Найдено научных статей и публикаций: 5, для научной тематики: Nanocomposites
1.
V. R. Galakhov, S. N. Shamin, V. V. Mesilov, N. A. Ovechkina, M. A. Uimin, A. Ye. Yermakov, L. Schneider, K. Balinski, B. V. Senkovskiy
- The Journal of Physical Chemistry C , 2014
Ni@C nanocomposites and the carbon shells extracted by etching Ni@C in nitric acid have been characterized by means of soft X-ray absorption and X-ray photoelectron spectroscopies. It was found on the base of Ni 2p X-ray absorption spectra and atomic multiplet calculations that Ni traces in the carb...
Ni@C nanocomposites and the carbon shells extracted by etching Ni@C in nitric acid have been characterized by means of soft X-ray absorption and X-ray photoelectron spectroscopies. It was found on the base of Ni 2p X-ray absorption spectra and atomic multiplet calculations that Ni traces in the carbon-shell sample are in the Ni2+ state formed probably by nickel nitrate hexahydrate, Ni(NO3)2·6H2O. Second derivatives of C 1s of X-ray absorption spectra and C 1s X-ray photoelectron spectra were used for characterization of functional groups linked to carbon shells of nanocomposites. The application of second derivatives of C 1s of X-ray absorption spectra allowed to confirm AA stacking of carbon layers for highly oriented pyrolytic graphite. The low-energy features in C 1s XAS spectra of Ni@C and carbon-shell samples are found to be of a different nature. Most likely, the low-energy C 1s XAS feature of the carbon-shell sample is formed due to hydrogenation of carbon atom.
2.
B. Samal, P. K. Rana, P. K. Sahoo
- Polymers & polymer composites , 2009
3.
I.R. Kamrupi, P. Phukon, S.K. Dolui and B.K. Konwer
- Journal of Supercritical Fluids , 2010
A novel method based on ex situ dispersion of silver nanoparticles within the monomers and subsequent emulsion polymerization using water-in-sc-CO2 medium is introduced in this paper. Silver nanoparticles were synthesized by chemical reduction of silver nitrate using sodium borohydrate as a reducing...
A novel method based on ex situ dispersion of silver nanoparticles within the monomers and subsequent emulsion polymerization using water-in-sc-CO2 medium is introduced in this paper. Silver nanoparticles were synthesized by chemical reduction of silver nitrate using sodium borohydrate as a reducing agent and polydimethylsiloxane (PDMS) as a stabilizer in the water-in-sc-CO2 medium. The stable dispersion of silver nanoparticles was added slowly during the polymerization of styrene in the water-in-sc-CO2 maintaining the temperature at 70oC and pressure at 20.68MPa respectively. The silver nanoparticles encapsulated within polymer particles were characterized by UV-visible spectroscopy, XRD, TGA, SEM and TEM. The silver/polystyrene nanocomposite particles exhibited antimicrobial activity against a number of bacteria. The current work represents a simple, reproducible and universal way to prepare a variety of metal–polymer nanocomposite particles.
4.
I.R. Kamrupi and S.K. Dolui
- Materials and manufacturing Processes , 2010
We have synthesized microparticles of polymer by emulsion polymerization of styrene in supercritical carbon dioxide (sc-CO2) using (polydimethylsiloxane) (PDMS) as a surfactant/stabilizer and azobisisobutyronitrile (AIBN) as initiator. The emulsion polymerization was carried out at different pressur...
We have synthesized microparticles of polymer by emulsion polymerization of styrene in supercritical carbon dioxide (sc-CO2) using (polydimethylsiloxane) (PDMS) as a surfactant/stabilizer and azobisisobutyronitrile (AIBN) as initiator. The emulsion polymerization was carried out at different pressures (2000-2600 psi). At the end of polymerization, powdered polymeric micoparticles were collected by depressurizing CO2. The powdered polymeric microparticles were characterized by SEM, GPC, DSC and TGA. The influence of pressure on conversion, molecular weight, particle size and polydispersity index was studied. The molecular weight (Mn) of the polymer is in the range of 35,542 to 45,078 g/mol. Polydispersity is in the range of 1.45-1.86 and particle size in the range of 3.25m-6.3m.
DOI: 10.1080/10426914.2010.491008
5.
Savchenko D., Kassiba A.., Ogurtsov N., Errien N., Makoswka-Janusik M., Pud A., Kodjikian S., Oueriagli A.
- IEEE Conference Proceeding: ICTON Mediterranean Winter Conference (Angers, France, December 10-12), 2009. ICTON-MW 2009. 3rd , 2010
Electron paramagnetic resonance (EPR) investigations were carried out on hybrid Core-Shell nanomaterials
associating silicon carbide nanoparticles and conducting polyaniline. The performed experiments compare the
paramagnetic centres, the electronic transport features and the interface effects in ...
Electron paramagnetic resonance (EPR) investigations were carried out on hybrid Core-Shell nanomaterials
associating silicon carbide nanoparticles and conducting polyaniline. The performed experiments compare the
paramagnetic centres, the electronic transport features and the interface effects in two classes of materials, bare
polymers and core-shell nanocomposites. By EPR, large doping rates were demonstrated in the bare doped
polymers through important saturation phenomena which alter significantly the EPR spectrum features.
Furthermore, memory effects were involved in the bare doped polymer with regard to the EPR spectrum features
depending on the conditions of its thermal treatments. In the hybrid core-shell nanocomposites nor such
saturation and nor memory effects were found on the EPR signals even if similar paramagnetic centres exist in
both classes of samples. These behaviors were discussed taking into account the thermal stability and the doping
efficiency in the considered classes of materials. Optimal doping levels were then realized and their effects on
the polymers and the nanocomposites were clarified by using EPR and DRS (dielectric relaxation spectroscopy)
measurements. Also, it is demonstrated that the charge carriers consist in polarons in the nanocomposites while
bipolarons contributions dominate the electrical conductivity in the bare doped polymers