from the gas phase to the surface of the liquid medium [4].
The research has shown that by varying the composition of liquid phases, it is
possible to control chemical transformations and obtain different inorganic synthesis
products. Thus, one part of the researches were aimed at synthesizing stable water
nanodispersions of silver using contact nonequilibrium low-temperature plasma.
The
use of plants as the production assembly of
MNPs
has drawn attention, because of its
rapid, ecofriendly, non-pathogenic, economical protocol, providing a single step
technique for the biosynthetic processes and containing important phytochemicals used
as reducing agents for
MNPs
synthesis. A large number of plants are reported to
facilitate
MNPs
syntheses with different sizes are mentioned.
However, an analysis of the pertinent literature revealed challenging issues and
shortcomings limiting the advancement of the green synthesis. Major issues, include:
technical, engineering, and economical limitations associated with the source/type and
concentration of plant extracts, stoichiometric ratios of the reagents, optimal
experimental
conditions
(temperature,
pH,
time),
yield,
and
product
characterization/application. One of the issues is the increasing concentration of
extracts of plant material. Increasing the efficiency of MNPs synthesis by increasing
the degree of extraction the plant material is reported in works [1, 2]. For this purpose,
the extraction is carried out under the action of UV, gamma and ultrasound irradiation.
Plasma-chemical formation of monometallic (Au, Ag), biometallic (Au/Ag)
nanoparticles, composite materials and their applications. The synthesis of stable
concentrated aqueous dispersions with desired physicochemical properties on the basis
of monometallic and bimetallic nanoparticles is a necessary step during the further
creation of nanostructured materials. Given this, the development of innovative high-
performance plasma-chemical methods aimed at synthesizing nanosized silver
particles and concentrated water dispersions on a basis is relevant. The research was
aimed at synthesizing stable water nanodispersions of monometallic and bimetallic
particles using contact nonequilibrium low-temperature plasma.
Materials and methods. Silver nitrate (99.8%, Kishida), hydrogen gold chloride
(HAuCl
4
, 99.9 %), trisodium citrate, polyvinyl alcohol (MW=40 000), polyvinyl
pyrrolidone
were purchased from Merck Co. Ltd. (Darmstadt, Germany). Aqueous
solutions of precursor were prepared using ultrapure water (Direct-Q UV, Millipore)
and were utilized as starting materials without further purification. Silver nanoparticles
were synthesized using synthesis reactor (Fig.1) [4]. The precursors were dissolved in
double distilled water to give a solution of 0.003 mol/L. The resulting reaction mixture
was treated in the reactor with the discharge of contact non-equilibrium low-
temperature plasma with fixed parameters (pressure, current strength, voltage). The
final product was obtained as a colloidal dispersion. The change in color of a mixture
of precursor indicates the synthesis of nanoparticles.
The strong SPR band in UV–Vis
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