Hydrogel Nanocomposites with Silver Nanoparticles

Copolymer hydrogels based on acrylic monomers (primarily acrylamide and acrylonitrile) are synthesized and their physicochemical properties are investigated. Methods of incorporation of nanoparticles of gold and silver into hydrogel pores and methods of their stabilization using reagents of different nature are developed. Our studies showed pronounced bactericidal properties of the nanocomposites regarding gram-positive and gram-negative bacteria and, at the same time, their biocompatibility to stem cells

Thermal effects of carbonated hydroxyapatite modified by glycine and albumin

In this work calcium phosphate powders were obtained by precipitation method from simulated solutions of synovial fluid containing glycine and albumin. X-ray diffraction and IR spectroscopy determined that all samples are single-phase and are presented by carbonate containing hydroxyapatite (CHA). The thermograms of solid phases of CHA were obtained and analyzed; five stages of transformation in the temperature range of 25-1000°C were marked. It is shown that in this temperature range dehydration, decarboxylation and thermal degradation of amino acid and protein connected to the surface of solid phase occur. The tendency of temperature lowering of the decomposition of powders synthesized from a medium containing organic substances was determined. Results demonstrate a direct dependence between the concentration of the amino acid in a model solution and its content in the solid phase

Electrospinning of hydrogels for biomedical applications

The field of biomedical applications for hydrogels requires the development of nanostructures with specific controlled diameter and mechanical properties. Nanofibers are ideally candidates for these advanced requirements, and one of the easiest techniques that can produce one-dimensional nanostructured materials in fibrous form is the electrospinning. This technique provides extremely thin fibres with controlled diameter, highly porous microstructure with interconnected pores; extremely versatile allowing the use of various polymers for tailoring various applications requirements and it is a simple cost-effective method on preparation of scaffolds. In this section, we will discuss recent and specific applications with a focus on their mechanisms. As such, we conclude this section with a discussion on perspectives and future possibilities on this field.ye

Factors affecting the water content of calcium alginate beads for agrotechnological purposes

The agricultural industry is facing decreasing availability of fertile soils and increasing water scarcity due to changing precipitation patterns as a result of global climate change. These challenges have led to the need to develop soil modifiers that, among other things, increase water retention in the soil, protecting crops from drought stress [1]

Composite Binders for Fastening High Temperature Wells

Abstract The article deals with the hydration of oil-well cement, intended for cementing high-temperature wells. At high temperatures and pressures (150°C, P = 30 MPa) Portland cement stone does not have the necessary density and resistance to high temperatures due to the formation of hydrated calcium silicates rich in lime during the hydration of Portland cement, therefore, the work was carried out primarily to find appropriate additives to Portland cement, providing the necessary properties of oil-well cement. From a number of additives to ensure the durability of service were selected reprocessing waste of titanium ores (titanomagnetite concentrate) and blast furnace slag. In addition, to improve the crack resistance of cement stone, the possibility of using expansive additives to oil-well cement was investigated. For these purposes, sulfoaluminate, sulfoferrite clinkers and alumina slag were used. It has been established that during hydration of calcium sulfoferrite ferrous ettringite is formed, which is more stable at elevated temperatures than ettringite formed at hydration of sulfoaluminate clinker and alumina slag. In the presence of sulfated phases and silica, at elevated temperatures and pressures, low-base calcium silicates hydrates and iron contained garnet hydrates are formed.</jats:p

Separation of nonreacted acrylamide from polyacrylamide gel for endoprothesing

The separation of toxic acrylic monomers (mainly acrylamide) from some polymeric hydrogels of medical application was studied. It was found that “clean hydrogel” can be obtained after 4-6 days of washing with nonpyrogenic water. The quantity of monomeric acrylamide remained in the samples was controlled by a liquid chromatography method

Synthetic hydrogels based on acrylic comonomers

Copolymer hydrogels on the base of acrylamide and acrylonitrile as well as acrylamide and acrylic acid were prepared using free-radical polymerization carried out in water medium at room temperature. It has been shown that depending on the monomers nature and ratio the swelling degree and the optical, deformational and diffusional properties of the obtained hydrogels can vary within wide limits