An effect of heating and stirring in a facile wet chemical route to synthesize entangled nanofibrous mesh of doped polyaniline(PANI) was reported. The structural, morphological, and optical properties of PANI nano-fib...An effect of heating and stirring in a facile wet chemical route to synthesize entangled nanofibrous mesh of doped polyaniline(PANI) was reported. The structural, morphological, and optical properties of PANI nano-fibers were found to be dependent on synthesis temperature and stirring. The XRD analysis confirms nano PANI formation with 2θ peaks around 15°, 21°, and 25° for(011),(020), and(200) crystal planes, respectively. The average crystallite size varies between 25 nm to 60 nm due to change in synthesis conditions. The SEM analysis reveals the clustered granule formation for PANI sample synthesized at 28 and 60 ℃ under continuous stirring, whereas, unstirred synthesis at 60 ℃ shows entangled nano-fibrous mesh morphology. The TGA study shows better thermal stability for PANI mesh over granular PANI. The FTIR spectra validates the emeraldine salt PANI formation with peaks corresponding to C-H, C-N, N=Q=N, N=B=N, and N-H vibration bands. The UV-Vis analysis shows the major absorbance peaks around λ: 340 nm(π-π* transition of benzenoid ring), and λ: 800 nm(π-π*, polaron-π*, π-polaron transitions). The dense entangled nano-fibrous coating of PANI synthesized at 60 ℃ without stirring shows highest electrical conductivity of 3.79 S·cm^-1.展开更多
Ni-doped BiFeO_(3) powders with the composition BiFe_(1-x)Ni_(x)O_(3)(x=0.05,0.1 and 0.15)were prepared by a self-propagating high-temperature synthesis(SHS),using metal nitrates as oxidizers and glycine as fuel.The X...Ni-doped BiFeO_(3) powders with the composition BiFe_(1-x)Ni_(x)O_(3)(x=0.05,0.1 and 0.15)were prepared by a self-propagating high-temperature synthesis(SHS),using metal nitrates as oxidizers and glycine as fuel.The X-ray diffraction(XRD)patterns depict that Ni-doped BiFeO_(3) ceramics crystallize in a rhombhohedral phase.The scanning electron micrographs of Ni-doped BiFeO_(3) ceramics show a dense morphology with interconnected structure.It is found that,the room-temperature magnetization measurements in Ni-incorporated BiFeO_(3) ceramics give rise to nonzero magnetization.The magnetization of Ni-doped BiFeO_(3) ceramics is significantly enhanced when Ni doping concentration reaches to x=0.1 at 5 K.The variations of dielectric constant with temperature in BiFe_(0.95)Ni_(0.05)O_(3),BiFe_(0.9)Ni_(0.1)O_(3) and BiFe_(0.85)Ni_(0.15)O_(3) samples exhibit clear dielectric anomalies approximately around 450℃,425℃and 410℃respectively,which correspond to antiferromagnetic to paramagnetic phase transition of the parent compound BiFeO_(3).展开更多
文摘An effect of heating and stirring in a facile wet chemical route to synthesize entangled nanofibrous mesh of doped polyaniline(PANI) was reported. The structural, morphological, and optical properties of PANI nano-fibers were found to be dependent on synthesis temperature and stirring. The XRD analysis confirms nano PANI formation with 2θ peaks around 15°, 21°, and 25° for(011),(020), and(200) crystal planes, respectively. The average crystallite size varies between 25 nm to 60 nm due to change in synthesis conditions. The SEM analysis reveals the clustered granule formation for PANI sample synthesized at 28 and 60 ℃ under continuous stirring, whereas, unstirred synthesis at 60 ℃ shows entangled nano-fibrous mesh morphology. The TGA study shows better thermal stability for PANI mesh over granular PANI. The FTIR spectra validates the emeraldine salt PANI formation with peaks corresponding to C-H, C-N, N=Q=N, N=B=N, and N-H vibration bands. The UV-Vis analysis shows the major absorbance peaks around λ: 340 nm(π-π* transition of benzenoid ring), and λ: 800 nm(π-π*, polaron-π*, π-polaron transitions). The dense entangled nano-fibrous coating of PANI synthesized at 60 ℃ without stirring shows highest electrical conductivity of 3.79 S·cm^-1.
基金This study was supported by UGC-SAP,DRS Phase II of Indiathe author Y.A.Chaudhari is very much thankful for the funding agency.
文摘Ni-doped BiFeO_(3) powders with the composition BiFe_(1-x)Ni_(x)O_(3)(x=0.05,0.1 and 0.15)were prepared by a self-propagating high-temperature synthesis(SHS),using metal nitrates as oxidizers and glycine as fuel.The X-ray diffraction(XRD)patterns depict that Ni-doped BiFeO_(3) ceramics crystallize in a rhombhohedral phase.The scanning electron micrographs of Ni-doped BiFeO_(3) ceramics show a dense morphology with interconnected structure.It is found that,the room-temperature magnetization measurements in Ni-incorporated BiFeO_(3) ceramics give rise to nonzero magnetization.The magnetization of Ni-doped BiFeO_(3) ceramics is significantly enhanced when Ni doping concentration reaches to x=0.1 at 5 K.The variations of dielectric constant with temperature in BiFe_(0.95)Ni_(0.05)O_(3),BiFe_(0.9)Ni_(0.1)O_(3) and BiFe_(0.85)Ni_(0.15)O_(3) samples exhibit clear dielectric anomalies approximately around 450℃,425℃and 410℃respectively,which correspond to antiferromagnetic to paramagnetic phase transition of the parent compound BiFeO_(3).
