Comparative studies of nitrogen plasma and argon plasma treatment on the strength of PBO fibre reinforced high-temperature resistant thermoplastic composite

2021 ◽  
pp. 095400832098729
Author(s):  
K Sudheendra ◽  
Jennifer Vinodhini ◽  
M Govindaraju ◽  
Shantanu Bhowmik
Keyword(s):  
Contact Angle ◽  
High Temperature ◽  
Plasma Treatment ◽  
Sessile Drop ◽  
Dynamic Contact Angle ◽  
Argon Plasma ◽  
Film Surface ◽  
Fibre Surface ◽  
Nitrogen Plasma ◽  
Thermoplastic Composite

The study involves the processing of a novel poly [1, 4-phenylene-cis-benzobisoxazole] (PBO) fibre reinforced high-temperature thermoplastic composite with polyaryletherketone (PAEK) as the matrix. The PBO fibre and the PAEK film surface was modified using the method of argon and nitrogen plasma treatment. The investigation primarily focuses on evaluating the tensile properties of the fabricated laminates and correlating it with the effect of plasma treatment, surface characteristics, and its fracture surface. A 5% decrease in tensile strength was observed post argon plasma treatment while a 27% increase in strength was observed post nitrogen plasma treatment. The morphology of the failure surface was investigated by scanning electron microscopy and an interfacial failure was observed. Furthermore, the effect of plasma on the wettability of PBO fibres and PAEK film surface was confirmed by the Dynamic Contact Angle analysis and sessile drop method respectively. FTIR spectral analysis was done to investigate the effect of plasma treatment on the chemical structure on the surface. The results of the wettability study showed that the argon plasma treatment of the fibre surface increased its hydrophobicity while nitrogen plasma treatment resulted in the reduction of contact angle.

Influence of argon plasma treatment on carbon fibre reinforced high performance thermoplastic composite

2020 ◽  
pp. 095400832095706
Author(s):  
Jennifer Vinodhini ◽  
K Sudheendra ◽  
Meera Balachandran ◽  
Shantanu Bhowmik
Keyword(s):  
Mechanical Properties ◽  
Contact Angle ◽  
Surface Energy ◽  
Carbon Fibre ◽  
Plasma Treatment ◽  
Dynamic Contact Angle ◽  
Argon Plasma ◽  
Dynamic Contact ◽  
Resin Matrix ◽  
Surface Modified

This investigation highlights argon plasma treatment on Poly-aryl-ether-ketone (PAEK) and carbon fibre (CF) surface. The PAEK and CF surface is modified for 300 sec and the change in physiochemical and mechanical properties were investigated through Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Contact angle, Atomic Force Microscope (AFM) and Tensile Test. FTIR of surface modified PAEK revealed the stretching of C-H, C=C and C=O functional groups. A reversal phenomenon of increased surface energy was observed through dynamic contact angle study of CF and to further examine the surface energy effect, AFM analysis on CF was carried out revealing increased roughness with numerous micro dents formation. PAEK/CF composite samples were fabricated through compression moulding technique. The change in mechanical properties due to surface modification were analysed through Tensile testing on surface modified PAEK/CF sample and untreated PAEK/CF samples. The surface treated PAEK/CF showed increased tensile strength than untreated PAEK/CF. The argon plasma treatment helped in creating depth striations that lead to better interlocking of resin matrix with the reinforced CF. The fracture surface was examined through Filed Emission Scanning Electron Microscope (FE-SEM) wherein the Micrographs of the tensile tested samples indicated failure of composite due to fibre breakage.

Wettability Determination of the CO2-Reservoir Brine-Reservoir Rock System at High Pressures and High Temperature for Different Salinities

2014 ◽  
Vol 675-677 ◽  
pp. 115-119 ◽  
Author(s):  
Hai Tao Wang
Keyword(s):  
Contact Angle ◽  
High Temperature ◽  
High Pressures ◽  
Sessile Drop ◽  
Pure Water ◽  
Dynamic Contact Angle ◽  
Water System ◽  
Dynamic Contact ◽  
Reservoir Rock ◽  
Rock System

An experimental method has been developed to determine the wettability, i.e., the contact angle, of a CO2-reservoir brine-reservoir rock system at high pressures and high temperature using the axisymmetric drop shape analysis (ADSA) technique for the sessile drop case. The laboratory experiments were conducted for dynamic contact angle of CO2-reservoir brine-reservoir rock covering three interesting salinities (0 mg/L, 14224.2 mg/L and 21460.6 mg/L) at P=6–35 MPa and T=97.5 °C. For pure water system, θad (static advancing contact angel) increases from 71.69° to 107.1° as pressure of CO2 increases from 6 MPa to 35 MPa. θad decreases from 71.48° to 42.01° for the 1# brine system and from 51.21° to 23.61° for the 2# brine system as pressure of CO2 increases from 6 MPa to 35 MPa. θad for 2# brine system (21460.6 mg/L) is lower than that for 1# brine system (14224.2 mg/L) under the each same pressure.

THE FRICTION BEHAVIOR OF NBR SURFACE MODIFIED BY ARGON PLASMA TREATMENT

2011 ◽  
Vol 25 (31) ◽  
pp. 4249-4252 ◽  
Author(s):  
JONG-HYOUNG KIM ◽  
SEOCK-SAM KIM ◽  
SI-GEUN CHOI ◽  
SEUNG-HUN LEE
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Functional Groups ◽  
Bias Voltage ◽  
Treatment Time ◽  
Argon Plasma ◽  
Butadiene Rubber ◽  
Friction Behavior ◽  
Water Drops ◽  
Surface Modified

Different treatment time and bias voltage with RF Ar plasma were used to improve tribological properties of NBR (Nitrile Butadiene Rubber). Chemical structure analyses of NBR by Attenuated Total Reflectance (ATR) were performed to clarify the functionality modification after the plasma treatment. In addition, wetting experiments were carried out by measuring the contact angle of distilled water drops on the NBR surface. ATR analysis revealed that the number of - C = O , - C - O , O - H functional groups increased after the argon plasma treatment. The functional groups led to changes in the contact angle from 100 to 50 degrees. The results showed that form-like nanostructures on the NBR was observed at the bias voltage of -400 V. The friction test showed that coefficient of friction after modified NBR in lubricated condition decreased from 0.25 to 0.15 with the increasing bias voltage due to the surface structure formations and better bonding with grease lubricant.

Enhanced Wettability of Nanocrystalline Diamond Films for Biocoating Applications

2012 ◽  
Vol 1395 ◽  
Author(s):  
Jason H. C. Yang ◽  
Kungen Teii
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Oxygen Plasma ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Film Surface ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Polar Component ◽  
Oxygen Plasma Treatment

ABSTRACTNanocrystalline diamond (NCD) films are prepared from Ar-rich/N2/CH4 and Ar-rich/H2/CH4 mixtures by microwave plasma-enhanced chemical vapor deposition, and further treated by microwave hydrogen and oxygen plasma exposures separately to enhance the wetting property. The hydrogen plasma treatment has small effect on the surface roughness, while the oxygen plasma treatment forms fine protrusions on the film surface. Results show that the wettability of the hydrogen plasma treated NCD film is nearly constant or little improvement as the polar component of the apparent surface free energy is close to the as-deposit NCD film. In contrast, the wettability of the oxygen plasma treated NCD film is improved dramatically such that the contact angle is reduced from 92º and 4.7º to almost 0º for water and 1-bromonaphthalene, respectively, and the polar component increases significantly to 34 mJ/m2. The low contact angle suggests that the film is considerably a cell adhesive friendly surface, which is essential in maintaining multicellular structure, and thus making it a favorable wetting surface for biological and biomedical applications.

scholarly journals On the microhydrodynamics of superspreading

2011 ◽  
Vol 670 ◽  
pp. 1-4 ◽  
Author(s):  
C. MALDARELLI
Keyword(s):  
Contact Angle ◽  
Aqueous Phase ◽  
Contact Line ◽  
Sessile Drop ◽  
Numerical Study ◽  
Dynamic Contact Angle ◽  
Hydrophobic Surface ◽  
Dynamic Contact ◽  
Spreading Rate ◽  
Spreading Rates

Droplets of an aqueous phase placed on a very hydrophobic, waxy surface bead-up rather than spread, forming a sessile drop with a relatively large contact angle at the edge of the drop. Surfactant molecules, when dissolved in the aqueous phase, can facilitate the wetting of an aqueous drop on a hydrophobic surface. One class of surfactants, superwetters, can cause aqueous droplets to move very rapidly over a hydrophobic surface, thereby completely wetting the surface (superspreading). A recent numerical study of the hydrodynamics of superspreading by Karapetsas, Craster & Matar (J. Fluid Mech., this issue, vol. 670, 2011, pp. 5–37) provides a clear explanation of how these surfactants cause such a dramatic change in wetting behaviour. The study shows that large spreading rates occur when the surfactant can transfer directly from the air/aqueous to the aqueous/hydrophobic solid interface at the contact line. This transfer reduces the concentration of surfactant on the fluid interface, which would otherwise be elevated due to the advection accompanying the drop spreading. The reduced concentration creates a Marangoni force along the fluid surface in the direction of spreading, and a concave rim in the vicinity of the contact line with a large dynamic contact angle. Both of these effects act to increase the spreading rate. The molecular structure of the superwetters allows them to assemble on a hydrophobic surface, enabling the direct transfer from the fluid to the solid surface at the contact line.

scholarly journals On the contact region of a diffusion-limited evaporating drop: a local analysis

2013 ◽  
Vol 739 ◽  
pp. 308-337 ◽  
Author(s):  
S. J. S. Morris
Keyword(s):  
Contact Angle ◽  
Boundary Value Problem ◽  
Sessile Drop ◽  
Contact Region ◽  
Boundary Value ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Apparent Contact Angle ◽  
Local Analysis ◽  
Separation Of Scales

AbstractMotivated by experiments showing that a sessile drop of volatile perfectly wetting liquid initially advances over the substrate, but then reverses, we formulate the problem describing the contact region at reversal. Assuming a separation of scales, so that the radial extent of this region is small compared with the instantaneous radius$a$of the apparent contact line, we show that the time scale characterizing the contact region is small compared with that on which the bulk drop is evolving. As a result, the contact region is governed by a boundary-value problem, rather than an initial-value problem: the contact region has no memory, and all its properties are determined by conditions at the instant of reversal. We conclude that the apparent contact angle$\theta $is a function of the instantaneous drop radius$a$, as found in the experiments. We then non-dimensionalize the boundary-value problem, and find that its solution depends on one parameter$\mathscr{L}$, a dimensionless surface tension. According to this formulation, the apparent contact angle is well-defined: at the outer edge of the contact region, the film slope approaches a limit that is independent of the curvature of bulk drop. In this, it differs from the dynamic contact angle observed during spreading of non-volatile drops. Next, we analyse the boundary-value problem assuming$\mathscr{L}$to be small. Though, for arbitrary$\mathscr{L}$, determining$\theta $requires solving the steady diffusion equation for the vapour, there is, for small$\mathscr{L}$, a further separation of scales within the contact region. As a result,$\theta $is now determined by solving an ordinary differential equation. We predict that$\theta $varies as${a}^{- 1/ 6} $, as found experimentally for small drops ($a\lt 1~\mathrm{mm} $). For these drops, predicted and measured angles agree to within 10–30 %. Because the discrepancy increases with$a$, but$\mathscr{L}$is a decreasing function of$a$, we infer that some process occurring outside the contact region is required to explain the observed behaviour of larger drops having$a\gt 1~\mathrm{mm} $.

Surface Treatment of Polystyrene Films with Inductively Coupled Plasma System

2008 ◽  
Vol 55-57 ◽  
pp. 753-756 ◽  
Author(s):  
R. Nakhowong ◽  
Toemsak Srikhirin ◽  
Tanakorn Osotchan
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Inductively Coupled Plasma ◽  
Gas Flow ◽  
Moisture Absorption ◽  
Treatment Time ◽  
Argon Plasma ◽  
Contact Angles ◽  
Inductively Coupled ◽  
Before And After

The surface of polystyrene (PS) thin films in argon plasma was modified to study the hydrophilicity properties. An inductively coupled plasma (ICP) system was used to generate the argon plasma. In the experiment, the effect of RF power levels, gas flow rate and treatment time was investigated. The surface morphology of PS films was examined by the atomic force microscopy (AFM), also the contact angle goniometry was used for measuring the wettability of PS films before and after plasma treatment. After the plasma treatment, AFM images of PS revealed the increasing of the surface roughness as increasing the power levels and treatment times. Moreover, after treated with argon plasma, the contact angles of polystyrene films also decrease where the power levels and treatment times were increased. It is clear that the effects of power levels and treatment time improve the wettability of PS films. It can also be observed that by placing the sample in air after plasma treatment, the contact angle gradually increases probably due to moisture absorption in the PS films.

CHARACTERIZATION OF DYNAMIC WETTING OF PLASMA-TREATED PTFE FILM

2007 ◽  
Vol 14 (04) ◽  
pp. 821-825 ◽  
Author(s):  
Q. F. WEI ◽  
Y. LIU ◽  
F. L. HUANG ◽  
S. H. HONG
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Surface Properties ◽  
Contact Angle Hysteresis ◽  
Frictional Coefficient ◽  
Dynamic Contact Angle ◽  
Contact Angles ◽  
Dynamic Wetting ◽  
Ptfe Film ◽  
Receding Contact

Polytetrafluoroethylene (PTFE) has been increasingly used in many industries due to its low frictional coefficient and excellent chemical inertness. The surface properties of PTFE are of importance in various applications. The surface properties of PTFE can be modified by different techniques. In this study, PTFE film was treated in oxygen plasma for improving surface wettability. The effects of plasma treatment on dynamic wetting behavior were characterized using Scanning Probe Microscopy (SPM), Fourier transform infrared spectroscopy (FTIR), and dynamic contact angle (DCA) measurements. SPM observations revealed the etching effect of the plasma treatment on the film. The introduction of hydrophilic groups by plasma treatment was detected by FTIR. The roughened and functionalized surface resulted in the change in both advancing and receding contact angles. Advancing and receding contact angles were significantly reduced, but the contact angle hysteresis was obviously increased after plasma treatment.

scholarly journals Comparative analysis of inactivated wood surfaces

Holzforschung ◽  
2004 ◽  
Vol 58 (1) ◽  
pp. 22-31 ◽  
Author(s):  
M. Šernek ◽  
F. A. Kamke ◽  
W. G. Glasser
Keyword(s):  
Contact Angle ◽  
High Temperature ◽  
Wood Species ◽  
Sessile Drop ◽  
Surface Composition ◽  
Contact Angles ◽  
Southern Pine ◽  
Hydrogen Atoms ◽  
Yellow Poplar ◽  
Wood Surfaces

Abstract The surface inactivation of two wood species, yellow poplar (Liriodendron tulipifera) and southern pine (Pinus taeda), was studied following high temperature drying. Surface analysis involved X-ray photoelectron spectroscopy, sessile drop wettability and fracture mechanics of the adhesively-jointed surfaces. The results showed that wood drying at high temperature (i.e., >160 to 180 °C) caused modifications in surface composition. The oxygen to carbon ratio (O/C) decreased and the ratio of carbon atoms bonded to other carbon or to hydrogen atoms vis-à-vis carbons bonded to oxygen atoms (i.e., the C1/C2 ratio) increased with drying temperature. In addition, the contact angle increased with the temperature of exposure, but decreased with time. A dependence on wood species was evident: southern pine surfaces always exhibited higher contact angles than yellow poplar. Also, the rate of contact angle decline with time, dθ/dt, was found to vary with surface composition: this rate corresponded to O/C ratio-changes, especially in the case of southern pine. Southern pine was most susceptible to inactivation particularly when bonded with PF adhesive. Yellow poplar surfaces did not show significant inactivation when exposed to drying temperatures below ca. 180 °C. The results are explained by a relative enrichment of wood surfaces with non-polar substances, hydrophobic extractives and volatile organic compounds that 'become visually evident during the drying process at temperatures above ca. 160 °C. Little change was observed if drying temperatures remained below 150 °C.

Formation of Metallic Droplets on the Surface of Indium Sulfide Films During Argon Plasma Treatment

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940066
Author(s):  
S. P. Zimin ◽  
A. S. Pipkova ◽  
L. A. Mazaletskiy ◽  
I. I. Amirov ◽  
E. S. Gorlachev ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Thermal Evaporation ◽  
Argon Plasma ◽  
Film Surface ◽  
Indium Sulfide ◽  
Thermal Evaporation Method ◽  
Inductively Coupled ◽  
Glass Substrates ◽  
Argon Ions ◽  
Metallic Droplets

Modification of indium sulfide (In2S3) film surface was performed by the treatment in high-density low-pressure inductively coupled argon plasma. The films with thickness of 500–800[Formula: see text]nm were fabricated on glass substrates by the thermal evaporation method and subsequent annealing in sulfur ambience. The plasma treatment of as-grown and annealed films was carried out with argon ions having the energy of 25–200[Formula: see text]eV. Nanostructuring of the film surface took place resulting in the formation of arrays of nanosized indium droplets.

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