Core–Shell Approach to Control Acid–Base Properties of Surface of Dielectric and Permittivity of Its Composite

Abstract

Hybrid organic–inorganic composites comprising cyanoethyl ester of poly(vinyl alcohol) (CEPVA) and submicron-sized barium titanate with a core–shell structure are studied. For the first time, the permittivity of obtained composites was studied in correlation with the acid–base properties of the filler and controlled via the filler surface modification by the formation of core–shell structures using sol–gel and plasma processes. The permittivity is found to grow with the increase in the content of Brønsted basic centers on the filler surface due to enhanced interactions with acid groups of polymer. This effect is especially prominent in the case of silica nanocoating deposited onto BaTiO3 surface. The permittivity of the studied composites is approximated by a modified Lichtenecker equation based on permittivity values of individual components, their concentrations, and a specific parameter characterizing their acid–base interaction.

The Improvement of Foam Concrete Geoecoprotective Properties in Transport Construction

“…This screen must be more reliable if saturate one side of the screen with silica sol and create a protective film preventing leakage through the screen into the soil during exploitation. These geoecoprotective properties are examined in papers [12][13][14][15][16][17][18][19][20].…”

Analysis of the Structure of Composite Systems by Means of Fractal Characteristics Using the BaTiO3–Fullerenol–CEPVA System as an Example

“…At the same time, establishing the relationship between the mathematical models describing the structure of composites and their target properties remains an important and largely unsolved problem. In [4][5][6][7], an integrated approach was proposed to control the electrical characteristics of polymer-inorganic composites, in particular, to increase the dielectric constant and to reduce dielectric losses by controlling the donor-acceptor interphase interactions in the filler-binder system, as well as by modifying the surface layer of ferroelectric fillers with nanocarbon additives. The maximum values of the dielectric constant of such composites were achieved by modifying barium titanate through precipitation of fullerenol from an aqueous suspension.…”

Анализ структуры композиционных систем с использованием фрактальных характеристик на примере системы BaTiO-=SUB=-3-=/SUB=--фуллеренол-ЦЭПС

“…Вместе с тем, важной и во многом нерешенной задачей остается установление взаимосвязи между математическими моделями, описывающими структуру композитов, и их целевыми свойствами. В [4][5][6][7] был предложен комплексный подход к управлению электрическими характеристиками полимерно-неорганических композитов, в частности повышению диэлектрической проницаемости и снижению диэлектрических потерь за счет регулирования донорно-акцепторных межфазных взаимодействий в системе наполнитель-связующее, в том числе модифицирования поверхностного слоя сегнетоэлектрических наполнителей наноуглеродными добавками. Максимальные значения диэлектрической проницаемости подобных композитов были достигнуты при модифицировании титаната бария осаждением фуллеренола из водной суспензии.…”