The influence of alumino-silicate matrix composition on surface hydrophobic properties

The purpose of this investigation is to investigate the hydrophobicity of geopolymers, new alumino-silicate materials and the influence of Si/Al ratio on their surface properties. Contact angle measurement (CAM) as reliable indicator of hydrophobicity was determined for synthesized geopolymers using water and ethylene-glycol as reference liquids. Geopolymers were synthesized from various precursors: kaolin, bentonite and diatomite. Characterization of phase structure and microstructure was performed by XRD, FTIR, SEM/EDX methods. Contact angle measurements confirmed that the geopolymers synthesized from metakaolin are the most porous, which can be explained by the smallest Si/Al ratio. The maximum value of contact angle and free surface energy (110.2 mJ/m2) has been achieved for geopolymer synthesized by diatoms (GPMD). SEM micrograph of GPMD shows a homogeneous surface with some longitudinal cavities in the gel and is significantly different from the micrographs of other two geopolymer samples, GPMB and GPMK.

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Measurement and improvement of the adhesion of copper to polyimide

Journal of Materials Research ◽

10.1557/jmr.1999.0544 ◽

1999 ◽

Vol 14 (10) ◽

pp. 4025-4034 ◽

Cited By ~ 18

Author(s):

M. Menezes ◽

I. M. Robertson ◽

H. K. Birnbaum

Keyword(s):

Contact Angle ◽

Interfacial Adhesion ◽

Reasonable Agreement ◽

Contact Angle Measurement ◽

Angle Measurement ◽

Polyimide Substrate ◽

Copper Clusters ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Strength Of Adhesion

A contact angle measurement technique has been used to obtain an estimate of the interfacial energy and thermodynamic adhesive strength between copper and polyimide [pyromellitic dyanhydride oxydianalyn (PMDA-ODA) and p-phenylene biphenyltetracarboinide (BPDA-PDA)]. Values of the strength of adhesion from these contact angle measurements are in reasonable agreement with values calculated using the Girifalco–Good–Fowkes nonpolar interfacial adhesion theory. Based on the surface energy it was predicted and experimentally observed that small copper clusters would embed into the polymer matrix if heated under ultrahigh vacuum conditions at temperatures near Tg of the polymer. Controlled embedding of nanometer clusters was utilized to produce a textured interface, where the partially embedded clusters acted as “nanonails” to anchor a metal overlayer to the underlying polyimide substrate. These nanonails greatly increased the bonding between the copper overlayer and the polyimide, as demonstrated by mechanical debonding studies.

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Surface Treatments of 4H-SiC Evaluated by Contact Angle Measurement

Materials Science Forum ◽

10.4028/www.scientific.net/msf.679-680.374 ◽

2011 ◽

Vol 679-680 ◽

pp. 374-377 ◽

Cited By ~ 1

Author(s):

Tomoaki Hatayama ◽

Hiroyuki Suzuki ◽

Hidenori Koketsu ◽

Hiroshi Yano ◽

Takashi Fuyuki

Keyword(s):

Contact Angle ◽

Oxide Layer ◽

Photoelectron Spectroscopy ◽

Contact Angle Measurement ◽

Contact Angles ◽

Angle Measurement ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements ◽

Substrate Surfaces

Surface properties of the 4H-SiC (0001) Si faces could be evaluated by the contact angle measurements with water droplet method, X-ray photoelectron spectroscopy and an atomic force microscope. The contact angles do not depend on the surface roughness under 3nm. The substrate surfaces with the contact angles over 30o will be terminated by hydrogen related species. The contact angles around 20o on 4H-SiC is caused by the removal of oxide layer with fluoride acid and terminated subsequently by the -CF species on the surface. The hydrophile surface of 4H-SiC is caused by the formation of chemical oxide layer as well as the case of the silicon wafers.

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Optimal Number of Contact Angle Measurements on Pyrite Surface

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.926-930.17 ◽

2014 ◽

Vol 926-930 ◽

pp. 17-21

Author(s):

Lukas Koval ◽

Jarmila Drozdova

Keyword(s):

Contact Angle ◽

Standard Deviation ◽

Statistical Evaluation ◽

Contact Angle Measurement ◽

Angle Measurement ◽

Optimal Number ◽

Pyrite Surface ◽

Quick Method ◽

Angle Measurements ◽

Contact Angle Measurements

Contact angle measurement is a simple and quick method that expresses the surface wettability. Resulting values vary and depend on many factors that significantly affect the interpretation of results. In this paper a set of seventeen samples from different deposits with different genesis were subjected to a statistical evaluation, to determine the optimal number of measurements needed to obtain the desired standard deviation.

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