3 Structural Peculiarities and Properties of Silver-Containing Polymer. . .
51
where m is the mass of the absorbent, V is the volume of the solution, and c in and
c eq are the initial and the equilibrium concentrations of silver ions. For IMC films
£ = 2.2 mmol/g.
The chemical reduction of Ag + ions in the IMC was realized with NaBH 4 (a
molar ratio of [BH 4
− ]:[Ag + ] ≥ 1.0) in an alkaline medium (pH 10.8) in a solvent
mixture of water–isopropanol (4:1 vol %) at µ = 20 ± 2 ◦ C for 3 h (until the release
of gaseous bubbles ceased). The concentration of NaBH 4 in the aqueous alcohol
solution was 0.1 mol/L. As a result of the reduction, IMC films changed color from
red to a metallic silver one.
The features of the structuring of the IPEC (pectin–P4VP), the IMC (pectin–
Ag + –P4VP), and nanocomposites of IPEC–Ag were studied by wide-angle Xray scattering (WAXS) with a DRON-4-07 diffractometer (scientific-production
company “Burevestnik,” Russia), whose X-ray optical scheme was used to “pass”
primary-beam radiation through samples.
The heterogeneous structuring of these polymeric systems (at the nanometer
level) was studied via small-angle X-ray scattering (SAXS) with a CRM-1 camera
(Orel scientific equipment factory, Russia), having a slit collimator of the primary
irradiation beam made via the Kratky method. The geometric parameters of the
camera satisfied the condition of infinite height of the primary beam [15]. The
intensity profiles were normalized to the volume of X-ray scattering and the
attenuation factor of the primary beam of the test sample.
All X-ray diffraction studies were performed at µ = 20 ± 2 ◦ C in Cu- α radiation
monochromated with a Ni filter.
Thermomechanical studies of polymer systems were conducted using the penetration method in the mode of a uniaxial constant load (σ = 0.5 MPa) with
a UIP-70 M device (central design engineering bureau of the special instrument
making of the Russian Academy of Sciences). Linear heating of samples was
performed at a rate of 2.5 ◦ C/min in the temperature range 0 to +250 ◦ C. Relative
penetration (%) was calculated as:
ε = ( l 0 ) · 100,
where l is penetration (μm) at certain temperature and l 0 is the initial thickness of
the sample (μm).
Comparing of the WAXS diffractograms of the cationic and anionic polyelectrolytes on whose basis the IPEC was formed (see Fig. 3.1), it was found that
P4VP has only short-range ordering while translated in bulk fragments of the main
macromolecular chains and their lateral branches – pyridine ring (curve 1) – and
pectin has an amorphous–crystalline structure (curves 4).
The analysis of the atomic structure of macromolecules P4VP showed that
low-intensity peak at 2θ max ∼ 10,6
◦ describes the near arrangement of basic
macromolecular chains, while 2θ max ∼ 19,7
◦ characterizes pyridine ring (Fig. 3.1,
curve 1).
Herewith, the average value of d period of the short-range ordering of fragments
of basic macrochains at their positioning in a space (in a volume of P4VP) according
51
where m is the mass of the absorbent, V is the volume of the solution, and c in and
c eq are the initial and the equilibrium concentrations of silver ions. For IMC films
£ = 2.2 mmol/g.
The chemical reduction of Ag + ions in the IMC was realized with NaBH 4 (a
molar ratio of [BH 4
− ]:[Ag + ] ≥ 1.0) in an alkaline medium (pH 10.8) in a solvent
mixture of water–isopropanol (4:1 vol %) at µ = 20 ± 2 ◦ C for 3 h (until the release
of gaseous bubbles ceased). The concentration of NaBH 4 in the aqueous alcohol
solution was 0.1 mol/L. As a result of the reduction, IMC films changed color from
red to a metallic silver one.
The features of the structuring of the IPEC (pectin–P4VP), the IMC (pectin–
Ag + –P4VP), and nanocomposites of IPEC–Ag were studied by wide-angle Xray scattering (WAXS) with a DRON-4-07 diffractometer (scientific-production
company “Burevestnik,” Russia), whose X-ray optical scheme was used to “pass”
primary-beam radiation through samples.
The heterogeneous structuring of these polymeric systems (at the nanometer
level) was studied via small-angle X-ray scattering (SAXS) with a CRM-1 camera
(Orel scientific equipment factory, Russia), having a slit collimator of the primary
irradiation beam made via the Kratky method. The geometric parameters of the
camera satisfied the condition of infinite height of the primary beam [15]. The
intensity profiles were normalized to the volume of X-ray scattering and the
attenuation factor of the primary beam of the test sample.
All X-ray diffraction studies were performed at µ = 20 ± 2 ◦ C in Cu- α radiation
monochromated with a Ni filter.
Thermomechanical studies of polymer systems were conducted using the penetration method in the mode of a uniaxial constant load (σ = 0.5 MPa) with
a UIP-70 M device (central design engineering bureau of the special instrument
making of the Russian Academy of Sciences). Linear heating of samples was
performed at a rate of 2.5 ◦ C/min in the temperature range 0 to +250 ◦ C. Relative
penetration (%) was calculated as:
ε = ( l 0 ) · 100,
where l is penetration (μm) at certain temperature and l 0 is the initial thickness of
the sample (μm).
Comparing of the WAXS diffractograms of the cationic and anionic polyelectrolytes on whose basis the IPEC was formed (see Fig. 3.1), it was found that
P4VP has only short-range ordering while translated in bulk fragments of the main
macromolecular chains and their lateral branches – pyridine ring (curve 1) – and
pectin has an amorphous–crystalline structure (curves 4).
The analysis of the atomic structure of macromolecules P4VP showed that
low-intensity peak at 2θ max ∼ 10,6
◦ describes the near arrangement of basic
macromolecular chains, while 2θ max ∼ 19,7
◦ characterizes pyridine ring (Fig. 3.1,
curve 1).
Herewith, the average value of d period of the short-range ordering of fragments
of basic macrochains at their positioning in a space (in a volume of P4VP) according