Open Access. Powered by Scholars. Published by Universities.®

Engineering Science and Materials Commons

Open Access. Powered by Scholars. Published by Universities.®

2008

Nanotechnology

Articles 1 - 3 of 3

Full-Text Articles in Engineering Science and Materials

Effect Of Concentration On Electrospun Polyacrylonitrile (Pan) Nanofibers, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu Jan 2008

Effect Of Concentration On Electrospun Polyacrylonitrile (Pan) Nanofibers, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu

Ji-Huan He

Abstract: An allometrical scaling relationship between the diameter of electrospun nanofiber and solution concentration is established, the scaling exponent differs greatly between different polymers and the same polymer with different molecules or the same molecules with different properties. The diameter of electrospun polyacrylonitrile (PAN) nanofibers increases approximately linearly with solution concentration.


Nanocomposite Powders For New Contact Materials Based On Copper And Alumina, Zeljko J. Kamberovic Jan 2008

Nanocomposite Powders For New Contact Materials Based On Copper And Alumina, Zeljko J. Kamberovic

Zeljko J Kamberovic

This paper is a contribution to characterization of Cu-Al2O3 powders with nanostructure designed for the production of dispersion strengthened contact materials. New materials with predetermined properties can be successfully synthesized by utilizing the principles of hydrometallurgy and powder metallurgy. The results show a development of a new procedure for the synthesis. The applied characterization methods were differential thermal and thermogravimetric analysis (DTA-TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM): Focused Ion Beam (FIB) and Analytical Electron Microscopy (AEM). Nanostructure characteristics, particle size in range 20-50 nm, and uniform distribution of dispersoide in copper matrix were validated.


Determination Of Al2o3 Particle Size In Cu-Al2o3 Nanocomposite Materials Using Uv Spectrophotometry, Zeljko J. Kamberovic Jan 2008

Determination Of Al2o3 Particle Size In Cu-Al2o3 Nanocomposite Materials Using Uv Spectrophotometry, Zeljko J. Kamberovic

Zeljko J Kamberovic

In order to achieve improved mechanical properties of dispersion strengthened nanocomposite, without influencing electrical and thermal conductivity it is necessary for dispersoide to be nano sized and uniformly distributed in base metal matrix. In this paper are presented the results concerning possibility of using UV spectrophotometry for determination of alumina particle size in Cu-Al2O3 system. Presented results show that this method is unefficient as method for determination of dispersoide particle size, due to the coalescence of particles false results are obtained, i.e. particle size significantly higher then one determined by image analysis.