Determination of Surface Free Energy and Contact Angle for Hydrolyzed Shellac

2012 ◽  
Vol 506 ◽  
pp. 270-273 ◽  
Author(s):  
P. Kraisit ◽  
S. Limmatvapirat ◽  
J. Nunthanid ◽  
Manee Luangtana-Anan ◽  
K. Terada ◽  
...  
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Polar Group ◽  
Sessile Drop Technique ◽  
Hydrolysis Process ◽  
Polar Force ◽  
Drop Technique

The purpose of this research was to determine surface free energy and contact angle of hydrolyzed shellac by using sessile drop technique. It is a method for determination of contact angle by placing a drop of liquid on a substrate and the surface free energy is then calculated by using the Wus equation. The substrate in this study was the hydrolyzed shellac prepared by hydrolysis of the native shellac at various times; 0, 15, 30 and 45 min using 2.0 %w/w sodium hydroxide. Water, formamide and ethylene glycol were liquids used for the investigation of the contact angle and surface free energy. The effect of hydrolysis time tended to reduce the contact angle and increase in the total surface free energy and polar force of hydrolyzed shellac. The result could be due to the breaking of the ester bonds of shellac during the hydrolysis process causing the higher free carboxyl group giving the higher polar group indicating by higher polar force and surface free energy. Therefore, the contact angle and surface free energy detected by sessile drop technique could be of benefit for the determination of hydrolysis process.

Effect of Various Types of Hydroxypropyl Methylcellulose (HPMC) Films on Surface Free Energy and Contact Angle

2014 ◽  
Vol 1060 ◽  
pp. 107-110 ◽  
Author(s):  
Pakorn Kraisit ◽  
Manee Luangtana-Anan ◽  
Narong Sarisuta
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Hydroxypropyl Methylcellulose ◽  
Physicochemical Characteristics ◽  
Basic Knowledge ◽  
Sessile Drop Technique ◽  
Buccal Films ◽  
Drop Technique

The aim of this study was to investigate the physicochemical characteristics of various viscosity grades of hydroxypropyl methylcellulose (HPMC) for mucoadhesive buccal films. The HPMC used in this study was K4M, K15M and K100M which their viscosity were 4000, 15000 and 100000 mPas respectively. Using HPMC as film forming base matrix, all intrinsic characteristics of each HPMC grade is required as basic knowledge for the development of mucoadhesive buccal films. To understand the primary essential parameters, surface free energy and contact angle of various HPMC grades were determined. Sessile drop technique was used in this study to determine contact angle of HPMC and surface free energy was then evaluated by using the Wu’s equation. The results showed that the increase in viscosity of HPMC film tended to decrease the polar force and total surface free energy but increased the contact angle. These parameters indicated that the hydrophilic character of HPMC was influenced by its viscosity. Our study suggested that the polar and dispersive force detected by sessile drop technique could be beneficial for the further design and development of mucoadhesive buccal films.

Wettability of plasma-polymerized vinyltriethoxysilane film

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Soňa Lichovníková ◽  
Jan Studýnka ◽  
Vladimír Čech
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Geometric Mean ◽  
Polar Component ◽  
Hydroxyl Groups ◽  
Sessile Drop Technique ◽  
Plasma Polymers ◽  
Drop Technique ◽  
Deposition Conditions

AbstractPlasma-polymerized films of vinyltriethoxysilane were surface characterized using the sessile drop technique. The surface free energy and its components were evaluated using the Owens-Wendt-Kaelble geometric mean method, Wu harmonic mean method, and van Oss, Chaudhury, and Good acid-base theory. Influence of deposition conditions on the surface free energy was demonstrated in the study. Improved wettability of the films was related to the diminished concentration of apolar methyl groups in plasma polymers. An increased concentration of carbonyl and hydroxyl groups resulted in a very small improvement of the polar component.

A modified sessile drop technique for the determination of the interactions at carbon-liquid interfaces

Carbon ◽  
1991 ◽  
Vol 29 (3) ◽  
pp. 449-455 ◽  
Author(s):  
Klaus J. Hüttinger ◽  
Sabine Höhmann ◽  
Marianne Seiferling
Keyword(s):  
Sessile Drop ◽  
Liquid Interfaces ◽  
Sessile Drop Technique ◽  
Drop Technique

Wetting and Interfacial Behaviors of Molten Ag, Cu and Ag-28Cu on WC-8Co Cemented Carbide

2016 ◽  
Vol 697 ◽  
pp. 555-560 ◽  
Author(s):  
Hao Fu ◽  
Xiang Zhao Zhang ◽  
Gui Wu Liu ◽  
Zi Wei Xu ◽  
Tie Zheng Pan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Sessile Drop ◽  
Testing Temperature ◽  
Cemented Carbide ◽  
Equilibrium Contact Angle ◽  
Sessile Drop Technique ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Drop Technique ◽  
Scanning Electron

The wetting and spreading of molten Cu, Ag and Ag-28Cu (wt.%) on the WC-Co cemented carbide were investigated by the sessile drop technique at different temperatures, and the interfacial behaviors of the metal/WC-Co couples were analyzed by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). The experimental results showed that the testing temperature and the composition of drop can play a key role in the wetting and spreading, and the good wettability with contact angle of less than 40o can be obtained. Moreover, the strongest interactions can be produced between the molten Cu and the WC-Co substrate at the higher temperature of 1100 oC due to the strong interdiffusion and solid solution between Cu and Co, resulting in the lowest equilibrium contact angle of ~0o. In addition, smooth and clean interfaces, without formation of visible interfacial reaction layer, were observed in all the three wetting systems. This work may also provide guidance to brazing of the cemented carbide.

Determination of Components of Cassiterite Surface Free Energy from Contact Angle Measurements

1993 ◽  
Vol 161 (1) ◽  
pp. 209-222 ◽  
Author(s):  
B. Jańczuk ◽  
J.M. Bruque ◽  
M.L. González-Martı́n ◽  
J.Moreno del Pozo
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Angle Measurements ◽  
Contact Angle Measurements

scholarly journals Some problems of characterization of a solid surface via the surface free energy changes

2017 ◽  
Vol 35 (7-8) ◽  
pp. 647-659 ◽  
Author(s):  
Emil Chibowski
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Experimental Determination ◽  
Surface Free Energy ◽  
Solid Surface ◽  
Contact Angles ◽  
Absolute Value ◽  
Receding Contact

During the processes occurring at a solid surface, the changes in the surface free energy take place. The knowledge about surface free energy is very helpful for understanding the processes taking place on the surface. However, experimental determination of solid surface free energy is still not a fully solved problem. In this paper, some problems dealing with calculation of solid surface free energy from contact angle are discussed based on literature values of advancing and receding contact angles measured on four different fluoropolymers surface. The four approaches most often used for the calculation are described and especial focus on the approach in which both the advancing and receding contact angles is paid. It is concluded that using probing liquids the absolute value of solid surface free energy cannot be determined. However, the determined apparent values of the energy are very helpful to understand the conditions necessary for a given process to occur.

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