PECULIARITY OF NANOLEVEL STRUCTURING IN SYNTHESIS OF NOVEL FUNCTIONAL SOLIDS AND NANOSTRUCTURED MATERIALS V.M. Smirnov,...
The State of Two-DimensionalNanostructures on the Silica Surface • А – with homogeneous character of d...
Energetic Diagram of Reaction with Kinetic and Thermodynamic Control [SiO2]m-1O1,...
The Scheme of Chemical Construction of Oxide Nanostructures by the Molecular Layering Method Si...
Stoichiometry of Interactions OH-groups of Silica with FeClз at Temperature above 200 Ca – initial content of ОН-groups b...
Interactions OH-groups of Silica with FeClз
The Scheme of State of Solid Chemical Compounds 3 1 – initial metal ...
The Fragment of Structure of Solid Matter, Consisting of the Parts of Different ChemicalComposition (Si–O and Ti–O Groups...
Dimensional Dependencies of the Properties of Solid Compounds 1...
Generalized View of Dependence of Properties on Size of Chemical Matter SubcrystalProperty ...
The State of Two-DimensionalNanostructures on the Silica Surface • А – with homogeneous character of d...
▒║–O–A–O–B–OH (sample АВ) Layered-▒║–O–В–O–А–OH (sample ВА) inhomogeneous ...
Influence of Fe-O and Ti-O Groups Ratio in Monolayer on the Catalytic Activity in Photo Induced Decomposition of H2O ...
Magnetic Susceptibility of One-Component and Two-Component Nanostructuresn – number of element-oxygen monolayers tw...
Sorption Properties of Nanostructured Materials The scheme of str...
Investigation of Mechanical Properties of Composite Materials on the Basis of Iron ...
Conclusion Therefore, we can ascertain that by present time, the scientific base is created allowing to solve complex...
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Published on: Mar 4, 2016
Published in: Technology      
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  • 1. PECULIARITY OF NANOLEVEL STRUCTURING IN SYNTHESIS OF NOVEL FUNCTIONAL SOLIDS AND NANOSTRUCTURED MATERIALS V.M. Smirnov, I.P. SuzdalevSaint-Petersburg State University, Department of Chemistry, Solid State Chemistry Division
  • 2. The State of Two-DimensionalNanostructures on the Silica Surface • А – with homogeneous character of distribution of chemical composition and state, for example, monolayers of element-oxygen groups of the same chemical composition, l – monolayer thickness, L – layer thickness, l1 = l2 = l3 = l4; 1– for example, Ti–O monolayers. • B – periodic distribution of element-oxygen layers along z axis, (L – layer thickness) consisting of the certain quantity of monolayers, for example, according to the scheme: 1 –Fe-O groups, 2 –Ti-O groups (a – two-layer group, l1 = l2 , б, в – four-layer group l1 = l3 и l2 = l4 ). • C – aperiodic distribution of element-oxygen layers along z axis, four-layer structure l1 l2 l3 l4 • D – aperiodic distribution of atoms on the plane of surface monolayer, top view: х –Fe-O groups, о –Ti-O groups; а, б – different ratios of groups Fe-O and Ti-O. • E - aperiodic distribution of “zero-dimensional" structures on the plane of support: 1 –Si , 2 – [ Fe]
  • 3. Energetic Diagram of Reaction with Kinetic and Thermodynamic Control [SiO2]m-1O1,5SiOH + Cl2 [SiO2]m-1O1,5SiCl SiCl4 A B C 1 – reaction A → B dominates, product B is kinetically stable;Free Energy 2 – side reaction A → C dominates; 3 – reaction A → B dominates, but the product B is kinetically unstable and converts rapidly into C. Reaction coordinate
  • 4. The Scheme of Chemical Construction of Oxide Nanostructures by the Molecular Layering Method Si-OH• O + CH3OH• Si Si-O-CH3 monolayer Functional groups mixture Solid matter surfacea – layer of the set thickness ; b – layer of the set arrangement ofmonolayers of different chemical nature; c – multicomponent monolayers
  • 5. Stoichiometry of Interactions OH-groups of Silica with FeClз at Temperature above 200 Ca – initial content of ОН-groups before reaction; b – Nchem/Nsurf = Fe/ОН;c – Standardization of the sample surface 2a and 2b was carried out by thermaltreatment in oxygen at 723 K for 8 hours and then thermal vacuum treatment at623 K for 20 hours (vacuum is 8·10-6 Pa).
  • 6. Interactions OH-groups of Silica with FeClз
  • 7. The Scheme of State of Solid Chemical Compounds 3 1 – initial metal oxide (MOn); 2 2–surface chemical compound [MO]n-11 (M– O)2 Si(OH)2 ; 3–spatially divided compound [MOn]– [SiO2]; 1 – conditional (internal) border of division
  • 8. The Fragment of Structure of Solid Matter, Consisting of the Parts of Different ChemicalComposition (Si–O and Ti–O Groups), Connected in 3 Different Ways •1 – spatially divided compound; • 2 – spatially divided adduct; •3 – mechanical mixture of particles of SiO2 and TiO2 .
  • 9. Dimensional Dependencies of the Properties of Solid Compounds 1 – crystal lattice 1 2 parameter for silicon (curve 1) and cerium dioxide (curve 2); 2 – critical temperature of 3 superconductivity Tc and derivative of critical magnetic field for tin layers on the glass;3 – tensile strength  of crystal.  – sample size.
  • 10. Generalized View of Dependence of Properties on Size of Chemical Matter SubcrystalProperty Massive crystal a – for the solid matter; b – change of the value of specific Surface S depending on Size of Solid Matter () b [according to V.B. Aleskovskii]. 1 – size of minimal solid matter (nanoobject); 2 – size of dispersed solid state (micro object); 3 – massive (macroscopic) solid.
  • 11. The State of Two-DimensionalNanostructures on the Silica Surface • А – with homogeneous character of distribution of chemical composition and state, for example, monolayers of element-oxygen groups of the same chemical composition, l – monolayer thickness, L – layer thickness, l1 = l2 = l3 = l4; 1– for example, Ti–O monolayers. • B – periodic distribution of element-oxygen layers along z axis, (L – layer thickness) consisting of the certain quantity of monolayers, for example, according to the scheme: 1 –Fe-O groups, 2 –Ti-O groups (a – two-layer group, l1 = l2 , б, в – four-layer group l1 = l3 и l2 = l4 ). • C – aperiodic distribution of element-oxygen layers along z axis, four-layer structure l1 l2 l3 l4 • D – aperiodic distribution of atoms on the plane of surface monolayer, top view: х –Fe-O groups, о –Ti-O groups; а, б – different ratios of groups Fe-O and Ti-O. • E - aperiodic distribution of “zero-dimensional" structures on the plane of support: 1 –Si , 2 – [ Fe]
  • 12. ▒║–O–A–O–B–OH (sample АВ) Layered-▒║–O–В–O–А–OH (sample ВА) inhomogeneous structures▒║–O–A–O–А–О–B–OH (sample 2АВ) The activity of two- component oxide nanostructures in catalytic gas phase reaction of CCl4 hydrolysis at 2400 C
  • 13. Influence of Fe-O and Ti-O Groups Ratio in Monolayer on the Catalytic Activity in Photo Induced Decomposition of H2O A – activity A = 300 at Fe3+/Ti4+ =0.69 in monolayer A = 1 at Fe3+/Ti4+ =0.69 in mixture Fe2O3 and TiO2 Fe2O3 and TiO2 mixture Fe3+/Ti4+ ratio in monolayer
  • 14. Magnetic Susceptibility of One-Component and Two-Component Nanostructuresn – number of element-oxygen monolayers two-component monolayer
  • 15. Sorption Properties of Nanostructured Materials The scheme of structure of ferromagnetic nanostructured sorbent of uranium ionsа – sample with two monolayers of Ti-O 1 – SiO2 particle (aerosil);groups 2 – layer of Fe3O4 (10 –15Åb – sample with iron-oxygen monolayers thick);and two monolayers of Ti-O groups, having 3 – layer of TiO2 (6 – 10Åferromagnetic properties thick).
  • 16. Investigation of Mechanical Properties of Composite Materials on the Basis of Iron •*Sample 1: on the basis of iron; •Sample 2: with iron carbide obtained by the addition of carbon powder ; •Sample 3: with titanium carbide obtained by the sedimentation of it from gas phase;• Sample 4: with ultrathin layer of titanium carbide obtained according to the reactions 7 and 8;• Sample 5: for the comparison disperse-reinforced material with titanium matrix and disperse-reinforced SiC fiber.
  • 17. Conclusion Therefore, we can ascertain that by present time, the scientific base is created allowing to solve complex synthetic problems, includingconstruction of highly organized nanostructured solid substances and materials.

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