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991.
Monomer acrylic acid (AA) and initiator azo‐bis(isobutyronitrile)were carried into Antheraea pernyi silk fibroin (SF) fibers using supercritical CO2 as a solvent and carrier, followed by free radical polymerization at a suitable temperature, resulting in PAA/SF blends. The binary system of CO2/AA and the ternary system of CO2/AA/AIBN systems were studied. Different impregnation conditions, such as time, pressure, and concentration of AA in the fluid phase on mass uptake, were studied. Fourier transform infrared spectroscopy and X‐ray diffraction results confirmed that PAA was indeed present in the silk and that there were intermolecular hydrogen bonds between PAA and SF. According to thermogravimetry and DTG, blending with PAA could enhance the thermal stability of SF slightly. The water retention values indicated that the hydrophilic nature of the fibers was improved. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 864–868, 2005 相似文献
992.
Gao Sujun Zhang Daijia Sun Yaqin Xiu Zhilong 《Frontiers of Chemical Engineering in China》2007,1(2):202-207
The separation of 1,3-propanediol from the glycerol-based fermentation broth of Klebsiella pneumoniae plays an important role during the microbial production of 1,3-propanediol. In this paper, the separation of 1,3-propanediol
from fermentative broth by a combination of ultrafiltration and alcohol dilution crystallization was investigated. The broth
was first filtered by ultrafiltration, and 99% of cells, 89.4% of proteins and 69% of nucleic acids were removed. The obtained
broth was further condensed by vacuum distillation, and then alcohol was added. The macromolecular impurities, such as nucleic
acids, polysaccharides and proteins, were precipitated, and inorganic and organic salts were crystallized. The optimal volume
ratio of alcohol added to the condensed fermentation broth was determined to be 2:1. As a result, proteins, nucleic acids
and electric conductivity decreased by 97.4%, 89.7% and 95.8%, respectively, compared with the fermentative broth. The influences
of pH and water content in condensed broth on alcohol precipitation and dilution crystallization were also investigated. The
experimental results indicated that alcohol precipitation and dilution crystallization was feasible and effective for the
separation of 1,3-propanediol from actual fermentation broth.
Translated from The Chinese Journal of Process Engineering, 2006, 6(3): 454–457 [译自: 过程工程学报] 相似文献
993.
994.
Single-walled carbon nanotubes coated with titania nanoparticles 总被引:2,自引:0,他引:2
995.
The self-assembly and crystallization behavior of a well-defined low molecular weight polyethylene-block-poly(ethylene oxide) (PE-b-PEO) diblock copolymer was studied. The number-average degrees of polymerization for the PE and PEO blocks were 29 and 20, respectively. The molecular weight distribution was 1.04 as determined by size-exclusion chromatography. The PE-b-PEO sample exhibited two melting points at 28.7 and 97.4 °C for the PEO and the PE crystals, respectively. The crystallization of the PE blocks was unconfined, while the crystallization of the PEO blocks was confined between pre-existing PE crystalline lamellae, as demonstrated by simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) studies. In the fully crystalline state, both PE and PEO blocks formed extended-chain crystals with PE chains tilted ∼22° from the lamellar normal and PEO chains parallel to the lamellar normal, as evidenced by two-dimensional WAXD study of shear-oriented samples. Regardless of hydrogen bonding among hydroxyl chain ends in the PEO blocks, interdigitated, single-crystalline layer morphology was observed for both PE and PEO crystals. The partial crystalline morphology, where the PE crystallizes and the PEO is amorphous, had the same overall d-spacing as the fully crystalline morphology. A double-amorphous PEO layer sandwiched between neighboring PE crystalline layers was deduced based on a chain conformation study using Fourier transform infrared. The confined crystallization kinetics for PEO blocks was investigated by differential scanning calorimetry, which could be explained by a heterogeneous nucleation mechanism. The slower crystallization rate in the PEO-block than the same molecular weight homopolymer was attributed to the effects of nanoconfinement and PEO chains tethered to the PE crystals. 相似文献
996.
水解酸化-好氧生物法处理工业废水 总被引:21,自引:0,他引:21
水解酸化—好氧生物处理法是近年提出的一种新型处理工业废水的方法。列举了水解酸化工序在生物处理工业废水中的优点,并就其在啤酒废水、屠宰废水、乳品废水、制浆废水以及制药废水中的应用作了介绍。 相似文献
997.
998.
文章采用模糊规划的方法证明了期望放出体在放矿中的合理性,从而使放矿这个复杂的过程能方便地采用数学手段来处理。同时说明了如何在崩落法矿山利用期望体来解决实际生产中的放矿问题。 相似文献
999.
1000.
借助拉曼光谱、原料C当量数测定及SC-132定硫仪分析等方法对玻璃气泡、配合料Redox数及硫溶解度之间的关系进行了研究. 相似文献