The surface wettability of ACNTs is important for the development of hybrid nano-materials to perform various functions. However, as-grown ACNTs are super-hydrophobic due to the large proportions of air trapping. By using O2 plasma etching, the surface wettability of ACNTs can be tuned from super-hydrophobic to hydrophobic, and then to hydrophilic by adjusting the flow rate of O2 gas during the etching process. Moreover, it was found that the surface wettability could be recovered by removing the top part of O2 plasma treated CNTs. Combining with laser-pruning technology, ACNT films with different kinds of patterns can be produced. Thus, CNT films with patterns of controlled wettability were produced and these can act as templates for the selective assembly of various nano-particles such as PS particles, CdTe quantum dots, and fluorescent particles ...
TY - CONF. T1 - Wettability alteration of sandstone with zinc oxide nano-particles. AU - Tola, Sreu. AU - Sasaki, Kyuro. AU - Sugai, Yuichi. PY - 2017/1/1. Y1 - 2017/1/1. N2 - In this research, we have investigated wettability alteration of sandstone and crude oil surfaces contacting nanofluids formulated by ZnO nanoparticles. The ZnO nanofluid was mixed by dispersing into water solution of Sodium Dodecyl Sulfate that is an anionic surfactant. ZnO concentration (w/w) in the fluid ranges from 500 ppm to 5000 ppm. Oil film spread on glass plate and surface of Berea sandstone saturated by light crude oil were used to measure fluid wettability evaluated by the contact angle of fluid droplets with the sessile drop methods. It has been confirmed that the ZnO nanofluid has a potential to shift wettability to more water wet condition on the surfaces of oil film and sandstone saturated by oil.. AB - In this research, we have investigated wettability alteration of sandstone and crude oil surfaces ...
CO2-rock wettability is a key factor which determines the fluid dynamics and CO2 geo-storage capacity. However, the full understanding of real reservoir CO2-wettability is yet to be gained. We thus systematically analysed the wettability of CO2/brine/South West Hub sandstones at various pressures (0.1 MPa, 5 MPa, 10 MPa, 15 MPa, and 20 MPa) at 334 K. A new procedure based on organic carbon isotope tracking (δ13Corg) was proposed to eliminate the effect of artificial organic matter introduced by drilling mud penetration. The results indicate that the advancing (θa) and receding (θr) water contact angles for the CO2/brine/South West Hub sandstone system increase with increase in pressure (ranging from 71° to 118° and 66° to 111°). It can thus be suggested that the system is weakly water-wet to intermediate-wet. When the samples were treated with dichloromethane, a slight decline in organic content was observed leading to slight decrease in water contact angles (i.e. TOC decreased from 0.019% to 0
Surface property of rock affects oil recovery during water flooding. Oil-wet polar substances adsorbed on the surface of the rock will gradually be desorbed during water flooding, and original reservoir wettability will change towards water-wet, and the change will reduce the residual oil saturation and improve the oil displacement efficiency. However there is a lack of an accurate description of wettability alternation model during long-term water flooding and it will lead to difficulties in history match and unreliable forecasts using reservoir simulators. This paper summarizes the mechanism of wettability variation and characterizes the adsorption of polar substance during long-term water flooding from injecting water or aquifer and relates the residual oil saturation and relative permeability to the polar substance adsorbed on clay and pore volumes of flooding water. A mathematical model is presented to simulate the long-term water flooding and the model is validated with experimental results. The
A method of treating a low hydrohead fibrous porous web material to increase its retentive wettability, by at least about 50%, as compared to untreated low hydrohead web material, is disclosed. The increase in retentive wettability is evidenced by the increase in the average number of runoff tests that the treated web material can sustain without unacceptable runoff is disclosed. The invention is also directed to products prepared or preparable by the process.
Excessive water formation inside the polymer electrolyte membrane (PEM) fuel cells structures leads to the flooding of the cathode gas diffusion layer (GDL) and cathode gas flow channels. This results in a negative impact on water management and the overall cell performance. Liquid water generated in the cathode catalyst layer and the water moved from anode to cathode side due to electro-osmotic drag transport through the GDL to reach the gas flow field channels, where it is removed by air cathode gas stream. Due to high and uniform capillary force distribution effect of the pores through the GDL plane and surface tension between the water droplets and gas flow field channels surfaces, liquid water tends to block/fill the pores of the GDL and stick to the surface of the GDL and gas flow channels. Therefore, it is difficult to remove the trapped water in GDL structure which can lead to flood of the PEM fuel cell. The GDL surfaces are commonly treated uniformly with a hydrophobic material in ...
A wettability switchable surface will be demonstrated to study the contact angle hysteresis of liquid droplet. Manipulation of surface wettability can be applied in the field of biomedical (cell-surface interaction) and fluids dynamics (friction reduction). The surface affinity of Polypyrrole (PPy) film can be switched reversibly between hydrophobic and hydrophilic by reduction and oxidation, which needs very low voltage, e.g. -0.5V to 2V. The experiments show that water droplet has 116.5° and 71.5° contact angle on an oxidized and reduced planar PPy surface respectively. According to Wenzel theory, increase of surface roughness can amplify either hydrophobicity or hydrophilicity, which promotes contact angle hysteresis. In this study, a PPy film is integrated with MEMS techniques to create a patterned 3D structure. The dynamic contact angle of water droplet on the fabricated structure will be measured and discussed in this paper. The impact of pattern geometry and oxidized state of PPy is also
Materials Science, Commodity Research and Production Certification O. V. Romankevich, O. A. Garanina, N. A. Bardash. Capillarity of Fibrous Materials. Thermodynamics of wettability of fibrous materials within the Guggenheim approach to description of surface phenomenons isconsidered. Characteristic of relative change of free energy of interfacial layer in wetting ΔGrelcan be determined without valuecapillary tension and can be used to characteristic of chemical structure changing of fibers surface after carrying out finishingprocesses. Key words: capillarity, criteria wettability, "phase", guggenheim, the contact angle. E. V. Voloskova, V. A. Poluboyarov, L. K. Baykina, F. K. Gorbunov The Influence of the Nano-dispersed Ceramic Particles on the Properties of the Films on the Basis of Molecular Collagen. The work proposes the way of change of physical and mechanical parameters of films on the basis of molecular collagen by modifying them with ceramic nanoparticles. It is shown that the ...
Purpose: : Ideally, soft contact lenses (SCLs) should be highly wettable and immune to oily and proteinaceous tear-film deposits during wear. Therefore, it is important to assess SCL wettability performance when the lens is in contact with human tear film especially the lipid layer. For the first time, we devise and evaluate an in-vitro blink-cycle cell that mimics contact-lens exposure to the human-eye environment during blinking and that permits contact-angle assessment. Methods: : An in-vitro blink-cycle cell was designed to measure contact angles of SCLs during model blink cycles. A syringe pump flows an artificial tear solution into and out of a blink-cycle cell, thereby raising and lowering the liquid level above and below the surface of the lens. The artificial tear solution contains phosphate-buffered saline (PBS), mucin, and tear-film proteins. Importantly, a model tear lipid is spread over the air/water interface to reflect exposure to meibomian lipids. One blink cycle corresponds to ...
Method of improving wetting and adhesive properties of dielectric materials by injecting electrical charges into the substrate under conditions such that the primary effect on the surface is that of charging so that improved wettability of the surface will be achieved. Flowable materials are then applied to the surface and cured in situ to permanently adhere the flowable materials to the surface.
This thesis is a part of the ongoing project, "Oil recovery from fractured chalk reservoirs", which is a collaboration between the Reservoir Physics Group at the University of Bergen and ConocoPhillips Research Center in Bartlesville, Oklahoma. The project was initiated in 1990 and for the last 15 years about 30 Master and PhD candidates have graduated and, mainly employed by the oil industry. Dedicated candidates combined with professional guidance and stable funding has been a key to the success of this long term research project. Early work in this project report experiments on large chalk blocks subjected to water floods. The dynamics of the water front propagation during water floods were monitored by nuclear tracer imaging for homogeneous whole blocks and when fractured. The impact of the fractures on the water flood could then be investigated. Emphasis was on the effect of wettability condition on the recovery mechanism. In addition to the saturation monitoring system, attempts to measure ...
Authors: Khang, Gilson , Lee, Sang Jin , Lee, Jin Ho , Kim, Yong Sik , Lee, Hai Bang Article Type: Research Article Abstract: Chemogradient surfaces whose properties are changed gradually along the sample length are of particular interest for the basic studies of the interaction between biological species and surfaces since the effect of a selected property can be examined in a single experiment on one surface. A wettability chemogradient on the poly(l‐lactide‐co‐glycolide) (PLGA) films by treating them in air with corona from a knife‐type electrode whose power increases gradually along the sample length. The PLGA surfaces oxidized gradually with the increasing corona power, and the wettability chemogradient was created on the surfaces as evidenced by the measurement of water contact angles and …electron spectroscopy for chemical analysis. The wettability chemogradient PLGA surfaces prepared were used to investigate the interaction of fibroblast cells in terms of the surface ...
Table 4.1. Water contact angles for self assembled monolayer surfaces on Au. Standard deviations are given in parentheses. A value of 0 indicates a low and ill defined angle. Samples of 180 and 181 used for these experiments were prepared using the method described in section 3.1.6.. The values for modified surfaces are significantly different from the bare gold samples indicating that SAM formation was successful. The observed angles fall into classes which parallel the gross structure of the molecules comprising the SAM. The amine and pyridine functionalized surfaces, 180, 181 and 184, exhibit lower advancing contact angles than the porphyrin monolayers. Monolayers terminated by polar functional groups have previously been reported to give rise to low qa.19 The mono- and di-thiol porphyrins, 227 - 229 and 223 - 225, all display qa in the range 102 - 108 consistent with a relatively hydrophobic surface, a result unsurprising given the alkyl substituents at the porphyrin periphery. qa of the ...
This thesis summarises the findings made in NFR-funded project "Capillary Pressure and Capillary Heterogeneities". The focus has been to determine the impact on oil recovery from wettability and fractures in carbonate rocks. Secondly a new method for measuring capillary pressure has been developed. The results of this work are reported in this thesis. The work presented in this thesis has improved the understanding of the interaction between wettability and fractures on the production mechanisms in carbonate reservoirs, in different directions. Figure 1 gives an overview of the project "Capillary Pressures and Capillary Heterogeneities", its fundamental building blocks and the interaction between them to better understand how main conclusions in this study may be drawn; Building block 1: A reproducible method for altering wettability has been developed, and continuously improved throughout the study. Feed-back from the large scale block experiments have actively been used to improve the ...
TY - JOUR. T1 - Why is it difficult to wash aphids off from superhydrophobic kale?. AU - Damle, Viraj G.. AU - Linder, Rubin. AU - Sun, Xiaoda. AU - Kemme, Nicholas. AU - Majure, Lucas C.. AU - Rykaczewski, Konrad. PY - 2016/10/3. Y1 - 2016/10/3. N2 - Many varieties of the cabbage family have leaves covered with superhydrophobic epicuticular wax, which provides them with self-cleaning characteristics. Since the wax also lowers insect adhesion, rinsing of the leaves with water should be an effective way of removing the insects. Conversely, we report that superhydrophobicity of tuscan kale increases resistance of aphids to hydrodynamic removal. The exterior surface of the insects is also superhydrophobic and acts as an extension of the leafs surface. As a result even at moderate impact velocities impinging water drops cannot penetrate under the pests. Consequently, liquid impact aids the insects adhesion by increasing the normal compressive forces they experience. We show that on a hydrophilic ...
Calculation of surface free energy (SFE) from contact angle results, measurement of contact angles on solids yields data that reflect the thermodynamics of a liquid/solid interaction.
TY - JOUR. T1 - Antibacterial properties and chemical stability of superhydrophobic silver-containing surface produced by sol-gel route. AU - Heinonen, S. AU - Huttunen-Saarivirta, E. AU - Nikkanen, J-P. AU - Raulio, Mari. AU - Priha, Outi. AU - Laakso, J. AU - Storgårds, Erna. AU - Levänen, E. PY - 2014. Y1 - 2014. N2 - Superhydrophobic surface with and without nano-sized silver particles (AgNPs) using a sol-gel technique were prepared for antibacterial and chemical stability tests and electrochemical characterization. Antibacterial tests showed that the surface with AgNPs reduced the number of the bacteria. However, to be used in long-term industrial applications, the surfaces are required to have sufficient chemical stability in the operation environment. This is why the stability of the produced surfaces was studied as a function of pH value of the solution. According the results, the produced surfaces are stable in neutral environments but release silver ions at high rates and dissolve or ...
The common classifications of hydrophobic and hydrophilic arose from the sessile drop method. In our study, all materials tested appeared to be more or less hydrophobic, as demonstrated by their high water contact angle reading. The PMMA (AMO DuraLens PS 101A), AcrySof (Alcon), the Siflex 4 and the Flex 60 have similar water contact angles (73.2, 73.3, 75.4 and 75.7 , respectively). The AMO soft acrylic Sensar had a somewhat higher water contact angle (81.7 ). Using the sessile drop method, we saw the influence of the trifluoroethylene component of the material. In the hydrophobic environment of the air, the fluorinated component of the Sensar material surfaced and thereby increased the water contact angle of the material so that its value was somewhat higher than that of PMMA. We saw relatively small differences between most materials with highest values for the heparin-surface-modified material; that is, critical surface tension values for these materials were similar. Thus, we would expect ...
In this paper, we detail how microantennae dedicated to Magnetic Resonance Imaging (MRI) can benefit from the advantages offered by polymer substrates, especially flexibility and dielectric properties. We present a monolithic and wireless design based on the transmission lines between conductor windings on both sides of a dielectric substrate and its fabrication process. This last one requires specific plasma treatments to improve polymer/metal adhesion. We have led a comparative study on the effects of the ageing time on the wettability and the metal adhesion to Kapton and Teflon surfaces. Correlation between wettability (water contact angle) and adhesion (tensile strength) has been established. Then, the use of PolyDiMethylSiloxane (PDMS) as biocompatible packaging material and the optimization of its thickness allows us to conserve suitable f0 and Q values in a conducting environment such as the biological tissues. These studies allow us to perform 7 Tesla in vivo MRI of the rat brain with a high
Highly hydrophobic surfaces have numerous useful properties; for example, they can shed water, be self-cleaning, and prevent fogging (1, 2). Surface hydrophobicity is generally characterized with contact angle (CA) goniometry. With a history of more than 200 years (3), the measurement of CAs was and still is considered the gold standard in wettability characterization, serving to benchmark surfaces across the entire wettability spectrum from superhydrophilic (CA of 0°) to superhydrophobic (CA of 150° to 180°). However, apart from a few reports [e.g., (4-8)], the inherent measurement inaccuracy of the CA goniometer has been largely overlooked by its users. The development of next-generation liquid-repellent coatings depends on raising awareness of the limitations of CA measurements and adopting more sensitive methods that measure forces. ...
A eutectic liquid (choline chloride and urea) that served as a templating agent in sol-gel processing was used to prepare thin silica films on glass microscope slides. Subsequent extraction of the eutectic liquid yielded a film with a rough surface. After treating the film surface with a fluoroalkyl silane, the surface became superhydrophobic with a contact angle not, vert, similar 170° and a contact angle hysteresis , 10°. The optical transmittance of the film coated on the glass slide was comparable to that of the microscope glass slide. Atomic Force Microscopy (AFM) was used to characterize the surface structures; a tipless probe allowed measurement of the force of interaction with superhydrophobic surfaces. The interaction force between the AFM probe and the superhydrophobic surface was reduced greatly compared to that between the probe and the flat surface treated with fluoroalkyl silane ...
A eutectic liquid (choline chloride and urea) that served as a templating agent in sol-gel processing was used to prepare thin silica films on glass microscope slides. Subsequent extraction of the eutectic liquid yielded a film with a rough surface. After treating the film surface with a fluoroalkyl silane, the surface became superhydrophobic with a contact angle not, vert, similar 170° and a contact angle hysteresis , 10°. The optical transmittance of the film coated on the glass slide was comparable to that of the microscope glass slide. Atomic Force Microscopy (AFM) was used to characterize the surface structures; a tipless probe allowed measurement of the force of interaction with superhydrophobic surfaces. The interaction force between the AFM probe and the superhydrophobic surface was reduced greatly compared to that between the probe and the flat surface treated with fluoroalkyl silane ...
Superhydrophobic films are produced by a simple and low cost method. Silica (SiO(2)) nanoparticles are dispersed in solutions of Rhodorsil 224, a commercial poly(alkyl siloxane) which is used for the protection of outdoor cultural heritage objects, and the suspensions are sprayed on glass surfaces. It is shown that the siloxane-nanoparticle composite films prepared from dispersions of high particle concentrations (,= 0.5% w/v) exhibit superydrophobic properties (high static contact angle and small hysteresis) which can be rationalized by the Cassie-Baxter model, according to quantitative measurements obtained by SEM images. Siloxane-nanoparticle films are then deposited (sprayed) on "Opuka", a fine-grained argillite which was used for the restoration of the castle of Prague. It is shown that the treated stone surfaces exhibit superydrophobic properties, similar to the treated glass surfaces. The efficacy of the superhydrophobic films to protect Opuka is evaluated by performing water contact ...
The sticking of product material to injection molding tools is a serious problem, which reduces productivity and reliability. Depositing alloy nitride coatings (TiN, ZrN, CrN, and TiAlCrN) using closed field unbalanced magnetron sputter ion plating and electrodeposition of chromium, and characterizing their surface free energies in the temperature range 20-120°C have led to the development of a non-sticking (with a low surface free energy) coating system for semiconductor IC packaging molding dies. The contact angles of water, diiodomethane and ethylene glycol on the coated surfaces were measured at temperatures in the range 20-120°C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the coatings and their components (dispersion and polar) were calculated using the Owens-Wendt geometric mean approach. The surface roughness of these coatings were investigated by atomic force microscopy (AFM). The adhesion force of these coatings were measured using direct tensile ...
We present a modeling approach that enables numerical simulations of a boiling Van der Waals fluid based on the diffuse interface description. A boundary condition is implemented that allows in and out flux of mass at constant external pressure. In addition, a boundary condition for controlled wetting properties of the boiling surface is also proposed. We present isothermal verification cases for each element of our modeling approach. By using these two boundary conditions we are able to numerically access a system that contains the essential physics of the boiling process at microscopic scales. Evolution of bubbles under film boiling and nucleate boiling conditions are observed by varying boiling surface wettability. We observe flow patters around the three-phase contact line where the phase change is greatest. For a hydrophilic boiling surface, a complex flow pattern consistent with vapor recoil theory is observed.. ...
Dry areas/non-wetting (i.e., assessment of the disruption of the front surface wettability of the contact lens), as assessed by the investigator for each eye individually. Dry areas/non-wetting was rated on a 5-point scale: 0=none, 1=very slight, 2=slight, 3=moderate, 4=severe. The combined percentage of lenses assessed as none or very slight is reported. Lenses from both eyes contributed to the percentage ...
Superhydrophobic coatings and compositions and methods for preparing superhydrophobic coatings and compositions are described herein whereby the coatings and compositions are prepared under mild conditions, yet the methods are amenable to chemical functionalization of the coatings and components therein. The methods are useful for tuning and optimizing the physical properties of the coatings. In an embodiment, the coatings comprise nanostructured fluorinated silica colloids.
The work presented in this Thesis explores the properties and potential applications of superhydrophobic supports created using electroless deposition of rough silver onto copper wires which were then cut to expose hydrophilic tips. Small aqueous sample droplets were dispensed onto these supports and their Raman spectra were probed either directly or after drying to increase the concentration. It was found that the best way to dispense the droplets, (typically < 1 ul), was to use a pipette whose needle was itself superhydrophobic. When droplets of aqueous glucose, sucrose or mixtures of these were dried they formed viscous dome-shaped deposits in which the sugars were sufficiently concentrated to allow normal Raman measurements to be carried out. With melamine solutions and tear fluid the deposits were dry solids. Detection limits for sucrose, glucose and melamine were found to be 5 x 10-4 M, 2.5 X 10.3 M and 1 X 10.6 M, respectively. The concentration through evaporation approach was combined ...
As all the three extruders are running at similar speeds, the end product is developed with minimal handling. A negative point of this process is the amount of production loss occurred, in case any of the three extruders is not running efficiently or there is some problem with only one of the extruders.. Wire coating is generally done by the use of single screw extruders, in which the crosshead extrusion process is carried out. The job of the extruder is to melt the resin & forward it to the die at an even & constant melt pressure and temperature. The crosshead extrusion process is carried out by using a general equipment in the line, which includes following basic pieces:. ...
AB Specialty Silicones new line of silicone resin blends combines unique carriers with trimethylsiloxysilicate (TMS). Carrier fluid selection can be volatile or non-volatile and, when combined with the other ingredients in your formulation, ha
20 videos from 10 participants who had worn the same type of silicone hydrogel lens for at least 8 hours were analysed. We imaged the spread of tear-film over the lens surface after a blink, in the morning after lens insertion and also after 8 hours of lens wear. Using a customized, calibrated ImageJ macro the velocity of reflective particles in the videos was determined. The results were analyzed using R and ProFit.. ...
A hybrid solar dryer, direct solar energy dryer and open sun drying under the climatic conditions of Yola, Nigeria was used to dry tomato slices. The effect of these drying methods on the functional and sensory quality of the dried tomatoes was examined. The functional properties of the dried tomatoes slices were significantly different (p|0.05). In open sun dried tomatoes, the bulk density ranged from 0.56 - 0.62 g/ml, water absorption index (WAI) 436.33 - 475.67 gH2O/sample, water solubility index (WSI) 6.00 - 14.00, specific volume 1.61 - 1.78 ml/g and wettability 10.33 - 13.33 s for 4 - 8 mm thick tomato samples. For solar dried tomatoes, the bulk density ranged from 0.52 - 0.57 g/ml, the WAI ranged from 412.00 - 454.00 gH2O/sample, the water solubility index (WSI) range was 12.33 - 16.67, specific volume range was 1.73 - 1.90 ml/g and wettability ranged from 5.85 - 10.63 s for 4 - 8 mm thick tomato samples. For the hybrid dried tomatoes, the bulk density ranged from 0.50 - 0.54 g/ml, the WAI values
In areas like drug discovery where target compounds are increasingly polar, it is critical to have a reverse phase column that performs well under aqueous conditions. Retention is critical, but cannot come with troublesome secondary interactions. Likewise, phase collapse and shifting retention times need to be avoided. The answer is our Polaris line of polar-modified columns. From the collapse-resistant pore structure of our base silica, to the "wettability" engineered into the bonded phases, Polaris columns have been designed for high aqueous conditions. The combination of high phase density bonding, ultra pure silica, and silanol shielding leads to excellent peak shape among polar-modified columns.. As a family, Polaris offers a variety of polar modifications in both C18 and C8 chemistries.. Polaris C18-A ...
The main task of a petroleum reservoir engineer is to produce oil and gas reservoirs with maximum economic rate and reaching the ultimate recovery. Reservoir evaluation processes need a reservoir description as completely and accurately as possible using a variety of methods from seismic and well testing to logging, cuttings analysis and coring. These methods present the engineer with a valuable and wide range of scales of information to well evaluate the reservoir and control its performance and improve oil recovery. The main goal of core analysis is to reduce uncertainty in reservoir evaluation processes created by the uncertainty degree in the input parameters at the different levels from reserve estimate level to the enhancement of reservoir performance level. In order to reach these targets, the exact determination of certain petrophysical properties are necessary such as rock porosity, relative permeability, water saturation, and capillary pressure at all stages of reservoir life and rock ...
Summary The complex physics of multiphase flow in porous media are usually modeled at the field scale using Darcy-type formulations. The key descriptors of such models are the relative permeabilities to each of the flowing phases. It is well known t
метод; способ; приём method for determination relative water wettability - метод определения относительной водосмачиваемости (пород); method for determination wettability - метод определения смачиваемости (пород) - airborne magnetometer method - air-hammer drilling method - airlift well operation method -.
Click here to report technical problems or to provide feedback on this system. For urgently needed technical support, phone 401-334-9902 between the hours of 8:30 AM and 6:00 PM Monday through Friday, US Eastern Standard Time (GMT -05:00), and provide support code 1438 ...
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The costs of academic publishing are absurd. The University of California is fighting back. https://t.co/4lZMxDAUPY via @voxdotcom, ...
A water soluble hydrophilic resin in an alcohol-free polymer solution and a method of application to natural rubber and synthetic latex products such as surgeons gloves, catheters and condoms to increase the lubricity of the rubber products where they come into contact with skin or other tissue. The hydrophilic resin is applied in a single application step in an aqueous solution in the absence of alcohol or a separate acid priming step.
This technique enable us to control the curvature of the top and the aspect ratio of the forming particles from two reasons. First, the capillary effect of the wetting solution and the formation of interfaces depend on the loading sequence. Secondly, the difference in densities of the solutions also determine the shape. Finally, the aspect ratio of the mold itself governs the resulting shape and size. In sequence A depicted in the figure, PEG-DA was added on a patterned PDMS micromold and the excess was removed, and the solution forms a contact angle at the interfaces. Then the n-hexadecane solution was added on top. The hydrophobicity of the wetting solution promotes higher wettability on the PDMS wall than the PEG-DA, which induces the capillary force on the mold surface. Consequently, the n-hexadecane moves down the well, pushing the PEG-DA solution away from the wall. Since the PEG-DA solution has to maintain its volume, the decrease in the width increases the height of the solution column. ...
A contact angle measurement device can be added to the Pendant Drop system IFT 10-P. The contact angle measurement is made by placing a liquid drop on a piece of quartz, core, or other test material. The angle of contact between the drop and the test piece is measured under reservoir pressure and temperature conditions. This system can also be supplied as a stand alone system. ...
contact angle meter SL200B, is standard Contact Angle Goniometers based on drop shape analysis, applicable to measure dynamic& static contact angle, surface free energy of solid and its distribution with standard equiped rotation system,USA KINO Industry Co., Ltd.
A method and structure for good adhesion of Intermetallic Compounds (IMC) on Cu pillar bumps are provided. The method includes depositing Cu to form a Cu pillar layer, depositing a diffusion barrier layer on top of the Cu pillar layer, and depositing a Cu cap layer on top of the diffusion barrier layer, where an intermetallic compound (IMC) is formed among the diffusion barrier layer, the Cu cap layer, and a solder layer placed on top of the Cu cap layer. The IMC has good adhesion on the Cu pillar structure, the thickness of the IMC is controllable by the thickness of the Cu cap layer, and the diffusion barrier layer limits diffusion of Cu from the Cu pillar layer to the solder layer. The method can further include depositing a thin layer for wettability on top of the diffusion barrier layer prior to depositing the Cu cap layer.
Pharmaceutical Hot Melt Extrusion Market to clinch a rising share of US$36.4 mn by 2024 after recording a US$26.6 mn in 2015. The world pharmaceutical hot melt extrusion market could maintain a 3.90% CAGR during the forecast period.
Abstract - Coalescing drops spontaneously jump out of plane on a variety of biological and synthetic superhydrophobic surfaces, with potential applications ranging from self-cleaning materials to self-sustained condensers. To investigate the mechanism of the self-propelled jumping, we report three-dimensional phase-field simulations of two identical spherical drops coalescing on a flat surface with a contact angle of 180°. The numerical simulations capture the spontaneous jumping process which follows the capillary-inertial scaling. The out-of-plane directionality is shown to result from the counter action of the substrate to the impingement of the liquid bridge between the coalescing drops. A viscous cutoff to the capillary-inertial velocity scaling is identified when the Ohnesorge number of the initial drops is around 0.1, but the corresponding viscous cutoff radius is too small to be tested experimentally. Compared to experiments on both superhydrophobic and Leidenfrost surfaces, our ...
Low Surface Energy PU Film With Small Contact Angle Hysteresis. Dou Qizheng 05-09-19. Beautiful lotus flowers. Water droplets. Self-cleaning. Surface roughness. Bar = 20 m. Introduction. lotus-effect. Barthlott, et al. Planta 1997 , 202 , 1. Slideshow 6726318 by forrest-riddle
An electrical contact of the type having a working surface and comprising a ductile metal and weld inhibiting material includes a wetting agent present in an amount sufficient to reduce the surface energy between said contact surface and the liquid phase of the ductile metal. Improved wettability of the surface results in reduced arc erosion due to the spattering loss of ductile metal. Also, described is a method for selecting and testing proposed additives.
To successfully build a machine that will accelerate evaporation, we need to achieve a hang time of at least 20 seconds for a water droplet that is 180 microns.. We could achieve smaller water droplet sizes, however the tradeoff is drift, and many customers have the restriction of retaining all drift within a lined area to comply with the EPA. In addition, our turbine has the capability of generating enough loft to produce an average hang time for water droplets in the range up 180 microns. This allows good average returns for evaporation of the total water droplets set aloft, while restricting drift by using this droplet size or larger.. If we wish to increase the overall percentage evaporated of the total pumped aloft, we can easily achieve this by reducing the nozzle size and thus the water droplet size. However, this not only increases the drift potential but it in fact has diminishing returns, in that it reduces the overall output of an evaporator unit.. For more information, please ...
The stacking of discotic molecules (hexakis(alkoxy)diquinoxalino[2,3-a:2,3-c]phenazines) in the columnar phase sandwiched between two flat glass substrates has been studied. The surface free energy of the substrates, measured by means of sessile drop technique, is found to have significant influence on the way that the discotic molecules anchor on the surface, and a steady thermal state of the system is crucial for a homogenous orientation of the discotic columns. On a surface of high free energy, the discotic molecules anchor with their disc-face toward the surface. A decrease in the surface free energy of the substrate causes the discotic columns to tilt away from the normal of the substrate.