An aromatic azo-polymer, poly（thiourea-azo-sulfone） （PTAS）, has been prepared using 4-（4- aminophenylsulfonyl）benzenamine and diazonium salt solution of 2,6odiaminopyridine. PTAS was easily processable using pol...An aromatic azo-polymer, poly（thiourea-azo-sulfone） （PTAS）, has been prepared using 4-（4- aminophenylsulfonyl）benzenamine and diazonium salt solution of 2,6odiaminopyridine. PTAS was easily processable using polar solvents and had high molar mass 63 × 103 g.mo1-1 according to GPC. Mechanically and thermally stable and electrically conducting polymer/CNTs nano-composites were obtained via melt processing technique. Fine distribution of CNTs in a polymer matrix performed an essential role in the preparation of polymer/CNTs nano-composites based on interfacial interaction between CNTs and polymer matrix. Scanning electron micrographs showed good dispersion of filler and adhesion of matrix on the surface of nanotubes. Accordingly, increasing the amount of CNTs from 0.1 wt% to 5 wt% increased the electrical conductivity from 2.99 S.cm-1 to 3.56 S.cm-1. Mechanical strength of functional nanotubes-based hybrids was enhanced from 43.22 MPa to 65.02 MPa compared with that of hybrids with non-functional filler in matrix 37.21 MPa. A rapport between nanotube loading and thermal stability of the materials was also observed. 10% gravimetric loss temperature was increased from 528 ~C to 578 ~C, while glass transition was improved from 241 ℃ to 271 ℃. Adding up of small quantity of functional CNTs strongly affected the tensile, electrical and thermal properties of materials. Improvement of the physical properties of CNT-reinforced polymer nano-composites was ascribed to the melt processing technique.展开更多
The effect of thiourea(TU) on the nickel deposition process was analyzed by means of linear-sweep voltammetry. Raman spectroscopy and infrared reflectance spectroscopy were used to investigate the adsorption of TU and...The effect of thiourea(TU) on the nickel deposition process was analyzed by means of linear-sweep voltammetry. Raman spectroscopy and infrared reflectance spectroscopy were used to investigate the adsorption of TU and the formation of nickel-TU complexes on copper surface. The experimental results indicate that the nucleation and the preceding conversion step are involved in the deposition of nickel on copper electrodes. TU makes the onset nucleation potential negative due to the formation of nickel-TU complexes, which can accelerate the nickel deposition. Moreover, the S atom in the TU molecule adsorbed on copper surface facilitates the coordination of TU to Ni 2+ . Meanwhile, TU might be adsorbed at a flatter orientation if no Ni 2+ is on the surface, while at a perpendicular orientation when Ni 2+ is coadsorbed.展开更多
文摘An aromatic azo-polymer, poly（thiourea-azo-sulfone） （PTAS）, has been prepared using 4-（4- aminophenylsulfonyl）benzenamine and diazonium salt solution of 2,6odiaminopyridine. PTAS was easily processable using polar solvents and had high molar mass 63 × 103 g.mo1-1 according to GPC. Mechanically and thermally stable and electrically conducting polymer/CNTs nano-composites were obtained via melt processing technique. Fine distribution of CNTs in a polymer matrix performed an essential role in the preparation of polymer/CNTs nano-composites based on interfacial interaction between CNTs and polymer matrix. Scanning electron micrographs showed good dispersion of filler and adhesion of matrix on the surface of nanotubes. Accordingly, increasing the amount of CNTs from 0.1 wt% to 5 wt% increased the electrical conductivity from 2.99 S.cm-1 to 3.56 S.cm-1. Mechanical strength of functional nanotubes-based hybrids was enhanced from 43.22 MPa to 65.02 MPa compared with that of hybrids with non-functional filler in matrix 37.21 MPa. A rapport between nanotube loading and thermal stability of the materials was also observed. 10% gravimetric loss temperature was increased from 528 ~C to 578 ~C, while glass transition was improved from 241 ℃ to 271 ℃. Adding up of small quantity of functional CNTs strongly affected the tensile, electrical and thermal properties of materials. Improvement of the physical properties of CNT-reinforced polymer nano-composites was ascribed to the melt processing technique.
基金the National Natural Science Foundation of China(No.2 0 0 730 35
文摘The effect of thiourea(TU) on the nickel deposition process was analyzed by means of linear-sweep voltammetry. Raman spectroscopy and infrared reflectance spectroscopy were used to investigate the adsorption of TU and the formation of nickel-TU complexes on copper surface. The experimental results indicate that the nucleation and the preceding conversion step are involved in the deposition of nickel on copper electrodes. TU makes the onset nucleation potential negative due to the formation of nickel-TU complexes, which can accelerate the nickel deposition. Moreover, the S atom in the TU molecule adsorbed on copper surface facilitates the coordination of TU to Ni 2+ . Meanwhile, TU might be adsorbed at a flatter orientation if no Ni 2+ is on the surface, while at a perpendicular orientation when Ni 2+ is coadsorbed.
