Isolation of single-walled carbon nanotubes (SWNTs) remains to be a key step for realization of the true potential of SWNTs, since the physical properties of SWNTs are dependent on the tube’s chirality index (n, m). Polymers with enhanced helical conformation are found to be an efficient sorting mechanism for SWNTs, as the cavity of polymer’s helical conformation can be tailored to facilitate an intimate interaction between polymer and SWNTs. Poly[(m-phenylenevinylene) (PmPV) demonstrates that the polymer helical conformation can be controlled to sort the SWNTs by their diameters. Poly[(m-phenyleneethynylene)-alt-(p-phenyleneethynylene)] (PPE) reveals the intriguing selectivity toward tube (6,5), illustrating the impact of carbon-carbon triple bonds on the SWNTs selectivity. In another approach, polyethyleneimine (PEI) is found to exhibit selective interaction with semiconducting SWNTs. By using this property, cellulose impregnated with PEI is found to be a column packing materials for separation of metallic SWNTs from a raw HiPco sample.  Analysis by AFM, 2D fluorescence and UV-vis-NIR absorption spectra suggests that the metallic SWNTs (13,4) can be separated from the armchair SWNTs (10,10) and (9,9).

关键词：碳纳米管；聚合物；硝酸；拉曼光谱；极限(单壁碳纳米管

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CO2 hydrogenation to olefins and ethylene oligomerization was investigated in efforts to improve catalyst composition and reaction conditions needed for scale-up. The hydrogenation of CO2 to hydrocarbons is investigated over -alumina-supported iron-based catalysts modified with manganese and potassium promoters and a silica-stabilized coating under fixed-bed reactor conditions to produce unsaturated hydrocarbons as feedstock chemicals for jet fuel synthesis. The stabilizer is introduced by impregnating the K/Mn/Fe on Al2O3 catalyst with tetraethylorthosilicate (TEOS) to minimize the deactivating effects of water on catalyst activity in CO2 hydrogenation. The K/Mn/Fe on Al2O3 catalyst modified with the TEOS and reduced in CO produced a lighter end fraction of olefins compared with the catalyst reduced in H2. To increase the chain length of the olefins formed in the CO2 hydrogenation step, investigation of oligomerization reaction is conducted in a separate experiment, where pure ethylene is used as a model olefin. Ethylene oligomerization over pelletized amorphous silica-alumina (ASA)-supported Ni catalysts demonstrated high conversion and selectivity towards the jet fuel fraction (C8-C16) at very low MHSV.

关键词：碳；聚合物；齐聚物；硅；高分子材料

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This article presents a comparative study on the synthesis and characterization of the binary and ternary ferrites for photocatalytic and photoelectrochemical applications. The importance and role of ferrite photocatalysts is discussed in context to the visible-light active photocatalyst application viz. for hydrogen production via. water-splitting. It also demonstrates that computational-exploration of any material system is key to identify, and achieve visible-light active photocatalysts.

关键词：光触媒；光电；氢能；铁氧体；高分子材料

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A novel fluorophore tagged exopolysaccharide (TEPS) was developed, synthesized, and tested for its potential implications toward locating Improvised Explosive Device (IEDs). Our TEPS exhibited unique and substantial properties that lend well to current change detection processing techniques and allows for significantly improved detection of objects implanted into the natural landscape. When coupled with a novel image processing package, or Automated Disturbance Detection System (ADDS), that automatically processes images, and creates a map of areas of interest (AOIs) that relate to the detection of a hidden object, TEPS has shown great success. For example, in pilot scale field testing it was able to accurately and automatically identify large (larger than 12') implanted devices nearly 100of the time and smaller objects (between 1' and 12') 87.5of the time from an aerial platform. Furthermore, the system only falsely detected one terrestrial disturbance for every fourteen that it correctly identified. An additional benefit of our TEPS system is that its computational requirements will be about 75less than comparable systems because computationally intense preprocessing algorithms are unnecessary. The combined TEPS and ADDS technologies can rapidly produce maps of AOIs, which would ultimately allow for greater and safer movement of troops in dangerous areas.

关键词：变化检测；简易爆炸装置；聚合物；自动化；耦合（互动）

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Polymers and other oxidizable materials used on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded away by reaction with atomic oxygen (AO). For spacecraft design, it is important to know the LEO AO erosion yield, Ey (volume loss per incident oxygen atom), of materials susceptible to AO erosion. The Stressed Polymers Experiment was developed and flown as part of the Materials International Space Station Experiment 6 (MISSE 6) to compare the AO erosion yields of stressed and non-stressed polymers to determine if erosion is dependent upon stress while in LEO. The experiment contained 36 thin film polymer samples that were exposed to ram AO for 1.45 years. This paper provides an overview of the Stressed Polymers Experiment with details on the polymers flown, the characterization techniques used, the AO fluence, and the erosion yield results. The MISSE 6 data are compared to data for similar samples flown on previous MISSE missions to determine fluence or solar radiation effects on erosion yield.

关键词：地球轨道环境；航天环境；氧原子；侵蚀；辐射效应

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Olefin polymerization catalysts containing redox-active moieties that may be tuned in situ via electrochemical or chemical oxidation and reduction were synthesized and examined. The redox capable functionalities were incorporated into specifically chosen ligand frameworks and metallated using organometallic reagents so as to produce precatalysts that could be activated using methylaluminoxane, borane, or boronate-based activators. Those catalysts were shown to be active toward olefin polymerizations,their electrochemistry studied, and their in situ switchability is currently underway yielding many promising results.

关键词：催化；烯烃；催化剂；中性镍催化剂；高分子材料

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We have performed extensive experimental and theoretical studies of interfacial friction, relaxation dynamics, and thermodynamics of polymer chains tethered to points, planes, and particles. A key result from our tribology studies using lateral force microscopy (LFM) measurements of polydisperse brushes of linear and branched chains densely grafted to planar substrates is that there are exceedingly low friction coefficients for these systems. Specific project achievements include: (1) Synthesis of three-tiered lubricant films containing controlled amounts of free and pendent PDMS chains, and investigated the effect of their molecular weight and volume fraction on interfacial friction. (2.) Detailed studies of a family of hairy particles termed nanoscale organic hybrid materials (NOHMs) and demonstration of their use as lubricants.

关键词：润滑油；混合动力系统；界面摩擦；分子量；聚合物

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A platform technology to prepare enzyme sensitive nanomedicine (ESNM), which integrates the imaging and treatment capability, has been developed to report and cure diseases. ESNM is prepared with multiple layers of polyelectrolytes, sequentially assembled on an inert gold nanoparticle, using alternating charged polymers. Potentially the release kinetics could be controlled by varying polyelectrolytes with different properties, such as length, ionic strength and bond stability. Upon incubation with cells, the assembled ESNMs are taken up efficiently. The tight packing and layered assembly of the quenched polyelectrolytes slow subsequent intracellular degradation, and then result in a prolonged intracellular fluorescence signal and therapeutic effect for up to 3 weeks with no noticeable toxicity.

关键词：医疗服务；肽水解酶；核糖核酸；蛋白酶

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A summary ot three years of work is difficult to reduce to a tew sentences. We have applied Hadamard transform mass spectrometry to stop-flow kinetics and shown how this technique can complement previous stop-flow studies that rely instead on spectroscopic signatures. We have also examined hypergolic reactions. In particular, we performed electrospray ionization mass spectrometry (ESI-MS) and MS/MS fragmentation studies to determine the composition ot a previously unknown precipitate. We discovered that the precipitate consisted of melamine oligomers and polymers. However, the majority ot the effort involved an ambient ionization method that can be carried out at atmospheric pressure at room temperature-- desorption electrospray ionization (DESI). Here charged droplets are fired at some surface and the resulting splash ot smaller droplets enter a mass spectrometer. We applied this technique to show how to overcome adverse effects from salt and detergent in electrokinetic separations using a spinning disk. We also applied this technique, we believe with great success, to study reaction intermediates and to demonstrate the potential of using DESI for mass spectrometric imaging.

关键词：动力学；质谱；流量；碎裂；电离

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Polyester polymer concrete (PPC) was used in a trial application on a section of pavement that suffers from extensive studded tire wear. The purpose of the trial section is to determine if PPC is a possible repair strategy for this type of pavement damage. The PPC was applied in three methods; (1) as a 1 inch thick inlay of the entire lane that was diamond ground to remove all rutting from studded tire wear, (2) as an inlay of just the wheel paths that were diamond ground, and (3) as a feathered overlay of the existing pavement which had no diamond grinding to remove rutting. The test sections will be monitored for a minimum of five years to determine the performance of the PPC with particular emphasis on its ability to resist studded tire wear.

关键词：聚酯聚合物混凝土(PPC)；路面损伤修复策略

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