigid-body pendulum rheometer (RPT) experiment. The results showed that the extent of reaction, conversion rate and speed varies directly with the concentration of the photoinitiator and monomer. The reaction level of propoxylated pentaerithritol triacrylate was higher than propoxylated neopentyl-glycol diacrylate. Moreover, the method using RPT shows better view of the molecule reaction status inside the photopolymer.  相似文献   
84.
In this study, silicon dioxide (SiO2) particles are mixed with acrylic series monomers (methyl metacrylate (MMA) and 2-hydroxyethyl methacrylate (2-HEMA)) by sol-gel process to prepare inorganic-organic hybrid materials for the optical film. The other optical film has the same composition and process as the above but tri(ethylene glycol) dimethacrylate (TEGDMA) is added.

An infrared spectrometer, differential scanning calorimeter, thermo gravimetric analysis, ultraviolet-visible spectrophotometer, and spectroscopic-ellipsometer have been used to explore the effect on optical, hardness, and thermal properties of the two series of thin films. TEGDMA used as a bonding resin in this study showed that not only a better hardness and thermal properties, but also maintain good optical properties in the SiO2 hybrid materials by sol-gel process.  相似文献   
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Fang-Chyou Chiu  Yu-Lun Chen 《Polymer》2005,46(25):11600-11609
Polyamide 6 (PA 6)-based nanocomposites were prepared using a melt-mixing technique in this study. One commercial organoclay (denoted 30B) and one maleated polyolefin elastomer (denoted POEMA) served as the reinforcing filler and toughener, respectively. The X-ray diffraction (XRD), scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS) and transmission electron microscopy (TEM) results confirmed the nano-scaled dispersion of 30B in the composites. Different mixing sequences presented similar phase morphology for the same formulated nanocomposites. XRD results also revealed that both 30B and POEMA would induce the formation of γ form PA 6 crystal, with 30B exhibiting a higher efficiency. Differential scanning calorimetry (DSC) results indicated that the addition of 30B altered the crystallization kinetics of PA 6, which was mainly attributed to the prevailing formation of γ form crystal. Complex melting behaviors were observed for neat PA 6 and the nanocomposites. These complex behaviors are associated with different polymorphs and the ‘melting-recrystallization-remelting’ phenomenon. Moderate thermal stability enhancement of PA 6 after adding 30B and/or POEMA was confirmed using thermogravimetric analysis (TGA). The storage modulus, Young's modulus and tensile strength of PA 6 were increased after adding 30B. However, these properties declined after further incorporation of POEMA. The different-processed PA 6/30B/POEMA nanocomposites displayed balanced tensile properties and toughness between those of neat PA 6 and PA 6/30B nanocomposite.  相似文献   
88.
Cellular fusion is a key process in many fields ranging from historical gene mapping studies and monoclonal antibody production, through to cell reprogramming. Traditional methodologies for cell fusion rely on the random pairing of different cell types and generally result in low and variable fusion efficiencies. These approaches become particularly limiting where substantial numbers of bespoke one‐to‐one fusions are required, for example, for in‐depth studies of nuclear reprogramming mechanisms. In recent years, microfluidic technologies have proven valuable in creating platforms where the manipulation of single cells is highly efficient, rapid and controllable. These technologies also allow the integration of different experimental steps and characterisation processes into a single platform. Although the application of microfluidic methodologies to cell fusion studies is promising, current technologies that rely on static trapping are limited both in terms of the overall number of fused cells produced and their experimental accessibility. Here we review some of the most exciting breakthroughs in core microfluidic technologies that will allow the creation of integrated platforms for controlled cell fusion at high throughput. © 2015 Society of Chemical Industry  相似文献   
89.
This paper introduces the fundamental physical characteristics of organic photovoltaic (OPV) devices. Photoelectric conversion efficiency is crucial to the evaluation of quality in OPV devices, and enhancing efficiency has been spurring on researchers to seek alternatives to this problem. In this paper, we focus on organic photovoltaic (OPV) devices and review several approaches to enhance the energy conversion efficiency of small molecular heterojunction OPV devices based on an optimal metal-phthalocyanine/fullerene (C(60)) planar heterojunction thin film structure. For the sake of discussion, these mechanisms have been divided into electrical and optical sections: (1) Electrical: Modification on electrodes or active regions to benefit carrier injection, charge transport and exciton dissociation; (2) Optical: Optional architectures or infilling to promote photon confinement and enhance absorption.  相似文献   
90.
The aim of this paper was to study the physical–chemical composition of the watermelon seed oil extracted by a mechanical process using an expeller and by a chemical process using hexane as the solvent. The watermelon seed oil had a high concentration of unsaturated fatty acids. The two primary sterols were stigmasterol and β-sitosterol, which corresponded to approximately 47 and 30% of the total phytosterols. The oil had a low tocopherol content (65.19 mg/kg for S and 73.19 mg/kg for E). Comparing the two extraction methods, extraction by expeller produced an oil of superior quality with respect to oxidative stability, carotenoids and Lovibond color. No significant differences were found between the two extraction methods with respect to the minor components of the oil considered as functional, such as phytosterols.  相似文献   
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