scholarly journals Investigation of the Impact of Cold Plasma Treatment on the Chemical Composition and Wettability of Medical Grade Polyvinylchloride

2020 ◽  
Vol 11 (1) ◽  
pp. 300
Author(s):  
Edward Bormashenko ◽  
Irina Legchenkova ◽  
Shiri Navon-Venezia ◽  
Mark Frenkel ◽  
Yelena Bormashenko
Keyword(s):  
Chemical Composition ◽  
Plasma Treatment ◽  
Polymer Surface ◽  
Polymer Chains ◽  
Exponential Fitting ◽  
Pronounced Increase ◽  
Near Surface ◽  
Hydrophobic Recovery ◽  
The Impact ◽  
Medical Grade

The impact of the Corona, dielectric barrier discharge, and low pressure radiofrequency air plasmas on the chemical composition and wettability of medical grade polyvinylchloride was investigated. Corona plasma treatment exerted the most pronounced increase in the hydrophilization of polyvinylchloride. The specific energy of adhesion of the pristine and plasma-treated Polyvinylchloride (PVC) tubing is reported. Plasma treatment increased markedly the specific free surface energy of PVC. The kinetics of hydrophobic recovery following plasma treatment was explored. The time evolution of the apparent contact angle under the hydrophobic recovery is satisfactorily described by the exponential fitting. Energy-dispersive X-ray spectroscopy of the chemical composition of the near-surface layers of the plasma-treated catheters revealed their oxidation. The effect of the hydrophobic recovery hardly correlated with oxidation of the polymer surface, which is irreversible and it is reasonably attributed to the bulk mobility of polymer chains.

scholarly journals Investigation of the Impact of Cold Plasma Treatment on the Chemical Composition and Wettability of Medical Grade Polyvinylchloride

2020 ◽  
Author(s):  
Edward Bormashenko ◽  
Irina Legchenkova ◽  
Shiri Navon-Venezia ◽  
Mark Frenkel ◽  
Yelena Bormashenko
Keyword(s):  
Chemical Composition ◽  
Plasma Treatment ◽  
Polymer Surface ◽  
Exponential Fitting ◽  
Pronounced Increase ◽  
Near Surface ◽  
Air Plasmas ◽  
Hydrophobic Recovery ◽  
The Impact ◽  
Medical Grade

Impact of the Corona, dielectric barrier discharge and low pressure radiofrequency air plasmas on the chemical composition and wettability of the medical grade polyvinylchloride was investigated. Corona plasma treatment exerted the most pronounced increase in the hydrophilization of polyvinylchloride. The specific energy of adhesion of the pristine and plasma treated PVC tubing is reported. The kinetics of hydrophobic recovery following the plasma treatment was explored. The time evolution of the apparent contact angle under the hydrophobic recovery is satisfactorily described by the exponential fitting. Energy-dispersive X-ray spectroscopy of the chemical composition of the near-surface layers of the plasma treated catheters revealed their oxidation. The effect of the hydrophobic recovery is hardly correlated with oxidation of the polymer surface, which is irreversible.

Mechanisms Influencing the Formation of the Carbonized Layer Relief on the Polymer Surface after the Ion-Plasma Treatment Modeling

2018 ◽  
Vol 938 ◽  
pp. 148-155
Author(s):  
A.Yu. Belyaev ◽  
A.L. Svistkov
Keyword(s):  
Plasma Treatment ◽  
Strain State ◽  
Polymer Surface ◽  
Polymer Chains ◽  
Simple Explanation ◽  
Near Surface ◽  
Ion Flow ◽  
Ion Plasma ◽  
Unit Surface ◽  
Material Heating

The work is devoted to the discussion of hypotheses that are put forward to explain the processes occurring during ion-plasma treatment of polyurethane. A carbonized layer forms on the surface of the polymer as a result of ion-plasma treatment. However this layer is not even. Wavy relief, the geometric features of which depend on the fluence (the number of ions entering the unit surface of the sample) and the energy of ions, is formed. It is shown that a simple explanation related to material heating and subsequent shrinkage does not allow explaining the cause of the phenomenon. The second hypothesis can be the pressure of the ion flow on the surface of the sample. It causes deformation and subsequent changes in the stress-strain state after the irradiation is stopped. Calculations show that this mechanism cannot explain the formation of the folded relief of the layer. A hypothesis, based on information about a significant material change, is expressed in the article. Polymer chains under ion-plasma treatment are broken into atoms. After striking ions move deep into the material causing the polymer to swell in the near-surface layer. This swelling can cause material to move close to the sample boundary and leads to the formation of a wavy surface.

The Impact Evaluation of Factors on the Adhesion of Modified Polytetrafluoroethylene Films in a Glow Discharge Non-Thermal Plasma

2020 ◽  
Vol 992 ◽  
pp. 658-662
Author(s):  
M.A. Mokeev ◽  
L.A. Urkhanova ◽  
A.N. Khagleev ◽  
Denis B. Solovev
Keyword(s):  
Glow Discharge ◽  
Plasma Treatment ◽  
Thermal Plasma ◽  
Graphical Model ◽  
Polymer Surface ◽  
Practical Method ◽  
Wetting Angle ◽  
Regression Equations ◽  
Non Thermal Plasma ◽  
The Impact

Mechanical, chemical and plasma treatment are the main kind of treatment of polytetrafluoroethylene (PTFE) films. Each method is different from each other by the adhesive force: the value of the wetting angle. Mechanical treatment allows different particles to permeate into the structure of the polymer. Chemical treatment creates new functional groups on the polymer surface, but this method is toxic and dangerous. Plasma treatment, in a glow discharge non-thermal plasma, is a more ecological and practical method. The experiment showed that the plasma treatment successfully increases the adhesion, this has been proven by infrared spectroscopy and scanning electron microscopy. According to the obtained data of the wetting angle, the regression equation was derived. A graphical model is constructed by regression equations allows you to determine the main processing factor and choose the optimal values of treatment.

scholarly journals The Effects of Acid Etching on the Morphology and Properties of Medical Grade Alumina and Zirconia Surfaces for Prosthetics

2020 ◽  
Author(s):  
Damian S Nakonieczny ◽  
Zbigniew Kazimierz Paszenda ◽  
Marianna Hundáková Hundáková ◽  
Gabriela Kratošová ◽  
Sylva Holešová ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Zirconia Ceramic ◽  
Ceramic Powders ◽  
Zirconia Ceramics ◽  
Acidic Solutions ◽  
Post Process ◽  
Piranha Solution ◽  
Surface Development ◽  
The Impact ◽  
Medical Grade

Abstract In this study we modify and functionalize the surface of alumina and zirconia ceramics for medical applications using chemical etching with mixtures of sulfuric, nitric, hydrofluoric acids and peroxide. After etching, the impact of processes on surface development, chemical composition, and topography is studied to select the most effective process of surface development. Medical grade alumina and zirconia ceramic powders have been chemically etched with selected three kinds of acidic solutions : 1.sulfuric and nitric acid, 2.sulfuric acid and peroxide, 3.fluoric acid various diluted aqueous solution during the selected time periods. Following heat treatment was performed and the samples characterization were undertaken: morphology and chemical composition , phase composition, functional group determination, and the specific surface area and porosity evaluation.. Comparing the results raised from acidic etching, it was noticed that the use of H2SO4:HNO3 solutions causes sulphur residues in ceramic in the form of sulphates. The application of HF negatively affects the structure of the material and cause agglomeration. The most advantageous modification of ceramic powders was application of piranha solution, the obtaining surface development was achieved, satisfactory degree of agglomeration and post-process pollution.

Population Study on the Impact Food Chemical Composition on Patients with Non-Alcoholic Fatty Liver Diseases

2018 ◽  
Vol 69 (4) ◽  
pp. 961-964
Author(s):  
Andrei Vasile Olteanu ◽  
Georgiana Emmanuela Gilca Blanariu ◽  
Gheorghe Gh. Balan ◽  
Dana Elena Mitrica ◽  
Elena Gologan ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Fatty Liver ◽  
Nutritional Value ◽  
Liver Steatosis ◽  
Saturated Fat ◽  
Control Group ◽  
Healthy Population ◽  
Alcoholic Fatty Liver ◽  
Major Interest ◽  
The Impact

Non-alcoholic fatty liver disease (NAFLD) has become of major interest worldwide, it is estimated that more than 20% of the general population suffer from liver steatosis. NAFLD is highly associated with metabolic risk factors like type 2 diabetes mellitus, obesity and dyslipidemia, the patients diagnosed with NAFLD should adopt a high fiber low calorie diet, with reduced saturated fat and carbohydrates content, leading to weight loss and improvement of metabolic profile. Our study is aiming to shape the profile of the patient interested in being informed related to food quality and chemical composition and to evaluate the aspects on the food products label which are important for the customer. Between June 2017 and December 2017, 83 patients diagnosed with NASH were included in the study, representing the study group, while 33 subjects, without metabolic syndrome or digestive diseases, selected from patient list belonging to two general practitioners, constituted the control group. Related to the interest of being informed about the chemical composition and nutritional value of the products bought, the study showed a low interest for the provided information on nutritional value. lack of confidence in the provided information and complexity of the information are understandable, the high number of subject reasoning through lack of immediate clinical benefit is surprising. Among the healthy population the willingness to pay attention to this aspect is extremely low.

Chemical Composition and Antimicrobial Activity of Bark and Leaf Extracts of Cupressus sempervirens and Juniperus phoenicea Grown in Al- Jabel Al-Akhdar Region, Libya

2019 ◽  
Vol 9 (4) ◽  
pp. 268-279
Author(s):  
Mohamed E.I. Badawy ◽  
Ibrahim E.A. Kherallah ◽  
Ahmed S.O. Mohareb ◽  
Mohamed. Z.M. Salem ◽  
Hameda A. Yousef
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Sea Level ◽  
Plant Extracts ◽  
Complex Mixture ◽  
Biologically Active ◽  
Cupressus Sempervirens ◽  
Leaf Extracts ◽  
Juniperus Phoenicea ◽  
The Impact

Background:Plant extracts are important products in the world and have been widely used for isolation of important biologically active products. Because of their significant environmental impact, extensive research has been explored to determine the antimicrobial activity of plant extracts.Methods:Acetone extracts of the bark and leaf of Cupressus sempervirens and Juniperus phoenicea, collected from three different altitudes (125, 391, and 851 m high of sea level) at Al- Jabel Al-Akhdar area, Libya were obtained and analyzed by GC/MS. The antimicrobial activity of the extracts was further evaluated against plant bacteria Rhizobium radiobacter, Erwinia carotovora, Rhodococcus fascians and Ralstonia solanacearum and fungus Botrytis cinerea.Results:The impact of the altitude from the sea level on the quantity and chemical constituents of the extracts was investigated. The yield was largely dependent on tree species and the highest yield (6.50%) was obtained with C. sempervirens L bark of altitude III (851 m of the sea level), while the lowest (1.17%) was obtained with the leaf extract of C. sempervirens L from altitude I (125 m). The chemical composition analyzed by GC/MS confirmed that the leaf extracts of C. sempervirens and J. phoenicea contained a complex mixture of monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolic, steroids and phthalates. However, the bark extracts of both trees contained a mixture of sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, phthalates, retinol and steroids. These constituents revealed some variability among the extracts displaying the highest interesting chemotype of totarol (terpenophenolic) in all extracts (14.63-78.19% of the total extract). The extracts displayed a noteworthy antifungal potency with varying degrees of inhibition of growth with EC50 values ranged from 78.50 to 206.90 mg/L. The extracts obtained from the leaves of C. sempervirens showed that the highest inhibitory activity was obtained with the extract of altitude II (391 m) with MIC 565, 510, 380 and 710 mg/L against E. carotovora, R. fascians, and R. radiobacter and R. solanacearum, respectively.Conclusion:Based on antimicrobial activity, raw plant extracts can be a cost-effective way to protect crops from microbial pathogens. Because plant extracts contain several antimicrobial compounds, the development of resistant pathogens can be delayed.

scholarly journals Treatment of wood with atmospheric plasma discharge: study of the treatment process, dynamic wettability and interactions with a waterborne coating

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jure Žigon ◽  
Matjaž Pavlič ◽  
Pierre Kibleur ◽  
Jan Van den Bulcke ◽  
Marko Petrič ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Treatment Process ◽  
Beech Wood ◽  
Treated Wood ◽  
Plasma Discharge ◽  
Contact Angles ◽  
Atmospheric Plasma ◽  
Waterborne Coating ◽  
Spruce Wood ◽  
The Impact

AbstractPlasma treatment is becoming a mature technique for modification of surfaces of various materials, including wood. A better insight in the treatment process and the impact of the plasma on properties of wood bulk are still needed. The study was performed on Norway spruce and common beech wood, as well as their thermally modified variations. The formations of the airborne discharge, as well as mass changes of the treated wood, were monitored. The impact of such treatment on wood-coating interaction was investigated by evaluating the dynamic wettability and penetration into wood. At the wood surface, plasma streamers were observed more intense on denser latewood regions. Wood mass loss was higher with increasing number of passes through the plasma discharge and was lower for thermally modified wood than for unmodified wood. Plasma treatment increased the surface free energy of all wood species and lowered the contact angles of a waterborne coating, these together indicating enhanced wettability after treatment. Finally, the distribution and penetration depth of the coating were studied with X-ray microtomography. It was found that the coating penetrated deeper into beech than into spruce wood. However, the treatment with plasma increased the penetration of the coating only into spruce wood.

Effect of plasma treatment on chemical composition, structure and sorption properties of lignocellulosic hemp fibers (Cannabis sativa L.)

2020 ◽  
Vol 236 ◽  
pp. 116000 ◽  
Author(s):  
Biljana M. Pejić ◽  
Ana D. Kramar ◽  
Bratislav M. Obradović ◽  
Milorad M. Kuraica ◽  
Andrijana A. Žekić ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Plasma Treatment ◽  
Cannabis Sativa ◽  
Sorption Properties ◽  
Hemp Fibers ◽  
Composition Structure ◽  
Structure And Sorption Properties

scholarly journals Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

2011 ◽  
Vol 2 ◽  
pp. 152-161 ◽  
Author(s):  
Hans J Ensikat ◽  
Petra Ditsche-Kuru ◽  
Christoph Neinhuis ◽  
Wilhelm Barthlott
Keyword(s):  
Chemical Composition ◽  
Water Repellency ◽  
Contact Angles ◽  
Dense Layer ◽  
Lotus Effect ◽  
Nano Structure ◽  
Lotus Leaf ◽  
Water Drops ◽  
The Impact ◽  
Unique Chemical

Lotus leaves have become an icon for superhydrophobicity and self-cleaning surfaces, and have led to the concept of the ‘Lotus effect’. Although many other plants have superhydrophobic surfaces with almost similar contact angles, the lotus shows better stability and perfection of its water repellency. Here, we compare the relevant properties such as the micro- and nano-structure, the chemical composition of the waxes and the mechanical properties of lotus with its competitors. It soon becomes obvious that the upper epidermis of the lotus leaf has developed some unrivaled optimizations. The extraordinary shape and the density of the papillae are the basis for the extremely reduced contact area between surface and water drops. The exceptional dense layer of very small epicuticular wax tubules is a result of their unique chemical composition. The mechanical robustness of the papillae and the wax tubules reduce damage and are the basis for the perfection and durability of the water repellency. A reason for the optimization, particularly of the upper side of the lotus leaf, can be deduced from the fact that the stomata are located in the upper epidermis. Here, the impact of rain and contamination is higher than on the lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves.

A Method for Evaluating Intensity of Water Cavitation Peening Processing

2011 ◽  
Vol 675-677 ◽  
pp. 747-750
Author(s):  
B. Han ◽  
Dong Ying Ju ◽  
Xiao Guang Yu
Keyword(s):  
Residual Stress ◽  
Process Capability ◽  
Diffraction Method ◽  
Spring Steel ◽  
Bubble Collapse ◽  
Plastic Layer ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Near Surface ◽  
The Impact

Water cavitation peening (WCP) with aeration, namely, a new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration a standard N-type almen strips of spring steel SAE 1070 was treated byWCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by means of the Almen-scale and X-ray diffraction method, respectively. The optimal fluxes of aeration and the optimal standoff distances were achieved. The maximum of arc height value reach around 150μm. The depth of plastic layer observed from the results of residual stresses is up to 150μm. The results verify the existence of macro-plastic strain in WCP processing. The distributions of residual stress in near-surface under different peening intensity can provide a reference for engineers to decide the optimal process conditions of WCP processing.

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