High Molecular Polyethylene Glycol Research Articles

Deep eutectic solvents regulation synthesis of multi-metal oxalate for electrocatalytic oxygen evolution reaction and supercapacitor applications

Design and fabrication of 2D multi-metal oxalate materials with desired electrochemical activities are highly needed in electrocatalysis and supercapacitors. Herein, assisted by the deep eutectic solvothermal (DES) method, multi-metal oxalate consisting of Fe, Co, Ni, Cu, and Zn with different morphology was the controlled synthesis. It was found that the structure and composition of DES can control the nucleation and growth of multi-metal oxalate. High molecular PEG and gradually slow-release oxalic acid are in favor of the formation of 2D structure, while the low molecular EG and abundant oxalic acid are positive for the formation of 3D nanoparticles. The properties of the obtained multi-metal oxalates are confirmed by multi-analysis, which involves the single Ni-oxalate phase, morphological evolution ranging from particles to nanosheets, and complex composition up to five metal elements including Fe, Co, Ni, Cu as well as Zn. Notably, the well-designed 2D (FeCoNiCuZn)(C2O4)·2H2O nanosheets exhibit an ultralow overpotential of 334 mV at 100 mA cm−2 for OER as electrocatalyst with prolonged durability over 30 h at 10 mA cm−2 and a high specific capacity of 1337 C g−1 for aqueous supercapacitor.

Effect of polyethylene glycol on mechanical properties of bamboo fiber‐reinforced polylactic acid composites

ABSTRACTThe bamboo fiber (BF)‐reinforced polylactic acid (PLA) composites were prepared using the twin‐screw extruder and injection molding. Thermal gravimetric analyzer results indicated the thermal stability of BF/PLA composites decreased with increasing BF content. Differential scanning calorimeter and X‐ray diffraction curves showed that BF played a role as a nucleating agent, but the crystallinity of composite materials decreased with the increasing BF content. The melt flow rate of composites reduced with the increase in BF content, resulting in a poorer processing property. The processability of the composites was improved with the addition of high molecular polyethylene glycol (PEG). Mechanics performance test showed that tensile strength and bending strength of composites increased at low loading with the BF content increased then decreased when the loading continued to increase. The tensile strength of the composite materials reached 65.46 MPa when alkali‐treated BF (ABF) content was 20 wt %. The flexural strength of the composites reached 97.94 MPa when ABF content was 10 wt %. Impact performance has also been improved. PEG‐20000 was the best plasticizer among the PEG‐6000，PEG‐10000, and PEG‐20000. When the component of PEG was 10 wt %, the elongation increased by 56%. The scanning electron microscopy (SEM) result showed that the fracture of the composites was smooth, most ABF were wrapped in matrix and distribution of ABF in PLA matrix was more uniform. It means that interfacial compatibility of bamboo fiber and PLA improved after BF modified by alkali. High molecular weight PEG enhance melt flow ability of polymer, result in fibers were further enclosed in the PLA matrix and increase properties of composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47709.

Glycocalyx Preservation and NO Production in Fatty Livers-The Protective Role of High Molecular Polyethylene Glycol in Cold Ischemia Injury.

Improving the protection of marginal liver grafts during static cold storage is a major hurdle to increase the donor pool of organs. The endothelium glycocalyx quality of preservation influences future inflammatory and oxidative responses. One cellular pathway responsible for the formation of nitric oxide by endothelial cells is dependent on the stimulation of proteoglycans present in the glycocalyx. We investigated the impact of the glycocalyx preservation in static cold storage of fatty liver preserved in different preservation solutions on the endothelium-mediated production of NO. Zucker fatty rat livers were preserved 24 h in static cold storage in either Institut Georges Lopez-1 (IGL-1) (n = 10), IGL-0 (i.e., without PEG35) (n = 5) or Histidine-Tryptophan-Ketoglutarate (HTK) (n = 10) preservation solutions before being processed for analysis. For Sham group (n = 5), the fatty livers were immediately analyzed after procurement. The level of transaminases and nitrites/nitrates were measured in the washing perfusate. Glycocalyx proteins expressions, Syndecan-1, glypican-1 and heparan sulfate (HS), were determined in the tissue (ELISA). Steatotic livers preserved 24 h in IGL-1 preservation solution have a significant lower level of transaminases (aspartate aminotransferase (AST), alanine aminotransferase (ALT)) and less histological damages than steatotic livers preserved 24 h with HTK (p = 0.0152). The syndecan-1 is significantly better preserved in IGL-1 group compared to HTK (p < 0.0001) and we observed the same tendency compared to IGL-0. No significant differences were observed with glypican-1. HS expression in HTK group was significantly higher compared to the three other groups. HS level in IGL-1 was even lower than IGL-0 (p = 0.0005) which was similar to Sham group. The better protection of the glycocalyx proteins in IGL-1 group was correlated with a higher production of NO than HTK (p = 0.0055) or IGL-0 (p = 0.0433). IGL-1 protective mechanisms through the formation of NO could be due to its better protective effects on the glycocalyx during SCS compared to other preservation solutions. This beneficial effect could involve the preservation state of syndecan-1 and the internalization of HS.

RETRACTED ARTICLE: Optimisation of compositions of PEG/PMMA binder system in ceramic injection moulding via water debinding

In this study, we have made a comprehensive investigation on the optimisation of the compositions of polyethylene glycol (PEG)/polymethyl methacrylate (PMMA) binder system for water debinding. An orthogonal test was designed, and L9(33) table was chosen to investigate the influence of the molecular weight of low molecular PEG (L-PEG), high molecular PEG (H-PEG) and the percentage of L-PEG in PEGs on flaws of the injection moulded compacts after water debinding. In addition, the ratio of PMMA content to PEG content on flaws is also investigated. Four regions were defined as high stress region, safe debinding region, low binder removal rate region and unavailable injection region respectively. It is believed that our work could provide comprehensive and convincing principles for the manufacturing of injection moulded ceramic parts via water debinding.

Assessment of Anti-nutritive Activity of Tannins in Tea By-products Based on In vitro Rumen Fermentation.

Nutritive values of green and black tea by-products and anti-nutritive activity of their tannins were evaluated in an in vitro rumen fermentation using various molecular weights of polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP) and polyvinyl polypyrrolidone as tannin-binding agents. Significant improvement in gas production by addition of PEG4000, 6000 and 20000 and PVP was observed only from black tea by-product, but not from green tea by-product. All tannin binding agents increased NH3-N concentration from both green and black tea by-products in the fermentation medium, and the PEG6000 and 20000 showed relatively higher improvement in the NH3-N concentration. The PEG6000 and 20000 also improved in vitro organic matter digestibility and metabolizable energy contents of both tea by-products. It was concluded that high molecular PEG would be suitable to assess the suppressive activity of tannins in tea by-products by in vitro fermentation. Higher responses to gas production and NH3-N concentration from black tea by-product than green tea by-product due to PEG indicate that tannins in black tea by-product could suppress rumen fermentation more strongly than that in green tea by-product.

Optimization of the Compositions of PEG/PMMA Binder System in Ceramic Injection Moulding via Water-Debinding

In this study, we have made a comprehensive investigation on optimization of the compositions of PEG/PMMA binder system for water-debinding. An orthogonal test was designed and L9(33) table was chosen to investigate the influence of the molecular weight of low molecular PEG (L-PEG), high molecular PEG (H-PEG) and the percentage of L-PEG in PEGs on flaws of the injection moulded compacts after water-debinding. In addition, the ratio of PMMA content to PEGs content on flaws is also investigated. Four regions were defined as high stress region, safe debinding region, low binder removal rate region and unavailable injection region respectively. It is believed that our work could provide comprehensive and convincing principles for the manufacturing of injection-moulded ceramic parts via water-debinding.

Use of partial molar volume for determining conformations of macromolecules in a solution

A formula was derived for determining the partial molar volume (PMO) of solute at various concentrations and on this basis a method was developed for determining the PMO at infinite dilution. The partial molar volumes of the homologous series of poly(ethylene glycol) with molecular masses 400, 1000, 1500, 2000, 4000, 20000 in aqueous solutions at infinite dilution were determined. Analysis of the calculated and experimental PMO showed that poly(ethylene glycol) molecules exist in dilute solutions in the conformations of elongated helices. In addition, the high-molecular polyethylene glycol molecules include the areas of statistical chaos, which leads to sites unavailable for the solvent molecules. Based on literature data were revealed the values of PMO for highly concentrated solutions of poly(ethylene glycol) PEG 400, PEG 4000, and PEG 6000. Effect of concentration on the structure of PEG solutions was demonstrated. We found that in the temperature range 25–40°C the conformational transitions were not observed.

DendroCT – Dendrochronology without damage

The paper describes an evaluation of the applicability of computer tomography in archaeological dendrochronology. Two different computer tomographs were tested, a Siemens Somatom Emotion single slice scanner developed for medical use, and a Nikon Metrology model XT H 225 LC, which is an industrial type scanner. Both scanners were tested against air-dried, archaeological oak wood, and more limited experiments were made with waterlogged archaeological oak wood and archaeological oak wood which had been treated with high-molecular polyethyleneglycol as a conservation treatment. After scanning the resulting imagery were measured and analysed for dendrochronology using off-the-shelf software for handling and measuring on the images and the specialist programme DENDRO for the dendrochronological analyses.The results showed that only the industrial scanner produced sufficiently clear imagery to allow for dendrochronological analyses. In the scans it was possible to separate tree-rings down to 0.2mm width, and it was possible to identify the sapwood–heartwood border when sufficient sapwood rings were present. It was found, however, that a visual inspection of the object was required to distinguish between sapwood and decayed wood. Comparisons between direct measurements of tree-rings and measurements based on CT-imagery revealed no significant differences. The scanning and subsequent dating of more than 90 objects showed that dendrochronological dating based on CT-scanning has a success rate equal to conventional dating, albeit more time consuming.The attempts to scan waterlogged and PEG-impregnated archaeological oak wood were unsuccessful, due to a low degree of contrast between the water/PEG and the preserved wood. The experiments were too limited to exclude, however, that a successful protocol can be developed also for these types of materials.

Characterization of Porous TiO&lt;sub&gt;2&lt;/sub&gt; Films Prepared Using PEG of Different Molecular Weight

Porous TiO2 films were prepared through dip-coating on glass substrates using different molecular weight of PEG. Surface roughness increased with increasing PEG molecular weight. The film prepared with PEG400 was fairly smooth with slight roughness. The films prepared with high molecular PEG became rougher and there were some larger particles on the films. When the PEG molecular weight got higher, adsorption edge of the films tended to move toward shorter wavelength region. In the wavelength range between 350 and 450 nm, larger PEG molecules made higher film transmittance. The particles prepared using higher or lower molecular weight of PEG had less surface area than using PEG1000. The average pore sizes were 14 nm, 15 nm, 28 nm, and 52 nm, and the total pore volume were 0.12 ml/g, 0.13 ml/g, 0.08 ml/g, and 0.09 ml/g for the TiO2 powders prepared using PEG400 to PEG 6000.

In vitro assessment of wheat tolerance to drought

Analyzed in this paper were the in vitro effects of drought stress in 13 genotypes of winter wheat, one genotype of spring wheat, and three Triticale genotypes of different geographic origin. Callus tissue was induced from immature zygotic embryos (10-15 days after pollination) on a modified MS nutrient medium. After two weeks, callus tissue was transplanted onto the same medium enriched with 5% high-molecular polyethylene glycol (PEG 6000), which was used as the stress agent to produce the effect of drought chemically. A control group of calluses was grown on an identical medium but without PEG. After four weeks of growing calluses on these mediums, we assessed callus mass survival ability of the genotypes before the transplantation as well as percentage reduction of callus fresh weight after the transplantation onto the nutrient medium with 5% PEG. Statistically significant differences were found among the genotypes in their response to the induced stress. The best survival ability before the transplantation was found in the genotype Mexicol20 (83%), while the lowest was recorded in Slavija (11.3%). Culture growing under stress conditions significantly reduced callus fresh weight in all of the genotypes. The lowest decrease of the callus mass relative to control was recorded in Rozofskaja (14.4%) and the highest in Miranovska (58.4%), indicating the genotypes' tolerance levels towards drought stress.

Simple Method of Circulating Immune Complex Detection in Human Sera by Polyethylene Glycol Precipitation

A rapid test for detection of circulating immune complexes in a small serum sample was developed to facilitate clinical diagnosis of immune complex disorders. The test is based on a selective precipitation of soluble circulating complexes of antigen-antibody in 3.75% concentration of high-molecular polyethylene glycol. Precipitation is followed photometrically at 450 nm, 1 cm cuv. after 1 h incubation at room temperature. Comparison of E450 values in groups of patients with immune complex disorders, such as rheumatoid arthritis, systemic lupus erythematosus and glomerulonephritis, with healthy controls or patients with non-immunological disorders revealed highly significant differences. Sera of all patients with high clinical activity of disease exhibited positive reaction. In 121 human sera the results of this examination were compared with the results of C 1 q binding test. There was 73.5% agreement between the results of both methods. Our test is more rapid, suited for routine clinical use.

CH2 rocking vibrations of polyethylene glycols

AbstractMeasurements were made of the infrared absorptions of ethylene glycol and polyethylene glycols (from a dimer to a heptamer) in liquid state. In the case of polyethylene glycols, three distinct peaks appear in the wave number range of CH2 rocking modes. This affords a conclusive evidence in support of the existence of the trans form as well as the gauche form of the O(CH2)2O portion of linear chains. This confirms the result of dipole moment measurements that both gauche and trans forms are realized in the configurations of the lower members of polyethylene glycols in solution. Although it is reported that high molecular polyethylene glycol in crystalline state assumes a highly crumpled helical structure resulting from the gauche minima, the molecular structure of low molecular polyethylene glycols is not restricted to the same helical configuration. These chain molecules take a more or less irregular form resulting from the trans and gauche minima of the internal rotation about single bonds. Ethylene glycol shows only two absorption peaks in the wave number range of CH2 rocking modes. A plausible explanation is presented based on the formation of intramolecular hydrogen bonds.