• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/boms/042/05/0243

    • Keywords

       

      Oxide nanocomposites; Zn$_x$O$_y$/SiO$_2$; Ni$_x$O$_y$/SiO$_2$; Mn$_x$O$_y$/SiO$_2$; physicochemical properties; heats of immersion.

    • Abstract

       

      A series of M$_x$O$_y$/SiO$_2$ (where M $=$ Ni, Zn and Mn) nanocomposites were synthesized at different M$_x$O$_y$ contents (0.2, 1 and 3 mmol per 1 g SiO$_2$) using a deposition method. The samples were characterized using nitrogen adsorption–desorption, X-ray diffraction, Fourier transform infrared spectroscopy, high resolution transmission electronmicroscopy and photon correlation spectroscopy. The heat of immersion in water ($Q_w$) and $n$-decane ($Q_d$) were measured using a microcalorimetry method, and the corresponding values of the hydrophilicity index $K_h = Q_w/Q_d$ were analysed.The formation of M$_x$O$_y$ on a silica surface leads to diminishing of the $Q_w$ and $Q_d$ values (calculated per 1 g of nanocomposites) because of the specific surface area reduction. However, the $Q_w$ values calculated per 1 m$^2$ increase for Zn$_x$O$_y$/SiO$_2$ andMn$_x$O$_y$/SiO$_2$ in comparison with the unmodified silica, and it remains unchanged for Ni$_x$O$_y$/SiO$_2$. Silica modification with M$_x$O$_y$ significantly changes the pH dependence of zeta potential and affects the surface charge density. A shift of the isoelectric point (pH$_{\rm IEP}$) and a character of the zeta potential $\zeta$ (pH) curve are affected by the M$_x$O$_y$ phase, and pH$_{\rm IEP}$ shifts toward higher values as follows Mn < Zn < Ni.

    • Author Affiliations

       

      OLENA GONCHARUK1 VIKTOR BOGATYROV1 OLGA KAZAKOVA1 MARIA GALABURDA1 OLENA ORANSKA1 EWA SKWAREK2 HALINA WANIAK-NOWICKA2 WŁADYSŁAW JANUSZ2 VOLODYMYR GUN’KO1

      1. Chuiko Institute of Surface Chemistry, NASU, 17 General Naumov Str., 03164 Kyiv, Ukraine
      2. Faculty of Chemistry, Maria Curie-Sklodowska University, M. Curie-Sklodowska Sq.3, 20031 Lublin, Poland
    • Dates

       
  • Bulletin of Materials Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.