共查询到19条相似文献,搜索用时 109 毫秒
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设计合成了带巯基的聚苯乙炔衍生物,在产物的红外光谱上,3312和776 cm-1处炔氢特征吸收与2106 cm-1处碳碳三键的特征红外吸收消失;在产物的1H-NMR谱上,对应单体上炔氢的化学位移(δ=3.0)消失而对应共轭烯烃的化学位移(δ=6.4)出现;这些谱学特征变化证明了聚合反应的发生.巯基官能化的聚苯乙炔不仅能够发挥聚苯乙炔衍生物对碳纳米管的增溶作用,而且具有将碳纳米管表面巯基功能化的特殊性能.通过巯基与ZnO之间的强相互作用,ZnO纳米粒子被组装到巯基官能化的聚苯乙炔/碳纳米管杂化结构的外壳.本研究提供了制备新的多元复合纳米结构材料的方法. 相似文献
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通过功能化聚对苯撑乙炔(含羟基与氨基)和聚丙烯酸之间的非共价键自组装制备了一系列含共轭聚合物的水溶性荧光纳米粒子,并进行了相关结构和光学性质表征.研究表明,纳米粒子的大小和聚丙烯酸/聚对苯撑乙炔质量比直接相关.光物理性质研究表明,形成水溶性纳米粒子后,疏水的聚苯撑乙炔链在纳米粒子中易于形成π-链间聚集,其光物理性质与其在薄膜态时相似. 相似文献
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以对苯二酚为目标化合物比较研究了金纳米粒子、碳纳米管、金纳米粒子/碳纳米管3种纳米粒子修饰电极的电催化性能,结果发现:3种纳米粒子修饰电极均对对苯二酚的电化学信号具有增强作用。电化学阻抗谱和修饰层数试验表明:金纳米粒子的增强效果来自于金纳米粒子的电催化作用,碳纳米管的增强作用来自于电催化作用与大的电极表面积,金纳米粒子/碳纳米管复合修饰电极综合利用了两种纳米粒子的特性,表现出了更为优良的电催化行为。对苯二酚在修饰电极上的电化学过程均为扩散控制过程。 相似文献
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纳米铜粒子催化乙炔聚合产物的IR表征 总被引:5,自引:0,他引:5
通过IR对气相法制得的纳米铜粒子催化乙炔聚合反应产物 (固、液态 )进行表征 .结果发现 ,其固态产物 (纳米纤维 )分子结构中既有CC共轭双键 ,又有饱和基团—CH3 ,—CH2 — .且暴露在空气中易氧化 ,其分子结构中存在CO及OH基团 ,同时也说明其中含共轭双键 (CHCH )基团 .液体产物为低聚物 ,其中含有相当多的饱和基团及非共轭的 CC 键 ,无羟基和羰基团存在说明不存在氧化现象 .由TEM观察发现 ,纳米铜粒子既可以位于纤维的端部 ,也可以位于纤维的中间 . 相似文献
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金属和半导体纳米粒子的制备及性质的研究是当今材料科学和物理化学的热门课题[1-6].在利用太阳能光降解环境污染物、生物传感器以及光生物等方面这些纳米粒子都具有实际应用的可能性.对纳米粒子表面进行修饰而形成的复合纳米粒子可以有效地调整单一颗粒的表面性质甚至颗粒的稳定性.另外,复合纳米粒子的制备对研究纳米粒子的尺寸量子化效应、非线性光学性质及其它光电性质都有重要的意义.人们已成功地制备了许多复合金属-金属纳米粒子,如Cu-Ag[7],Ag-Pd[8]及Ag-Pt[9]等.关于复合半导体-半导作纳米粒子也有报导,如C… 相似文献
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Sidney W. Benson 《国际化学动力学杂志》1992,24(3):217-237
The literature on the pyrolysis of acetylene below 1000 K is reviewed and it is shown that the reaction is a radical chain polymerization initiated by H atoms. The induction period is examined and shown to arise from a rapid autocatalysis produced by the very first product, vinyl acetylene. Data from studies of acetylene polymerization induced by vinyl acetylene and styrene are examined and shown to be in good qualitative agreement with the radical chain process presented. Measured and where needed, estimated rate constants are given to produce numerical estimates of chain length, rates of polymerization, induction period, and rates of initiation. It is further shown that all the products of the polymerization are capable of efficiently initiating chains in the system. An examination of the possible kinetics of vinylidene shows that it does not play any role in acetylene chemistry. 相似文献
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负载型Ni-B非晶态合金催化剂的表征及催化性能 总被引:22,自引:0,他引:22
采用ICP,XRD,DSC,BET,SEM和TEM等技术对负载型Ni-B非晶态合金催化剂进行了表征,研究了这类催化剂对乙烯中微量乙炔的选择加氢性能.结果表明,在负载型非晶态合金催化剂中,Ni-B以超细微粒的形式分散在载体上,但在不同载体上的分散度不同.通过载体的引入,提高了非晶态合金的热稳定性,阻止了超细Ni-B的聚集.负载型非晶态合金催化剂对乙烯中微量乙炔的选择加氢表现出优良的催化性能. 相似文献
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The results of an experimental study of ethylene and acetylene polymerizations under conditions of high-frequency gas-discharge plasma are described. As established by mass spectroscopy, polymerization of ethylene in a plasma is accompanied by partial dissociation to hydrogen and acetylene which in turn polymerizes. When acetylene is used as monomer, its polymerization is rapid and is not accompanied by dissociation or other side reactions. Acetylene polymerization proceeds entirely in the gas phase to give a dispersed amorphous product with a stoichiometric C:H = 1:1. 相似文献
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Momoh PO Soliman AR Meot-Ner M Ricca A El-Shall MS 《Journal of the American Chemical Society》2008,130(39):12848-12849
We present direct evidence for low temperature associative charge transfer (ACT) reactions of acetylene onto the benzene cation that catalyze the conversion of acetylene molecules into polymerized cations and for high temperature addition/elimination reactions that lead to the generation of naphthalene-type ions. At low temperatures acetylene molecules bind noncovalently to the benzene cation, where partial charge transfer from the ion activates an acetylene molecule for addition polymerization with other associated acetylene molecules, thus amounting to catalytic cyclization/polymerization of the acetylene molecules. At high temperatures the barrier of the covalent addition of acetylene to the benzene cation to form a styrene-type ion is measured as 3.5 kcal/mol. The second acetylene addition followed by H elimination to form a naphthalene-type ion is calculated to be highly exothermic and without a barrier. These reactions can explain the formation of complex organics by gas phase ion-molecule reactions under a wide range of temperatures and pressures in astrochemical environments. 相似文献
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采用种子微乳液聚合法和单体预乳化法分别合成了室温交联型有机硅改性聚丙烯酸酯微胶乳,研究了硅烷单体的添加和氨化反应对改性微胶乳粒子大小及分布的影响。结果表明:采用种子微乳液聚合法得到的硅丙微胶乳粒子大小与硅烷单体的种类、用量和添加顺序无关,平均粒径约为40~60nm。TEM照片显示出,采用种子微乳液聚合法合成的硅丙微胶乳粒子由于内部存在交联结构而导致表面形状不规则,有“乳突”现象;而采用预乳化法合成的硅丙微胶乳粒径粗大,呈规则的球形,氨化后粒径从100nm以上减小到80nm左右,粒子表面出现“绒毛”现象,这是由于硅烷组分的水解反应受到抑制而使粒子内部的交联密度降低的缘故。 相似文献
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Nanocomposite materials made of carbon nanoparticles dispersed in a crosslinked polymer have been produced by light-induced polymerization of a multifunctional acrylic resin containing graphite, oxidized graphite or acetylene black. Exfoliation of graphite was achieved by sonication of the filled resin, and confirmed by sedimentation analysis. Under intense illumination the solvent-free resin was transformed within a fraction of a second into a hard and tough material, at ambient temperature. The photopolymerization was followed by infrared spectroscopy and shown to proceed effectively up to 85% conversion of the acrylate double bonds. The slowing down effect of the carbon particles by screening of the UV-radiation is becoming increasingly important as the sample thickness and the filler content are increased. A redox initiator consisting of benzoyl peroxide and a tertiary amine was used to achieve a deep through-cure of thick samples, a process which was markedly accelerated in presence of acetylene black. These carbon nanocomposite materials proved to be more flexible and resistant to shocks than the neat acrylic polymer. Electrical conductivity was found in nanocomposites containing acetylene black at concentrations above 1 wt.%. 相似文献
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Synthesis of Functional Poly(disubstituted acetylene)s through the Post‐Polymerization Modification Route 下载免费PDF全文
We report the recent progress in the preparation of functional poly(disubstituted acetylene)s (PDSAs) through post‐polymerization modification routes. The metathesis polymerization of disubstituted acetylene monomers activated by Mo/W–Sn complex catalysts, which do not tolerate highly polar functionalities, was assumed to be a key step in the polymer synthetic procedures. We and other groups have explored several approaches to prepare PDSAs with latent reactive functionalities, which are inactive to Mo/W–Sn complex catalysts but can be used as highly reactive sites for post‐polymerization modification. Click chemistry, Michael‐type addition reactions, the use of activated esters and other strategies are demonstrated by recently published examples. These works indicate that post‐polymerization modification is an efficient route to the synthesis of various functional PDSAs. 相似文献
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A study has been made on the plasma polymerization of acetylene/CO_2/H_2 in a capacitively coupled RF plasma. The monomer mixture yielded a crosslinked film with light brown color. A kinetic study is reported for the plasma polymer ization of acetylene/CO_2/H_2. The effects of discharge power level and reactor geometry on the rate of polymer formation are reported. The structure of the plasma polymer is investigated by IR study. 相似文献