Utilization of Plasma Treated Polymeric Macro-Fibers as Reinforcement in Concrete Constructions

2017 ◽  
Vol 1144 ◽  
pp. 70-75
Author(s):  
Jan Trejbal ◽  
Josef Fládr ◽  
Lubomír Kopecký
Keyword(s):  
Mechanical Properties ◽  
Plasma Treatment ◽  
Treatment Duration ◽  
Negative Impact ◽  
Fiber Surface ◽  
Cement Matrix ◽  
Bending Tests ◽  
Four Point Bending ◽  
Angle Measurements ◽  
Contact Angle Measurements

Polymeric macro fibers BeneSteel having diameter equal to 480 μm and length 55 mm were treated in low pressure oxygen plasma by different treatment duration from 5 to 480 s to attain the better interaction with cement matrix (focused on both, chemical and physical bond). An effect of realized treatment was examined through fiber surface water wettability observation by direct horizontal optical method enabling contact angle measurements. Next, the pertinent negative impact of plasma treatment on fibers mechanical properties was examined by several methods. It was shown that the most effective plasma treatment duration is up to 30 s. Thus treated fibers exhibited the better wettability by ca. 110 % in comparison with reference fibers, while its mechanical properties were not negatively affected. Finally, reference and 30 s plasma treated fibers were used as randomly dispersed reinforcement in concrete specimens. Mechanical properties of these composites were examined by four-point bending tests. Specimens containing treated fibers exhibited bigger fracture toughness by ca. 30 % beside the reference ones, while the first cracking strength stayed constant in all cases.

Mechanical Properties of Thermal Barrier Coatings at Room Temperature

2005 ◽  
Vol 290 ◽  
pp. 336-339 ◽  
Author(s):  
G. Guidoni ◽  
Y. Torres Hernández ◽  
Marc Anglada
Keyword(s):  
Mechanical Properties ◽  
Thermal Barrier Coatings ◽  
Room Temperature ◽  
Inconel 625 ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Bending Tests ◽  
Four Point Bending ◽  
Barrier Coating ◽  
Plasma Sprayed

Four point bending tests have been carried out on a thermal barrier coating (TBC) system, at room temperature. The TBC system consisted of a plasma sprayed Y-TZP top coat with 8 % in weight of Yttria, a bond coat of NiCrAlY and a Ni-based superalloy Inconel 625 as substrate. The TBC coating was deposited on both sides of the prismatic specimens. Efforts have been done in detecting the damage of the coating by means of Maltzbender et al [1] model.

scholarly journals Biomaterial Embedding Process for Ceramic–Polymer Microfluidic Sensors

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1745 ◽  
Author(s):  
Witold Nawrot ◽  
Karol Malecha
Keyword(s):  
Plasma Treatment ◽  
Anodic Bonding ◽  
Plasma Modification ◽  
Biochemical Processes ◽  
Angle Measurements ◽  
Plasma Activation ◽  
Microfluidic Sensors ◽  
Contact Angle Measurements ◽  
Novel Method ◽  
Sample Structure

One of the major issues in microfluidic biosensors is biolayer deposition. Typical manufacturing processes, such as firing of ceramics and anodic bonding of silicon and glass, involve exposure to high temperatures, which any biomaterial is very vulnerable to. Therefore, current methods are based on deposition from liquid, for example, chemical bath deposition (CBD) and electrodeposition (ED). However, such approaches are not suitable for many biomaterials. This problem was partially resolved by introduction of ceramic–polymer bonding using plasma treatment. This method introduces an approximately 15-min-long window for biomodification between plasma activation and sealing the system with a polymer cap. Unfortunately, some biochemical processes are rather slow, and this time is not sufficient for the proper attachment of a biomaterial to the surface. Therefore, a novel method, based on plasma activation after biomodification, is introduced. Crucially, the discharge occurs selectively; otherwise, it would etch the biomaterial. Difficulties in manufacturing ceramic biosensors could be overcome by selective surface modification using plasma treatment and bonding to polymer. The area of plasma modification was investigated through contact-angle measurements and Fourier-transform infrared (FTIR) analyses. A sample structure was manufactured in order to prove the concept. The results show that the method is viable.

scholarly journals Improved de-inking of inkjet-printed paper using environmentally friendly atmospheric pressure low temperature plasma for paper recycling

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rodolphe Mauchauffé ◽  
Seung Jun Lee ◽  
Isaac Han ◽  
Sang Hyeong Kim ◽  
Se Youn Moon
Keyword(s):  
Plasma Treatment ◽  
Atmospheric Pressure ◽  
Paper Recycling ◽  
Temperature Plasma ◽  
Water Contact ◽  
Angle Measurements ◽  
Natural Energy ◽  
Contact Angle Measurements ◽  
Speed Up ◽  
Uv Visible

Abstract Nowadays, due to environmental pollution and natural energy consumption caused by waste paper, many researches are being conducted on the reuse of printed-paper. To recycle the paper, de-inking has to be performed. In this article, in order to reduce the use of the commonly used de-inking chemicals, the effect of an atmospheric pressure helium plasma treatment on the de-inking enhancement of printed-paper is studied. Through colorimeter and UV-visible spectrometer measurements the plasma treatment is shown to speed up the de-inking. While SEM observations and FTIR measurements suggest that the paper quality is retained upon plasma treatment, the increase of surface hydrophilicity measured by water contact angle measurements, compared to non-treated paper, is believed to enhance the fiber swelling of the paper and lead to a faster ink removal.

The Effect of Polypropylene Fiber on the Mechanical Properties of Self-Compacting Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1325-1329
Author(s):  
Ye Ran Zhu ◽  
Jun Cai ◽  
Dong Wang ◽  
Guo Hong Huang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Polypropylene Fiber ◽  
Flexural Properties ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Bending Tests ◽  
Flexural Toughness ◽  
Four Point Bending

This paper investigates the mechanical properties (compressive strength, splitting tensile strength and flexural toughness) of polypropylene fiber reinforced self-compacting concrete (PFRSCC). The effect of the incorporation of polypropylene fiber on the mechanical properties of PFRSCC is determined. Four point bending tests on beam specimens were performed to evaluate the flexural properties of PFRSCC. Test results indicate that flexural toughness and ductility are remarkably improved by the addition of polypropylene fiber.

Surface-modified halloysite nanotubes as fillers applied in reinforcing the performance of polytetrafluoroethylene

Clay Minerals ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 643-656 ◽  
Author(s):  
Zhi-Lin Cheng ◽  
Xing-Yu Chang ◽  
Zan Liu ◽  
Dun-Zhong Qin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Sodium Dodecyl ◽  
Halloysite Nanotubes ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
Ftir Spectrometry ◽  
Surface Modified ◽  
Scanning Electron

ABSTRACTIn order to improve the dispersibility of halloysite nanotubes (HNTs) in polytetrafluoroethylene (PTFE), the modification of HNT surfaces was studied with three types of modifiers (polymethyl methacrylate [PMMA], sodium dodecyl sulfate [SDS] and carboxylic acid). The modified HNTs were characterized by Fourier-transform infrared (FTIR) spectrometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and contact angle measurements. The HNTs were used to reinforce the mechanical properties of PTFE. The mechanical results indicated that the tensile strength of the modified HNT-filled PTFE nanocomposites (F-HNT/PTFE) improved to an acceptable degree and Young's modulus increased significantly. The tribological results showed that the wear rate of F-HNT/PTFE decreased by 21–82 and 9–40 times compared to pure PTFE and the pristine F-HNT/PTFE, respectively.

Utilization of Surface-Modified Polymer and Glass Micro-Fibers as Reinforcement in Cement Composites

2018 ◽  
Vol 760 ◽  
pp. 225-230
Author(s):  
Jan Trejbal ◽  
Zdeněk Prošek ◽  
Josef Fládr ◽  
Pavel Tesárek
Keyword(s):  
Polymer Fibers ◽  
Cement Matrix ◽  
Interphase Interaction ◽  
Bending Tests ◽  
Chemical Surface ◽  
Modified Polymer ◽  
Four Point Bending ◽  
Macro Scale ◽  
Strong Adhesion ◽  
Surface Modified

The presented work focuses on plasma modifications of polymer and glass micro-fibers (having 32 and 14 μm in the diameter, respectively) used as randomly distributed and oriented reinforcement of concrete composites. Fiber surfaces were modified by means of the low-pressure coupled cold oxygen plasma in order to attain a strong adhesion with the cement matrix. From the perspective of micro scale, an impact of modifications on both the physical and the chemical surface changes of treated fibers was examined using: (i) a wettability measurements – an evaluation of an interphase interaction between demineralized water and fibers and (ii) the SEM microscopy – an assessment of a surface morphology. From the perspective of macro scale, the interaction between the two materials was examined by destructive four-point bending tests of the cement paste containing both the reference and treated fibers (specimens having dimensions equal to 40×40×160 mm, water to cement ration 0.4) were done. It was shown that the wettability of modified fibers was increased by approx. 10 % and 70 % in the case of glass and polymer fibers, respectively. The SEM morphology analysis revealed fine roughening of treated fibers, if compared to the reference ones. The mechanical testing pointed out on a toughness increase in the post-cracking response of loaded specimens.

Effect of Anodic Surface Treatment on PAN-Based Carbon Fiber and its Relationship to the Fracture Toughness of the Carbon Fiber-Reinforced Polymer Composites

2007 ◽  
Vol 567-568 ◽  
pp. 233-236
Author(s):  
Hamid Sarraf ◽  
Ludmila Škarpová
Keyword(s):  
Fracture Toughness ◽  
Contact Angle ◽  
Carbon Fiber ◽  
Surface Treatment ◽  
Polymer Composites ◽  
Fiber Surface ◽  
Resin Matrix ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Current Densities

The effect of anodic surface treatment on the polyacrylonitrile (PAN)-based carbon fibers surface properties and the mechanical behavior of the resulting carbon fiber-polymer composites has been studied in terms of the contact angle measurements of fibers and the fracture toughness of composites. Results from contact angle measurements revealed that the angle of electrolyte solution largely decreases with increasing current densities of treatments up to 0.4-0.5 A m-2. The results obtained from the evolution of KIC with flexure of the composites as a function of electric current density shown that the KIC of the composite continually increases with increased current densities of the treatments up to 0.5 A m-2, and a maximum strength value is found about 294 MPa cm1/2 at the anodic treatment of 0.5 A m-2. It can be concluded that the anodic surface treatment is largely influenced in the fiber surface nature and the mechanical interfacial properties between the carbon fiber and epoxy resin matrix of the resulting composites, i.e., the fracture toughness. We suggest that good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices of the resulting composites.

Surface Modification of Fluorosilicone Acrylate RGP Contact Lens by Low-Temperature Ammonia Plasma

2009 ◽  
Vol 610-613 ◽  
pp. 1273-1277 ◽  
Author(s):  
Li Ren ◽  
Lian Na Zhao ◽  
Shi Heng Yin ◽  
Ying Jun Wang ◽  
Hao Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Low Temperature ◽  
Plasma Treatment ◽  
Contact Lens ◽  
Photoelectron Spectroscopy ◽  
Ammonia Plasma ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Surface Contact Angle

In order to improve the surface hydrophilicity and the resistance to protein deposition of fluorosilicone acrylate RGP (rigid gas permeable) contact lens, low temperature ammonia plasma treatment was used to modify the lens surface. The changes of surface structures and properties were characterized by contact angle analyzer, X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). Effects of exposure time and plasma generating power on surface properties of the RGP contact lens were investigated. The surface contact angle measurements showed a great improvement of hydrophilicity after plasma treatment. XPS analysis indicated that the oxygen content and the nitrogen content increased remarkably after ammonia plasma treatment. Furthermore, the content of the hydrophilic group O-C=O/N-C=O on the surface increased and the content of the hydrophobic group CF2 decreased after plasma treatment. AFM results showed that ammonia plasma could lead to surface etching.

scholarly journals Novel green biodegradable polylactide based polyurethane triblock copolymers reinforced with cellulose nanowhiskers

2021 ◽  
Author(s):  
Noha Ali Abdel Hady
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Cell Attachment ◽  
Triblock Copolymers ◽  
Cellulose Nanowhiskers ◽  
Angle Measurements ◽  
Degradation Rates ◽  
Contact Angle Measurements ◽  
Enhance Cell Attachment ◽  
Final Composition

Novel green classes of biodegradable polylactide-based triblock polyurethane (TBPU) polymers were synthesized. Owing to their tailored mechanical properties, improved degradation rates, and the enhance cell attachment potential compared with polylactide-homopolymer, they tested for biomedical applications. Triblock copolymers (TB) of different lactide and polyethylene glycol composition were first fabricated by ring-opening polymerization using tin octoate as catalyst. Afterwich polycaprolactone diole (PCL-diole) is reacted with TB copolymers using 1,4-butane diisocyanate (BDI) as nontoxic chain extender to form the final TBPUs. Final composition, molecular weight, thermal properties, hydrophilicity and biodegradation of the obtained TB and TBPU were studied and characterized using 1H-NMR, GPC, FTIR, DSC, SEM and contact angle measurements. Results obtained from the high molecular weight members of TBPUs showed improved hydrophilicity and degradation rates along with tailored mechanical properties. Nanocomposites obtained by reinforcing TBPU3 with 7% (w/w) BCNW showed ~16% increase in tensile strength and 330% in % elongation compared with PL-homopolymer. Those polymers and their nanocomposites demonstrated promising potential to be used as bone cement, and in regenerative medicin.

Delayed Photoactivation of Dual-cure Composites: Effect on Cuspal Flexure, Depth-of-cure, and Mechanical Properties

2019 ◽  
Vol 44 (2) ◽  
pp. E97-E104 ◽  
Author(s):  
KO Hughes ◽  
KJ Powell ◽  
AE Hill ◽  
D Tantbirojn ◽  
A Versluis
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Degree Of Cure ◽  
Bending Tests ◽  
Depth Of Cure ◽  
Four Point Bending ◽  
Tooth Surfaces

SUMMARY Objectives: This study tested whether delayed photoactivation could reduce shrinkage stresses in dual-cure composites and how it affected the depth-of-cure and mechanical properties. Methods and Materials: Two dual-cure composites (ACTIVA and Bulk EZ) were subjected to two polymerization protocols: photoactivation at 45 seconds (immediate) or 165 seconds (2 minutes delayed) after extrusion. Typodont premolars with standardized preparations were restored with the composites, and cuspal flexure caused by polymerization shrinkage was determined with three-dimensional scanning of the external tooth surfaces before restoration (baseline) and at 10 minutes and one hour after photoactivation. Bond integrity (intact interface) was verified with dye penetration. Depth-of-cure was determined by measuring Vickers hardness through the depth at 1-mm increments. Elastic modulus and maximum stress were determined by four-point bending tests (n=10). Results were analyzed with two- or three-way analysis of variance and pairwise comparisons (Bonferroni; α=0.05). Results: Delayed photoactivation significantly reduced cuspal flexure for both composites at 10 minutes and one hour (p≤0.003). Interface was >99% intact in every group. Depth-of-cure, elastic modulus, and flexural strength were not significantly different between the immediate and delayed photoactivation (p>0.05). The hardness of ACTIVA reduced significantly with depth (p<0.001), whereas the hardness of Bulk EZ was constant throughout the depth (p=0.942). Conclusions: Delayed photoactivation of dual-cure restorative composites can reduce shrinkage stresses without negatively affecting the degree-of-cure or mechanical properties (elastic modulus and flexural strength).

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