SYNTHESIS, STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF IN-SITU SYNTHESIZED POLYANILINE/SILVER NANOCOMPOSITES

2012 ◽  
Vol 05 (03) ◽  
pp. 1250026 ◽  
Author(s):  
FAHAD ALAM ◽  
SAJID ALI ANSARI ◽  
WASI KHAN ◽  
M. EHTISHAM KHAN ◽  
A. H. NAQVI

Polyaniline (PANI) is recognized as one of the most important conducting polymers due to its high conductivity and good stability. In this paper, polyaniline/silver (PANI/Ag) nanocomposites were synthesized by in-situ polymerization of aniline using ammonium peroxydisulphate (APS) as oxidizing agent with varying concentration of Ag nanoparticles colloids (0 ml, 25 ml and 50 ml). Silver nanoparticles were synthesized separately in colloidal form from silver nitrate (Ag2NO3) with the help of reducing agent sodium borohydride (NaBH4). The PANI/ Ag nanocomposites were characterized by XRD, SEM, AFM, UV-visible, temperature dependent resistivity and dielectric measurements. All samples show a single phase nature of the nanoparticles. The electrical resistivity as function of temperature was measured in the temperature range 298–383 K, which indicates a semiconducting to metallic transition at 373 K and 368 K for 25 ml and 50 ml silver colloid samples, respectively.

2002 ◽  
Vol 17 (2) ◽  
pp. 336-342 ◽  
Author(s):  
Zhijian Shen ◽  
Hong Peng ◽  
Mats Nygren

The abnormal grain growth in α–sialon ceramics was investigated. The preparations had stoichiometric compositions on the oxygen-rich phase boundary, and they were stabilized by Y, Nd, Sm, Dy, and Yb, respectively. Specimens were prepared from α–Si3N4 as precursor powder by applying conventional hot pressing and a novel rapid consolidation process, namely spark plasma sintering (SPS). Single-phase α–sialon ceramics with in situ reinforced bimodal microstructure, i.e., large elongated grains embedded in a matrix consisting of small equiaxed grains, were obtained above 1750 °C in all systems compacted by SPS and above 1800 °C in systems stabilized by Nd and Sm but not Dy, Y, or Yb by a two-step hot-pressing procedure. It was observed that the formation of abnormally grown α–sialon grains was strongly temperature-dependent, indicating that it was encouraged by the formation of a transient liquid phase that stimulated the dissolution of any remaining nitride precursors and early formed small α–sialon grains and sequentially facilitated supersaturation by the α–sialon constituents. The presence of elongated grains improves fracture resistance in the obtained materials.


2015 ◽  
Vol 1120-1121 ◽  
pp. 220-224
Author(s):  
Ying Wang ◽  
Dong Hao Sun ◽  
Yan Feng Guo

Functional Polyaniline (PANI) nanotubes are easily synthesized in high yield by an in situ polymerization using a fibrillar complex of acid orange II (AO II) and FeCl3as a template. During the process, the complex templates help direct the growth of fibrillar PANI on their surfaces, resulting in the formation of composite micro/nanofibers of PANI. After polymerization, by the post-treatment of removing templates in 1.0 M hydrochloric acid solution, PANI nanotubes with azo function and high electric conductivity of PANI are readily fabricated. The PANI nanotubes have about 150nm-300nm in diameter and several microns in length. At room temperature, the electric conductivity of PANI nanotubes is up to 10-1S/cm order of magnitude. The characterizations, including FTIR, UV-visible, XRD and TG, are presented.


2012 ◽  
Vol 557-559 ◽  
pp. 371-374
Author(s):  
Lian Liu ◽  
Teng Yu ◽  
Pei Wang ◽  
Guang Shuo Wang

Nanocomposites of poly(ε-caprolactone) (PCL) and layered double hydroxide (LDH) were prepared by in situ polymerization at low LDHs loadings in this work. The resultants were characterized by FTIR spectroscopy, X-ray diffraction (XRD), differential scanning calorimeter (DSC) and UV-visible spectroscopy (UV-vis). FTIR showed that the PCL/LDHs nanocomposites were prepared successfully by in situ polymerization and XRD spectra showed that the crystal structure did not change greatly in the presence of LDHS. DSC results confirmed that LDHs could act as nucleating agents. UV-vis spectra showed that LDHs had stronger absorbance peak than LDH. Moreover, the PCL/LDHs nanocomposites had strong anti-ultraviolet effect by introduction of LDHs into polymer matrix.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
S. C. Nagaraju ◽  
Aashis S. Roy ◽  
J. B. Prasanna Kumar ◽  
Koppalkar R. Anilkumar ◽  
G. Ramagopal

Polyaniline- (PANI) praseodymium Oxide (Pr2O3) composites have been synthesized by in situ polymerization method with different weight percentages. The synthesized composites have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The temperature dependent conductivity shows that the conductivity is due to the hopping of polarons and bipolarons. These composites show negative thermal coefficient (α) behavior as a function of temperature, which is characteristic behavior of semiconducting materials. Sensor studies have been carried out by two-probe method and found that the sensitivity increases with increase in % RH. It is noticed that stability increase is due to the presence of Pr2O3in polyaniline up to 30 wt%. A fast recovery and response time along with high sensitivity make these composites suitable for humidity sensors.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2140 ◽  
Author(s):  
Róbert Boros ◽  
Praveen Rajamani ◽  
József Kovács

We investigated products manufactured by in situ polymerization, which were reinforced with overmolded ribs. We developed our own mold and prototype product for the project. We used three different materials as preform: a material with a magnesium catalyst, manufactured by in situ polymerization, a Brüggemann AP-NYLON-based in situ polymerization material and an injection-molded PA6 (Durethan B30S, Lanxess GmbH) material. The ribs were formed from the same PA6 material (Durethan B30S, Lanxess GmbH). We examined the effect of the different technological parameters through the pull-off of the overmolded ribs. We measured the effect of melt temperature, holding pressure and holding time, and mold temperature. Considering the individual preforms, we pointed out that monomer migration and binding strength are related, which we concluded from the temperature-dependent mass loss of the materials, measured by thermogravimetric analysis (TGA). Finally, we designed a mold suitable for manufacturing overmolded parts. We designed and built pressure and temperature sensors into the mold to examine and analyze pressures and temperatures around the welding zone of the materials.


RSC Advances ◽  
2019 ◽  
Vol 9 (41) ◽  
pp. 23459-23464 ◽  
Author(s):  
Zheng Zhang ◽  
Ge Yang ◽  
Chuanzhen Zhou ◽  
Ching-Chang Chung ◽  
Ibrahim Hany

Temperature-dependent resistivity and cathodoluminescence (CL) measurements of solution-processed Cs2AgBiBr6 double perovskite single crystals.


2021 ◽  
Vol 3 (2) ◽  
pp. 49-53
Author(s):  
Panigrahi M.K

Various inorganic acid doped PMMA/PANI composite are prepared by in-situ polymerization technique. Morphology, room temperature (RT) conductivity and DC-conductivity with temperature variation (77-300 K) are analyzed by scanning electron microscopy (SEM) and linear four probe technique, respectively. Fibril structures with different diameter are observed in doped PMMA/PANI composite, whereas smooth texture is found in PMMA polymer film. Room temperature DC conductivity is found 0.1497 × 10-2 S/cm for H2SO4-and 0.309 × 10-3 S/cm for H3PO4-, 0.244 × 10-3S/cm for HCl-doped conductive composite, respectively. Temperature dependent DC Conductivity is measured and it behaves like semiconductor.


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