Abstract
The binding of water in heterogeneous systems containing polymethylsiloxane (PMS) pyrogenic nanosilica (A-300) water and the surface-active substance decametoxin (DMT) was studied. Composite systems were created using metered mechanical loads. The low-temperature 1H NMR spectroscopy was used to measure the structural and thermodynamic parameters of bound water. It is shown that when filling PMS interparticle gaps with hydrocompaction, the interfacial energy of water in the interparticle gaps of hydrophobic PMS with the same hydration is twice as large as the interfacial energy of water in hydrophilic silica A-300. This is due to the smaller linear dimensions of the interparticle gaps in the ICP compared with the A-300. In the composite system, A-300/PMS/DMT/H2O, a non-additive growth of water binding energy is observed, which is likely due to the formation, under the influence of mechanical load in the presence of water, of microheterogeneous sites, consisting mainly of the hydrophobic and hydrophilic components (microcoagulation). Thus, using mechanical loads, you can control the adsorption properties of composite systems.
Highlights
One of the basic principles of formation of stable heterophase liquids is their desire to minimize free energy [1]
An integral indicator that can be used to judge the free energy reduction in heterogeneous systems containing the same amount of water is the amount of interfacial energy of water, which is determined from the data of low-temperature 1H NMR
It is shown that when filling the inter-particle gaps of polymethylsiloxane by the method of hydro-sealing, the inter-phase energy of water in the inter-particle gaps of hydrophobic PMS with the same hydration is twice the inter-phase energy of water in hydrophilic silica
Summary
One of the basic principles of formation of stable heterophase liquids is their desire to minimize free energy [1]. Non-miscible liquids (eg, water and oil) exist in the form of spatially separated layers, and their mixing in ultrasound treatment is thermodynamically unprofitable, since it is accompanied not by a decrease but by an increase in free energy. Surfactants having a high affinity for both liquids make it possible to create a stable colloidal system in which the non-miscible phases are separated by a thin molecular layer of surfactants. The increase in free energy due to the dispersion of one of the liquids (formation of a micellar structure) is compensated by its decrease due to the molecular interactions of the surfactants with the hydrophobic and hydrophilic components of the heterogeneous system [2]. An integral indicator that can be used to judge the free energy reduction in heterogeneous systems containing the same amount of water is the amount of interfacial energy of water, which is determined from the data of low-temperature 1H NMR spectroscopy [6, 9,10,11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
