| 11. |
- Naboka, Olga, 1981, et al.
(författare)
-
Carbon Nanofibers Synthesized from Electrospun Cellulose for Advanced Materials Applications
- 2013
-
Ingår i: Materials Science Forum. - 1662-9752 .- 0255-5476. ; 730-732, s. 903-908
-
Konferensbidrag (refereegranskat)abstract
- Carbon nanofibrous sheets (conductivity 1.9 to 35.5 S×cm-1, water contact angle up to 137°) consisting of amorphous fibers with diameter of 20 - 150 nm (C:O atomic ratio 25.4 - 86.0) were synthesized by carbonization of cellulose regenerated from electrospun cellulose acetate mats with three methods of alkaline deacetylation. It was established that C:O atomic ratio, conductivity and hydrophobicity depended on the regeneration method and on the temperature of carbonization. The highest flexibility, lowest conductivity and lowest water contact angle was observed for carbon synthesized from cellulose regenerated with NaOH in ethanol (0.05 mol/l) for 24 hours at room temperature. The highest conductivity, highest water contact angle and lowest flexibility was observed for carbon synthesized from cellulose regenerated with water solution of NaOH/NaCl (3.75 M NaOH, 2.1 M NaCl) during 15 minutes at 65°C.
|
|
| 12. |
|
|
| 13. |
- Naboka, Olga, 1981, et al.
(författare)
-
Cobalt (II) Chloride Promoted Formation of Honeycomb Patterned Cellulose Acetate Films
- 2012
-
Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 367:1, s. 485-493
-
Tidskriftsartikel (refereegranskat)abstract
- CoCl2 containing honeycomb patterned films were prepared from cellulose acetate (CA)/CoCl2/acetone solutions by the breath figure method in a wide range of humidities. Size and pore regularity depend on the CA/CoCl2 molar ratio and humidity. When replacing CoCl2 with Co(NO3)2 or CoBr2, no formation of ordered porosity in the cellulose acetate films is observed. According to data from scanning electron microscopy (SEM), Energy Dispersive X-ray Microanalysis (EDX), X-ray Diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, the key role in the formation of honeycomb structures can be attributed to the physical and chemical properties of CoCl2 – hygroscopicity, low interaction with CA, and extraction from CA/CoCl2/acetone solution by water droplets condensed on the surface of the CA/CoCl2 solution. Obtained films are prospective for using in catalysis, hydrogen fuel cells, and optical sensing materials.
|
|
| 14. |
|
|
| 15. |
- Naboka, Olga, 1981, et al.
(författare)
-
Ni/C/SiO2 nanostructured composites synthesized by carbonization of carboxymethyl cellulose
- 2012
-
Ingår i: ECCM 15 - 15th European Conference On Composite Materials, 24-28 June 2012, Venice, Italy, paper 1052 (1-7).. ; 367:1, s. 485-493
-
Konferensbidrag (refereegranskat)abstract
- Ni/C/SiO2 porous composites were synthesized by one-pot approach by carbonization of sodium carboxymethyl cellulose/SiO2 xerogels containing NiCl2. Synthesized composites are mesoporous materials (average pore size 11.8 -15.1 nm) with the surface area 72.1 – 91.1 m2. Ni nanoparticles of 30-90 nm in diameter are evenly distributed within the volume of composites. The hydrogen sorption capacity at -196°C and 20 bar measured for as-synthesized samples was up to 0,32%.
|
|
| 16. |
- Nafari, Alexandra, 1980, et al.
(författare)
-
Combining Scanning Probe Microscopy and Transmission Electron Microscopy
- 2011
-
Ingår i: Scanning Probe Microscopy in Nanoscience and Nanotechnology. - 9783642104961 ; , s. 59-134
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter is a review of an in situ method where a scanning electron microscope (SPM) has been combined with a transmission electron microscope (TEM). By inserting a miniaturized SPM inside a TEM, a large set of open problems can be addressed and, perhaps more importantly, one may start to think about experiments in a new kind of laboratory, an in situ TEM probing laboratory, where the TEM is transformed from a microscope for still images to a real-time local probing tool. In this method, called TEMSPM, the TEM is used for imaging and analysis of a sample and SPM tip, while the SPM is used for probing of electrical and mechanical properties or for local manipulation of the sample. This chapter covers both instrumental and application aspects of TEMSPM.
|
|
| 17. |
|
|
| 18. |
- Raeissi, Bahman, 1979, et al.
(författare)
-
The Role of Mobile Charge in Oxygen Plasma-Enhanced Silicon-to-Silicon Wafer Bonding
- 2010
-
Ingår i: Electrochemical and Solid-State Letters. - : The Electrochemical Society. - 1099-0062. ; 13:6, s. H179-H181
-
Tidskriftsartikel (refereegranskat)abstract
- Mechanical bonding energies of oxygen plasma treated and room-temperature wafer bonded silicon surfaces have been measured as a function of storage time in parallel with measurements of electrical interface properties. The surface energy increases with time dependence similar to that of decreasing interface state concentration. The current vs voltage behavior reveals the existence of mobile ions. We suggest that these mobile charges, after the reaction with the interface states, give rise to the increased surface energy responsible for bonding.
|
|
| 19. |
- Sanz-Velasco, Anke, 1971, et al.
(författare)
-
Low-Temperature Direct Wafer Bonding
- 2012
-
Ingår i: Lattice Engineering: Technology and Applications. ; , s. 135-187
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The breakthrough of directwafer bondingwas achieved with siliconon-insulator (SOI) allowing for high-power and high-frequency electronics, microelectronics components with low energy consumption. After this, several bonding techniques have been developed (e.g. silicon direct bonding, anodic bonding) and are being developed (e.g. low-temperature plasma-assisted direct bonding) to achieve hybrid components, as III-V semiconductors on silicon-based substrates, monolithic integration of optoelectronic devices with high-speed silicon integrated circuits, three-dimensional stacking of integrated circuits (ICs) or circuits transfer onto a varietyof substrates. An overview of more recent activities on several techniques for attaining low-temperature bonding is presented.
|
|
| 20. |
- Schaller, Vincent, 1979, et al.
(författare)
-
Determination of nanocrystal size distribution in magnetic multicore particles including dipole-dipole interactions and magnetic anisotropy: A Monte Carlo study
- 2010
-
Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. - 9780735408661 ; 1311, s. 42-50
-
Konferensbidrag (refereegranskat)abstract
- A correct estimate of the size distribution (i.e., median diameter D and geometric standard deviation σ) of the magnetic nanocrystals (MNCs) embedded in magnetic multicore particles is a necessity in most applications relying on the magnetic response of these particles. In this paper we use a Monte Carlo method to simulate the equilibrium magnetization of two types of multicore particles: (I) MNCs fused in a random compact cluster, and (II) MNCs distributed on the surface of a large carrier sphere. The simulated magnetization data are then fitted using a common method based on a Langevin equation weighted with a size distribution function. Finally, the fitting parameters Dm and σm are compared to the real parameters Dp and σp used to generate the MNCs. Our results show that fitting magnetization data with a Langevin model that neglects magnetic anisotropy and dipole-dipole interactions leads to an erroneous estimate of the size distribution of the MNCs in multicore particles. The magnitude of the error depends on the particle morphology, number of MNCs contained in the particle and magnetic properties of the MNCs.
|
|
