Nanocomposites of triazole functionalized multi-walled carbon nanotube with chemically grafted polyimide: preparation,characterization, and properties

In order to improve the dispersion of multi-walled carbon nanotubes (MWCNTs) in polyimide (PI) matrix and the interfacial interaction between MWCNTs and PI, 3,5-diamino-N-(1H-[1,2,4]triazol-3-yl)-benzamide (DTB)-functionalized MWCNTs (DTB-MWCNTs) were synthesized by amidation reaction. The DTB-MWCNTs were analyzed by several techniques. DTB-MWCNTs were used as a platform for the grafting of a DTB-based PI in N,N′-dimethylformamide solution with different loadings of DTB-MWCNTs to produce PI-grafted MWCNT (PI-g-MWCNT) composites. The thermal, mechanical, and electrical properties of the PI-g-MWCNT composites were improved compared with PI due to the homogeneous dispersion of DTB-MWCNTs and strong interfacial covalent bonds between DTB-MWCNTs and the PI chain.     

电石炉气处理和利用综述

介绍了电石炉气处理利用的方法,分析评价了各种利用方式的适用范围和优缺点,提出了电石行业实现资源利用、节能减排的途径和循环经济发展方向。     

生物氧化—氰化炭浸提金工艺的优化改造

对三和金业生物氧化—氰化炭浸提金工艺进行了优化改造。通过优化生物氧化作业参数,使其处理能力提高了42.49 t/d;增设氧化洗涤液二段沉淀回收高品位含金微细氧化渣、采用二段沉淀—压滤工艺回收粉炭、增设摇床重选工艺回收氰渣中的金等,金的总回收率提高了0.46%。企业年增产黄金884.4 kg,取得了显著的经济效益。     

利用鸡蛋壳制备过氧化钙的工艺研究

以鸡蛋壳为钙源，制备过氧化钙，并考察了反应时间，蛋壳灰分的用量以及稳定剂（双氧水）的用量等因素对产物产率的影响。由实验结果得出最佳条件为反应时间20mm，稳定剂用量为21mL，蛋壳灰份用量为2．0g，其产率最高。最高产率为78．1％。     

One‐Step Formulation of Protein Microparticles with Tailored Properties: Hard Templating at Soft Conditions

Formulation of therapeutic proteins into particulate forms is a main strategy for site‐specific and prolonged protein delivery as well as for protection against degradation. Precise control over protein particle size, dispersity, purity, as well as mild preparation conditions and minimal processing steps are highly desirable. It is, however, hard to fit all these criteria with conventional preparation techniques. Here a one‐step hard‐templating synthesis of microparticles composed of functional, non‐denatured protein is reported. The method is based on filling porous CaCO₃ microtemplates with the protein near to its isoelectric point (pI) followed by pH‐ or EDTA‐mediated dissolution of the tempplates. In principle, a wide variety of proteins can be converted into microparticles using this approach. The main requirement is an overlap of the protein insolubility and a template solubility for a certain parameter (here pH or EDTA). Here the formulation of insulin particles is studied in detail and it is shown that particles consisting of high molecular weight protein (catalase) can also be prepared. In this context, the synthesis of CaCO₃ templates with controlled size, the mechanism of the protein microparticle formation and mechanical properties of the microparticles are discussed. For the first time, the fabrication of mesoporous monodispersed CaCO₃ microtemplates with identical porocity but tuned diameter from 3 to 20 μm is demonstrated. The protein particle diameter can be adjusted by choosing the appropriate template size that is critical for successful pulmonary delivery of insulin. As a first step towards insulin delivery, the in vitro release of insulin at physiological conditions is studied.     

Effects of embedding direct reduction followed by magnetic separation on recovering titanium and iron of beach titanomagnetite concentrate

Embedding direct reduction followed by magnetic separation was conducted to fully recover iron and titanium separately from beach titanomagnetite(TTM).The influences of reduction conditions,such as molar ratio of C to Fe,reduction time,and reduction temperature,were studied.The results showed that the TTM concentrate was reduced to iron and iron-titanium oxides,depending on the reduction time,and the reduction sequence at 1 200°C was suggested as follows:Fe_(2.75)Ti_(0.25)O_4→Fe_2TiO_4→FeTiO_3→FeTi_2O_5.The reduction temperature played a considerable role in the reduction of TTM concentrates.Increasing temperature from 1 100 to 1 200°C was beneficial to recovering titanium and iron,whereas the results deteriorated as temperature increased further.The results of X-ray diffraction and scanning electron microscopy analyses showed that low temperature(≤1 100°C)was unfavorable for the gasification of reductant,resulting in insufficient reducing atmosphere in the reduction process.The molten phase was formed at high temperatures of 1 250-1 300°C,which accelerated the migration rate of metallic particles and suppressed the diffusion of reduction gas,resulting in poor reduction.The optimum conditions for reducing TTM concentrate are as follows:molar ratio of C to Fe of 1.68,reduction time of 150 min,and reduction temperature of 1 200°C.Under these conditions,direct reduction iron powder,assaying 90.28 mass%TFe and 1.73 mass% TiO_2 with iron recovery of 90.85%,and titanium concentrate,assaying 46.24mass% TiO_2 with TiO_2 recovery of 91.15%,were obtained.     

Physicochemical characterisation of corn extrudates prepared with varying levels of beetroot (Beta vulgaris) at different extrusion temperatures

This study examines the effect of beetroot powder (BRP) incorporation (0%, 5%, 10% and 15%) at different extrusion temperatures (125, 150 and 175 °C) on the physicochemical, antioxidant and sensory properties of corn grit (CG) extrudates. BRP showed higher values of total phenolic content (TPC = 9095 μg GAE g^?1) and free radical inhibition (ABTS = 6.5 μm trolox mg^?1 and DPPH = 7.9 μm trolox mg^?1) than CG (1346 μg GAE g^?1, 1.5 μm trolox mg^?1 and 2.2 μm trolox mg^?1, respectively). Pasting viscosity (peak, breakdown and final) decreased, while pasting temperature of CG increased with the level of BRP incorporation. Analyses of the extrudates showed an increase in redness, bulk density, hardness, TPC, free radical inhibition, total dietary fibre (TDF) and a decrease in water absorption index (WAI), water solubility index (WSI), expansion ratio and oil uptake with the increase in the level of BRP incorporation. On the other hand, higher extrusion temperature increased porosity, WAI, WSI, oil uptake but decreased redness, bulk density, hardness and TPC.     

Micronized drug powders in binary mixtures and the effect of physical properties on aerosolization from combination drug dry powder inhalers

Objectives: To evaluate physicochemical properties of two micronized drugs, salbutamol sulfate (SS) and beclomethasone dipropionate (BDP) prepared as dry powder inhalation physical blends. Methods: Five different blends of SS:BDP ratios of 0:100, 25:75, 50:50, 75:25, and 100:0 (w/w) were prepared. Aerosolization performance was evaluated using a multistage impinger and a Rotahaler® device. Results: The median SS particle diameter was larger than BDP (4.33?±?0.37 µm compared to 2.99?±?0.15 µm, respectively). The SS appeared to have a ribbon-like morphology, while BDP particles had plate-like shape with higher cohesion than SS. This was reflected in the aerosolization performance of the two drugs alone, where SS had a significantly higher fine particle fraction (FPF) than BDP (12.3%, 3.1% and 2.9%, 0.2%, respectively). The study of cohesion versus adhesion for a series of SS and BDP probes on SS and BDP substrates suggested both to be moderately adhesive, verified using scanning Raman microscopy, where a physical association between the two was observed. A plot of loaded versus emitted dose indicated that powder bed fluidization was significantly different when the drugs were tested individually. Furthermore, the FPF of the two drugs from the binary blends, at all three ratios, were similar. Conclusions: Such observations indicate that when these two drugs are formulated as a binary system, the resulting powder structure is altered and the aerosolization performance of each drug is not reflective of the individual drug performance. Such factors could have important implications and should be considered when developing combination dry powder inhalation systems.