This paper reported the results of application of screen printed electrodes (SPE) based on polymer/carbon nanostructures (multi wall carbon nanotubes -MWCNT and grapheme -G) for gas sensors. Commercial SPEs were modified by polymers such as conductive polymer Poly Vinylidene Fluorid -PVDF and biocompatible Poly Ethylene Glycol -PEG. Modified SPEs were tested in ammonia vapors with different concentration: 3, 6.2, 12.5 and 25% (wt.). Sensor-testing was performed by monitoring the change in the electrical resistance of the electrodes. The physical characterization of the sensing electrodes was performed by Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) in ATR mode. The surface morphology of CNT/PEG and CNT/ PVDF modifications, after coating with 25% NH3, expressed the effects of ammonia on the surface of the nanocomposite layer. The ammonia solution acts aggressively on the modified surface, causing furrows to form in the uniform structure and very small nanorods of oxides.

The subject of this research work was to analyze the structural and morphological changes of TiO2 as a result of incorporation of CNTs and interpret the underlying principles for the observed interactions. Hybrid TiO2/CNTs nanostructures were prepared by simplified sol-gel method followed by monitoring the thermally-induced alterations occurring up to 400 ºC. The effects of different type of CNTs (activated MWCNTs and as prepared SWCNTs) as well as the variation of the content of MWCNTs in association with the metal-dopant (Pt or Co) influencing the structural parameters of TiO2 was monitored. Addition of CNTs and metallic phase causes reduction of TiO2 (anatase) crystallite size. The applied instrumental techniques such as XRPD, Raman spectroscopy and thermal (TG, DTA and DTG) analysis points out on achieved interaction between TiO2 and incorporated CNTs. Morphological changes, observed from the SEM micrographs, revealed better inter-locking of the TiO2 matrix with SWCNTs than with MWCNTs. Formation of a more structurally disordered and non-stoichiometric anatase phase seemed to be a preferred choice for the obtained TiO2-CNT-metalic phase nanocomposites for further utilization in sensor-design products.

The processes of generation, management, treatment and disposal of fly ash industrial waste particles, all over the world, were considered as serious issues of solid waste. The subject of this research work was to create and to characterize the Fly ash/Chitosan composites aimed for heavy metal adsorption in polluted waters. Three different types of fly ash waste particles were used, two types supplied from EURONICKEL and one supplied from OSLOMEJ, Macedonia. The surface of the fly ash (FA) particles was modified by treated with nitric acid (HNO3). Several types of composite adsorbents were prepared using the chitosan as a polymer matrix. The characterization of the metallurgical waste particles was performed by XRF, XRD, TGA, SEM and FTIR analysis, while the obtained composites were tested by TGA, SEM and FTIR analysis. It was observed that the structure, morphology, and some other characteristics of FA particles have been significantly changed after treatment with chitosan and it is expected that it will improve their adsorption capacity of heavy metal ions.