Experimental part

L.O. Zaskokina, V.V. Osipova, Y.G. Galyametdinov, A.A. Momzyakov.

NANOCOMPOSITE FOILS BASED ON SILICATE PRECUSOR WITH SURFACE-ACTIVE COMPOUNDS.

Keywords: silicate matrix, liquid crystals, composite films, luminescence.

Composites obtaining the complex Eu(DBM)₃bpy has been obtained. The use of a liquid crystal matrix results in a more uniform and orderly arrangement of the complex and silicate on the substrate.

Introduction

Liquid crystals are extremely flexible that is driven under the influence of a relatively weak external factors leading to changes in macroscopic physical properties of the sample. Therefore, materials based on them have found practical application in the most advanced fields of science and technology [1].

Great interest is the creation based on lyotropic liquid crystals of nanoscale materials with improved physical properties by doping silicate matrices and lanthanide ions and other metals into them [2-3]. Adding silicate matrix to LCD systems allows to stabilize nanoorganized structure [4].

One of the most important areas of modern material engineering aligned with the obtaining of nanostructures with desired properties. For this widely used approach of obtaining composite nanomaterials, i.e. particles of prisoners in a chemically inert matrix. In many cases, by way of such matrices we use different porous materials In these pores, various compounds may be administered and then, after chemical modification provide particles of the desired material, size and shape are the same shape as the cavities of the matrix, and its walls prevent their aggregation and to protect against environmental influences. [5] The aim of this work was to obtain nanocomposites lanthanide complexes with silicate matrices.

Experimental part

Silicate matrices were prepared by the sol-gel process from reaction mixtures consisting of vinyl trimethoxysilane (VMOS) / phenyl trimethoxysilane (PhTEOS), ethanol and water [6]. Firstly, we measured the weight of precursor and then we added ethanol plus water. The samples obtained were placed on a magnetic stirrer at a rate of 450 rev/min at temperature of 50⁰C for time duration of 2-4 days. Periodically we checked pH value (2-3 times), time by time the water phase was transformed into a gel. A few hours later we could observe a condensation into a solid continuous network. Cooked system are characterized by composition of the initial components, that is the molar and weight ratio.

Lyomesophases synthesis was carried out as described in article [8], based on non-ionic surfactants (С12EO4, С12EO9, С12EO10). Identification of liquid-crystalline properties conducted according to the polarization-optical microscopy (POM) (Olympus BX 51) - the observed textures set the type of mesophase and the phase transition temperature.

Silicate was built in liquid crystal matrix between micellar aggregates. Incorporation of small amounts of hydrochloric acid necessary sought pH (2 ÷ 3) system, wherein the water phase is gelled. Few hours later we could observe the condensation into solid continuous network. [9]

Using spin coating (SPIN COATER LAU-TELL WS - 400 - 6NPP - LITE) we obtained films of nanocomposites including Si/C12EOn/H2O. Following this method, we should introduce a system for glass and rotate it into device at a rate of 1000 rev/min.

Luminescent characteristics of multicomponent films by focusing mesophases become better, which allows passing from the supramolecular organization of the sample to streamline the entire volume.

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