关键词：纤维增强复合材料；聚合物；复合材料；高分子材料

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It is shown by magnetic field dependent ac susceptibility, magnetic force microscopy, and ferromagnetic resonance that exposure of C(sub 60) to fluorine at 160 deg C produces a stable ferromagnetic material with a Curie temperature well above room temperature. The exposure to fluorine is accomplished by decomposing a fluorine rich polymer, trifluorochloroethylene, F(sub 2) (C-CFCl)(sub n) which has C(sub 60) imbedded in it. Based on previous experimental observations and molecular orbital calculations, it is suggested that the ferromagnetism is arising from crystals of C(sub 60)-F.

关键词：铁磁性；铁磁谐振；聚合物；拉曼光谱

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The study of fractures of glass, glassy type materials, and plastic has long been of interest to the forensic community. The focus of this interest has been the use of glass and polymer fractures to reconstruct past events and to associate items of evidence. One example of this association is the matching of glass fragments from various locations where they can be shown to have come from a common origin. In the materials science community, fractography is the means and methods for characterization of fractured specimens or components in order to study or identify the mechanism of such failures, which is the focus on most of the literature on the subject. The ability to show that each and every fracture is, in fact, unique has not been a matter of consequence or of interest to the engineering or scientific community. In contrast, the basic premise that fractures are not likely to be reproducible is very relevant to the forensic science community. The issue arises when a given fracture pattern is restored or component pieces are physically fitted together and 'matched' and the conclusion is drawn that this is unlikely to be possible unless all the components were derived from the same part. Despite the importance of this assumption, very limited research has actually been done to confirm that this is indeed the case. This study documented the very controlled fracture patterns of 60 glass panes, 60 glass bottles, and 60 plastic tail light lens covers. The pane and bottle specimens were fractured with three different types of penetration tips: sharp tip, round tip, and blunt tip.

关键词：聚合物；玻璃；玻璃破裂；断口；高分子材料

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关键词：铕配合物；三苯基氧化膦；白光发射；高分子材料

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The aging infrastructure in the United States puts a huge burden on bridge engineers and officials who strive to ensure public safety and meet community demands. Strengthening existing bridge structures instead of the more expensive replacement alternative has therefore been a more feasible choice in many cases, which led to large research efforts to develop new strengthening methods and explore the use of new materials. Fiber Reinforced Polymer (FRP) composites is considered one of the new materials that continue to grow and gain popularity for structural applications. Successful use of FRP relies on understanding its behavior and being able to confidently assess its properties. Characterizing material properties from random samples is important in order to better understand the behavior of FRP composites and implement them in design codes. Reliable and consistent methods of characterizing the material resistance are essential for the successful employment of any material. There are two popular statistical methods used for finding characteristic values for FRP composites: The first method is recommended by the American Concrete Institute (ACI) in publications produced by Committee 440 (Fiber-Reinforced Polymer Reinforcement), while the other is adopted by the American Society for Testing and Materials (ASTM International) in a standard for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering Structural Applications, ASTM D7290. In this study, tensile and flexural tests are conducted on different FRP composite materials for the purpose of investigating the differences between these two methods. The experimental results were complemented with simulations of virtual specimens. The experimental and simulation results are then used to estimate the material properties following both characterization methods and to conduct comparisons between both methods.

关键词：桥梁；复合材料；力学性能；纤维增强复合材料

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Removal of two macronutrients, nitrogen (N) and phosphorus (P), from wastewater is critical before discharging the treated effluent to prevent eutrophication. But N and P are also essential components of any fertilizer; thus their recovery from wastewater will be an added bonus. This is especially critical for P since it is a non-renewable resource and its supply potential is getting diminished. For any process to have the ability to recover N and P from wastewater, it should be able to selectively remove the target ion containing N (NK_4~+_-N in this case) from a background of competing cations that may be present at a higher concentration (primarily Na~+ and Ca~(2+)) and the target ion containing P (H_2PO_4~- or HPO_4~2) which faces strong competition from competing anions such as Cl- and SO_4~(2-). Moreover, selective removal of NH_4~+_-N and P are not enough; the process should be efficiently able to desorb N and P to produce a small-volume, high concentration, regenerating solution. And finally, a solid-phase fertilizer of high purity should be extractable from the regenerating solution. On top of this, if the remaining regenerant solution can be reused in the next cycle, this process would be highly sustainable. Details of a process are provided where an inorganic zeolite (clinoptilolite) and a polymeric anion exchanger impregnated with iron oxide nanoparticles and preloaded with Cu as a selective ligand for phosphate are used to achieve selective N and P removal. The exchangers are efficiently regenerated with a combination of NaCl and NaOH and a solid-phase, high-purity fertilizer as MgNH_4PO_4 (struvite) is extracted. Three hybrid polymers were studied for P removal and recovery: HAIX, DOW-HFO, and DOW-HFO-Cu. Each material combines the durability, robustness, and ease-of-use of a polymeric ion-exchanger with the high sorption affinity of Hydrated Ferric Oxide (HFO) towards P. DOW-HFO-Cu was found to be the most efficient exchanger for removal of P. This was because both the HFO and the Cu, selective ligands for Cu sorption, acted in combination, thus providing maximum overall selectivity. The regenerating solution can be reused in the next cycle, thus creating a sustainable process with minimal waste effluent.

关键词：斜发沸石；磷酸盐配体；水合氧化铁纳米颗粒；高分子材料

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A cassette of uncured composite materials with epoxy resin matrixes was exposed in the stratosphere (40 km altitude) over three days. Temperature variations of -76 to 32.5C and pressure up to 2.1 torr were recorded during flight. An analysis of the chemical structure of the composites showed, that the polymer matrix exposed in the stratosphere becomes crosslinked, while the ground control materials react by way of polymerization reaction of epoxy groups. The space irradiations are considered to be responsible for crosslinking of the uncured polymers exposed in the stratosphere. The composites were cured on Earth after landing. Analysis of the cured composites showed that the polymer matrix remains active under stratospheric conditions. The results can be used for predicting curing processes of polymer composites in a free space environment during an orbital space flight.

关键词：平流层；环氧基复合材料；环氧树脂；固化

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This document compiles recent research findings related to corrosion of metals in preservative treated wood into a single report on corrosion of metals in wood. The research was conducted as part of the Research, Technology and Education portion of the National Historic Covered Bridge Preservation (NHCBP) Program administered by the Federal Highway Administration. The compilation addresses: corrosion rates of metals embedded in treated wood, the mechanism of corrosion in treated wood, the effect of extractives on corrosion, methods for predicting the service life of metals in treated wood, and suitable non-metallic replacement fasteners. The document was created to serve as a desk reference for engineers to aid in materials selection when building with treated wood.

关键词：防腐剂；紧固件；木材；腐蚀；纤维增强聚合物

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Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures including helical, buckled, and beads-on-a- string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self- cleaning materials.

关键词：纤维；纳米结构；生物检测;生物；能源；

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This chapter discusses the utilization of polybenzoxazine/urethane alloys with fine-tuning properties for ballistic impact composite application. The ballistic impact study of Kevlar? fiber-reinforced polybenzoxazine alloys under the test weapon with standard 124 grains round lead projectile and a copper outer coating (Full Metal Jacket) typically used in the 9-mm handgun at an impact velocity of 426-431 m/s is reported. The polybenzoxazine/urethane alloy matrices at various urethane prepolymer contents were prepared to evaluate the effect of different urethane contents on the thermal, mechanical as well as ballistic resistant properties. Experimental results reveal a synergy in glass transition temperature and some mechanical properties of the alloys at the composition range of 10-30by weight of urethane fraction the thus provide a fascinating group of high temperature polymers with improved flexibility and enhanced a ballistic resistant characteristic.

关键词：聚苯并恶嗪；氨基甲酸乙酯；弹道性能；芳纶；高分子材料

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