PANa/Covalent Organic Framework Composites with Improved Water Uptake and Proton Conductivity

It is a challenge to effectively load proton carriers in COFs to improve their proton conductivity. Herein, we report a series of COF-based composites, PANa@UCOF-x (PANa: sodium polyacrylate, x: weight...

Synthesis of Antibacterially ActiveSilver Nanoparticles by Galvanic Replacement on Magnesium in Solutions of Sodium Polyacrylate in an Ultrasound

“Green” synthesis of silver nanoparticles (AgNPs) by a galvanic replacement (GR) on magnesium in solutions of sodium polyacrylate (NaPA) under ultrasound (42 kHz) is reported. The mechanism of combined action of GR and ultrasound on the formation of nanoparticles is proposed. Synthesized solutions of AgNPs are characterized by an absorption maximum at 410 nm, the value of which does not depend on the concentrations of precursors (AgNO3 and NaPA) and the duration of the process. The dimensions of nanoparticles that have a spherical shape do not exceed 30 nm. With increasing concentration of surfactant, there is a tendency to decrease in size. The rate of synthesis of AgNPs increases almost in proportion to the concentration of AgNO3 in the solution, while the effect of NaPA concentration is negligible. The synthesized nanoparticles efficiently demonstrated a bactericide effect on Escherichia coli and Staphylococcus aureus.

Influence of ultrasound on the synthesis of silver nanoparticles by galvanic replacement in sodium polyacrylate solutions

Sonogalvanic replacement and galvanic replacement synthesis of silver nanoparticles (AgNPs) by magnesium scrap in sodium polyacrylate solutions were studied. It was found that during these processes in NaPA solutions silver is practically not deposited on the magnesium surface. Sodium polyacrylate provides stabilization of AgNPs with the formation of yellow solutions with maximum absorption of ~415 nm. It is shown that sonogalvanic replacement synthesis of AgNPs occurs due to the simultaneous course of galvanic replacement by magnesium and sonoreduction of Ag (I) by radicals and reducing agents. The rate of sonogalvanic replacement synthesis of AgNPs is 20-30% higher compared to galvanic substitution by mechanical stirring.

Opposite Effects Induced by Cholinium-Based Ionic Liquid Electrolytes in the Formation of Aqueous Biphasic Systems Comprising Polyethylene Glycol and Sodium Polyacrylate

Cholinium-based ionic liquids ([Ch]-based ILs) were investigated as electrolytes in the formation of aqueous biphasic systems (ABS) composed of polyethylene glycol (PEG) and sodium polyacrylate (NaPA) polymers. Both enhancement and decrease in the liquid-liquid demixing ability induced by electrolytes in PEG-NaPA aqueous biphasic systems were observed. It is shown that the ILs that most extensively partition to the PEG-rich phase tend to act as inorganic salts enhancing the two-phase formation ability, while those that display a more significant partition to the NaPA-rich phase decrease the ABS formation capacity. The gathered results allowed us to confirm the tailoring ability of ILs and to identify, for the first time, opposite effects induced by electrolytes on the PEG-NaPA ABS formation ability. The distribution of the electrolyte ions between the coexisting phases and the polyelectrolyte ion compartmentalization are key factors behind the formation of PEG-NaPA-based ABS.

Microplasma Synthesis of Antibacterial Active Silver Nanoparticles in Sodium Polyacrylate Solutions

The great demand for functional, particularly biologically active, metal nanoparticles has led to the search for technologically effective, green, and controlled methods of synthesizing these metal nanoparticles. Plasma glow discharge is one of the most promising techniques in this direction. The results of studies based on the synthesis of colloidal solutions of stabilized silver nanoparticles (AgNPs) by the microplasma method in solutions of a nontoxic surfactant sodium polyacrylate (NaPA) are presented. It is shown that AgNPs with a size of 2–20 nm are formed in solutions of 0.05–0.2 mmol⋅L−1 AgNO3 + 5 g⋅L−1 NaPA at U = 250 V by tungsten cathode plasma glow discharge. At 20°C, the yellow solutions are formed with λmax ≈ 410 nm, which are stable during long-term storage. It was found that the process of AgNPs formation corresponds to a first-order reaction on the AgNO3 concentration. Its value has little effect on the geometry of nanoparticles, so the Ag(I) concentration in solution is one of the main factors influencing the rate of microplasma synthesis of AgNPs. The antimicrobial activity of synthesized AgNPs solutions against strains of Escherichia coli, Staphylococcus aureus, and Candida albicans was established.

Nanoporous Carbon Magnetic Hybrid Derived From Waterlock Polymers and Its Application for Hexavalent Chromium Removal from Aqueous Solution

Sodium polyacrylate is the superabsorbent waterlock polymer used in disposable diapers, which are the third largest single consumer item in landfills. As diapers are difficult to recycle, their use produces an incredible amount of environmental waste. In the present article, we present a reliable and facile approach to transform sodium polyacrylate, the main constitute in the used diapers, in a carbon-based magnetic sorbent material, capable for use in environmental applications. A nanoporous carbon magnetic hybrid material was prepared by reacting NaPA with iron acetate species under chemical activation conditions. Analysis of the characterization results revealed, the creation of a nanoporous structure, with high specific surface area value (SgBET = 611 m2/g), along with the formation of nanosized zero valent iron nanoparticles and iron carbide (Fe3C), inside the carbon pore system. 57Fe Mössbauer spectroscopy verified also the existence of these two main iron-bearing phases, as well as additional minor magnetic phases, such as Fe3O4 and γ-Fe2O3. Vibrating sample magnetometry (VSM) measurements of the obtained hybrid confirmed its ferromagnetic/ferrimagnetic behavior. The hybrid material demonstrated a rapid sorption of Cr(VI) ions (adsorption capacity: 90 mg/g, 24 h pH = 3). The results showed highly pH-dependent sorption efficiency of the hybrids, whereas a pseudo-second-order kinetic model described their kinetics.

Sodium Polyacrylate as a Super Absorbent

This work is devoted to the study of synthesis, properties and practical Applications of class of acrylic-based sodium Polyacrylate superabsorbent polymers. The techniques of solution, emulsion/gel polymerization were used for synthesis. Each absorbent was mainly characterized by its equilibrium capacity of water absorption and by the rate of absorption. The swelling characteristics of the polymers were evaluated in terms of change in polymerization variables which include, type and amount of cross linker, monomer composition, and process of polymerization, temperature, initiator concentration, monomer concentration, Rate of agitation and particle size of the product. The swelling dependency on salinity, ionic strength and PH was also examined. The rapid growing nanotechnology has led to more explorations of SAPs and SAPCs for applications in biomedical, biotechnology and advanced technologies. Examples of research work of SAPs and SAPCs published in refereed, reviewed articles are referred.