Improved interfacial performance of carbon fiber/polyetherimide composites by polyetherimide and modified graphene oxide complex emulsion type sizing agent

In the field of interfacial enhancement of composite, sizing method has attracted extensive attention. In this research, a new complex emulsion type sizing agent containing polyetherimide (PEI) and covalently chemical functionalized graphene oxide (GO) was first proposed to further improve the interfacial adhesion of carbon fiber (CF)/PEI composites, adapt to the high processing temperature, and overcome the shortcomings of the solution type sizing agent. The emulsion was prepared by the emulsion/solvent evaporation method. In order to avoid the agglomeration of nanomaterials on CF surface, the monomer and polymer structure of PEI was used to functionalize GO, so as to achieve better compatibility and dispersion of GO in PEI. The physicochemical state of CF surface was characterized and the successful introduction of GO was verified. The microbond test revealed that the introduction of GO further improved the IFSS compared with only PEI sizing. When GO grafted with PEI was used as the main component of the sizing agent, the IFSS reached the largest with an increasement of 55.96%. The mechanism of interfacial reinforcement was proposed. Increased ability of mechanical interlocking, the mutual solubility between PEI molecular chains, and the improvement in wettability may be beneficial to the interfacial strength. This mild and effective modification method provided theoretical guidance for the interfacial enhancement of composites and was expected to be applied in industrial production.

NanoTraPPED—A New Method for Determining the Surface Energy of Nanoparticles via Pickering Emulsion Polymerization

Surface energy with its polar and disperse components describes the physicochemical state of nanoparticles’ (NPs) surfaces, and can be a valuable parameter for predicting their bulk behavior in powders. Here, we introduce a new method, namely, Nanoparticles Trapped on Polymerized Pickering Emulsion Droplets (NanoTraPPED), for measuring the surface energy of a series of silica NPs bearing various surface functional groups. The method consists in creating Pickering emulsions from vinyl bearing monomers, immiscible with water, whereas NPs of interest have a stabilizing role, and in the process, become trapped at the monomer/water interface of emulsion droplets. The Pickering emulsion is polymerized, and polymer microspheres (colloidosomes) decorated with NPs are obtained. NanoTraPPED relies on measuring contact angles from the immersion depth of nanoparticles at the interface of various polymer colloidosomes with the electron microscope. The contact angle values are used as input for the Owens-Wendt-Rabel-Kaelble (OWRK) model, to quantitatively determine the total surface energy with water γNP/water, air γNP, and the corresponding polar and dispersive interaction components of NPs carrying -NH2, -SH, -OH, -CN and -C8 surface functional groups, ranking these according to their polarity. Our findings were confirmed independently by calculating the interfacial desorption energies of NPs from contact angles.

Quality Of Spelt And Cold Seeds With Pesticide-Free Cultivation

Under the conditions of the Kaliningrad region, without the use of fertilizers and fungicides, a yield of 32.2 centners / ha of spelled Alcoran and 27.8 centners / ha of naked spelled Gramme 2U was ensured. Using the methods of biological, washout and centrifugation, Berman, ELISA, the authors studied the phytopathological, qualitative and physicochemical state. According to the results of the comprehensive assessment, it was found that spelled is distinguished by its unpretentiousness to soil conditions, cultivation technology, and nitrogen nutrition. Spelled grains of the Alcoran variety are covered with spikelet scales, which protects the grain from the harmful effects of the environment, insects and pathogenic organisms. The difference between filmy spelled and naked spelled in the degree of infection with the fungus Fusarium sp. Was established. and Alternaria sp. Considering the bare-grain spelled of the Gramme variety, the Fusarium infestation turned out to be 2 times higher than the filmy spelled of the Alcoran variety.

Lithium-induced modiphication of the physicochemical state of membrane proteins and lipids in human erythrocytes

The effect of various concentrations of lithium sulfate on human erythrocytes in vitro has been studied. It has been shown that the effect of lithium salt in maximum pharmacological and toxic concentrations on cells leads to a modification of the physicochemical state of membrane-bound proteins and lipids. It was found that in human erythrocytes exposed to lithium ions, there is a decrease in the activity of membrane-bound acetylcholinesterase and methgemoglobin reductase, as well as a change in the microviscosity of the lipid bilayer of membranes. The results obtained can be used to create a cell test system for assessing the toxicity of lithium compounds.

Use of coarse-grained soils reinforced with cement in the construction of pavement layers

Problem. When designing and building pavements, it is necessary to make full use of local low-strength stone materials reinforced with inorganic binders (cement, lime, activated ash, etc.). The economic feasibility of using cement soils for paving in areas not provided with local stone materials is particularly significant. Under these conditions, the cost of 1 m² of cement-soil layer is often 1.5-2 times lower than the cost of 1 m² of a uniform layer of imported materials. layer of imported materials. When using the technology of soil strengthening with inorganic binders, there is no need for a significant amount of transport, as it is possible to strengthen the local soil, which is located nearby, and only binders can be delivered to the work site. It is possible to unload cement in the car for distribution of binder directly on a place of carrying out works. Strengthening local soils can provide a solid foundation. Soils suitable for cement hardening are much more common than stone materials. The strength of coarse-grained soils depends on the constituent rocks and the density of laying. Fragments of igneous rockshave the greatest strength, sedimentary rocks have the lowest. The most active part of the cement-soil mixture, which provides the creation of a new structure of the reinforced soil, is cement. As a result of the interaction of cement with water, with salts present in the soil and partially with the fine part of the soil, a new water-resistant crystallization structure appears in the strengthened soil. The strength of this structure is determined mainly by the composition and quality of cement. During soil treatment with cement, hydration processes, as well as other chemical reactions will increase or slow down dependingon the chemical and mineral compositions of cement, the nature of the soil and its physicochemical state at the time of treatment. When strengthening soils with cements of the same brands, but of different mineral composition, cement soils with different properties will be obtained. Therefore, the final decision on the suitability of cement and its dosage is made based on the results of tests of cement soil samples. In each case, the decision to use highquality cements or additives that increase thestrength and frost resistance of the cement soil must be economically justified.

Into the Deep: New Data on the Lipid and Fatty Acid Profile of Redfish Sebastes mentella Inhabiting Different Depths in the Irminger Sea

New data on lipid and fatty acid profiles are presented, and the dynamics of the studied components in muscles in the males and females of the beaked redfish, Sebastes mentella, in the depth gradient of the Irminger Sea (North Atlantic) is discussed. The contents of the total lipids (TLs), total phospholipids (PLs), monoacylglycerols (MAGs), diacylglycerols (DAGs), triacylglycerols (TAGs), cholesterol (Chol), Chol esters, non-esterified fatty acids (NEFAs), and wax esters were determined by HPTLC; the phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), and lysophosphatidylcholine (LPC) were determined by HPLC; and fatty acids of total lipids were determined using GC. The Chol esters prevailed in muscles over the storage TAGs, and the wax ester content was high, which is a characteristic trait of vertically migrating species. Specific dynamics in certain PL in redfish were found to be depended on depth, suggesting that PLs are involved in the re-arrangement of the membrane physicochemical state and the maintenance of motor activity under high hydrostatic pressure. The high contents of DHA and EPA were observed in beaked redfish muscles is the species’ characteristic trait. The MUFAs in muscles include dietary markers of zooplankton (copepods)—20:1(n-9) and 22:1(n-11), whose content was found to be lower in fish sampled from greater depths.

PHYSICAL PRINCIPLES OF THE MESSBAUER EFFECT FOR SOLVING INNER-NUCLEAR PHENOMENA IN SOLIDS

In this work, using a number of examples, it is shown that one of the promising methods for studying the physicochemical state of matter is Mössbauer spectroscopy with all the variety of its methodological approaches. The processes occurring in the shell of atoms have a negligible effect on intranuclear phenomena, and often turn out to be inaccessible for detection by other methods. Mössbauer spectroscopy reveals these influences. Four methodological approaches have been implemented and an experimental base has been created for observing the resonant absorption of квантов-quanta by 57Fe nuclei. Techniques for absorption (MS), emission Mössbauer spectroscopy (EMS), characteristic X-ray radiation (CXR), conversion electron Mössbauer spectroscopy (CEMS) allow, practically without restrictions on the elemental composition and geometric dimensions of samples (from bulk to nanometer), to carry out studies