Search results

1

Influence of Volume Drop on Surface Free Energy of Glass

100%

Rymuszka D., Terpiłowski K., Hołysz L.

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EN

The aim of the research was to determine how the drop size affects the contact angle values and determine its optimal size for further contact angle measurements and comparison of the contact angle values measured for three probe liquids (water, formamide, diiodomethane) on the glass surface using the: sessile drop and tilting plate methods. Next, using the measured contact angles, the total surface free energy and its components were determined from the van Oss et al. (Lifshitz-van der Waals acid- base component, LWAB), Owens-Wendt, Neumann and contact angle hysteresis (CAH) approaches. The studies showed, that drop size is very important for contact angle measurements and consequently, for surface free energy estimation.

2

Comparison of contact angle measurement methods of liquids on metal alloys

80%

Terpiłowski K., Hołysz L., Rymuszka D., Banach R.

Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

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2016

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vol. 71

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issue 1

EN

The paper presents the studies of metal wettability using two methods: the sessile droplet and immersion ones. Based on the measured contact angles, there was calculated apparent surface free energy from the acidic–basic approach and the contact angle hysteresis. The advancing contact angles measured using the immersion method exhibit a little higher values than those measured by the sessile droplet method. The application of the immersion method leads to obtaining higher contact angle hysteresis. Both methods give different values of contact angles but they can be applied independently for estimation of metal surface wettability.

3

Wetting properties of the sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and polyoxyethylene (23) lauryl ether (Brij 35) binary mixtures in the poly(tetrafluoroethylene)-solution-air system

80%

Krawczyk J.

Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

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2015

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vol. 70

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issue 1

EN

Wettability of poly(tetrafluoroethylene) (PTFE) by aqueous solutions of binary mixtures composed of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) with polyoxyethylene (23) lauryl ether (Brij 35) was considered on the basis of the measured values of contact angle and surface tension. It was shown that the value of the critical surface tension of PTFE surface wetting at the studied system (23.5 mN/m), does not depend on the concentration and composition of the binary mixtures of studied surfactants in water, and it was higer than the surface tension of PTFE (20.2 mN/m). The best wettability of polytetrafluoroethylene (PTFE) by studied aqueous solutions of binary surfactants mixtures occurs at the mixtures concentration corresponding to the critical micelle concentration of their solutions.

4

Contact angles of protein black foam films under dynamic and equilibrium conditions

70%

Nedyalkov M., Sultanem C., Benattar J.-J.

Open Chemistry

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2007

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vol. 5

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issue 3

748-765

EN

The contact angles of protein Newton black foam films from ALG (alpha-lactalbumin), BLG (beta-lactoglobulin) and BSA (bovine serum albumin) are measured here within. The measurements are carried out under dynamic and equilibrium conditions. For all proteins, a strong hystheresis effect of the contact angle is observed under dynamic conditions. An attempt is made to explain these results by the slow adsorption and desorption kinetics of the protein bilayers and by the dynamic structure and the rheology of the protein network forming the bubble walls. In addition, we propose a modification of the experimental device reported previously for contact angle measurements of large flat films in equilibrium. The advantages of this method are discussed in detail. Some shortcomings (precision, reproducibility) of this preliminary variant of the device in this initial stage of its application, do not allow one to draw reliable conclusions about the interactions of these films. Some improvements of the measurement quality are proposed. [...]

5

WETTING PROPERTIES OF CHITOSAN-MODIFIED AND PLASMA-TREATED PEEK SURFACES

70%

Przykaza K., Jurak M., Wiącek A. E.

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EN

In this paper, the wettability of chitosan/phospholipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine – DPPC), chitosan/lipid (cholesterol – Chol) and chitosan/protein (cyclosporine A – CsA) films on air plasma activated polyetheretherketone (PEEK) plates was studied. The layers were prepared using the solution spreading technique and their surface wetting properties were determined based on the measurements of the advancing and receding contact angles of water, formamide and diiodomethane. Moreover, based on the contact angle hysteresis model of Chibowski, values of total surface free energy were estimated. Significant changes in PEEK polarity were observed after plasma activation and modifications with Ch/DPPC, Ch/Chol and Ch/CsA layers. These molecules modulate the chitosan film surface by changing the type and magnitude of interactions, which is revealed in the values of surface free energy. These results may be important for the development and implementation of highly biocompatible bone substitution polymers coated with chitosan film with anti-fungal and anti-bactericidal properties. Those systems based on chitosan may also carry and release biologically active substances which could be relevant in the new generation of drug delivery systems.

6

Spatially resolved spectroscopy of an atmospheric pressure microwave plasma jet used for surface treatment

70%

Potočňáková L., Hnilica J., Kudrle V.

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issue 1

EN

In this study, the variations of properties of a microwave plasma jet (surfatron) along the discharge axis have been investigated using optical emission spectroscopy. As the argon jet is not enclosed, the spatial distribution of individual species in effluent plasma is the result of rather complicated interplay between energy loss and gradual mixing with the air. Spatial 2D relative intensity profiles of atomic lines and molecular bands at 310 nm, 336 nm, 391 nm and 656 nm are presented in the form of colour maps revealing different positions of maximum emission intensity for 310 nm and 336 nm (in the effluent plasma) and for 391 nm and 656 nm (inside the discharge tube). The plasma jet was used for surface treatment of heat resistant samples (stainless steel, aluminium, silicon wafer) and the effectiveness of the plasma treatment was evaluated by measuring the sessile drop contact angle, with water and glycerol as testing liquids. The optimal position for plasma treatment (close to the tube nozzle) combined with longer treatment time (10 s) lead to hydrophilic properties of samples with contact angles as low as 10°.

7

Atmospheric pressure plasma treatment of polyamide-12 foils

70%

Hanusová J., Kováčik D., Stupavská M., Černák M., Novák I.

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issue 1

EN

The surface of a polyamide-12 (PA-12) foil was modified in order to improve the adhesive properties by two types of atmospheric pressure plasma sources. The samples were characterized using contact angle measurement, adhesive properties measurement and X-ray photoelectron spectroscopy (XPS). The ageing of the plasma modification was also studied. A significant increase in wettability was observed at different treatment times. The same effect was also seen in the adhesive properties - the adhesion was increased almost 12 times for 10 s DCSBD treatment in comparison to untreated PA-12. XPS analysis confirmed chemical changes due to the plasma modification of the PA-12. It was concluded that both plasma sources improve the adhesive properties of PA-12, with DCSBD obtaining better results.

8

EFFECT OF CHITOSAN FILM SURFACE STRUCTURE ON THE CONTACT ANGLE

70%

Jagodzińska S., Pałys B., Wawro D.

Progress on Chemistry and Application of Chitin and its Derivatives

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2021

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vol. 26

89-100

EN

The aim of this study was to evaluate the influence of the surface microstructure of chitosan films on the contact angle. Films without plasticising additives made of chitosan or regenerated chitosan were selected for the tests. A sessile drop method based on the European Pharmacopoeia was used to determine the contact angle. Due to the method of film production, the contact angle measurements were made on both the top and bottom surfaces of the film. For chitosan or regenerated chitosan films, the method of preparation slightly affected the difference in wettability between the top and bottom of the films, as confirmed by scanning electron microscopy. On the other hand, the wettability of the top and bottom of cellulose films varied greatly depending on the side of the film. Both chitosan and cellulose films had a homogeneous structure. There were differences in the microstructure between the top and the bottom of the sample in the cellulose film, a factor that affected the contact angle and thus the wettability of the surface.

9

Failure Characteristics and Strength Model of Composite Rock Samples in Contact Zone Under Compression

61%

Wang Q., Wang J., Ye Y., Jiang W., Yao N., Wang Q., Wang J., Ye Y., Jiang W., Yao N.

Archives of Mining Sciences

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2020

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vol. 65

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issue 2

10

Do combinations of insecticides and acaricides influence spray droplet formation and the interaction with citrus leaves?

61%

Della Vechia J. F., Santos R. T., Griesang F., Santos C. M., Ferreira M. C., Andrade D. J., Della Vechia J. F., Santos R. T., Griesang F., Santos C. M., Ferreira M. C., Andrade D. J.

Journal of Plant Protection Research

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2019

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vol. 59

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issue 4

11

SURFACE PROPERTIES OF CHITOSAN ACETATE, POLYACRYLAMIDE AND THEIR MIXTURES

61%

Lewandowska K.

Progress on Chemistry and Application of Chitin and its Derivatives

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2013

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vol. 18

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issue 18

29-34

EN

The surface properties of chitosan acetate (ChA), polyacrylamide (PAM) and ChA/PAM mixtures have been investigated by the tapping-mode atomic force microscopy (AFM) and monitored by contact angle measurements. Chitosan is blended with polyacrylamide in acetic acid solution and this solution is cast to prepare the mixture film. Measurements of the contact angle for two different liquids (diiodomethane and glycerol) on the surface of chitosan acetate. The surface free energy (γs) as well as dispersive (gsd) and polar (gsp) components were calculated from contact angle values by Owens-Wendt methods using an appropriate computer program. The values of polar and dispersive components of surface free energy show that PAM films are more polar than chitosan acetate films. In the case of ChA/PAM mixtures, the values of surface free energy and polar component are reduced significantly compared with pure polymers. This behavior indicates rather hydrophobic character of this surface. The changes of topography images were considered by determining the root mean square (RMS) deviation in the image data. The study of blends by AFM showed a completely different morphology when compared with pure components. The roughness of blends increases with the increase of ChA content. This may indicates a strong interaction between the polymeric components.

Refine search results

Influence of Volume Drop on Surface Free Energy of Glass

Comparison of contact angle measurement methods of liquids on metal alloys

Wetting properties of the sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and polyoxyethylene (23) lauryl ether (Brij 35) binary mixtures in the poly(tetrafluoroethylene)-solution-air system

Contact angles of protein black foam films under dynamic and equilibrium conditions

WETTING PROPERTIES OF CHITOSAN-MODIFIED AND PLASMA-TREATED PEEK SURFACES

Spatially resolved spectroscopy of an atmospheric pressure microwave plasma jet used for surface treatment

Atmospheric pressure plasma treatment of polyamide-12 foils

EFFECT OF CHITOSAN FILM SURFACE STRUCTURE ON THE CONTACT ANGLE

Failure Characteristics and Strength Model of Composite Rock Samples in Contact Zone Under Compression

Do combinations of insecticides and acaricides influence spray droplet formation and the interaction with citrus leaves?

SURFACE PROPERTIES OF CHITOSAN ACETATE, POLYACRYLAMIDE AND THEIR MIXTURES