desorption curves. Similar results were obtained for compositions PVPZ +
(8102) + P and PVSZ (8102) n and mixtures with aerosil;
In - Third, the sorption capacity of organic-inorganic sorbent, both with
(8102), and with aerosil, lower compared to the original components, ie, has a
clear negative deviation from the additive sorption models. Especially brightly
this effect in the medium and high humidity.
Within the framework of traditional concepts, this means a decrease in the
share of the available sorption sites per unit volume of the sorbent. By real
deviation sorption capacity of the additive judged accessibility of the functional
groups (A) to interact with the molecules of the sorbate. According to some
results of calculations of But it turned out that all the hydrophilic polymers
observed trend in single parameter A on the composition of the mixture with an
offset extreme. Thus, the minimum availability of functional groups is observed
in the middle range of compositions for PVSZ and PVPZ in the area with 20
30
%
amorphous silica mixtures for PVC. Increasing humidity results in
displacement curve minima to compositions with higher concentration (8102). It
can be seen that the absolute values close availability of functional groups in the
entire concentration range for the mixtures of PVA and PVP, while for PVC
mixtures are considerably higher. These results suggest that the mechanism for
changing the accessibility of functional groups, and, consequently, the
adsorption capacity for all systems studied.
If you follow the quasi-chemical model of water vapor sorption on active
centers (functional groups), we can write the following scheme of interaction
between the functional groups of the hydrophilic polymer (ATS2) and
amorphous silica (ATS1) with each other and with the water molecules. It can be
seen that each of them in accordance with the numbers hydrated, forms
complexes with the sorbate molecules. The reaction of the functional groups to
each other (+ ATS1 ATS2), part of them is removed from the sorption process.
In this approach, the calculated parameters but is characterized by the proportion
of active sites that joined the sorption interaction with water.
In support of intermolecular interactions in the studied compositions
obtained IR-spectra of the mixtures and their components. It is shown that in all
systems have the hydrogen bonding between the hydroxyl groups of the
amorphous silica and the functional groups of the hydrophilic polymers and
intensive interaction of water molecules adsorbed to the available functional
groups of organic components - inorganic systems. In addition, for IVSZ + л
CL) on the IR-spectra revealed a new absorption band relevant connection L -
O-C, indicating their chemical interaction between the components.
101