Temperature effect on the nucleation and growth mechanisms (NGM) of poly(thiophene) (PTh) was investigated through experimental and computational tools. The computational simulation method was based on a kinetic Monte...Temperature effect on the nucleation and growth mechanisms (NGM) of poly(thiophene) (PTh) was investigated through experimental and computational tools. The computational simulation method was based on a kinetic Monte Carlo algorithm. It reproduced key processes such as diffusion, oligomerization, and the precipitation of oligomers onto the electrode surface. Electrochemical synthesis conditions at temperatures between 263 and 303 K were optimized. The deconvolution of the i-t transients reflected two contributions: a progressive nucleation with three-dimensional growth controlled by diffusion and the other by charge transfer, PN3Ddif and PN3Dct, respectively. As temperature decreased, a diminution of the charge associated to each contribution was observed and the nucleation induction time increased. Experimental and computational evidence indicated that temperature does not change the nucleation and growth mechanism (NGM). This effect was ascribed to kinetic factors rather than to film conductivity. This work contrasts simulation and experimental evidence and demonstrates how computational simulations can help to understand the electrochemical process of conducting polymers formation.展开更多
Amphiphilic terpolymer（TPR） exhibits good film-forming behavior on pure water observed by means ofπ-A isotherms.To gain insight into physical properties of TPR,the films have been deposited on silicon substrates at...Amphiphilic terpolymer（TPR） exhibits good film-forming behavior on pure water observed by means ofπ-A isotherms.To gain insight into physical properties of TPR,the films have been deposited on silicon substrates at different surface pressure by Langmuir-Blodgett（LB） technique.It was found that the increase in peak intensities of stretching mode was due to orderly packing of the films.The contact angles increased with increasing surface pressure,indicating an increase in hydrophobicity due to dense packing of chains of TPR.The cyclic voltammetric measurements indicated that TPR showed good current shielding effect for electron-transfer.In a word,LB films of TPR can produce a variety of structures with varied topography,enabling us to control not only the functionality of the surface,but also the interfacial transport characteristics.展开更多
基金M.R.is grateful to CONICYT for a Ph.D.fellowship(grant nº57090050)M.B.C.acknowledges Innova-Chile-CORFO(Project Code#09CEII-6991) M.A.del V.acknowledges FONDECYT grant nº1100055,for the financial support.
文摘Temperature effect on the nucleation and growth mechanisms (NGM) of poly(thiophene) (PTh) was investigated through experimental and computational tools. The computational simulation method was based on a kinetic Monte Carlo algorithm. It reproduced key processes such as diffusion, oligomerization, and the precipitation of oligomers onto the electrode surface. Electrochemical synthesis conditions at temperatures between 263 and 303 K were optimized. The deconvolution of the i-t transients reflected two contributions: a progressive nucleation with three-dimensional growth controlled by diffusion and the other by charge transfer, PN3Ddif and PN3Dct, respectively. As temperature decreased, a diminution of the charge associated to each contribution was observed and the nucleation induction time increased. Experimental and computational evidence indicated that temperature does not change the nucleation and growth mechanism (NGM). This effect was ascribed to kinetic factors rather than to film conductivity. This work contrasts simulation and experimental evidence and demonstrates how computational simulations can help to understand the electrochemical process of conducting polymers formation.
基金financially supported by 863 project(No.2007AA03Z316)National Natural Science Foundation of China(Nos.20977021 and 30970829)+1 种基金National Natural Science Foundation of Heilongjiang Province (No.E-2007-12)State Key Lab of Urban Water Resource and Environment(No.2010TS07)
文摘Amphiphilic terpolymer（TPR） exhibits good film-forming behavior on pure water observed by means ofπ-A isotherms.To gain insight into physical properties of TPR,the films have been deposited on silicon substrates at different surface pressure by Langmuir-Blodgett（LB） technique.It was found that the increase in peak intensities of stretching mode was due to orderly packing of the films.The contact angles increased with increasing surface pressure,indicating an increase in hydrophobicity due to dense packing of chains of TPR.The cyclic voltammetric measurements indicated that TPR showed good current shielding effect for electron-transfer.In a word,LB films of TPR can produce a variety of structures with varied topography,enabling us to control not only the functionality of the surface,but also the interfacial transport characteristics.
