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掺杂质子酸的类型对聚苯胺结构和电导率的影响 总被引:18,自引:4,他引:18
采用化学氧化聚合法以苯胺为单体,过硫酸铵为氧化剂,在不同质子酸的水溶液中合成聚苯胺,考察质子酸对聚苯胺电性能影响,并通过傅立叶红外吸收光谱(FTIR)和紫外可见光吸收光谱(UV-vis)研究聚苯胺掺杂前后结构的变化。结果表明,龙质子酸掺杂后聚 胺具有导电性是因为其分子链上电荷离城形成了共轭结构,具有不同质子酸中生成的聚苯胺氧化程度不同;分子链共轭程度与掺杂酸对阴离子大小有关,掺杂质子酸对阴离子越大,聚苯胺分子链共轭程度越大,电导率也就越高。 相似文献
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对聚苯胺在有机溶剂中掺杂质子酸的反应进行了in-situ UV-Vis光谱跟踪,用因子分析法对掺杂反应机理进行了研究.结果表明,聚苯胺在有机溶剂中掺杂质子酸的过程可能存在着两个并行反应:一个是掺杂与脱掺杂的动态平衡过程,在实验条件下反应的平衡常数约为k=5.16(24℃);另一个反应为副反应,生成的产物结构介于本征态与平衡掺杂态之间,很可能是反应过程中形成的包含不同掺杂形态的混合体. 相似文献
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用电化学方法聚合分子筛孔道内的苯胺, 根据聚苯胺在无机质子酸中的掺杂反应研究了ZSM-5,Y型分子筛对磷钼杂多酸的形状选择作用 相似文献
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掺杂聚苯胺能带结构和导电机理的研究 总被引:7,自引:1,他引:7
用EHMO-CO方法对质子掺杂聚苯胺进行了模型化理论计算,得到与吸收光谱实验数据一致的能带结构,研究表明,掺杂苯胺中的载流子是极化子,能满意地解释掺杂聚苯胺的导电机制。 相似文献
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导电聚苯胺的合成、结构、性能和应用 总被引:41,自引:0,他引:41
概述了中国科学院长春应用化学研究所对导电聚苯胺合成、结构、性能和应用的研究.从合成可溶性的聚苯胺入手,阐明了聚苯胺的若干基本化学和结构问题,提出并证明了掺杂态聚苯胺的结构模型和掺杂机理;除了质子酸掺杂外,发现了聚苯胺的碘氧化掺杂、光助氧化掺杂和K+注入还原掺杂;开发了分别以环氧树脂和聚氨酯为载体的聚苯胺防腐涂料;运用掺杂剂诱导的溶解性,通过合成带聚乙二醇链的膦酸掺杂剂,实现了导电态聚苯胺的水体系加工.其中的聚苯胺树脂及防腐涂料的生产技术,已经完成中试,正在走向产业化. 相似文献
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不同掺杂酸对纤维聚苯胺电化学性能的影响 总被引:2,自引:0,他引:2
采用界面聚合法通过不同质子酸掺杂分别制备了平均直径约为50,62,95nm的纤维聚苯胺。通过傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电镜(TEM)对其化学组成和微观形貌进行了表征,采用循环伏安、恒流充放电和交流阻抗研究了不同质子酸掺杂纤维聚苯胺的超级电容器电容行为,并利用X射线衍射(XRD)、氮气吸脱附及X射线光电子能谱(XPS)等方法对纤维聚苯胺的微观结构进行了深入研究。结果表明:高氯酸(HClO4)掺杂制备的聚苯胺在0.5A/g电流密度下的比容量可以达到397F/g,高于盐酸(HCl,334F/g)和樟脑磺酸(HCSA,383F/g)掺杂聚苯胺的测试结果,纤维的电化学性能主要受其规整度、孔隙率及掺杂度的影响。 相似文献
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LaFe1-xCuxO3的光催化性及正电子湮没研究 总被引:2,自引:0,他引:2
研究LaFeO3及微量掺铜LaFeO3的光催化活性,利用正电子湮没谱分析掺杂的影响,发现随着掺杂百分比的增加,正电子寿命逐渐下降达到一最小值,然后又上升;而光催化活性随掺杂百分比的增加逐渐上升达到最大值,然后下降。结果表明:LaFeO3掺杂后光催化活性得以提高;正电子湮没技术是研究点阵缺陷结构的有效方法之一。 相似文献
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The Ti-doped SnO2(110) surface has been investigated by using first-principles method with a slab model. The geometrical optimizations and band-structure calculations have been performed for four possible doping models. Our results indicate that the substitution of Ti for sixfold-coordinated Sn atom at the top layer is most energetically favorable. Compared to the undoped surface, those Sn and O atoms located above Ti atom tend to move toward the bulk side. Besides the surface relaxations, the doping of Ti has significant influences on the electronic structures of SnO2(110) surface, including the value and position of minimum band gap, the components of valence and conduction bands, the distributions of the charge densities, and the work function of the surface. Furthermore, the effects introduced by the substitution of Ti atom observed in the experiments can be well explained when the sixfold-coordinated Sn atom at the first layer is replaced by Ti atom. 相似文献
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Doping effects on the structural and electronic properties of ladderanes and ladder polysilanes have been studied using density functional theory. Two types of doping: substitution with isoelectronic atoms or heteroatoms (or radicals), have been used to design low band gap ladderanes. It is found that the B-doped [n]-ladderanes and 1,2 P-doped [n]-silaladderanes exhibit a very noticeable bent conformation, whereas the 1,2 and 1,3 N-doped ladderanes, P-doped ladderanes, and silaladderanes keep the relatively straight ladder shapes. The isoelectronic atom doping reduces the HOMO-LUMO (H-L) gaps of [n]-ladderanes but increases those of [n]-silaladderanes with n > 5. The present results show that isoelectronic atom doping is not an effective way to decrease the H-L gaps of ladderanes and silaladderanes. Heteroatom doping has a more pronounced effect than the isoelectronic atom doping. The HOMOs of heteroatom-doped ladderanes and silaladderanes are destabilized and LUMOs are stabilized, leading to significant reduction of H-L gaps. Most of the B-, N-, and P-doped [n]-silaladderanes we designed have H-L gaps below 1.5 eV. Therefore, it is expected that these silaladderanes are promising candidates of conductive or semiconductive materials. The heteroatom doping is a viable approach to reduce H-L gaps for the silaladderanes. In addition, it is found that nine different density functionals, including B3LYP, SVWN LDA, four pure GGAs, and three hybrid GGAs, as well as the time-dependent B3LYP method, all lead to the same predictions on the H-L gaps of ladderanes, silaladderanes, as well as their doped derivatives. 相似文献
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《Journal of solid state chemistry》2002,163(2):491-497
Crystals of calcium tartrate tetrahydrate were grown in silica gel medium in pure form and with barium, strontium, cobalt, nickel, manganese, zinc, and cadmium as dopants. The crystals, with formula DxCa1-x(C4H4O6).4H2O (where D=doping atom), were characterized by X-ray diffraction, photoelectron spectroscopy, and Raman spectroscopy. Some of the doping atoms are located in the host lattice and others are distributed at random positions, especially on the surface of the crystals. In the host lattice the doping atom replaces Ca when an earth alkaline atoms is used but occupies an interstitial site when a transition metal atom is used. The dielectric permittivity is higher in doped compounds. 相似文献
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Central Doping of a Foreign Atom into the Silver Cluster for Catalytic Conversion of CO2 toward C−C Bond Formation 下载免费PDF全文
Yuanyuan Liu Xiaoqi Chai Xiao Cai Dr. Mingyang Chen Prof. Rongchao Jin Prof. Weiping Ding Prof. Yan Zhu 《Angewandte Chemie (International ed. in English)》2018,57(31):9775-9779
Clusters with an exact number of atoms are of particular interest in catalysis. Their catalytic behaviors can be potentially altered with the addition or removal of a single atom. Now the effects of doping with a single foreign atom (Au, Pd, and Pt) into the core of an Ag cluster with 25 atoms on the catalytic properties are explored, where the foreign atom is protected by 24 Ag atoms (Au@Ag24, Pd@Ag24, and Pt@Ag24). The central doping of a single atom into the Ag25 cluster has a substantial influence on the catalytic performance in the carboxylation reaction of CO2 with terminal alkyne through C?C bond formation to produce propiolic acid. These studies reveal that the catalytic properties of the cluster catalysts can be dramatically changed with the subtle alteration by a single atom away from the active sites. 相似文献
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基于密度泛函理论研究了钠对焦炭非均相还原NO的微观作用机理。计算结果表明,Na原子可以在焦炭边缘游离,最倾向于吸附在焦炭边缘穴位,释放出174.2 kJ/mol的能量。波函数分析显示,Na原子以强静电吸引的方式与边缘碳原子结合,电子由Na转移到焦炭上。NO以O临近Na原子的方式吸附在焦炭边缘最稳定。Na促进第一个NO分子的吸附,但对第二个NO分子的吸附影响不大。内禀反应坐标计算与Mayer键级分析表明非均相还原通道中Na与O之间经历"结合-分离",通过"氧化-还原"的方式影响反应的进行。N_2分子的化学解吸附步是非均相还原的速控步。采用正则变分过渡态理论进行动力学分析,发现Na对速控步的活化能影响不大,但会增加焦炭上活性位点的数量,加快反应的进行。 相似文献
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Single atom chemically doped graphene has been theoretically studied by density functional theory. The largest band gap, 0.62 eV, appears in arsenic atom doped graphene, then 0.60 eV comes by the tin atom, whose deformations can neither be ignored. It is also found that oxygen and iron single atom embedded graphene can open band gap by 0.52 and 0.54 eV, respectively. Moreover, doping O atom shows little distortion and high stability by charge redistribution. The band gap of Fe doped graphene is opened by orbital hybridization. The other heteroatom doped results are a little inferior to them. 相似文献
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采用密度泛函理论研究了H2在碱金属(M=Li, K)掺杂的扶手椅型单壁碳纳米管上的吸附. 对于碱金属管内掺杂, 模拟了4种氢吸附构型; 对于管外掺杂, 考虑了两种吸附结构, 同时还考虑了两种不同的掺杂浓度. 所有吸附模型都进行了全优化. 计算结果表明, 碱金属掺杂后, 碱金属与碳纳米管之间发生电子授受作用使得碱金属带正电荷, 对于金属Li, 管内掺杂更有利于电子向碳纳米管转移; 与管内掺杂相比, Li原子的管外掺杂更有利于H2分子吸附. 碱金属管外掺杂的碳纳米管吸附H2的最稳定结构, 存在碱金属原子与H2分子的配位作用. 相似文献
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The geometries, stabilities, and electronic and magnetic properties of Y(n)Al (n=1-14) clusters have been systematically investigated by using density functional theory with generalized gradient approximation. The growth pattern for different sized Y(n)Al (n=1-14) clusters is Al-substituted Y(n+1) clusters and it keeps the similar frameworks of the most stable Y(n+1) clusters except for Y(9)Al cluster. The Al atom substituted the surface atom of the Y(n+1) clusters for n<9. Starting from n=9, the Al atom completely falls into the center of the Y-frame. The Al atom substituted the center atom of the Y(n+1) clusters to form the Al-encapsulated Y(n) geometries for n>9. The calculated results manifest that doping of the Al atom contributes to strengthen the stabilities of the yttrium framework. In addition, the relative stability of Y(12)Al is the strongest among all different sized Y(n)Al clusters, which might stem from its highly symmetric geometry. Mulliken population analysis shows that the charges always transfer from Y atoms to Al atom in all different sized clusters. Doping of the Al atom decreases the average magnetic moments of most Y(n) clusters. Especially, the magnetic moment is completely quenched after doping Al in the Y(13), which is ascribed to the disappearance of the ininerant 4d electron spin exchange effect. Finally, the frontier orbitals properties of Y(n)Al are also discussed. 相似文献
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Lu Wang Jiaxin Zheng Jing Zhou Rui Qin Hong Li Wai-Ning Mei Shigeru Nagase Jing Lu 《Theoretical chemistry accounts》2011,130(2-3):483-489
By performing first-principles transport simulations, we demonstrate that n-type transfer curves can be obtained in armchair-edged graphene nanoribbon field effect transistors by the potassium atom and cobaltocene molecule doping, or substituting the carbon by nitrogen atom. The Dirac point shifts downward from 0 to ?12?V when the n-type impurity concentration increases from 0 to 1.37%, while the transfer curves basically maintain symmetric feature with respect to the Dirac point. In general, the on/off current ratios are decreased and subthreshold swings are increased with the increasing doping level. Therefore, the performance of armchair-edged graphene nanoribbon field effect transistors can be controlled via tuning the impurity doping level. 相似文献