Polyacene (PAS), polypyridinopyridine (PPyPy) obtained by substitution of -N = for -CH = in PAS, and paracyanogen (Pc) molecules have been studied using quantum chemistry MNDO, 1D tight-binding CNDO/2-CD methods. The ...Polyacene (PAS), polypyridinopyridine (PPyPy) obtained by substitution of -N = for -CH = in PAS, and paracyanogen (Pc) molecules have been studied using quantum chemistry MNDO, 1D tight-binding CNDO/2-CD methods. The analyses of the energy band structures indicate that the substitution of N atoms changes the molecular structures and increases the activity points of electrophilic or nucleophilic doping, but intrinsical conductivity is not improved.展开更多
he adsorption beliavior of lithium cation (Li￣+) on the surface of polyacenesemiconductor (PAS) molecule was investigated using quantum chemistry MNDOand CNDO/2 methods. There are two stable adsorption sites of Li￣+...he adsorption beliavior of lithium cation (Li￣+) on the surface of polyacenesemiconductor (PAS) molecule was investigated using quantum chemistry MNDOand CNDO/2 methods. There are two stable adsorption sites of Li￣+ over C=Cbond and benzene ring center of PAS. In the second site, adsorption energy is larg-er. Lithium adsorbed at other sites can easily migrate towards the two sites. Thecalculation of EHMO-CO energy band structures indicated that after lithium wasadsorbed at other different sites on the surface of PAS, the energy gap of the sys-tem had a little increase in most cases , but when Li￣+ was adsorbed at the hole site ,the energy gap had a little decrease, which is in favor of furtlier improvement ofconductive property. As an electrode material , the hole site may be the best site ofLi￣+ being adsorbed and desorbed.展开更多
Lithium heteropoly blue(Li 5PW Ⅵ 10 W Ⅴ 2O 40 ) was used as a non aqueous electrolyte in the polyacenic semiconductor (PAS) Li secondary battery instead of LiClO 4. The properties of the PAS Li secon...Lithium heteropoly blue(Li 5PW Ⅵ 10 W Ⅴ 2O 40 ) was used as a non aqueous electrolyte in the polyacenic semiconductor (PAS) Li secondary battery instead of LiClO 4. The properties of the PAS Li secondary battery, especially the effect of Li 5PW Ⅵ 10 W Ⅴ 2O 40 on the capacity, the cycle property and the self discharging of the battery have been investigated. The results indicate that not only Li 5PW Ⅵ 10 W Ⅴ 2O 40 can overcome the disadvantages of LiClO 4, which is apt to explode when heated or rammed, but also the PAS Li secondary battery assembled with the novel electrolyte has a larger capacity and smaller self discharging than that assembled with LiClO 4. Therefore, it is believed that lithium heteropoly blue is a better and novel electrolyte for the PAS secondary battery and exhibits significant and practical application.展开更多
The dispersing process of polyacenic semiconductor(PAS) in polyethylene(PE) was simulated by using molecular dynamics(MD) methods. The results show that this process can be divided into three stages. In the first stag...The dispersing process of polyacenic semiconductor(PAS) in polyethylene(PE) was simulated by using molecular dynamics(MD) methods. The results show that this process can be divided into three stages. In the first stage, PAS particles in the crystal region of PE are expelled to the amorphous region; in the second stage, PAS particles aggregate due to small surface areas and PE chains are adjusted continuously, which makes the crystal region complete; PAS particles are separated from each other and the total energy increases in the third stage. During the whole dispersing process, PAS particles are more stable in the amorphous region than in the crystal region. All the simulation results are in good agreement with the experimental results.展开更多
文摘Polyacene (PAS), polypyridinopyridine (PPyPy) obtained by substitution of -N = for -CH = in PAS, and paracyanogen (Pc) molecules have been studied using quantum chemistry MNDO, 1D tight-binding CNDO/2-CD methods. The analyses of the energy band structures indicate that the substitution of N atoms changes the molecular structures and increases the activity points of electrophilic or nucleophilic doping, but intrinsical conductivity is not improved.
文摘he adsorption beliavior of lithium cation (Li￣+) on the surface of polyacenesemiconductor (PAS) molecule was investigated using quantum chemistry MNDOand CNDO/2 methods. There are two stable adsorption sites of Li￣+ over C=Cbond and benzene ring center of PAS. In the second site, adsorption energy is larg-er. Lithium adsorbed at other sites can easily migrate towards the two sites. Thecalculation of EHMO-CO energy band structures indicated that after lithium wasadsorbed at other different sites on the surface of PAS, the energy gap of the sys-tem had a little increase in most cases , but when Li￣+ was adsorbed at the hole site ,the energy gap had a little decrease, which is in favor of furtlier improvement ofconductive property. As an electrode material , the hole site may be the best site ofLi￣+ being adsorbed and desorbed.
基金Supported by Education Com mittee Foundation of L iaoning Province(No.970 912 12 11) .
文摘Lithium heteropoly blue(Li 5PW Ⅵ 10 W Ⅴ 2O 40 ) was used as a non aqueous electrolyte in the polyacenic semiconductor (PAS) Li secondary battery instead of LiClO 4. The properties of the PAS Li secondary battery, especially the effect of Li 5PW Ⅵ 10 W Ⅴ 2O 40 on the capacity, the cycle property and the self discharging of the battery have been investigated. The results indicate that not only Li 5PW Ⅵ 10 W Ⅴ 2O 40 can overcome the disadvantages of LiClO 4, which is apt to explode when heated or rammed, but also the PAS Li secondary battery assembled with the novel electrolyte has a larger capacity and smaller self discharging than that assembled with LiClO 4. Therefore, it is believed that lithium heteropoly blue is a better and novel electrolyte for the PAS secondary battery and exhibits significant and practical application.
文摘The dispersing process of polyacenic semiconductor(PAS) in polyethylene(PE) was simulated by using molecular dynamics(MD) methods. The results show that this process can be divided into three stages. In the first stage, PAS particles in the crystal region of PE are expelled to the amorphous region; in the second stage, PAS particles aggregate due to small surface areas and PE chains are adjusted continuously, which makes the crystal region complete; PAS particles are separated from each other and the total energy increases in the third stage. During the whole dispersing process, PAS particles are more stable in the amorphous region than in the crystal region. All the simulation results are in good agreement with the experimental results.
