Biodegradation of ultrathin fiber materials based on mixtures of polyhydroxybutyrate and polylactid

2021 ◽  
Vol 2 ◽  
pp. 17-31
Author(s):  
A. A. Olkhov ◽  
◽  
R. Yu. Kosenko ◽  
V. S. Markin ◽  
O. V. Staroverova ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Uv Irradiation ◽  
Epr Spectroscopy ◽  
Comparative Studies ◽  
Glass Substrate ◽  
Natural Polymers ◽  
Oxygen Effects ◽  
Resistance To Oxidation ◽  
Electrospinning Method ◽  
Fiber Materials

Comparative studies of ozone and oxygen effects, hydrolytic destruction, biodegradation of nonwoven fibrous and film materials based on mixtures of natural polymers - polyhydroxybutyrate and polylactide are carried out in this work. Fibers were obtained from a solution in chloroform via electrospinning method. The films were formed by pouring a solution onto a glass substrate. The structure of materials was investigated by methods of electron and optical microscopy, DSC, EPR spectroscopy. It has been shown that materials enriched with polylactide have greater resistance to oxidation, low resistance to hydrolysis and UV irradiation, in comparison with polyhydroxybutyrate.

scholarly journals Investigation of Superhydrophobic/Hydrophobic Materials Properties Using Electrospinning Technique

2019 ◽  
Vol 16 (3) ◽  
pp. 0632 ◽  
Author(s):  
Jaafar Et al.
Keyword(s):  
Polymer Solution ◽  
Glass Substrate ◽  
Low Cost ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Metal Substrate ◽  
Electrospinning Technique ◽  
Electrospinning Method ◽  
Surface Alteration ◽  
Measurement Surface

     The aim of this research is to study the surface alteration characteristics and surface morphology of the superhydrophobic/hydrophobic nanocomposite coatings prepared by an electrospinning method to coat various materials such as glass and metal. This is considered as a low cost method of fabrication for polymer solutions of Polystyrene (PS), Polymethylmethacrylate (PMMA) and Silicone Rubber (RTV). Si were prepared in various wt% of composition for each solutions. Contact angle measurement, surface tension, viscosity, roughness tests were calculated for all specimens. SEM showed the morphology of the surfaces after coated. PS and PMMA showed superhydrophobic properties for metal substrate, while Si showed hydrophobic characteristics for both metal and glass substrate. Polymer solution of (15%Si/Thinner (Th)) owned best roughness for glass substrate and polymer solution of (4%PMMA/Tetrahydrofuran (THF)) owned best roughness for metal substrate.

scholarly journals Influence of Hydroxyapatite Nanoparticles and Surface Plasma Treatment on Bioactivity of Polycaprolactone Nanofibers

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1877
Author(s):  
Eva Stastna ◽  
Klara Castkova ◽  
Jozef Rahel
Keyword(s):  
Cell Proliferation ◽  
Plasma Treatment ◽  
Discharge Plasma ◽  
Hydroxyapatite Nanoparticles ◽  
Surface Plasma ◽  
Natural Polymers ◽  
Plasma Surface Treatment ◽  
Argon Discharge ◽  
Electrospinning Method ◽  
The Impact

Nanofibers are well known as a beneficial type of structure for tissue engineering. As a result of the high acquisition cost of the natural polymers and their environmentally problematic treatment (toxic dissolution agents), artificial polymers seem to be the better choice for medical use. In the present study, polycaprolactone nano-sized fibrous structures were prepared by the electrospinning method. The impact of material morphology (random or parallelly oriented fibers versus continuous layer) and the presence of a fraction of hydroxyapatite nanoparticles on cell proliferation was tested. In addition, the effect of improving the material wettability by a low temperature argon discharge plasma treatment was evaluated, too. We have shown that both hydroxyapatite particles as well as plasma surface treatment are beneficial for the cell proliferation. The significant impact of both influences was evident during the first 48 h of the test: the hydroxyapatite particles in polycaprolactone fibers accelerated the proliferation by 10% compared to the control, and the plasma-treated ones enhanced proliferation by 30%.

scholarly journals Co3O4 composite nano-fibers doped with Mn4+ prepared by the electro-spinning method and their electrochemical properties

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24125-24131
Author(s):  
Dasong Peng ◽  
Lianwei Duan ◽  
Xiaodong Wang ◽  
Yanchao Ren
Keyword(s):  
Electrochemical Properties ◽  
Electrospinning Method ◽  
Nano Fiber ◽  
Fiber Materials

In this work, based on the electrospinning method, pure Co3O4, pure MnO2, and Co3O4 composite nano-fiber materials doped with different ratios of Mn4+ were prepared.

Photochromic Characteristics of Tungsten Trioxide Films Prepared by Electric Current Heating Using Tungsten Wire

2009 ◽  
Vol 421-422 ◽  
pp. 364-367 ◽  
Author(s):  
Takumi Hagizawa ◽  
Takayuki Honma ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Particle Size ◽  
Electric Current ◽  
Wavelength Range ◽  
Uv Irradiation ◽  
Glass Substrate ◽  
Tungsten Trioxide ◽  
Tungsten Wire ◽  
Absorption Peak ◽  
Heating Method ◽  
Peak Intensity

Tungsten trioxide films were deposited on the glass substrate by electric current heating method using tungsten wire in air. Applied voltages to the tungsten wire were increased at rates of 0.05, 0.5, 5 and 50 V/min. The resultant films consisted of particles. A particle size of the crystals increased with increasing voltage applying rate. The effects of an ultraviolet (UV) irradiation on the reflectance of the films were investigated. The reflectance in the wavelength range of 500 - 2500 nm decreased by the irradiation. When the films were left in dark after the irradiation, the reflectance returned to the initial. With increasing voltage applying rate, absorption peak shifted toward longer wavelength in the region of 1250 - 1500 nm and the peak intensity decreased.

scholarly journals Effect of UV irradiation on free radicals in synthetic melanin and melanin biopolymer from Sepia officinalis – EPR examination

Nukleonika ◽  
2015 ◽  
Vol 60 (3) ◽  
pp. 483-488 ◽  
Author(s):  
Magdalena Zdybel ◽  
Barbara Pilawa
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Uv Irradiation ◽  
Epr Spectroscopy ◽  
Microwave Power ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Relaxation Processes ◽  
Sepia Officinalis ◽  
Spin Lattice

AbstractFree radicals in synthetic melanin and melanin fromSepia officinaliswere studied by electron paramagnetic resonance (EPR) spectroscopy. The effect of time of ultraviolet (UV) irradiation on free radicals in these melanins was tested. The samples were exposed to UV during 15, 30, and 60 minutes. EPR spectra were measured with microwaves from an X-band (9.3 GHz) in the range of microwave power of 2.2–70 mW. The performed EPR examinations indicate that high concentrations (~1021–1022spin/g) ofo-semiquinone free radicals withgfactors of 2.0039–2.0045 exist in all the tested samples. For nonirradiated samples, free radical concentration was higher in natural melanin than in synthetic melanin. UV irradiation caused the increase of free radical concentrations in synthetic melanin samples and this effect depends on the time of irradiation. The largest free radical formation in the both melanins was obtained for 60 min of UV irradiation. Free radical concentrations after the UV irradiation of melanins during 30 min were lower than during irradiation by 15 min, and probably this effect was the result of recombination of the radiatively formed free radicals. EPR lines of the tested samples broadened with increasing microwave power, so these lines were homogeneously broadened. The two types of melanins differed in the time of spin-lattice relaxation processes. Slower spin-lattice relaxation processes exist in melanin fromSepia officinalisthan in synthetic melanin. UV irradiation did not change the time of spin-lattice relaxation processes in the tested melanins. The performed studies confirmed the usefulness of EPR spectroscopy in cosmetology and medicine.

EPR spectroscopy and optical microscopy study of ferroic states in pyrochlore

1998 ◽  
Vol 10 (41) ◽  
pp. 9309-9316 ◽  
Author(s):  
N N Kolpakova ◽  
S Waplak ◽  
W Bednarski
Keyword(s):  
Optical Microscopy ◽  
Epr Spectroscopy ◽  
Microscopy Study

scholarly journals Electron Paramagnetic Resonance Examination of Free Radical Formation in Salicylic Acid and Urea Exposed to UV Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Paweł Ramos ◽  
Barbara Pilawa
Keyword(s):  
Salicylic Acid ◽  
Free Radicals ◽  
Free Radical ◽  
Uv Irradiation ◽  
Epr Spectroscopy ◽  
Irradiation Time ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Radical Concentration ◽  
Free Radical Concentration

Free radicals formed by UV irradiation of the two magistral formulas applied on the skin, salicylic acid and urea, were examined by X-band (9.3 GHz) EPR spectroscopy. The influence of the time of UVA (315–400 nm) irradiation on free radical properties and concentrations in the drug samples was determined. The nonirradiated magistral formula did not contain free radicals. Amplitudes (A) and linewidths (ΔBpp) of EPR spectra were analysed. Fast spin-lattice relaxation process existed in the tested drugs. UV irradiation did not change spin-lattice interactions in the tested magistral formula. Concentrations of free radicals formed by UV irradiation in salicylic acid and urea were ~1017–1018 spins/g. The strongest formation of free radicals under UV irradiation was observed for salicylic acid than for urea. Free radical concentration in salicylic acid increased with the increase of UV irradiation time from 15 minutes to 30 minutes, and after its value remained unchanged. The increase of free radical concentration in urea with UV irradiation time was stated. Salicylic acid is characterized with higher photosensitivity than urea. Salicylic acid, urea, and the skin treated by them should not be stored on UV exposure. The usefulness of EPR spectroscopy to optimize storage conditions of recipe drugs was conformed.

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