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991.
Heqing Fu Hong Huang Qi Wang Hui Zhang Huanqin Chen 《Journal of Dispersion Science and Technology》2013,34(5):634-638
The aqueous polyurethane hybrid dispersion modified by the epoxy resin were synthesized using 1,4-butanediol ( BDO ) and dimethylolpropionic(DMPA) as chain extenders. A kind of automobile interior decoration adhesive was made by the modified hybrid dispersions. Effects of the content and the kinds of epoxide resin on the properties of dispersions and dispersion-cast films such as appearance, pot life, viscosity, particle size, molecular mass, hardness, swelling in water, contact angle, strength of stress, elongation at break, and other mechanical properties were studied. At the same time the effect of the E20 content on the peel strength of the adhesive for several automobile interior decoration substrates such as rubber/wood, poly(vinyl chloride)/wood; leather/wood, sponge/wood was investigated. The experimental results show that when the epoxy resin E20 content was 8%, the modified polyurethane hybrid dispersions possess better properties and the adhesive made by the modified dispersions posses better adhesion for automobile interior decoration substrates. The stress-strain curve of the modified aqueous polyurethane hybrid dispersions films shows the modified aqueous cast films possess better rigidity and toughness. 相似文献
992.
Wei Chang Lijuan Liu Jin Zhang Qiwei Pan 《Journal of Dispersion Science and Technology》2013,34(5):639-642
A kind of emulsifier-free latex (FL) was successfully synthesized from styrene (St) and butyl acrylate (BA) with 2-acrylamido-2-methyl propane sulfonic acid (AMPS) as a reactive emulsifier. The particle size of latex particles, stability against electrolytes, minimum film forming temperature (MFT) and water contact angle (CA) were evaluated and compared with a conventional latex (CL). Test results show that FL has larger particle size, better stability against electrolytes and lower MFT value compared with CL; higher AMPS content leads to smaller particle size and smaller water CA. 相似文献
993.
Based on the J(x) fractal distribution function of aperture given by Jaroniec, this article suggests another function K(x), a variant of J(x) but offering new insight. We then use these two functions to characterize three kinds of activated carbon fiber (ACF) of different specific areas. This article also provides the fractal distribution of the aperture and the isotherm of nonpolarity benzene steam on the ACF specimens and the relationship between them. 相似文献
994.
Aggregation behavior of didodecyldimethylammonium bromide (DDAB) in aqueous solution was investigated using negative-staining and freeze-fracture transmission electron microscopy (TEM) methods. With the concentration increase, the vesicle size enlarged from the range of 100–200 nm to 500–3000 nm and the structure transform from unilamella to multilamella. Rheological and viscosity measurement results indicated that the system exhibited a gel-like material characteristic and shearing thinning in property, as shown that the apparent viscosity decreased gradually during the shear rate ascended from 1 × 10?4–1 × 104 s?1. Furthermore, the relationship between aggregate conformation and solution rheological properties was discussed. 相似文献
995.
采用体外酶抑制活性检测方法结合超滤质谱(UF-LC/MS)筛选方法对中药提取物中的α-葡萄糖苷酶抑制剂进行了筛选.以4-硝基苯-α-D-吡喃葡萄糖苷(PNPG)为底物,阿卡波糖为阳性对照药,对5种富含黄酮类化合物的中药提取物进行了α-葡萄糖苷酶抑制活性的初步测定.结果表明,银杏叶具有最强的α-葡萄糖苷酶抑制活性,可作为进一步复筛的对象.利用超滤质谱技术对银杏叶中潜在的α-葡萄糖苷酶抑制剂进行了筛选,从中筛选出4种潜在的α-葡萄糖苷酶抑制剂,并利用液相色谱-串联质谱技术(LC-MSn)对其结构进行了鉴定.本文结果为开发新一代安全有效的降糖药物奠定了基础. 相似文献
996.
采用FeOOH纳米棒为前驱体,通过层层自组装法及随后的热处理过程制备出α-Fe2O3-Ag复合纳米棒.采用透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)和电化学性能测试对样品的形貌、结构及电化学性能进行了表征.结果表明,Ag纳米颗粒均匀地分布在α-Fe2O3纳米棒的表面.作为锂离子电池负极材料,α-Fe2O3-Ag复合纳米棒表现出了较好的循环性能和较高的比容量.180个循环后,其比容量高达549.8 mA.h/g. 相似文献
997.
为掌握生物质中钾对生物质超临界水降解过程的影响,选择生物质气化转化过程中生成的重要小分子中间产物甲醛作为研究对象,研究不同工艺条件下(反应温度400~650℃、压力23~29 MPa、停留时间4~12 s),单一钾成分(KHCO3/K2CO3/KCl)或混合钾成分(KHCO3、K2CO3、KCl)对甲醛超临界水降解气体产物的影响。结果表明,KHCO3、K2CO3、KCl、混合钾均降低了气体产物中CO的体积分数,提高了CO2的体积分数,但KCl的影响程度弱于其他三种钾成分。此外,由于不同钾成分均不利于气体产物中CO和H2体积分数的提高,从而使得气体产物的热值降低。KHCO3、K2CO3、KCl、混合钾均降低了H2、CO、CO2的产率以及气化率,其对H2产率以及气化率的抑制程度从大到小依次为:混合钾、KHCO3、K2CO3、KCl,且提高反应温度、延长反应停留时间时抑制气体生成的作用相对越明显。而当反应压力改变时,钾成分对H2产率及气化率的影响程度变化较小。较高反应温度、较高反应压力、较长停留时间时,混合钾中各成分出现协同作用,明显抑制了气体产物的生成。 相似文献
998.
CdS/石墨烯纳米复合物的可见光催化效率和抗光腐蚀行为 总被引:1,自引:0,他引:1
制备了一系列CdS纳米晶/石墨烯(CdS/GR)复合物,并在可见光照条件下评价了其光催化降解亚甲基蓝的光催化效率和抗光腐蚀行为. 研究表明,石墨烯的引入加速了CdS纳米晶(NCs)光生电子的迁移速率,抑制了其光生电子-空穴的复合,有效改善了其光催化降解有机污染物的性能. CdS/GR复合物中的石墨烯含量显著影响其光催化效率,其中石墨烯含量为4.6%的光催化剂效率最高,其光电流是CdS NCs的2.3倍. 利用光电化学和X射线衍射技术进一步证实,石墨烯的引入抑制了CdS NCs光腐蚀的发生,提高了CdS/GR复合物的光催化稳定性. 相似文献
999.
The mixed-metal cluster Yb4O4(OiPr)16Na12 has been synthesized and structurally determined by IR, elemental analysis, and single-crystal X-ray diffraction. The crystal belongs to the cubic system, space group P23 with a = b = c = 13.9788(3), V = 2731.55(10)3 , Z = 1, Dc = 1.202 g/cm 3 , Mr = 1977.42, = 3.480 mm-1 , F(000) = 972, the final R = 0.0288 and wR = 0.1511 for 1677 observed reflections with Ⅰ > 2σ(Ⅰ). X-ray analysis reveals that Yb4O4 (OiPr)16Na12 is centrosym-metric and the structure contains four ytterbium metals and twelve sodium metals, and each ytterbium atom is coordinated by six oxygen atoms. In addition, an ancillary computational analysis of the optimized molecular unit was provided. The large energy gap (3.31 eV) between HOMO and LUMO indicates that the structure framework is particularly stable. 相似文献
1000.
In this paper, a new D-A copolymer, PFDBCPDT, which consists of benzo-2,1,3-thiadiazole as acceptor units and cyclopentadithiophene and fluorene as donor units, was synthesized. The thermal, electrochemical, photophysical and photovoltaic properties of PFDBCPDT were studied. PFDBCPDT showed a low optical band gap of 1.84 eV, and relatively low HOMO level of ?5.69 eV. The best device performance was obtained by PFDBCPDT/PC61BM (1:3) with 0.5 vol% DIO. The device exhibited a power conversion efficiency of 3.06%, with a relatively high open circuit voltage of 0.87 eV. 相似文献