scholarly journals Influence of Low-Pressure RF Plasma Treatment on Aramid Yarns Properties

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3476
Author(s):  
Alicja Nejman ◽  
Irena Kamińska ◽  
Izabela Jasińska ◽  
Grzegorz Celichowski ◽  
Małgorzata Cieślak
Keyword(s):  
Weight Loss ◽  
Free Energy ◽  
Radio Frequency ◽  
Plasma Treatment ◽  
Surface Free Energy ◽  
Low Pressure ◽  
Rf Plasma ◽  
Polar Component ◽  
Specific Strength ◽  
Dispersion Component

The aim of the study was to modify the surface free energy (SFE) of meta- (mAr) and para-aramid (pAr) yarns by their activation in low-pressure air radio frequency (RF) (40 kHz) plasma and assessment of its impact on the properties of the yarns. After 10 and 90 min of activation, the SFE value increased, respectively, by 14% and 37% for mAr, and by 10% and 37% for pAr. The value of the polar component increased, respectively by 22% and 57% for mAr and 20% and 62% for pAr. The value of the dispersion component for mAr and pAr increased respectively by 9% and 25%. The weight loss decreased from 49% to 46% for mAr and 62% to 50% for pAr after 90 min of activation. After 90 min, the specific strength for mAr did not change and for pAr it decreased by 40%. For both yarns, the 10 min activation in plasma is sufficient to prepare their surface for planned nanomodification.

SURFACE MODIFICATION OF PLASMA TREATMENT ON SiO2 LAYER WITH UNDERFILL

2007 ◽  
Vol 14 (04) ◽  
pp. 849-852 ◽  
Author(s):  
BO-IN NOH ◽  
SEUNG-BOO JUNG
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Modification ◽  
Plasma Treatment ◽  
Surface Free Energy ◽  
Treatment Condition ◽  
Operating Time ◽  
Polar Component ◽  
Gas Atmosphere ◽  
Substrate Surfaces

The plasma treatment on SiO 2 substrate surfaces increased the oxygen-containing functional groups or the polar component of the surface free energy and, the wetting characteristics of the underfills/ SiO 2. The plasma treatment condition which gave the smallest contact angle between the underfills and SiO 2 was an operating time of 60 sec under O 2 gas atmosphere and a power of 200 W.

Interaction at interfaces and induction of surface free energy components

1987 ◽  
Vol 52 (2) ◽  
pp. 271-286 ◽  
Author(s):  
Jan Kloubek
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Organic Liquid ◽  
Interaction Mechanism ◽  
Work Of Adhesion ◽  
Polar Component ◽  
Published Data ◽  
Free Energies ◽  
Dispersion Component ◽  
Mechanism Of Interaction

A set of published data on surface free energy (γ1, γ2) and interfacial energy (γ12) for interfaces mercury-organic liquid, mercury-water, and water-organic liquid (125 pairs altogether) has been critically evaluated. It has been found that the Antonow rule does not hold, that the Neumann equation is suitable for determining the work of adhesion, if γ1 and γ2 are not too different, and that the Fowkes equation can be used to assess the type of interaction at the interface. A hypothesis has been suggested which states that, besides the interaction between dispersion components of the surface free energies of the adjoining phases and the interaction between the non-dispersion components of the same type in bulk, a non-dispersion component of one phase may interact by inducing a component of the same type in the other phase near the interface. Relations concerning the mechanism of interaction at the interface have been derived. Also, the relation between the Girifalco-Good, Neumann and complemented Fowkes equation has been evaluated. For the particular liquids the dispersion portion of their surface free energies and the interaction mechanism at their interface with water and mercury have been estimated. For water, e.g. the polar component of the surface free energy (14.7 mJ m-2) and the hydrogen-bond component (36.3 mJ m-2) have been determined. The introduction of the induced component of the surface free energy is shown, as an example, for water-aromatic hydrocarbons and water-alcohols systems.

scholarly journals Surface modification of polycarbonate (bisphenol A) by low pressure rf plasma

1970 ◽  
Vol 1 (2) ◽  
pp. 115-118 ◽  
Author(s):  
Deepak P Subedi ◽  
Lenka Zajickova ◽  
Vilma Bursikova ◽  
Jan Janca
Keyword(s):  
Free Energy ◽  
Surface Modification ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Photoelectron Spectroscopy ◽  
Peel Test ◽  
Low Pressure ◽  
Rf Plasma ◽  
Modified Surface ◽  
The Stability

Effects of low pressure radio frequency (rf) plasma treatment on the surface properties of polycarbonate are presented in this paper. Results obtained from the surface energy measurement after different conditions of treatment are compared. After treatment the surface free energy increased from the original value of 35 mJ/m2 to 63-74 mJ/m2. X-ray photoelectron spectroscopy measurements showed an increase in oxygen to carbon ratio after the treatment indicating an increase of oxygen-containing functional groups on the polycarbonate surface. A study of the stability of the modified surface property has been made on the basis of surface free energy. To study the improvement of adhesion between the polycarbonate and thin coatings, organosilicon thin films were deposited on the untreated and plasma treated polycarbonate. The adhesion of film to substrate was quantitatively analysed by ‘cross-hatch peel test’. Key words: Polycarbonate, surface modification, rf plasma, ageing, surface energy Himalayan Journal of Sciences 1(2): 115-118, 2003

Molecular orientation of liquid aliphatic hydrocarbons on the surface and at the interface with water

1989 ◽  
Vol 54 (12) ◽  
pp. 3171-3186 ◽  
Author(s):  
Jan Kloubek
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Molecular Orientation ◽  
Phase Changes ◽  
Aliphatic Hydrocarbons ◽  
Water Molecules ◽  
Free Energies ◽  
Dispersion Component ◽  
System Water ◽  
Orientation Of Molecules

The validity of the Fowkes theory for the interaction of dispersion forces at interfaces was inspected for the system water-aliphatic hydrocarbons with 5 to 16 C atoms. The obtained results lead to the conclusion that the hydrocarbon molecules cannot lie in a parallel position or be randomly arranged on the surface but that orientation of molecules increases there the ration of CH3 to CH2 groups with respect to that in the bulk. This ratio is changed at the interface with water so that the surface free energy of the hydrocarbon, γH, rises to a higher value, γ’H, which is effective in the interaction with water molecules. Not only the orientation of molecules depends on the adjoining phase and on the temperature but also the density of hydrocarbons on the surface of the liquid phase changes. It is lower than in the bulk and at the interface with water. Moreover, the volume occupied by the CH3 group increases on the surface more than that of the CH2 group. The dispersion component of the surface free energy of water, γdW = 19.09 mJ/m2, the non-dispersion component, γnW = 53.66 mJ/m2, and the surface free energies of the CH2 and CH3 groups, γ(CH2) = 32.94 mJ/m2 and γ(CH3) = 15.87 mJ/m2, were determined at 20 °C. The dependence of these values on the temperature in the range 15-40 °C was also evaluated.

On the analysis of surface free energy of DLC coatings deposited in low pressure RF discharge

2004 ◽  
Vol 54 (S3) ◽  
pp. C877-C882 ◽  
Author(s):  
Z. Navrátil ◽  
V. Buršíková ◽  
P. St’ahel ◽  
M. Šíra ◽  
P. Zvěřina
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Low Pressure ◽  
Rf Discharge ◽  
Dlc Coatings

scholarly journals Uses of radio emission spectroscopy for non-contact and in situ diagnostics of low pressure radio frequency plasma processing

2021 ◽  
Author(s):  
Rajani K. Vijayaraghavan ◽  
Sean Kelly ◽  
David Coates ◽  
Cezar Gaman ◽  
Niall MacGearailt ◽  
...  
Keyword(s):  
Radio Emission ◽  
Radio Frequency ◽  
Emission Spectroscopy ◽  
Near Field ◽  
Plasma Processing ◽  
Diagnostic Technique ◽  
Primary Source ◽  
Low Pressure ◽  
Chamber Pressure ◽  
Rf Plasma

Abstract We demonstrate that a passive non-contact diagnostic technique, radio emission spectroscopy (RES), provides a sensitive monitor of currents in a low pressure radio frequency (RF) plasma. A near field magnetic loop antenna was used to capture RF emissions from the plasma without perturbing it. The analysis was implemented for a capacitively coupled RF plasma with an RF supply at a frequency of 13.56 MHz. Real-time measurements are captured in scenarios relevant to contemporary challenges faced during semiconductor fabrication (e.g. window coating and wall disturbance). Exploration of the technique for key equipment parameters including applied RF power, chamber pressure, RF bias frequencies and chamber wall cleanliness shows sensitive and repeatable function. In particular, the induced RES signal was found to vary sensitively to pressure changes and we were able to detect pressure and power variations as low as ~2.5 %/mtorr and ~3.5 %/watt, respectively, during the plasma processing during a trial generic plasma process. Finally, we explored the ability of RES to monitor the operation of a multiple frequency low-pressure RF plasma system (f1 = 2 MHz, f2 = 162 MHz) and intermixing products which suggests strongly that the plasma sheaths are the primary source of this non-linear diode mixing effect.

scholarly journals Optical Properties and van der Waals - London Dispersion Interactions of Polystyrene Determined by Vacuum Ultraviolet Spectroscopy and Spectroscopic Ellipsometry

2007 ◽  
Vol 60 (4) ◽  
pp. 251 ◽  
Author(s):  
Roger H. French ◽  
Karen I. Winey ◽  
Min K. Yang ◽  
Weiming Qiu
Keyword(s):  
Free Energy ◽  
Optical Properties ◽  
Surface Free Energy ◽  
Vacuum Ultraviolet ◽  
Van Der Waals ◽  
Interband Transitions ◽  
Dispersion Interactions ◽  
Dispersion Component ◽  
London Dispersion ◽  
Hamaker Constants

The interband optical properties of polystyrene in the vacuum ultraviolet (VUV) region have been investigated using combined spectroscopic ellipsometry and VUV spectroscopy. Over the range 1.5–32 eV, the optical properties exhibit electronic transitions we assign to three groupings, E1, E2, and E3, corresponding to a hierarchy of interband transitions of aromatic (π → π*), non-bonding (n → π*, n → σ*), and saturated (σ → σ*) orbitals. In polystyrene there are strong features in the interband transitions arising from the side-chain π bonding of the aromatic ring consisting of a shoulder at 5.8 eV (E1′) and a peak at 6.3 eV (E1), and from the σ bonding of the C–C backbone at 12 eV (E3′) and 17.1 eV (E3). These E3 transitions have characteristic critical point line shapes associated with one-dimensionally delocalized electron states in the polymer backbone. A small shoulder at 9.9 eV (E2) is associated with excitations possibly from residual monomer or impurities. Knowledge of the valence electronic excitations of a material provides the necessary optical properties to calculate the van der Waals–London dispersion interactions using Lifshitz quantum electrodynamics theory and full spectral optical properties. Hamaker constants and the van der Waals–London dispersion component of the surface free energy for polystyrene were determined. These Lifshitz results were compared to the total surface free energy of polystyrene, polarity, and dispersive component of the surface free energy as determined from contact angle measurements with two liquids, and with literature values. The Lifshitz approach, using full spectral Hamaker constants, is a more direct determination of the van der Waals–London dispersion component of the surface free energy of polystyrene than other methods.

scholarly journals Fecal Coliforms and Total Coliforms Removal in Water Using Radio-Frequency (RF) Plasma System

2015 ◽  
Vol 9 (7) ◽  
pp. 80 ◽  
Author(s):  
Reni Desmiarti ◽  
Ariadi Hazmi ◽  
Yenni Trianda
Keyword(s):  
Drinking Water ◽  
Radio Frequency ◽  
Plasma Treatment ◽  
Death Rate ◽  
Fecal Coliforms ◽  
Rf Plasma ◽  
Radio Frequency Plasma ◽  
Plasma System ◽  
Total Coliforms ◽  
Frequency Plasma

A radio-frequency plasma system (RF) was used to investigate the removal of microorganisms from water.Plasma generated by RF radiation can produce active compounds (H•, •OH, H2O2, O3, etc.) that have a highoxidation potential and can kill microorganisms present in water (fecal coliforms and total coliforms). Thefrequency of the plasma system was set to 3.0, 3.3 and 3.7 MHz and applied to river water for 60 minutes. Theresults show that in all runs, the pH of the water produced was in the range from 7.4 to 7.9. The removalefficiencies of fecal coliforms achieved were between 83.75 and 95% and were higher than the removalefficiencies of total coliforms, which were between 82.61 and 93.48%. Meanwhile, the death rate (kD) of fecalcoliforms wasfaster than that of total coliforms. Therefore, the removal of total coliforms is the key to removingmicroorganisms fromwater. RF plasma treatment can be used for treatment of drinking water to decreasemicroorganisms.

INFLUENCE OF SURFACE FREE ENERGY ON ADHESION OF CrN THIN FILM DEPOSITED BY AIP METHOD

2012 ◽  
Vol 06 ◽  
pp. 509-514 ◽  
Author(s):  
HIKARU NOUDA ◽  
HIROATSU ODA ◽  
DAISUKE YONEKURA ◽  
RI-ICHI MURAKAMI
Keyword(s):  
Thin Film ◽  
Free Energy ◽  
Surface Free Energy ◽  
High Speed ◽  
Gas Flow ◽  
Sessile Drop ◽  
Ion Bombardment ◽  
Polar Component ◽  
Scratch Testing ◽  
The Relationship

The purpose of this study is to examine the relationship between adhesion of CrN thin film and the surface free energy of substrate. CrN film was deposited on JIS SKH2 high speed tool steel by arc ion plating (AIP) method. The surface free energy of the substrate was measured with/without ion bombardment process using nitrogen and argon gas under various gas flow rate before CrN deposition. The surface free energy was measured by the sessile drop method using distilled water and methylene iodide. The adhesion was evaluated by scratch testing and the relationship between a critical load and the surface free energy in each ion bombardment condition was discussed. As a result, it was found that the adhesion increased with decreasing the surface free energy, in particular the polar component strongly affects the adhesion.

Sign in / Sign up

Export Citation Format

Share Document