Nanocomposites and nanomaterials

Predefined formation of nanodimensional particles of inorganic ion-exchangers in porous polymers 
Yu.S. Dzyazko1, L.M. Ponomaryova2 , Yu.M. Volfkovich3, O.V. Perlova4, Yu.G. Zmiexskii5
1 V.I. Vernadskii Institute of General and Inorganic Chemistry of the NAS of Ukraine, 32/34 Palladin ave., 03142, Kyiv, Ukraine
E-mail: dzyazko@gmail.com
2 Sumy National Agrarian University, Gerasim Kondrat'ev str. 160, 40000, Sumy, Ukraine
3 A..N. Frumkin  Institute of Physical Chemistry and Electrochemistry of the RAS, Leninskii pr. 31, 119071, Moscow, RF
4 Odesa I.I. Mechnikov National University, 2 Dvoryanska Str., 65082, Odesa, Ukraine 
5 National University of Food Technology, Volodymyrska str. 68, 01033, Kyiv, Ukraine

Main regularities for precipitation of inorganic modifiers inside ion exchange (weakly and strongly acidic as well as strongly basic; flexible and rigid) and inert polymers are considered. The Ostwald-Friendlich equation was applied to obtain the relations, which allows us to  determine the conditions for purposeful formation of one or other particles (non-aggregated nanoparticles, aggregates and agglomerates). The obtained composites were investigated with methods of transmission and scanning electron microscopy, standard contact porosimetry, 31P NMR spectroscopy. The effect of temperature, solvent viscosity, concentration of impregnating salts and precipitators, ion exchange capacity of the polymer matrices are considered. The particles of oxides are smaller than those of phosphates. As a result, oxides are deposited in active layer of the membranes for filtration processes, phosphates are formed only in the macroporous substrate. Namely oxide particles provide rejection ability of the membranes: the separators are transformed from microfiltration into ultrafiltration or nanofiltration materials.
Regarding ion exchange polymers, the particles are formed in hydrophilic and hydrophobic pores providing additional swelling pressure, which squeezes and stretches pore walls. Additional hydrophilic micropores are formed in the polymer. matrix, they are selective centers, when large ions are sorbed.