Investigation of Carbon Fiber Wetting Process by Wilhelmy Method and Force Analysis Method

2013 ◽  
Vol 591 ◽  
pp. 338-342 ◽  
Author(s):  
Hui Wang ◽  
Ji Zhi Huang ◽  
Xiang Gang Yin ◽  
Feng Wei

Carbon fiber dynamic wetting measurement system is established based on DCAT 21 tensiometer. The same carbon fiber wetting property are measured by Wilhelmy method and based on force analysis method, which obtained the contact angle is 78.15°and 81°respectively. The results show that complicated preparation exists on the Wilhelmy method, as well as soft fiber is not suitable by this process. However, force analysis method can solve this problem, measuring speed of this method is quickly and applicable. Keywords: contact angle; Wilhelmy method; carbon fiber; wetting; force analysis method

2014 ◽  
Vol 1061-1062 ◽  
pp. 170-174
Author(s):  
Jian Li

The effects of surface treatment of a carbon fiber (CF) by Polyethylene-polyamine (PEPA) on the interfacial adhesion behavior and morphology of polypropylene/polystyrene (PP/PS) matrix blends filled CF composites were investigated. Effects of surface treated a commercial CF on mechanical properties are studied. Contact angle was measured to examine the changes in wettability of the carbon fiber. The chemical and morphological changes were characterized by using X-ray photoelectron spectroscopy (XPS). PP/PS/CF composites were fabricated with and without PEPA treatment, and their interlaminar fracture toughnesses were compared. The results showed that the interlaminar shear strength (ILSS) of composites has been greatly improved filled PEPA modification CF. The water contact angle of resin sample decreased 50% after addition of PEPA surface treated CF.


Author(s):  
Erol Sancaktar ◽  
Weijian Ma ◽  
Steven W. Yurgartis

Abstract A novel method for tailoring the interphase of carbon fiber-polymer composites by resistive electric heating is presented. The single fiber-epoxy resin tensile test is used to investigate the adhesion and fracture properties of the interphase. Electric resistive heating is shown to increase adhesion and toughness at the interphase region. In analyzing the results, the strength and fracture energy of the interphase are related to the thermal postcure conditions created by resistive electric heating. For this purpose, difference analysis method is used to obtain numerical solution for heat conduction problem in the single fiber test specimen and the temperature distributions are plotted. Improvements obtained using resistive electric heating via carbon fiber are compared with those obtained by postcuring of the whole sample via convective thermal postcuring. The results obtained using these two different postcure methods seem to be similar with electric heating procedure producing superior benefits in both increased toughness and adhesion.


TANSO ◽  
2021 ◽  
Vol 2021 (296) ◽  
pp. 2-8
Author(s):  
Norio Iwashita ◽  
Hiromichi Watanabe ◽  
Naofumi Yamada

2021 ◽  
Vol 899 ◽  
pp. 326-331
Author(s):  
Zhanna I. Kurdanova ◽  
Kamila T. Shakhmurzova ◽  
V.A. Guchinov ◽  
Ilya Kobyhno ◽  
Andrey Bezborodov

The wettability of reinforcing fillers such as glass and carbon fibers is a significant factor influencing the mechanical properties of the composite. This study focuses on the effect of finishing glass fiber surfaces with different concentrations of oligophenylene sulfide sulfone solution on fiber wettability, which is determined by contact angle and wetting time. The Adam-Schütte method was chosen as a method for determining the contact angle. According to the study results a 1.5% solution of oligophenylene sulfide sulfone in N, N'-dimethylacetamide gives a contact angle of 45°, forming over time a thin film on the fiber surface, which indicates a sufficiently high sizing ability.


Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1029
Author(s):  
Dina V. Shmeliova ◽  
Sergey V. Pasechnik ◽  
Semen S. Kharlamov ◽  
Alexandre V. Zakharov ◽  
Eugeny P. Pozhidaev ◽  
...  

In this paper we report the new experimental results on the rise of a liquid crystal in flat capillaries with inner photosensitive surfaces. The capillaries with different surface orientations were prepared by the use of the photo-alignment technique. Such a surface treatment makes it possible to eliminate the noncontrollable influence of a nanorelief on the wetting process, which takes place in the rubbing treatment technique previously used in similar experiments. The dynamics of the capillary rise of a nematic liquid crystal 5CB (4-cyano-4′-pentylbiphenyl) in vertical plane capillaries with photo-aligned substrates were studied for the first time. It was found that the stationary value of a contact angle weakly depends on the direction of a planar surface orientation relative to the direction of a capillary rise. It has been shown that the application of strong electric fields resulted in a decreasing of the contact angle. The results, obtained for the nematic liquid crystal, are compared with the results of an investigation of the capillary flow in a shock-free ferroelectric smectic phase.


2020 ◽  
Vol 229 (10) ◽  
pp. 1945-1977 ◽  
Author(s):  
Yulii D. Shikhmurzaev

Abstract After a brief overview of the ‘moving contact-line problem’ as it emerged and evolved as a research topic, a ‘litmus test’ allowing one to assess adequacy of the mathematical models proposed as solutions to the problem is described. Its essence is in comparing the contact angle, an element inherent in every model, with what follows from a qualitative analysis of some simple flows. It is shown that, contrary to a widely held view, the dynamic contact angle is not a function of the contact-line speed as for different spontaneous spreading flows one has different paths in the contact angle-versus-speed plane. In particular, the dynamic contact angle can decrease as the contact-line speed increases. This completely undermines the search for the ‘right’ velocity-dependence of the dynamic contact angle, actual or apparent, as a direction of research. With a reference to an earlier publication, it is shown that, to date, the only mathematical model passing the ‘litmus test’ is the model of dynamic wetting as an interface formation process. The model, which was originated back in 1993, inscribes dynamic wetting into the general physical context as a particular case in a wide class of flows, which also includes coalescence, capillary breakup, free-surface cusping and some other flows, all sharing the same underlying physics. New challenges in the field of dynamic wetting are discussed.


2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Ho Seon Ahn ◽  
Joonwon Kim ◽  
Moo Hwan Kim

Dynamic wetting behaviors of water droplet on the modified surface were investigated experimentally. Dynamic contact angles were measured as a characterization method to explain the extraordinary pool boiling critical heat flux (CHF) enhancement on the zirconium surface by anodic oxidation modification. The sample surface is rectangular zirconium alloy plates (20 × 25 × 0.7 mm), and 12 μl of deionized water droplets were fallen from 40 mm of height over the surface. Dynamic wetting movement of water on the surface showed different characteristics depending on static contact angle (49.3 deg–0 deg) and surface temperature (120 °C–280 °C). Compared with bare surface, wettable and spreading surface had no-receding contact angle jump and seemed stable evaporating meniscus of liquid droplet in dynamic wetting condition on hot surface. This phenomenon could be explained by the interaction between the evaporation recoil and the surface tension forces. The surface tension force increased by micro/nanostructure of the modified zirconium surface suppresses the vapor recoil force by evaporation which makes the water layer unstable on the heated surface. Thus, such increased surface force could sustain the water layer stable in pool boiling CHF condition so that the extraordinary CHF enhancement could be possible.


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