Leica Stereoscan

The cross-section of the cotton fibers was prepared by an RMC PT-XL ultramicrotome system, and then investigated by SEM (Leica Stereoscan 440). 

The surface morphology of the SMPU fibers was studied by a Leica Stereoscan 440 SEM. A single fiber of the produced multi-filament SMPU fibers was attached to the SEM sample holder. The accelerated voltage of the electron beam was 20 kV and the secondary electron images were recorded by the CCD system in the SEM. 

Leica Cambridge Stereoscan 360). The SEM micrographs of H-ZSM-5, Zn-H-ZSM-5 and Ga-H-ZSM-5 exhibited the typical crystal form of ZSM-5 zeolite and the average crystal size was 2 pm-4 pm. The quantitative analysis of the Ga and Zn content in the ZSM-5 zeolite was performed by an X-ray fluorescence analyzer X-MET 880 (Outokumpu). The specific surface area of the synthesized zeolite catalysts was determined by nitrogen adsorption using a Sorptomatic 1900 (Carlo Erba Instmments). The specific surface area calculated by the Dubinin method was found to be 427, 445 and 372 m /g for Zn-H-ZSM-5, Ga-H-ZSM-5 and H-ZSM-5, respectively. It was observed from different characterization techniques that the introduction of Ga and Zn by this method did not destroy the structure of the ZSM-5 zeolite. 

The surface morphologies of the PAni fibers were investigated with a scanning electron microscope (SEM, Leica Model Stereoscan 440) with a secondary electron detector. To obtain clear cross-section images, the fibers were frozen in liquid nitrogen before snapping them. 

The SEM observations were carried on different instruments (Jeol 6500 FEG, Cambridge Stereoscan 360, and FEl Quanta 200) after sputtering a conductive layer of C, Pt or Au on the samples. The samples for the TEM observation (Zeiss EM900) were included in an Epon Araldite matrix and cured at 60 °C for 3 days the cross-sections were cut in 80 nm thick slices with a Leica Ultracut UCT ultramicrotome. 

For SEM analyses, the samples were fixed with a 2.5% glutaraldehyde solution in O.IM cacodilate buffer (pH 7.2), dehydrated through a graded series of ethanol (up to 100%), and critical point-dried using CO2. Specimens, mounted on aluminium stubs, were sputter-coated with gold, and examined with a Leica Cambridge Stereoscan 440 microscope at 3-7 kV acceleration voltage. 

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