CAREER NETWORK World's one of the largest Research Career Network Benefits Academic & Industry jobs Project funding Visiting faculty positions Visiting scientist positions Invited talks and more... Register FREE Global Journal of Physical Chemistry. Volume 2, Issue 1 (2011) pp. 1-13 Research Article Optical and structural investigation on NiS quantum dots / Poly(vinyl)-alcohol novel composites Antonino Bartolotta, Pietro Calandra* Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico Fisici U.O. di Messina, Viale Ferdinando Stagno d'Alcontres, n. 37, 98158 Messina, Italy Abstract NiS quantum dots / poly(vinyl) alcohol (PVA) novel composites were prepared by simply mixing aqueous solutions of NiCl2 and Na2S in presence of PVA under stirring and successively allowing water evaporation. The photophysical properties were studied by UV-Vis absorption spectroscopy, whereas the structural features were investigated by FT-IR spectroscopy, X-Ray diffraction and by Dynamical Mechanical Thermal Analysis. It was found that the NiS quantum dots Energy Gap can be widely tuned by simply changing the precursors concentration. Moreover, all experimental data consistently show that the PVA acts as a chemical stabilizer through PVA OH - Ni2+ complexes formation. These interactions allow the stabilisation of NiS quantum dots within the PVA matrix and causes an increase of the polymeric amorphous phase fraction at the expenses of the crystalline one together with an increase in the free volume. This results in an enhanced molecular mobility which is worth to tailor for specific applications. Keywords NiS quantum dots; Poly(vinyl) alcohol; Composites