scholarly journals Enhanced Hydrofobicity of Polymers for Personal Protective Equipment Achieved by Chemical and Physical Modification

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 106
Author(s):  
Emilia Irzmańska ◽  
Ewa Korzeniewska ◽  
Ryszard Pawlak ◽  
Mariusz Tomczyk ◽  
Aleksandra Smejda-Krzewicka ◽  
...  
Keyword(s):  
Contact Angle ◽  
Silicone Rubber ◽  
Pulse Repetition Frequency ◽  
Surface Condition ◽  
Scanning Speed ◽  
Beam Power ◽  
Laser Surface Modification ◽  
Power Pulse ◽  
Nanosecond Pulsed Laser ◽  
Before And After

The article presents significant results in research on creating superhydrophobic properties of materials which can be used as an interesting material for use in self-cleaning polymer protective gloves and similar applications where the superhydrophobicity plays a significant role. In this work the influence of laser surface modification of MVQ silicone rubber was investigated. The research was conducted using a nanosecond-pulsed laser at 1060 nm wavelength. After a process of laser ablation, the surface condition was examined using a SEM microscope and infrared spectroscopy. During the tests, the contact angle was checked both before and after the laser modification of samples pre-geometrised in the process of their production. The test results presented in the paper indicate that the chemical and physical modifications contribute to the change in the MVQ silicone rubber contact angle. A significant increase (by more than 30°) in the contact angle to 138° was observed. It was confirmed that surface geometrisation is not the only factor contributing to an increase in the contact angle of the analyzed material; other factors include a change in laser texturing parameters, such as mean beam power, pulse duration, scanning speed and pulse repetition frequency.

scholarly journals Laser-Textured Rubbers with Carbon Nanotube Fillers

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1091 ◽  
Author(s):  
Mariusz Siciński ◽  
Ewa Korzeniewska ◽  
Mariusz Tomczyk ◽  
Ryszard Pawlak ◽  
Dariusz Bieliński ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Surface Condition ◽  
Pulsed Laser ◽  
Contact Angles ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Vulcanized Rubber ◽  
Nanosecond Pulsed Laser ◽  
Before And After ◽  
Styrene Butadiene

This paper describes a method of laser ablation for improving the hydrophobic properties of vulcanized rubber. The treatment was tested on acrylonitrile rubber (NBR) and styrene butadiene rubber (SBR) containing carbon nanotubes and soot as fillers. The surface layer of the vulcanizates was modified using a nanosecond-pulsed laser at 1060 nm wavelength. The parameters of the ablation process were congruent, so no chemical changes in the polymeric material were observed. Evaluation of the surface condition of the laser-textured samples was performed using a Leica MZ6 stereoscopic microscope, operating with MultiScan 8.0 image analysis software. The contact angles were determined for all the samples before and after the surface modification process. Following modification of the surface morphology, with the best parameters of laser ablation, the contact angle increased, reaching 147°, which is very close to the threshold of superhydrophobicity (150°). On the basis of the results from several tests, laser ablation with a fiber-pulsed laser can be considered a very useful method for producing rubbers with superhydrophobic surfaces.

scholarly journals Surface condition, microstructure and microhardness of boronized layers produced on Vanadis-6 steel after modification by diode laser

2017 ◽  
Vol 37 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Aneta Bartkowska ◽  
Peter Jurči ◽  
Dariusz Bartkowski ◽  
Damian Przestacki ◽  
Mária Hudáková
Keyword(s):  
Laser Beam ◽  
Diode Laser ◽  
Heat Affected Zone ◽  
Surface Condition ◽  
Beam Power ◽  
Laser Surface Modification ◽  
Laser Beam Power ◽  
Study Results ◽  
Diffusion Boriding ◽  
Two Phases

AbstractThe paper presents the study results of surface condition, microstructure and microhardness of Vanadis-6 tool steel after diffusion boriding and laser modification by diode laser. As a result of diffusion boriding the layers consisted of two phases: FeB and Fe2B. A bright area under the continuous boronized layers was visible. This zone was probably rich in boron. As a result of laser surface modification of boronized layers, the microstructure composed of three zones: remelted zone, heat affected zone and the substrate was obtained. The microstructure of remelted zone consisted of boron-martensite eutectic. The depth of laser track (total thickness of remelted zone and heat affected zone) was dependent on laser parameters (laser beam power density and scanning laser beam velocity). The microhardness of laser remelting boronized layer in comparison with diffusion boronized layer was slightly lower. The presence of heat affected zone was advantageous, because it allowed to obtain a mild microhardness gradient between the layer and the substrate.

scholarly journals Investigation of Hydrothermally Stressed Silicone Rubber/Silica Micro and Nanocomposite for the Coating High Voltage Insulation Applications

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3567
Author(s):  
Faiza Faiza ◽  
Abraiz Khattak ◽  
Safi Ullah Butt ◽  
Kashif Imran ◽  
Abasin Ulasyar ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Structural Changes ◽  
Polymer Chains ◽  
Hydrothermal Conditions ◽  
Silica Filler ◽  
Before And After ◽  
Aging Conditions ◽  
The Stability ◽  
Micro Silica ◽  
Applied Stresses

Silicone rubber is a promising insulating material that has been performing well for different insulating and dielectric applications. However, in outdoor applications, environmental stresses cause structural and surface degradations that diminish its insulating properties. This effect of degradation can be reduced with the addition of a suitable filler to the polymer chains. For the investigation of structural changes and hydrophobicity four different systems were fabricated, including neat silicone rubber, a micro composite (with 15% micro-silica filler), and nanocomposites (with 2.5% and 5% nanosilica filler) by subjecting them to various hydrothermal conditions. In general, remarkable results were obtained by the addition of fillers. However, nanocomposites showed the best resistance against the applied stresses. In comparison to neat silicone rubber, the stability of the structure and hydrophobic behavior was better for micro-silica, which was further enhanced in the case of nanocomposites. The inclusion of 5% nanosilica showed the best results before and after applying aging conditions.

Curing Time and Water Repellent Properties of Dammar-Titanium Dioxide Thin Film

2015 ◽  
Vol 1112 ◽  
pp. 359-362
Author(s):  
Aisyah Nor Hasnan ◽  
Azizah Hanom Ahmad
Keyword(s):  
Contact Angle ◽  
Titanium Dioxide ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Repellent ◽  
Coating System ◽  
Curing Time ◽  
Coating Surface ◽  
Natural Resin ◽  
Before And After

Dammar plant resin is a local natural resin that can be bled from Dipterocaupacea sp of tree. It can be found abundantly in Malaysia’s tropical forest especially in Sarawak. Dammar and Titanium Dioxide was mixed in a various wt% to produce Dammar-modified Titanium Dioxide coating system. The modified coating systems were then spin-coated onto Aluminium Q-panel as the substrate. Coated Q-panels were left to cure at room temperature. The curing time was evaluated using dust free stage. The addition of Titanium Dioxide into the coating system fastens the curing time taken for the coated Q-panel to be cure. It only took about 11-12 minutes to dry compared to the coating system before the addition of Titanium Dioxide where a quite long duration required, 32 minutes. Contact angle measurement was also carried out in order to determine the wettability of the coating system. The surface coated with dammar-modified titanium dioxide found to be hydrophobic where a quite large contact angle obtained for the sample with 3 wt% of Titanium Dioxide (PDT3). The water droplets actually rest on the coating surface without wetting the surface. Water absorption test was done to strengthen the contact angle results where coated substrate was soaked into distilled water for 24 hours and being weighed before and after soaking. The difference of before and after soaking weigh showed that the coating surface does not absorb that much water where only approximately 0.02% of water being absorbed by the coating system for 3 wt%. It proved that the coating systems applied are hydrophobic.

scholarly journals Laser Irradiation of a Bio-Waste Derived Carbon Unlocks Performance Enhancement in Secondary Lithium Batteries

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3183
Author(s):  
Mariangela Curcio ◽  
Sergio Brutti ◽  
Lorenzo Caripoti ◽  
Angela De Bonis ◽  
Roberto Teghil
Keyword(s):  
Laser Irradiation ◽  
Performance Enhancement ◽  
Laser Source ◽  
Thermal Treatments ◽  
Carbon Particles ◽  
Nanosecond Pulsed Laser ◽  
Negative Electrodes ◽  
Before And After ◽  
Hazelnut Shell ◽  
Compositional Changes

Pyrolyzed carbons from bio-waste sources are renewable nanomaterials for sustainable negative electrodes in Li- and Na-ion batteries. Here, carbon derived from a hazelnut shell has been obtained by hydrothermal processing of the bio-waste followed by thermal treatments and laser irradiation in liquid. A non-focused nanosecond pulsed laser source has been used to irradiate pyrolyzed carbon particles suspended in acetonitrile to modify the surface and morphology. Morphological, structural, and compositional changes have been investigated by microscopy, spectroscopy, and diffraction to compare the materials properties after thermal treatments as well as before and after the irradiation. Laser irradiation in acetonitrile induces remarkable alteration in the nanomorphology, increase in the surface area and nitrogen enrichment of the carbon surfaces. These materials alterations are beneficial for the electrochemical performance in lithium half cells as proved by galvanostatic cycling at room temperature.

scholarly journals Effect of surface modifications on the properties of UHMWPE fibres and their composites

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 40-49
Author(s):  
Cuiyu Li ◽  
Yameng Shi ◽  
Rui Zhang ◽  
Gaopan Wang ◽  
Jingyan Jia
Keyword(s):  
Contact Angle ◽  
Chemical Composition ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Bending Performance ◽  
Specific Strength ◽  
Sample Extraction ◽  
Bending Load ◽  
Ultrahigh Molecular Weight ◽  
Before And After ◽  
Effect Of Surface

AbstractIn this study, ultrahigh-molecular-weight polyethylene (UHMWPE) fibres, modified by acetic acid, sulfuric acid and water at a ratio of 20:25:2 for different time periods and modified UHMWPE/EP composites were prepared. The micromorphology, chemical composition, contact angle, H sample extraction, tensile properties and bending performance of the composite material of the UHMWPE fibres before and after modification were tested and analysed. The results show that, after the UHMWPE fibres were treated with the modified liquid, the surface roughness of the fibre increased, the contact angle decreased, and the surface chemical composition and species significantly changed; the mechanical properties of the composites are best when the fibres were treated for 9 min. For the same fibre content, the specific strength, specific modulus and bending load of UHMWPE composites treated for 9 min were increased by 16.7%, 82.9% and 55.3%, respectively, compared with untreated samples.

scholarly journals Polyimide Surface Modification Using He-H2O Atmospheric Pressure Plasma Jet-Discharge Power Effect

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 662
Author(s):  
Essam Abdel–Fattah ◽  
Mazen Alshaer
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Plasma Treatment ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Discharge Power ◽  
Force Microscopy ◽  
Before And After ◽  
Power Effect

The atmospheric pressure He- H 2 O plasma jet has been analyzed and its effects on the Kapton polyimide surface have been investigated in terms of discharge power effect. The polyimide surfaces before and after plasma treatment were characterized using atomic force microscopy (AFM), X-ray photoelectrons spectroscopy (XPS) and contact angle. The results showed that, increasing the discharge power induces remarkable changes on the emission intensity, rotational and vibrational temperatures of He- H 2 O plasma jet. At the low discharge power ≤5.2 W, the contact angle analysis of the polyimide surface remarkably decrease owing to the abundant hydrophilic polar C=O and N–C=O groups as well as increase of surface roughness. Yet, plasma treatment at high discharge power ≥5.2 W results in a slight decrease of the surface wettability together with a reduction in the surface roughness and polar groups concentrations.

Preparation and Performance Study of Fluorosilicone Oligomer Anti-Sticking Coatings

2020 ◽  
Vol 841 ◽  
pp. 209-213
Author(s):  
Dong Bo Guan ◽  
Xiao Jie Zhai ◽  
Ying Nan Biansai ◽  
Bo Jun Cao ◽  
Yong Fu Zhu ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Contact Angle ◽  
Infrared Spectroscopy ◽  
Contact Time ◽  
Curing Agent ◽  
Performance Study ◽  
Film Forming ◽  
Increasing Trend ◽  
Before And After ◽  
And Performance

In this paper, fluorosilicone oligomer and its curing agent are used as the main film-forming materials, and fluorosilicone POSS is added to reduce the surface energy of the composites to prepare a coating with certain anti-sticking effect. The changes of molecular structure before and after the reaction were obtained by infrared spectroscopy. The contact angle and anti-sticking property of the coating surface were studied by changing the content of POSS containing fluorine. It was found that the contact angle of fluorine-containing POSS reached 98.7° when the content of fluorine-containing POSS was 3 Wt.%. With the increase of POSS content, the anti-sticking force of composites changed little, but with the increase of the contact time of tape, the anti-sticking force showed an increasing trend.

Influence of Silica Sand Particles on Disc Brake Squeal Noise

2013 ◽  
Vol 471 ◽  
pp. 81-85 ◽  
Author(s):  
Ahmad Razimi Mat Lazim ◽  
Abd Rahim Abu Bakar ◽  
Mohd Kameil Abdul Hamid ◽  
Izzat Mohd Asri
Keyword(s):  
Surface Condition ◽  
Surface Characteristics ◽  
Silica Sand ◽  
Brake Pad ◽  
Brake Squeal ◽  
The Road ◽  
Film Distribution ◽  
Before And After ◽  
Sand Particles ◽  
On The Road

Researchers in recent years begin to explore on tribological behavior of automotive brake squeal phenomena which covers the morphology, chemical composition, friction and wear, phase composition and third body or friction film distribution. However less effort has been made to study the tribological on the influence of small particles on brake squeal. During braking condition, both rotor and pads are exposed to road environmental particle which may affect pads surface condition. In order to assess the influence of this particle on brake squeal a series of squeal tests were performed. Silica sand grit particles with a size range between 400 to 200 μm which most available on the road surface were used in this experiment. Brake pad and disc surface characteristics were analyzed before and after squealing condition using Scanning Electron Microscope (SEM) and Energy dispersive X-ray analysis (EDX). The result shows that the silica sand particles had influence the squeal and surface behavior of the brake pad.

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