• Composites Research
• /
• v.34 no.5
• /
• pp.305-310
• /
• 2021

Mechanical properties of fiber reinforced composites were affected to fiber volume fractions (FVF) and interfacial property by sizing agent conditions. An optimum interface can relieve stress concentration by transferring the mechanical stress from the matrix resin to the reinforcements effectively, and thus can result in the performance of the composites. The interfacial properties and wettability between the epoxy resin and glass fiber (GF) were evaluated for different sizing agent conditions and FVFs. The surface energies of epoxy resin and different sizing agent treated GFs were calculated using dynamic and static contact angle measurements. The work of adhesion, W_a was calculated by using surface energies of epoxy matrix and GFs. The wettability was evaluated via the GF tow capillary test. The interfacial shear strength (IFSS) was evaluated by microdroplet pull-out test. Finally, the optimized GFRP manufacturing conditions could be obtained by using wettability and interfacial property.

• Korean Journal of Metals and Materials
• /
• v.46 no.5
• /
• pp.289-295
• /
• 2008

The effect of the alloy elements(Si/Mn) ratio on the coating quality including wettabilty with molten zinc, galvannealing kinetics and crater has been investigated in interstitial-free high strength steel(IFHSS) containing Si and Mn. When the Si/Mn ratio was below 0.75, IF-HSS exhibited a good wettability leading to a good galvannealed coating quality after annealing at $800^{\circ}C$ for 40s in $15%H_2-N_2$ mixed gas with dew point $-60^{\circ}C$. In contrast, the wettability and galvannealed coating quality were deteriorated in the Si/ Mn ratio above 0.75. It is shown that they have relevance to oxides forms by selective oxidation on the steel surface. The oxide particles dispersed on the steel surface with a surface coverage of below 40% resulted in good wettability and galvannealed coating quality. The oxide particle is mainly consisted of $Mn_2SiO_4$ with low contact angle in molten zinc. On the other hand, the continuous oxide layer on the steel surface, such as network- and film-type,caused to poor wettability and galvannealed coating quality. The coverage of oxide layer was above 80%, and its chemical species was $SiO_2$ with high contact angle in molten zinc. Consequently, the Si/Mn alloy ratio played an importance role in galvannealed coating quality of IF-HSS.

• Tribology and Lubricants
• /
• v.29 no.5
• /
• pp.304-309
• /
• 2013

Shark skin has functionalities such as self-cleaning and antifouling; it also exhibits excellent drag reduction owing to a hierarchical structure of microgrooves and nanometer-long chain mucus drag reduction interfaces around the shark body. In this study, the wettability of a shark skin surface and its replicas are evaluated. First, a shark skin template is taken from a real shark. Then, shark skin replicas are produced directly from a shark skin template, using a micromolding technique. The quantitative replication precision of the shark skin replicas is evaluated by comparing the geometry of the shark skin template to the replica using 2D surface profiles. Contact angles at the solid-air-water interfaces are evaluated for the shark skin template and its replicas under two conditions: with and without hydrophobic coating. The results show that the microriblets on shark skin improve the hydrophobic feature and play a critical role in self-cleaning.

• Journal of the Korean Ceramic Society
• /
• v.32 no.4
• /
• pp.405-412
• /
• 1995

In order to estimate the wettability of the borosilicate glasses with different composition on the noble metals of gold and silver, the measurements of the contact angle between the solid and the liquid were made at various temperatures and holding times using the sessil-drop method. The wetting behavior and the adhesion of the phases were strongly influenced by the thermal or the physical characteristics of the materials. The dependence of wetting angle ($\theta$) on the holding time (t) could be represented by the relation of $\theta$=a.tb, whereby the wettability of the systems was quantitatively compared. Also with increasing content of borosilicate glass in the glass-gold matrix composite, the tensile strength was decreased whereas the elastic modulus was increased.

• Journal of Welding and Joining
• /
• v.16 no.6
• /
• pp.77-85
• /
• 1998

Effects of non-cleaning and cleaning fluxes on the wetting properties and defects at flow soldered joints were investigated. Non-cleaning flux (R-type of 3.3% solid content) and cleaning flux (RMA-type of 15% solid content) were used. Wetting test was accomplished by wetting balance method with changing surface state of wetting specimen, CU. Sn-37%Pb solder was used for wetting test and flow soldering. As experimental results, the wetting time for vertical force from the surface tension being zero was mainly affected by surface state of the wetting specimen. Non-cleaning flux had a good wettability compared with cleaning flux. In case of non-cleaning flux, conveyor speed had a great affection to defects of bridge, icicle, and poor solder.

• Textile Coloration and Finishing
• /
• v.15 no.4
• /
• pp.51-56
• /
• 2003

Poly(ethylene terephthalate) (PET) fabrics were dyed with a series of ethoxylated alkylaminoanthraquinone dyes synthesized by the reaction of 1-aminoanthraquinone with poly(ethylene glycol) via a series of methylene spacer, and their hydrophilicity and durability to laundering were investigated. The results obtained are as follows: 1) Ethoxylated alkylaminoanthraquinone were successfully exhausted on PET fabric without any aid of chemical auxiliary. 2) The wettability of the dyed PET fabric was increased with the length of ethoxylate chain. 3) The durability of the wettability was good enough as to maintain the initial wettability even after 30 repeated launderings.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.10
• /
• pp.1451-1457
• /
• 2002

When an aqueous liquid such as water having high electric conductivity and high surface tension is discharged from a nozzle under a strong DC electric field, fine drops ranging from 30 to 450 microns can be obtained only through the spindle mode. In the present study, effects of the electric conductivity and the surface wettability of nozzle materials on formation of drops with this mode were investigated. For that, three nozzles with the same size but with different materials were prepared and tested; a stainless steel needle, and a plain and a metal (gold)-coated (except for the tip portion) silica needles. Uniform drops were obtained with the gold-coated silica nozzle over the wider range of the DC voltage input. That is, formation of the liquid cone and detachment of the liquid spindle (ligament) can be more stabilized and frequent with the needles having high electric conductivity but with low surface wettability at their tips.

• Journal of Biomedical Engineering Research
• /
• v.10 no.3
• /
• pp.237-242
• /
• 1989

The physical properties and drug release behaviours of polyethylene glycol grafted poly ${\gamma}$- benzyl L-glutamate (PEG- g- PBLG), polyethylene glycol crosslinked poly ${\gamma}$-benzyl L- glutamate(PEG-c-PBLG), and PBLG homopolymer are compared. PBLG containing PEG segements showed higher wettability and larger enlongation than PBLG homoplymer, but lower elastic modulus. The release rate of rhodamine is strongly influenced by the wettability of the polymer. Rhodamine is more rapidly released from PEG-c-PBLG membrane having a larger water contact angle than from other polymer having a lower water contact angle. The surfaces of PBLG derivative membranes are modified by substitution reaction using hydroxyalkylamine. The resulting polymer membranes showed hider wettability and swelling ratio than virgin membranes.

• Proceedings of the KWS Conference
• /
• 2002.10a
• /
• pp.791-797
• /
• 2002

This paper introduces the partial melting process for solder application and characterization of its feasibility using Sn-Ag, and Sn-Cu solder alloys. ill order to show that the liquid phase in the semi-liquid state maintains the similar wettability as single-phase liquid, the wetting balance tests are conducted with varying temperatures and compositions. Also, as a new soldering technology, the microstructural and mechanical test were investigated. The results from this research indicate that the partial melting can yield satisfactory sider joints as long as the liquid phase acquires sufficient chemical activity. At a condition where the partial melting is effective, a direct correlation between the wettability and the surface tension is found to exist.

• Journal of Information Display
• /
• v.11 no.4
• /
• pp.140-143
• /
• 2010

A simple and versatile method of fabricating color patterns in two-dimension (2D) and three-dimension (3D) was developed using the selective-wettability approach. Red, green, and blue color elements are sequentially formed on a single substrate in a pattern-by-pattern and/or pattern-on-pattern fashion, through a simple coating process. Either 2D or 3D structures in an array format are produced by controlling the thickness of the hydrophobic layer (HL) coating a substrate within the framework of wetting transition. Moreover, it was demonstrated that the stacked geometry of two successive patterns can be easily tailored for various types of color arrays, with the pattern fidelity of a few tens of nanometers in terms of only a parameter of the HL thickness.