Papers by Keyword: Contact Angle

Abstract: Acrylonitrile Butane Styrene (ABS) is a type of polymer that can be metallized with metal through the electroless plating process so as to produce a strong and economical layer bond compared to metal. In this study, ABS plastic will be coated with nickel and the contact angle of ABS after the coating process will be examined. The first step is the etching process for 55 and 75 minutes using chromic acid to improve the adhesiveness and uniformity of the coating metal later. After the etching process is complete, then the surface roughness test is carried out using Mitutoyo SJ 201 Surface Roughness. Furthermore, the activation process with stannous chloride as a catalyst is carried out to accelerate the deposition of metal particles on the substrate surface so that during the electroless plating process the polymer turns into a conductor. Then the electroless plating process with time variations of 15, 25, 35, 45, 55 minutes using nickel sulfate, ammonium chloride, sodium hypophosphite, and sodium hydroxide to deposit nickel metal on the ABS surface. The results of the coating are then analyzed for surface topography using AFM and SEM, as well as investigating the contact angle of the droplets that are dropped on the coated ABS surface. It can be said that the etching variation of 55 minutes electroless nickel plating 75 minutes is the most hydrophobic because it has the largest contact angle and the smoothest surface topography compared to other variations.

Abstract: The wettability of reinforcing fillers such as glass and carbon fibers is a significant factor influencing the mechanical properties of the composite. This study focuses on the effect of finishing glass fiber surfaces with different concentrations of oligophenylene sulfide sulfone solution on fiber wettability, which is determined by contact angle and wetting time. The Adam-Schütte method was chosen as a method for determining the contact angle. According to the study results a 1.5% solution of oligophenylene sulfide sulfone in N, N'-dimethylacetamide gives a contact angle of 45°, forming over time a thin film on the fiber surface, which indicates a sufficiently high sizing ability.

Abstract: Investigation of the effect of low-pressure NLTP in nitrogen, argon, propane-butane and air on the properties of a multilayer medical-purpose material based on polypropylene used for the manufacture of sanitary-hygienic and medical products. It is shown that after plasma treatment of argon, nitrogen, propane-butane, the surface polarity of the CMC material changes significantly, as evidenced by a decrease in the wettability angle and an increase in capillarity. The most significant changes in indicators are observed in the case of plasma treatment in argon and nitrogen. However, in the case of argon, less processing time is required to achieve the effect. Plasma treatment leads to a slight decrease in tensile strength, no more than 10-15%. It is also shown that when plasma is treated in an argon atmosphere, such characteristics of a nonwoven material as air permeability, hygroscopicity increase, and a decrease in rigidity is observed. The study of the structure of the material (pore size) showed that the treatment with NLTP leads to a significant decrease in the size of large pores and an increase in the size of medium and small pores

Abstract: In this study, organic strip, particle removal efficiency and wettability were investigated at different mixing concentrations of diluted Sulfuric-Peroxide-HF (DSP⁺) solutions with and without the addition of IPA. Organic strip evaluation was carried out with KrF photoresist (PR), and the strip rate was increased rapidly with the increase in H₂SO₄ concentration mixed with DI water (DIW). The effects of H₂O₂ and IPA addition on diluted H₂SO₄ were observed below 30 vol% of H₂SO₄. The thickness of PR was increased with the addition of H₂O₂ to the solutions and the strip rate was increased when IPA was added. Silica particles were used to evaluate particle removal efficiency. The concentration of HF was the predominant factor of increasing PRE, and the addition of H₂SO₄ and H₂O₂ assisted in obtaining high PRE, while IPA addition reduced PRE. Decreasing of contact angle was observed with an increase of IPA addition to DSP⁺ solutions, and improved wettability of DSP⁺ solutions was expected to effectively clean particles in high-aspect-ratio (HAR) contact holes.

Abstract: The natural oxide layer, which spontaneously covers the surface of aluminium and its alloys, is well adherent to the surface, but it does not show adequate corrosion resistance in many conditions. In order to improve the material anti-corrosion performance, it is necessary to replace the surface oxide by a conversion coating. The first step to do this is to prepare the alloy surface to subsequent treatments. The pre-treatment implemented before the conversion treatment is one of the main factors responsible for the performance of the conversion coating. It involves several phases, including desmutting that encompasses the part immersion in an acid or alkaline solution bath. In this work, the influence of hydrofluoric acid concentration in the desmutting bath's formulation was investigated. The samples surface were characterised by using electrochemical techniques, glow discharge optical emission spectrometry and contact angle measurements.

Abstract: In this work we studied the effect of surface treatment of PET films, which are widely used in food packaging, on the adhesion value of ink layers based on polyvinyl chloride. To give high barrier properties to packaging laminates, the films used in their structure are coated with a nanolayer of aluminum oxide (AlOx). However, these films have a disadvantage associated with the low adhesion of adhesive and ink layers to the AlOx nanolayer. To eliminate this disadvantage, aluminium oxide nanolayer is additionally coated with various polymer coatings. In this work we studied the effect of a polyacrylic coating applied on top of an AlOx layer on improving the adhesion of ink layers. For PET films used in food packaging, optical and surface properties are also important. In this regard, additionally we measured surface free energy, coefficient of friction, and optical properties of the studied PET films. We also highlight the relationship of contact angles of wetting and the work of adhesion for the printing ink with the measured adhesion of ink layers.

Abstract: Borneol and dimethyl sulphoxide (DMSO) have been used as the skin penetration enhancers. Different concentrated borneol solutions in aprotic DMSO were prepared as the binary mixtures and determined their surface tension and contact angle behaviors using goniometer. Low borneol concentration minimized the surface tension and there was nearly stable contact angle for 30-70% borneol solutions. The trend contact angle value was decreased on glass slide, acrylic and LDPE whereas increasing on agarose gel and porcine tissues including buccal mucosa, gum and tongue with borneol concentration dependence. However, the borneol-DMSO binary mixture exhibited high wettability owing to its contact angle on glass surface was less than 90°. The solvent exchange between DMSO of borneol solutions and aqueous phase form agarose gel and porcine tissues including tongue, gum and buccal mucosa initiated the phase transformation from solution into matrix-like and promoted the higher contact angle with borneol concentration dependence. The understanding of surface tension and contact angle behaviors of aprotic borneol-DMSO binary mixture is useful for developing them into in situ forming gel for drug delivery such as in the oral cavity.

Abstract: Vanadium doped semi-insulating (SI) 6H-SiC {0001} substrates and their wetting properties were characterized using precisely dispensed de-ionized (DI) water drops. Radius, contact angle, width (chord), height and cap volume of a DI water drop on the SiC surface were quantitatively determined by analyzing sideview images of DI water drop in contact with SI 6H-SiC {0001} substrates using image processing software. The average of ten (10) contact angle measurements showed approximately 4 ° difference between the Si-face (48.48°) and the C-face (44.33º). Contact angle on the Si-face (0001) measured after native oxide removal showed significant decrease of contact angle, from 55° to 25° and recovered over time by room temperature oxidation in air. In contrast, contact angle on the C-face (000-1), measured after native oxide removal, showed significant increase of contact angle, from 40° to 54°, and continue to increase contact angle up to 71° after room temperature oxidation for 24 hours in air. Contact angle is found to be very sensitive to SiC surface polarity and specific surface conditions. Contact angle measurement, using image analysis techniques, can be applied as an in-line identification and surface condition characterization technique for SiC polytypes of specific surface polarities.

Abstract: The recycling of paper and paperboard waste for obtaining powder cellulose has a positive impact on environmental and economic benefits due to its possibility to be applied in various fields of industry, including the fabrication of wood-polymer composite^1,2. The extraction of cellulose from cellulose-containing wastes can be carried out by their mechanical disintegration with acid or alkali hydrolysis. In comparison with the known method³ the proposed method can be realized under more gentle conditions. For this aim, recycled de-inked waste paper was cut into small pieces (d < 5 mm) which were soaked in 0,05% hydrochloric solution at hydromodulus 1/20 (paper/water) for 2 hours at the intensive mechanical stirring for paper pieces disintegration. After soaking, the excessive water was pressed, and the disintegrated paper mass was dried, at first, at 60 °C for 16 hours and then at 120 °C for 2 hours. After drying, the paper mass was milled in a planetary mill for 15 minutes at a moderate rotation speed. The obtained cellulose particles were characterized by physicochemical properties. It was found, that obtained recycled paper particles (RPAP) had a similar contact angles with water compared to reference cellulose powder. However, polarity of RPAP was 20,5%, but of reference cellulose – 43,5%. RPAP could be characterized as more amorphous than cellulose because its crystallinity index was 61%, but reference cellulose powder – 81%. Using laser granulometry, it was found, that 99% of particles were less than 200 μm, and 90% of particles were less than 140 μm.

Abstract: 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.