Contact Angle Measurements of Wetting In Pristine and Ion Implanted High Modulus Benzene Derived Graphite Fibers

1984 ◽  
Vol 40 ◽  
Author(s):  
O. C. de Hodgins ◽  
M. S. Dresselhaus ◽  
D. Uhlmann

AbstractMeasurements are reported of the contact angles of benzene-derived carbon fibers with de-ionized water, aminopropyltriethoxy silane and du Pont 5878 polyimide solutions. Both pristine fibers and fibers implanted with 5×1012 cm-2 and 1×1015 cm-2 fluences of 31p ions were investigated. Such implantation was observed to decrease the contact angle in all three solutions. The ion implantation had no significant effect on tensile strength, but did result in increased structural disorder (as reflected in the width of the main wide angle X-ray diffraction peak) and increased surface roughness. The increased disorder and roughness are believed to be principally responsible for the observed change in wetting angle.

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
S. A. Gangawane ◽  
V. P. Malekar ◽  
V. J. Fulari

In this paper, the effects of electron beam irradiation on the CdTe thin films are studied. The CdTe thin films are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and contact angle measurements for different bath concentration. The thin film layers are subjected to irradiation of 6 MeV electrons. Finally the effect of irradiation is correlated to crystal size, grain size and contact angle measurements of the CdTe thin films


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Semra Karaca ◽  
Ahmet Gürses ◽  
Mehtap Ejder Korucu

The orientation of CTA+in the interlayer of organic pillared montmorillonite prepared by adding different amounts of surfactant corresponding to the CEC of the pristine clay mineral has been studied using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectra. Morphology of the samples was examined by scanning electron microscopy (SEM). The results are supported by the measurements of zeta potentials and contact angles of pristine clay and organoclay samples. From the XRD results, a series of arrangement models of CTA+in the interlayer of montmorillonite have been proposed as lateral-bilayer, pseudotrilayer, paraffin-type-monolayer and pseudotrilayer, paraffin-type-bilayer and pseudotrilayer for 0.5, 1, 1.5, and 2.0 CEC, respectively. FTIR spectrum and contact angle measurements of pristine montmorillonite and organoclays indicated the incorporation of surfactant and the changing of hydrophility in the different OMts. This study demonstrates that not only the arrangement model of surfactant, but also the morphology of organoclay strongly depends on the surfactant packing density within the montmorillonite interlayer space. In addition, it can be also proposed that, the magnitude of surface charge or its distribution on clay mineral might be an important factor for expansion characteristics of organoclay.


2016 ◽  
Vol 869 ◽  
pp. 913-917 ◽  
Author(s):  
Ana Lucia do Amaral Escada ◽  
Javier Andres Muñoz Chaves ◽  
Ana Paula Rosifini Alves Claro

The purpose of this study was to evaluate the TiO2 nanotubes growth and the variation in its diameter to improve the surface properties of Ti-7.5Mo to use for biomedical applications. For the nanotubes TiO2 growth, the samples were anodized in glycerol and ammonium fluoride and divided according to the anodizing potential at 5V to 10V and 24 hour time. The surfaces were examined by scanning electron microscope (SEM), X-ray analysis (XRD) and contact angle measurements. The average tube diameter, ranging in size from 13 to 23 nm, was found to increase with increasing anodizing voltage. It was also observed a decrease in contact angle in accordance with the increase in the anodizing potential. The X-ray analysis showed the presence of anatase phase in samples whose potential was 10V and this condition represents a simple surface treatment for Ti-7.5Mo alloy that has high potential for biomedical applications.


2016 ◽  
Vol 69 (4) ◽  
pp. 431 ◽  
Author(s):  
Ten It Wong ◽  
Hao Wang ◽  
Fuke Wang ◽  
Sau Leng Sin ◽  
Cheng Gen Quan ◽  
...  

In contact angle measurements, direct identification of the contact angles from images taken from a goniometer suffers from errors caused by optical scatterings. Contact angles can be more accurately identified by the height and width of the droplet. Spherical dome is a simple model used to correlate the contact angles to the droplet shape; however, it features intrinsic errors caused by gravity-induced shape deformation. This paper demonstrates a simple method of obtaining an empirical formula, determined from experiments, to correct the gravity-induced error in the spherical dome model for contact angle calculations. A series of contact angles, heights, and surface contact widths are simultaneously collected for a large amount of samples, and the contact angles are also calculated using the spherical dome model. The experimental data are compared with those obtained from the spherical dome model to acquire an empirical formula for contact angles. Compared with the spherical dome model, the empirical formula can reduce the average errors of the contact angle from –16.3 % to 0.18 %. Furthermore, the same method can be used to correct the gravity errors in the spherical dome for the volume (calculated by height and width), height (calculated by contact angle and volume), and width (calculated by contact angle and volume), and the spherical dome errors can be reduced from –20.9 %, 24.6 %, and –4.8 % to 2 %, –0.13 %, and –0.6 %, respectively. Our method is generic and applicable for all kinds of solvent and substrates, and the derived empirical formulae can be directly used for water droplets on any substrate.


2013 ◽  
Vol 798-799 ◽  
pp. 1061-1066 ◽  
Author(s):  
Yan Wei Zhao ◽  
Lu Liu ◽  
Xiang Han ◽  
Jing Guan

We prepared N, O-carboxymethyl chitosans (CMCSs) with different substitutional degrees (SDs) to evaluate their effects of hemostasis, and provided experimental basis on biomedical materials. Chloroethanoic acid was used to synthesize CMCSs. The structure were characterized by Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WXRD). Potentiometric titration and Ubbelohde viscometer were adopted to determine the SD and intrinsic viscosity of CMCSs. Contact angle measurements were investigated to determine surface wettability. Method of dynamic clotting time and coagulation test in vivo were used to evaluate their effects of hemostasis. SDs of CMCSs were from 50% to 110%. As the SD increased, molecular weight decreased. CMCS powder with SD 63% possessed excellent hemostasis both in vitro and in vivo. CMCS powder owned hemostatic capability prior to CS. CMCS powder with SD 63% (neither too high, nor too low) possessed excellent hemostasis both in vitro and in vivo.


Author(s):  
Matthias Van Zele ◽  
Hannes Rijckaert ◽  
Davy Deduytsche ◽  
Christophe Detavernier ◽  
Isabel Van Driessche ◽  
...  

In this paper, a novel synthesis for a chemical precursor for nanocrystalline VO2 coatings is elaborated. The compatibility of the precursor towards the substrate is optimized for spin coating. This is done by subjecting multiple solvents to contact angle measurements. A suitable thermal treatment is developed to densify the coating and to induce crystallization. Afterwards the microstructure of the coating is investigated using X-Ray diffraction, electron microscopy and ellipsometry techniques. To assess the thermochromic properties of the fabricated device, optical transmission experiments were conducted both at room temperature and at elevated temperature. A correlation between these thermochromic properties and coating thickness was investigated in order to obtain an optimized thermochromic device, where both high visual transparency and prominent thermochromic switching abilities are aimed for. In this work, an optimal coating thickness is proposed for a thermochromic coating with high switching ability and solar modulation.


2018 ◽  
Author(s):  
M. Elsharafi ◽  
K. Vidal ◽  
R. Thomas

Contact angle measurements are important to determine surface and interfacial tension between solids and fluids. A ‘water-wet’ condition on the rock face is necessary in order to extract oil. In this research, the objectives are to determine the wettability (water-wet or oil-wet), analyze how different brine concentrations will affect the wettability, and study the effect of the temperature on the dynamic contact angle measurements. This will be carried out by using the Cahn Dynamic Contact Angle. Analyzer DCA 315 to measure the contact angle between different fluids such as surfactant, alkaline, and mineral oil. This instrument is also used to measure the surface properties such as surface tension, contact angle, and interfacial tension of solid and liquid samples by using the Wilhelmy technique. The work used different surfactant and oil mixed with different alkaline concentrations. Varying alkaline concentrations from 20ml to 1ml were used, whilst keeping the surfactant concentration constant at 50ml.. It was observed that contact angle measurements and surface tension increase with increased alkaline concentrations. Therefore, we can deduce that they are directly proportional. We noticed that changing certain values on the software affected our results. It was found that after calculating the density and inputting it into the CAHN software, more accurate readings for the surface tension were obtained. We anticipate that the surfactant and alkaline can change the surface tension of the solid surface. In our research, surfactant is desirable as it maintains a high surface tension even when alkaline percentage is increased.


Author(s):  
Matthew A. Trapuzzano ◽  
Rasim Guldiken ◽  
Andrés Tejada-Martínez ◽  
Nathan B. Crane

Many important processes depend on the wetting of liquids on surfaces. Wetting is commonly controlled through material selection, coatings, and/or surface texture, however these means are sensitive to environmental conditions. Some “hydrophobic” fluoropolymer coatings are sensitive to extended water exposure as evidenced by declining contact angles and increasing contact angle hysteresis. Understanding degradation of these coatings is critical to processes that employ them. To accomplish this, contact angle measurements were taken before, during, and after slides coated with FluoroSyl 3750 or Cytop were submerged in water, or vibrated while covered in water. Both methods demonstrated similar changes in advancing contact angle though vibration increased degradation rates significantly. However, it does not simply accelerate the process as different trends are apparent in receding contact angles. The FluoroSyl 3750 showed no clear degradation under either condition. Surface profilometry did not detect any surface morphology differences that might cause contact angle change.


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