scholarly journals The Effect of Exposed Glass Fibers and Particles of Bioactive Glass on the Surface Wettability of Composite Implants

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Aous A. Abdulmajeed ◽  
Lippo V. Lassila ◽  
Pekka K. Vallittu ◽  
Timo O. Närhi
Keyword(s):  
Bioactive Glass ◽  
Sessile Drop ◽  
Glass Fibers ◽  
Contact Angles ◽  
Surface Wettability ◽  
Reinforced Composites ◽  
Predictive Index ◽  
Plane Distribution ◽  
Composite Substrates ◽  
Hydrophilic Materials

Measurement of the wettability of a material is a predictive index of cytocompatibility. This study was designed to evaluate the effect of exposed E-glass fibers and bioactive glass (BAG) particles on the surface wettability behavior of composite implants. Two different groups were investigated: (a) fiber reinforced composites (FRCs) with different fiber orientations and (b) polymer composites with different wt. % of BAG particles. Photopolymerized and heat postpolymerized composite substrates were made for both groups. The surface wettability, topography, and roughness were analyzed. Equilibrium contact angles were measured using the sessile drop method. Three liquids were used as a probe for surface free energy (SFE) calculations. SFE values were calculated from contact angles obtained on smooth surfaces. The surface with transverse distribution of fibers showed higher () polar () and total SFE () components (16.9 and 51.04 mJ/m2, resp.) than the surface with in-plane distribution of fibers (13.77 and 48.27 mJ/m2, resp.). The increase in BAG particle wt. % increased the polar () value, while the dispersive () value decreased. Postpolymerization by heat treatment improved the SFE components on all the surfaces investigated (). Composites containing E-glass fibers and BAG particles are hydrophilic materials that show good wettability characteristics.

Modeling of Sessile Droplet Evaporation on Engineered Surfaces

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Jyoti Prakash ◽  
Basant Singh Sikarwar
Keyword(s):  
Experimental Study ◽  
Relative Humidity ◽  
Evaporation Rate ◽  
Sessile Drop ◽  
Droplet Evaporation ◽  
Contact Angles ◽  
Surface Wettability ◽  
Aluminum Surface ◽  
Complex Nature ◽  
Wide Range

The evaporation of sessile drop has a wide range of application that includes printing, washing, cooling, and coating. Due to the complex nature of drop evaporation process, this phenomenon is reliant on several parameters such as ambiance and physiochemical properties of liquid and surface. In the present study, a mathematical model of water droplet evaporation on an engineered aluminum surface is developed. Experimental study is carried out for the validation of code. The data obtained from the simulation is validated against the data obtained from an experimental study as well as the data available in the literature and good agreement was found among them. Post-validation, the effect of surface wettability and environment conditions on a droplet evaporation rate is estimated. It is inferred from the outcomes that the temperature at the apex of the drop varies linearly with the increasing relative humidity. Droplet volume has a significant impact on the evaporation rate and comparatively higher evaporative flux for a smaller volume of the drop with large contact angles. This unveils the possibility of achieving the required evaporation rate by controlling surface wettability and relative humidity conditions near the drop.

scholarly journals Wettability and solubility behavior of Fe–B–C binder on (Cr–Ti–C)-reinforced composites

2019 ◽  
Vol 27 (2) ◽  
pp. 43-46
Author(s):  
O. V. Sukhova
Keyword(s):  
Sessile Drop ◽  
Base Alloy ◽  
Contact Angles ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Iron Base ◽  
Iron Base Alloy ◽  
Wetting Properties ◽  
Solubility Behavior ◽  
Base Matrix

Iron-base matrix composites containing Cr-20Ti-10C reinforcement fabricated by infiltrating at 1200°C to 1280°C for 30 to 60 mins are investigated in this work. Peculiarities of the formation of the interfaces between Cr-20Ti-10C hard alloy and Fe-3.1B-0.1C liquid alloy (wt. pct) are determined. It includes the study of the solubility between the iron-base binder and the reinforcement combined with the investigation of the contact angles of the liquid phase formed at  infiltration temperature by sessile drop method. X-ray analysis as well as optical and scanning electron microscopy is employed to investigate the binder/particulate interfaces. The interfacial zones produced as a result of contact interaction consist of (Cr,Ti)7C3 and (Ti,Cr)3C phases embedded in α-Fe3(C,B) eutectic alloyed with Cr and Ti. The origin of the formation of the interfaces is probably related to the partial dissolution of the low-melting-temperature particulate phase identified as (Cr,Ti)7C3 in the molten Fe–B–C binder. When raising the infiltrating temperature and prolonging the infiltrating period, wetting properties of Cr-20Ti-10C improve. This fact opens the possibility to replace copper-base alloys as binder by a cheaper and stronger iron-base alloy.

Temperature Dependence of the Contact Angle of Water on a Hydrophobic Surface at Pressurized Condition

2020 ◽  
Author(s):  
Jia-Wen Song ◽  
Meng-Chen Ma ◽  
Li-Wu Fan
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Temperature Dependence ◽  
Sessile Drop ◽  
Hydrophobic Surface ◽  
Contact Angles ◽  
Surface Wettability ◽  
Surface Thermodynamics ◽  
Temperature Spectrum ◽  
Phase Change Heat Transfer

Abstract It is of both practical and scientific significance to study the temperature dependence of contact angles, towards development of surface wettability manipulation techniques for enhanced phase change heat transfer as well as the theoretical estimation of solid interfacial energy. However, the variations of surface wettability of a hydrophobic solid with altering temperature remain unclear. In this work, in situ characterizations of the contact angle of water on Teflon (PTFE) surfaces as well as the surface tension of water over a temperature spectrum from ∼25 °C to 160 °C at pressurized condition (2 MPa) were conducted by employing the sessile drop and pendant drop methods, respectively. A nearly invariant trend of the contact angle of water was observed over the entire temperature range. Moreover, it was shown that the surface tension of water linearly declines with raising the temperature. Based on the theory of surface thermodynamics, the effects of temperature on the contact angles were analyzed with the variations of interfacial tensions.

Influence of the Oxygen Plasma Treatments on Surface Wettability of Glass Micro Fibers Used as Reinforcement in any Mortars

2016 ◽  
Vol 714 ◽  
pp. 148-151 ◽  
Author(s):  
Jan Trejbal ◽  
Lubomír Kopecký ◽  
Pavel Tesárek ◽  
Zdeněk Prošek
Keyword(s):  
Contact Angle ◽  
Oxygen Plasma ◽  
Glass Fibers ◽  
Contact Angles ◽  
Surface Wettability ◽  
Distilled Water ◽  
Angle Measurements ◽  
Plasma Treatments ◽  
Static Contact ◽  
Contact Angle Measurements

Presented work deals with the surface treatments and its effect on micro fibers using as randomly dispersed reinforcement in many types of composite materials. Cool oxygen plasma was used to surface wettability modification of chopped glass fibers having diameter equal to 14 μm. Plasma treatments were carried out at three different times of exposition equal to 4 min, 8 min and 16 min. The influence of executed treatments was observed by the horizontal direct optical method enabling static contact angle measurements on micro fibers which were submerged in a distilled water. The identified differences between the contact angles size of original fibers and the treated fibers were equal to several tens of percent.

Hemp Fiber Reinforced Composites: Morphological and Mechanical Properties

2011 ◽  
Vol 332-334 ◽  
pp. 121-125
Author(s):  
Xing Mei Guo ◽  
Yi Ping Qiu
Keyword(s):  
Polymer Composites ◽  
Unsaturated Polyester ◽  
Glass Fibers ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Hemp Fiber ◽  
Plant Fibers ◽  
Natural Plant ◽  
Reinforcing Fillers

The use of natural plant fibers as reinforcing fillers in fiber-polymer composites has drawn much interest in recent years. Natural plant fibers as reinforcing fillers have several advantages over inorganic fillers such as glass fibers; they are abundant, readily available, renewable, inexpensive, biodegradable, of low density, and of high specific strength. Hemp fibers are one of the most attractive natural plant fibers for fiber-reinforced composites because of their exceptional specific stiffness. In this review, we summarize recent progress in developments of the hemp fiber reinforced composites such as hemp fiber reinforced unsaturated polyester (UPE), hemp fiber reinforced polypropylene (PP), hemp fiber reinforced epoxy composites, and so on, illustrate with examples how they work, and discuss their intrinsic fundamentals and optimization designs. We are expecting the review to pave the way for developing fiber-polymer composites with higher strength.

scholarly journals Soldering of Electronics Components on 3D-Printed Conductive Substrates

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3850
Author(s):  
Bartłomiej Podsiadły ◽  
Andrzej Skalski ◽  
Marcin Słoma
Keyword(s):  
Additive Manufacturing ◽  
Solder Joints ◽  
Rapid Development ◽  
Surface Preparation ◽  
Contact Angles ◽  
Electronic Components ◽  
Optimal Method ◽  
Structural Electronics ◽  
3D Printed ◽  
Composite Substrates

Rapid development of additive manufacturing and new composites materials with unique properties are promising tools for fabricating structural electronics. However, according to the typical maximum resolution of additive manufacturing methods, there is no possibility to fabricate all electrical components with these techniques. One way to produce complex structural electronic circuits is to merge 3D-printed elements with standard electronic components. Here, different soldering and surface preparation methods before soldering are tested to find the optimal method for soldering typical electronic components on conductive, 3D-printed, composite substrates. To determine the optimal soldering condition, the contact angles of solder joints fabricated in different conditions were measured. Additionally, the mechanical strength of the joints was measured using the shear force test. The research shows a possibility of fabricating strong, conductive solder joints on composites substrates prepared by additive manufacturing. The results show that mechanical cleaning and using additional flux on the composite substrates are necessary to obtain high-quality solder joints. The most repeatable joints with the highest shear strength values were obtained using reflow soldering together with low-temperature SnBiAg solder alloy. A fabricated demonstrator is a sample of the successful merging of 3D-printed structural electronics with standard electronic components.

scholarly journals Droplet infiltration dynamics and soil wettability related to soil organic matter of soil aggregate coatings and interiors

2016 ◽  
Vol 64 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Miroslav Fér ◽  
Martin Leue ◽  
Radka Kodešová ◽  
Horst H. Gerke ◽  
Ruth H. Ellerbrock
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Preferential Flow ◽  
Water Drop ◽  
Soil Aggregates ◽  
High Water ◽  
Contact Angles ◽  
Surface Wettability ◽  
Mineral Coatings ◽  
Droplet Infiltration

Abstract The organo-mineral coatings of soil aggregates, cracks, and biopores control sorption and macropore-matrix exchange during preferential flow, in particular in the clay-illuvial Bt-horizon of Luvisols. The soil organic matter (SOM) composition has been hypothesized to explain temporal changes in the hydraulic properties of aggregate surfaces. The objective of this research was to find relations between the temporal change in wettability, in terms of droplet infiltration dynamics, and the SOM composition of coated and uncoated aggregate surfaces. We used 20 to 40 mm sized soil aggregates from the Bt2 horizon of a Haplic Luvisol from loess that were (i) coated, (ii) not coated (both intact), and (iii) aggregates from which coatings were removed (cut). The SOM composition of the aggregate surfaces was characterized by infrared spectroscopy in the diffuse reflection mode (DRIFT). A potential wettability index (PWI) was calculated from the ratio of hydrophobic and hydrophilic functional groups in SOM. The water drop penetration times (WDPT) and contact angles (CA) during droplet infiltration experiments were determined on dry and moist aggregate samples of the three types. The decrease in the CA with time was described using the power function (CA(t) = at−b). For dry aggregates, the WDPT values were larger for coated as compared to uncoated regions on the aggregate surfaces, and increased with increasing PWI value (R2 = 0.75). The a parameter was significantly related to the WDPT (R2 = 0.84) and to the PWI (R2 = 0.64). The relations between the b parameter and the WDPT (R2 = 0.61) and the PWI (R2 = 0.53) were also significant. The WDPT values of wet soil aggregates were higher than those of dry aggregates due to high water contents, which limited the droplet infiltration potential. At the wet aggregate surfaces, the WDPT values increased with the PWI of the SOM (R2 = 0.64). In contrast to dry samples, no significant relationships were found between parameters a or b of CA(t) and WDPT or PWI for wet aggregate surfaces. The results suggest that the effect of the SOM composition of coatings on surface wettability decreases with increasing soil moisture. In addition to the dominant impact of SOM, the wettability of aggregate surfaces could be affected by different mineralogical compositions of clay in coatings and interiors of aggregates. Particularly, wettability of coatings could be decreased by illite which was the dominant clay type in coatings. However, the influence of different clay mineral fractions on surface wettability was not due to small number of measurements (2 and 1 samples from coatings and interiors, respectively) quantified.

Thermomechanical Stability of Interphases in Glass Reinforced Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
A. T. Dibenedetto ◽  
Jaime A. Gomez ◽  
C. Schilling ◽  
F. Osterholtz ◽  
G. Haddad
Keyword(s):  
Thermal Stability ◽  
Shear Strength ◽  
Glass Fibers ◽  
Boiling Water ◽  
Reinforced Composites ◽  
Matrix Interface ◽  
Force Transmission ◽  
Silane Coating ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

AbstractThe thermomechanical stability of organosilane surface treatments for E-glass fibers used in fiber reinforced composites was evaluated. The effect of molecular structure of 40 to 80 namometer coatings on the force transmission across the fiber/matrix interface was measured as a function of temperature and exposure to water using a fiber fragmentation test. It was found that phenyl-substituted amino silanes exhibited better thermal stability, but were less resistant to boiling water, than the commierically available γ-amino propyl silanes. A bis-trimethoxy γ-amino propyl silane showed an increase in both the hydrolytic and thermal stability when compared to the commiercial product. A good balance of thermal and hydrolytic stability was also obtained with a methylaminopropyltrimethoxy silane coating.The strain energy released from the glass fibers upon decoupling from the poxy matrix or silane coating was found to be in the range of 145 to 186 g/m2 and varied no more than 20 percent over a temperature range of 25 to 75°C or when exposed to boiling water and then redried. It also varied very little with the silane coating used. In addition, the average shear stress attained at the fiber-matrix interface in an imbedded single fiber test at 25°C was as much as two times higher than the shear strength of the epoxy matrix and as much as five times higher at elevated temperature. These data lead one to the conclusion that the interphase failure in these composites is controlled by a plane strain fracture in the constrained region of the organic phase, near the fiber surface, rather than by the maximum shear strength in the interphase.

scholarly journals Molecular Dynamics Simulation of Wetting Behavior: Contact Angle Dependency on Water Potential Models

2021 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Lukman Hakim ◽  
Irsandi Dwi Oka Kurniawan ◽  
Ellya Indahyanti ◽  
Irwansyah Putra Pradana
Keyword(s):  
Molecular Dynamics ◽  
Contact Angle ◽  
Liquid Droplet ◽  
Center Of Mass ◽  
Contact Angles ◽  
Surface Wettability ◽  
Dynamics Simulation ◽  
Potential Models ◽  
Surface Hydrophilicity ◽  
Dynamics Simulations

The underlying principle of surface wettability has obtained great attentions for the development of novel functional surfaces. Molecular dynamics simulations has been widely utilized to obtain molecular-level details of surface wettability that is commonly quantified in term of contact angle of a liquid droplet on the surface. In this work, the sensitivity of contact angle calculation at various degrees of surface hydrophilicity to the adopted potential models of water: SPC/E, TIP4P, and TIP5P, is investigated. The simulation cell consists of a water droplet on a structureless surface whose hydrophilicity is modified by introducing a scaling factor to the water-surface interaction parameter. The simulation shows that the differences in contact angle described by the potential models are systematic and become more visible with the increase of the surface hydrophilicity. An alternative method to compute a contact angle based on the height of center-of-mass of the droplet is also evaluated, and the resulting contact angles are generally larger than those determined from the liquid-gas interfacial line.

scholarly journals Wetting ofAl2O3by Molten Aluminum: The Influence ofBaSO4Additions

2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Joaquin Aguilar-Santillan
Keyword(s):  
High Temperatures ◽  
Firing Temperature ◽  
Molten Aluminum ◽  
Sessile Drop ◽  
Contact Angles ◽  
Sessile Drop Technique ◽  
Pure Alumina ◽  
Two Temperatures ◽  
Drop Technique

The effects ofBaSO4additions on the wetting of alumina by molten aluminum were studied by the sessile drop technique. To study the effect ofBaSO4decomposition(1100–1150∘C), the additions were treated at two temperatures700∘C(973 K) and1450∘C(1723 K), respectively.BaSO4additions at low and high temperatures did not improve the nonwetting character of these compositions. However, at higher firing temperature, the formation ofBA6 (BaO•6Al2O3)has a nonwetting trend with increasing its content. To address theBA6specifically a pureBaO•6Al2O3was produced and tested. It was more nonwetting than the pure alumina. After the analysis of the contact angles for theBaSO4and theBA6 (BaO•6Al2O3), it was concluded that these additions to alumina do not inhibit wetting by molten aluminum. In fact, at the addition levels common for refractories, the wetting tendency of molten aluminum is enhanced. Alternative explanations for the effectiveness ofBaSO4additions to alumina refractories are discussed.

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