scholarly journals Aluminium Alloy 8011: Surface Characteristics

2015 ◽  
Vol 719-720 ◽  
pp. 29-37 ◽  
Author(s):  
Maral Rahimi ◽  
Peter Fojan ◽  
Leonid Gurevich ◽  
Alireza Afshari
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Heat Exchanger ◽  
Aluminium Alloy ◽  
Construction Material ◽  
Surface Characteristics ◽  
Cold Surface ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Native Surface

Aluminium alloys are the predominant materials in modern industries. Increased knowledge about the surface characteristics of bare aluminium can enhance the understanding about how to optimize the working conditions for the equipment involving aluminium parts. This work focusses on the properties of native surface of aluminium alloy 8011, which is the main construction material for the production of air-to-air heat exchanger fins. In this study, we address its water wettability, surface roughness and frost formation in different psychometric parameters. The contact angle measurements revealed that this aluminium alloy exhibits a relatively high contact angle of about 78 degree, i.e. is not wetted completely. AFM measurements revealed significant surface roughness of typical heat exchanger fins. The thickness of formed frost was studied in relation to the wettability, humidity and the cold surface temperature.

scholarly journals Comments on “An Essay on Contact Angle Measurements”: Determination of Surface Roughness and Modeling of the Wetting Behavior

2011 ◽  
Vol 8 (11) ◽  
pp. 998-1002 ◽  
Author(s):  
Antonia Terriza ◽  
Rafael Alvarez ◽  
Francisco Yubero ◽  
Ana Borras ◽  
Agustin R. González-Elipe
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Wetting Behavior ◽  
Angle Measurements ◽  
Contact Angle Measurements

Contact angles and hysteresis, with some reference to flotation research

1977 ◽  
Vol 30 (1) ◽  
pp. 205 ◽  
Author(s):  
IW Wark
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Gas Phase ◽  
Water Vapour ◽  
Relative Motion ◽  
Solid Surface ◽  
Contact Angles ◽  
Russian School ◽  
Angle Measurements ◽  
Contact Angle Measurements

A technique used in flotation research for contact angle measurements is recommended for wider use. The effect of one aspect of surface roughness on the relative motion of fluid/solid systems is discussed. The function of the water vapour present in the gas phase adjacent to the line of triple contact is examined. A claim of the Russian school of surface chemists is questioned, namely, that a discrete film of water on the solid surface invariably dominates both hysteresis and contact angle.

Water Repellent Cellulose Nanofibers by Acetylation

2011 ◽  
Vol 332-334 ◽  
pp. 209-212 ◽  
Author(s):  
Alireza Shakeri ◽  
Mehdi Joonobi
Keyword(s):  
Contact Angle ◽  
Cellulose Nanofibers ◽  
Surface Characteristics ◽  
Water Repellent ◽  
High Pressure Homogenization ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Isolation Methods ◽  
Mechanical Isolation

Kenaf nanofibers (NF) were isolated from the kenaf pulp using mechanical isolation methods (refining with super grounding and high pressure homogenization). The kenaf NF were acetylated to produce hydrophobic NF. FTIR results displayed a successful acetylation of the NF. X-ray analysis exhibited that the acetylation process reduced the crystallinity of kenaf NF but also that isolation to NF leads to higher crystallinity than corresponding micro-sized fibers. The contact angle measurements indicated that the acetylation treatment changed the surface characteristics of the kenaf NF from hydrophilic to more hydrophobic.

Changes in color and structure of birch wood (Betula pendula) caused by bleaching with hydrogen peroxide solution

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Kirsi Mononen ◽  
Leila Alvila ◽  
Tuula T. Pakkanen
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Surface Roughness ◽  
Contact Angle ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Birch Wood ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Microscopic Studies

Abstract The effect of bleaching with a hydrogen peroxide (H2O2) solution on coloring of secondary xylem of kiln-dried birch wood (B. pendula) was investigated with CIELAB color measurements. Structure of unbleached and bleached wood pieces was studied by light microscopy (LM), environmental scanning electron microscopy (ESEM), and transmission electron microscopy (TEM). In addition, hardness and surface roughness of unbleached and bleached wood pieces were characterized with Brinell hardness and contact angle measurements. The results indicated that surface bleaching with H2O2 solution changed the color of birch wood toward white and less red, simultaneously increasing the porosity and roughness of the uppermost surface as well as decreasing the hardness of bleached wood pieces. With embedding bleaching for 24 h with H2O2, the color of the wood pieces could be changed further; however, microscale defects were detected in fiber secondary cell walls. Consequently, complementary to results obtained from microscopic studies, lower hardness values supported the degradation of fiber secondary cell wall in bleached wood pieces. In addition, contact angle measurements indicated increased surface roughness of wood pieces after embedding bleaching with H2O2.

scholarly journals Innovative Manufacturing Process of Functionalized PA2200 for Reduced Adhesion Properties

2020 ◽  
Vol 4 (2) ◽  
pp. 36
Author(s):  
Giovanna Rotella ◽  
Antonio Del Prete ◽  
Maurizio Muzzupappa ◽  
Domenico Umbrello
Keyword(s):  
Contact Angle ◽  
Pure Titanium ◽  
Surface Characteristics ◽  
Patterned Surfaces ◽  
Commercially Pure Titanium ◽  
Adhesion Properties ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Patterned Structures ◽  
Bacteria Adhesion

This work proposes an approach to fabricate micro patterned surfaces on PA2200 polyamide in order to improve its performance in terms of wettability and adhesion. In more detail, the present work aims to change the wettability of the surface and decrease their bacteria adhesion tendency. The experimental procedure consists of imprinting a set of different micro patterned structures over the polymer in order to verify the effectiveness of the methodology to change the contact angle of the surface, and in turn, reduce the occurrence of bacteria adhesion. Four different surface patterning were produced by laser ablation of a commercially pure titanium alloy, and then imprinted over the polyamide by surface stamping. The resulting surfaces were analyzed by topographical characterization and scanning electron microscopy. The wettability was probed by contact angle measurements while the bacteria adhesion was analyzed by adhesion test. The experimental results demonstrate the effectiveness of the method to modify the surface characteristics and to obtain a reliable patterned surface without using chemical hazardous material; opening to the possibility to replicate more complex structures and to obtain graded engineering surfaces.

scholarly journals Potentials of lignocellulosic agricultural residues in paper production

2021 ◽  
Vol 11 (3) ◽  
pp. 72-77
Author(s):  
Ivana Plazonić ◽  
Maja Rudolf ◽  
Valentina Radić Seleš ◽  
Irena Bates ◽  
Katja Petric Maretić
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Surface Characteristics ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Hydrophilic Material ◽  
Printing Processes ◽  
High Absorption

Surface characteristics of printing substrates are of the utmost importance to all types of paper that interact with ink. During all types of printing processes, the behaviour of the liquid phase (ink or dye) on the paper is directly defined by the paper cellulose-based surface. The printed ink spreads and penetrates more into paper fibres when the paper surface is rougher and more permeable. Contact angle measurements by sessile drop method are considered the most appropriate for determining the paper sheet surface energy. Paper as hydrophilic material has a high absorption rate resulting in a low contact angle. The objective of this study was to evaluate the surface free energy of laboratory-made papers containing straw pulp obtained from residues after the harvest of the most cultivated cereals in Croatia (wheat, barley and triticale). The obtained surface free energy results are promising for straw pulp usage in the manufacture of printing paper.

Investigation of treated PEN foil surface properties for inkjet application

2015 ◽  
Vol 27 (3) ◽  
pp. 108-111
Author(s):  
Aneta Araźna ◽  
Konrad Futera ◽  
Małgorzata Jakubowska ◽  
Łucja Dybowska-Sarapuk
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Glow Discharge ◽  
Surface Properties ◽  
Contact Angles ◽  
Polyethylene Naphthalate ◽  
Content Type ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Afm Micrographs

Purpose – The purpose of this paper is to report surface properties of treated Teonex Du Pont polyethylene naphthalate (PEN) foil substrates. Design/methodology/approach – There were three different cleaning treatments among other: argon glow discharge, dipping into alkaline solution at 60°C as well as washing in an ultrasonic bath of acetone and ethyl alcohol in room temperature. The relation between PEN foil morphology and surface properties has been studied by contact angle measurements as well as evaluation of surface roughness of PEN foil samples by atomic force microscopy (AFM). Findings – It was found that argon glow discharge (T3) of PEN treatment caused the maximum reduction in both values of contact angles. In addition, the argon glow discharge yielded the highest PEN surface energy (51.9 mJ/m2) and polarity (0.89). On the other hand, the AFM micrographs showed that the samples T3 had the highest value of average and root mean square surface roughness. Based on the experiments results, the authors stated that the alkaline cleaning (T2 treatment) could be considered as an effective method of PEN substrate treatment. Originality/value – The influence of different cleaning treatment on the surface properties of PEN foil to inkjet application was analyzed. In the literature, there are not a lot of papers describing examinations of surface properties of PEN foil to inkjet application by contact angle measurements and AFM analysis.

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