scholarly journals Effect of the Hemin Molecular Complexes on the Structure and Properties of the Composite Electrospun Materials Based on Poly(3-Hydroxybutyrate)

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4024
Author(s):  
Polina Tyubaeva ◽  
Ivetta Varyan ◽  
Anton Lobanov ◽  
Anatoly Olkhov ◽  
Anatoly Popov
Keyword(s):  
Composite Materials ◽  
Supramolecular Structure ◽  
Molecular Complexes ◽  
Fibrous Materials ◽  
Structure And Properties ◽  
Elongation At Break ◽  
Structure Morphology ◽  
Electrospinning Method ◽  
The Creation ◽  
The One

The creation of innovative fibrous materials based on biodegradable semicrystalline polymers and modifying additives is an urgent scientific problem. In particular, the development of biomedical materials based on molecular complexes and biopolymers with controlled properties is of great interest. The paper suggests an approach to modifying the structure and properties of the composite materials based on poly(3-hydroxybutyrate) (PHB) obtained by the electrospinning method using molecular complexes of hemin. The introduction of 1–5 wt. % of hemin has a significant effect on the supramolecular structure, morphology and properties of PHB-based fibers. Changes in the supramolecular structure intensified with the increasing hemin concentration. On the one hand, a decrease in the fraction of the crystalline phase by 8–10% was observed. At the same time, there is a decrease in the density of the amorphous phase by 15–70%. Moreover, the addition of hemin leads to an improvement in the strength characteristics of the material: the elongation at break increased by 1.5 times, and in the tensile strength, it increased by 3 times. The antimicrobial activity of the hemin-containing composite materials against Escherichia coli and Staphylococcus aureus was confirmed. The obtained materials are proposed to be used in the creation of composite systems for regenerative medicine.

Structure and Properties of Fibrous Materials Based on Poly(-3-Hydroxybutyrate)

2020 ◽  
Vol 992 ◽  
pp. 375-379
Author(s):  
A.A. Olkhov ◽  
P.M. Tyubaeva ◽  
A.L. Iordansky
Keyword(s):  
Molecular Structure ◽  
Fibrous Materials ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Paramagnetic Resonance ◽  
Electrospinning Method ◽  
Ultrathin Fibers ◽  
Model Drug ◽  
Electron Paramagnetic ◽  
Scanning Electron

The article studies the supramolecular structure of polymer matrices for sustained isolation of drugs based on ultrathin fibers of polyhydroxybutyrate obtained by electrospinning method. Dipyridamole was chosen as a model drug. The concentration of dipyridamole in the fibers ranged from 1 to 5%. The morphology of nonwoven fibrous materials was investigated by scanning electron microscopy, differential scanning calorimetry, electron paramagnetic resonance. It was shown that the addition of the dipyridamole leads to a change in the fiber geometry. Fibers based on polyhydroxybutyrate are characterized by non-equilibrium molecular structure. In the current work, it was found that the addition of dipyridamole causes extra crystallization processes and the molecular mobility in the amorphous regions of the polymer slows down

scholarly journals Modification of Polyurethane Solutions by Means of a Hard Depositor for Fibre Production by the Electrospinning Method

2018 ◽  
Vol 26 (6(132)) ◽  
pp. 63-67 ◽  
Author(s):  
Elena S. Bokova ◽  
Grigory M. Kovalenko ◽  
Maria Pawlowa ◽  
Ksenia S. Bokova ◽  
Nataliya V. Evsyukova
Keyword(s):  
Metastable State ◽  
Applied Research ◽  
Fiber Diameter ◽  
Fibre Production ◽  
Fibrous Materials ◽  
Structure And Properties ◽  
Nonwoven Materials ◽  
Electrospinning Method ◽  
The Impact ◽  
Material Porosity

The article is devoted to fundamental and applied research in the field of the processing of polymer solutions. The purpose of this work was to identify the possibility of using modified solutions of polyurethanes for processing by electrospinning, and also to study the impact of the composition of the moulding solution on the structure and properties of fibrous materials. Nonwoven materials were obtained by electrospinning fibers from PUR solutions using NanospiderTM technology. The transfer of solutions into a metastable state, both in the case of film systems and fibres, leads to a change in the structure of the material: porosity and fiber diameter.

Hybrid polymer composite materials. Part 2. Preparation technology

2020 ◽  
pp. 8-13
Keyword(s):  
Composite Materials ◽  
Impact Toughness ◽  
Polymer Composites ◽  
The Other ◽  
Polymer Materials ◽  
Hybrid Polymer ◽  
Preparation Technology ◽  
Advantages And Disadvantages ◽  
Hybrid Polymer Composite ◽  
The One

The main methods (pressing and winding) of the processing of hybrid polymer composites to obtain items were examined. Advantages and disadvantages of the methods were noted. Good combinations of different-module fibers (carbon, glass, boron, organic) in hybrid polymer materials are described, which allow one to prepare materials with high compression strength on the one hand, and to increase fracture energy of samples and impact toughness on the other hand.

Study of the Composite Materials Optimal Structure Containing a Hollow Aluminum and Silica Microsphere Dependence on Humidity

2020 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Atyaksheva ◽  
Yermek Sarsikeyev ◽  
Anastasia Atyaksheva ◽  
Olga Galtseva ◽  
Alexander Rogachev
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Strength Function ◽  
Theory And Practice ◽  
Optimal Structure ◽  
Optimal Size ◽  
Structure And Properties ◽  
Power Functions ◽  
Silica Microsphere ◽  
Heat Engineering

Aims:: The main goals of this research are exploration of energy-efficient building materials when replacing natural materials with industrial waste and development of the theory and practice of obtaining light and ultra-light gravel materials based on mineral binders and waste dump ash and slag mixtures of hydraulic removal. Background.: Experimental data on the conditions of formation of gravel materials containing hollow aluminum and silica microsphere with opportunity of receipt of optimum structure and properties depending on humidity with the using of various binders are presented in this article. This article dwells on the scientific study of opportunity physical-mechanical properties of composite materials optimization are considered. Objective.: Composite material contains hollow aluminum and silica microsphere. Method.: The study is based on the application of the method of separation of power and heat engineering functions. The method is based on the use of the factor structure optimality, which takes into account the primary and secondary stress fields of the structural gravel material. This indicates the possibility of obtaining gravel material with the most uniform distribution of nano - and microparticles in the gravel material and the formation of stable matrices with minimization of stress concentrations. Experiments show that the thickness of the cement shell, which performs power functions, is directly related to the size of the raw granules. At the same time, the thickness of the cement crust, regardless of the type of binder, with increasing moisture content has a higher rate of formation for granules of larger diameter. Results.: The conditions for the formation of gravel composite materials containing a hollow aluminosilicate microsphere are studied. The optimal structure and properties of the gravel composite material were obtained. The dependence of the strength function on humidity and the type of binder has been investigated. The optimal size and shape of binary form of gravel material containing a hollow aluminosilicate microsphere with a minimum thickness of a cement shell and a maximum strength function was obtained. Conclusion.: Received structure allows to separate power and heat engineering functions in material and to minimize the content of the excited environment centers.

The Image of the Hasmoneans: A New Perspective

2018 ◽  
Author(s):  
Vered Noam
Keyword(s):  
First Generation ◽  
Second Temple ◽  
The Other ◽  
Three Generations ◽  
The Creation ◽  
New Perspective ◽  
The One

In attempting to characterize Second Temple legends of the Hasmoneans, the concluding chapter identifies several distinct genres: fragments from Aramaic chronicles, priestly temple legends, Pharisaic legends, and theodicean legends explaining the fall of the Hasmonean dynasty. The chapter then examines, by generation, how Josephus on the one hand, and the rabbis on the other, reworked these embedded stories. The Josephan treatment aimed to reduce the hostility of the early traditions toward the Hasmoneans by imposing a contrasting accusatory framework that blames the Pharisees and justifies the Hasmonean ruler. The rabbinic treatment of the last three generations exemplifies the processes of rabbinization and the creation of archetypal figures. With respect to the first generation, the deliberate erasure of Judas Maccabeus’s name from the tradition of Nicanor’s defeat indicates that they chose to celebrate the Hasmonean victory but concealed its protagonists, the Maccabees, simply because no way was found to bring them into the rabbinic camp.

Structure and Properties of Novel Superhard Nanocrystalline/Amorphous Composite Materials

1995 ◽  
Vol 400 ◽  
Author(s):  
S. Vepřek ◽  
M. Haussmann ◽  
S. Reiprich
Keyword(s):  
Elastic Modulus ◽  
Composite Materials ◽  
Transition Metal ◽  
Theoretical Concept ◽  
Structure And Properties ◽  
Superhard Materials ◽  
Transition Metal Nitride ◽  
Upper Limit ◽  
Amorphous Si ◽  
Matrix Hardness

AbstractWe have developed a theoretical concept for the design of novel superhard materials and verified it experimentally on several systems nc-MenN/a-Si3N4 (nc-MenN is a nanocrystalline transition metal nitride imbedded in a thin amorphous Si3N4 matrix). Hardness in excess of 5000 kg/mm2 (about 50 GPa) and elastic modulus of ≥550 GPa have been achieved [1-3]. Here we address the questions of the universality of the concept for the design of a variety of nc/a systems and the upper limit of the hardness which may be achieved.

scholarly journals Monitoring the degradation of partly decomposable plastic foils

2014 ◽  
Vol 6 (1) ◽  
pp. 39-44
Author(s):  
Gabriella Rétháti ◽  
Krisztina Pogácsás ◽  
Tamás Heffner ◽  
Barbara Simon ◽  
Imre Czinkota ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Molecular Mass ◽  
Structural Changes ◽  
Thermoplastic Starch ◽  
Medium Density ◽  
Insulating Layer ◽  
Elongation At Break ◽  
One Year ◽  
The One

Abstract We have monitored the behaviour of different polyethylene foils including virgin medium density polyethylene (MDPE), MDPE containing pro-oxydative additives (238, 242) and MDPE with pro-oxydative additives and thermoplastic starch (297) in the soil for a period of one year. A foil based on a blend of polyester and polylactic acid (BASF Ecovio) served as degradable control. The experiment was carried out by weekly measurements of conductivity and capacity of the soil, since the setup was analogous to a condenser, of which the insulating layer was the foil itself. The twelve replications allowed monthly sampling; the specimen taken out from the soil each month were tested visually for thickness, mechanical properties, morphological and structural changes, and molecular mass. Based on the obtained capacity values, we found that among the polyethylene foils, the one that contained thermoplastic starch extenuated the most. This foil had the greatest decrease in tensile strength and elongation at break due to the presence of thermoplastic starch. The starch can completely degrade in the soil; thus, the foil had cracks and pores. The polyethylene foils that contained pro-oxydant additives showed smaller external change compared to the virgin foil, since there was no available UV radiation and oxygen for their degradation. The smallest change occurred in the virgin polyethylene foil. Among the five examined samples, the commercially available BASF foil showed the largest extenuation and external change, and it deteriorated the most in the soil.

scholarly journals SINTESIS DAN KARAKTERISASI NANOFIBER KOMPOSIT Zn-PVDF KOPOLIMER

2014 ◽  
Vol 16 (1) ◽  
pp. 49-52
Author(s):  
Yelfira Sari ◽  
Muhamad Nasir ◽  
Chandra Risdian ◽  
Syukri Syukri
Keyword(s):  
Crystal Structure ◽  
Phase Structure ◽  
Research Study ◽  
Fiber Diameter ◽  
Average Diameter ◽  
Nanofiber Composite ◽  
Β Phase ◽  
Α Phase ◽  
Structure Morphology ◽  
Electrospinning Method

Sintesis nanofiber komposit Zn-PVDF kopolimer dengan metoda elektrospinning telah berhasil dilakukan. Proses pembuatan nanofiber komposit serta  morfologi yang terbentuk dipengaruhi oleh penambahan Zn-asetat dengan perubahan diameter rata-rata serat dari 357,13 nm menjadi 777,24 nm. Analisis FTIR menunjukkan bahwa struktur kristal nanofiber komposit Zn-PVDF kopolimer didominasi oleh strukturβ-phase, dengan bilangan gelombang 1190,08 cm-1 dan 487,99 cm-1 untuk struktur α-phase dan 1404,18 cm-1; 1280,73 cm-1; 1074,35 cm-1; 881,47 cm-1; dan 840,96 cm-1 untuk struktur β-phase.Kata kunci :nanofiber komposit, Zn-PVDF kopolimer komposit, elektrospinning,kristal struktur, morfologi, diameter fiber The fabrication of Zn-PVDF copolymer nanofiber composite has been investigated in this research study by using electrospinning method. Fabrication and morphology of nanofiber composite is influenced by the addition of Zn-acetate. The average diameter of nanofiber composites increase with an addition of Zn-acetate, from 357,13 to 777,24nm. FTIRanalysisshowedthat thecrystalstructure ofPVDFnanofiberis dominatedby β-phase , thewave number 1190,08 cm-1 and 487,99 cm-1 for α-phase structure and 1404,18cm-1; 1280,73cm-1; 1074,35cm-1; 881,47cm-1and840,96cm-1 for β-phase structure respectively.Key words : nanofiber composite, Zn-PVDF copolymer composite, electrospinning, crystal structure,  morphology, fiber diameter

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