On-demand evaporation mode of sessile droplet by designing substrate surface wettability patterns

2021 ◽  
Vol 33 (12) ◽  
pp. 122015
Author(s):  
Yongshuai Wen ◽  
Yongshou Liu
Keyword(s):  
Substrate Surface ◽  
Surface Wettability ◽  
Sessile Droplet ◽  
On Demand

scholarly journals PLLA Honeycomb-Like Pattern on Fluorinated Ethylene Propylene as a Substrate for Fibroblast Growth

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2436
Author(s):  
Klára Fajstavrová ◽  
Silvie Rimpelová ◽  
Dominik Fajstavr ◽  
Václav Švorčík ◽  
Petr Slepička
Keyword(s):  
Surface Properties ◽  
Substrate Surface ◽  
Surface Wettability ◽  
Material Surface ◽  
Growth Enhancement ◽  
Fibroblast Growth ◽  
Ethylene Propylene ◽  
Preparation Step ◽  
Cell Material Interactions ◽  
Fluorinated Ethylene Propylene

In this study, we present the surface patterning of a biopolymer poly(l-lactide) (PLLA) for fibroblast growth enhancement. The patterning is based on a self-organized pore arrangement directly fabricated from a ternary system of a solvent-nonsolvent biopolymer. We successfully created a porous honeycomb-like pattern (HCP) on a thermally resistant polymer—fluorinated ethylene propylene (FEP). An important preparation step for HCP is activation of the substrate in Ar plasma discharge. The polymer activation leads to changes in the surface chemistry, which corresponds to an increase in the substrate surface wettability. The aim of this study was to evaluate the influence of the PLLA concentration in solution on the surface morphology, roughness, wettability, and chemistry, and subsequently, also on fibroblast proliferation. We confirmed that the amount of PLLA in solution significantly affects the material surface properties. The pore size of the prepared layers, the surface wettability, and the surface oxygen content increased with an increasing amount of biopolymer in the coating solution. The optimal amount was 1 g of PLLA, which resulted in the highest number of cells after 6 days from seeding; however, all three biopolymer concentrations exhibited significantly better results compared to pristine FEP. The cytocompatibility tests showed that the HCP promoted the attachment of cell filopodia to the underlying substrate and, thus, significantly improved the cell–material interactions. We prepared a honeycomb biodegradable support for enhanced cell growth, so the surface properties of perfluoroethylenepropylene were significantly enhanced.

scholarly journals Prediction of Contact Angle of Nanofluids by Single-Phase Approaches

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4558 ◽  
Author(s):  
Nur Çobanoğlu ◽  
Ziya Haktan Karadeniz ◽  
Patrice Estellé ◽  
Raul Martínez-Cuenca ◽  
Matthias H. Buschmann
Keyword(s):  
Contact Angle ◽  
Single Phase ◽  
Substrate Surface ◽  
Droplet Surface ◽  
Force Balance ◽  
Radius Of Curvature ◽  
Geometrical Parameters ◽  
Ambient Conditions ◽  
Sessile Droplet ◽  
Droplet Shape

Wettability is the ability of the liquid to contact with the solid surface at the surrounding fluid and its degree is defined by contact angle (CA), which is calculated with balance between adhesive and cohesive forces on droplet surface. Thermophysical properties of the droplet, the forces acting on the droplet, atmosphere surrounding the droplet and the substrate surface are the main parameters affecting on CA. With nanofluids (NF), nanoparticle concentration and size and shape can modify the contact angle and thus wettability. This study investigates the validity of single-phase CA correlations for several nanofluids with different types of nanoparticles dispersed in water. Geometrical parameters of sessile droplet (height of the droplet, wetting radius and radius of curvature at the apex) are used in the tested correlations, which are based on force balance acting on the droplet surface, energy balance, spherical dome approach and empirical expression, respectively. It is shown that single-phase models can be expressed in terms of Bond number, the non-dimensional droplet volume and two geometrical similarity simplexes. It is demonstrated that they can be used successfully to predict CA of dilute nanofluids’ at ambient conditions. Besides evaluation of CA, droplet shape is also well predicted for all nanofluid samples with ±5% error.

Sessile droplet freezing and ice adhesion on aluminum with different surface wettability and surface temperature

2015 ◽  
Vol 58 (7) ◽  
pp. 1-8 ◽  
Author(s):  
JunFei Ou ◽  
QingWen Shi ◽  
ZhiLe Wang ◽  
FaJun Wang ◽  
MingShan Xue ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Surface Wettability ◽  
Sessile Droplet ◽  
Ice Adhesion

scholarly journals Dynamics Behaviors of Droplet on Hydrophobic Surfaces Driven by Electric Field

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 778 ◽  
Author(s):  
Jie Liu ◽  
Sheng Liu
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Substrate Surface ◽  
Contact Angles ◽  
Droplet Microfluidics ◽  
Phase Field Method ◽  
Sessile Droplet ◽  
Hydrophobic Surfaces ◽  
Droplet Motion ◽  
Plate Electrode

Droplet microfluidic technology achieves precise manipulation of droplet behaviors by designing and controlling the flow and interaction of various incompatible fluids. The electric field provides a non-contact, pollution-free, designable and promising method for droplet microfluidics. Since the droplet behaviors in many industrial and biological applications occur on the contact surface and the properties of droplets and the surrounding environment are not consistent, it is essential to understand fundamentally the sessile droplet motion and deformation under various conditions. This paper reports a technique using the pin-plate electrode to generate non-uniform dielectrophoresis (DEP) force to control sessile droplets on hydrophobic surfaces. The electrohydrodynamics phenomena of the droplet motion and deformation are simulated using the phase-field method. It is found that the droplet moves along the substrate surface to the direction of higher electric field strength, and is accompanied with a certain offset displacement. In addition, the effect of pin electric potentials, surface contact angles and droplet volumes on the droplet motion and deformation are also studied and compared. The results show that higher potentials, more hydrophobic surfaces and larger droplet volumes exhibit greater droplet horizontal displacement and offset displacement. But for the droplet vertical displacement, it is found that during the first revert process, the release of the surface tension can make the droplet with low potentials, small contact angles or small droplet volumes span from negative to positive. These results will be helpful for future operations encountered in sessile droplets under non-uniform electric fields towards the droplet microfluidics applications.

scholarly journals Formation of Polymer Walls by Monomer Aggregation Control Utilizing Substrate-Surface Wettability for Flexible LCDs

2017 ◽  
Vol E100.C (11) ◽  
pp. 1005-1011 ◽  
Author(s):  
Seiya KAWAMORITA ◽  
Yosei SHIBATA ◽  
Takahiro ISHINABE ◽  
Hideo FUJIKAKE
Keyword(s):  
Substrate Surface ◽  
Surface Wettability ◽  
Aggregation Control

Electron microscopy studies of plasma-sprayed materials

1983 ◽  
Vol 41 ◽  
pp. 70-71
Author(s):  
K.R. Subramanian ◽  
A.H. King ◽  
H. Herman
Keyword(s):  
Plasma Spraying ◽  
Substrate Surface ◽  
Flame Temperature ◽  
Ceramic Coatings ◽  
Metallic Substrates ◽  
Hot Plasma ◽  
Almost All ◽  
Plasma Sprayed ◽  
Hostile Environments ◽  
Plasma Spraying Process

Plasma spraying is a technique which is used to apply coatings to metallic substrates for a variety of purposes, including hardfacing, corrosion resistance and thermal barrier applications. Almost all of the applications of this somewhat esoteric fabrication technique involve materials in hostile environments and the integrity of the coatings is of paramount importance: the effects of process variables on such properties as adhesive strength, cohesive strength and hardness of the substrate/coating system, however, are poorly understood.Briefly, the plasma spraying process involves forming a hot plasma jet with a maximum flame temperature of approximately 20,000K and a gas velocity of about 40m/s. Into this jet the coating material is injected, in powder form, so it is heated and projected at the substrate surface. Relatively thick metallic or ceramic coatings may be speedily built up using this technique.

Feasibility of Molecular Structure Determination With a High Resolution Electron Microscope

1968 ◽  
Vol 26 ◽  
pp. 338-339
Author(s):  
T. A. Welton
Keyword(s):  
Electron Microscope ◽  
Substrate Surface ◽  
Helical Axis ◽  
Base Plane ◽  
Resolution Electron ◽  
High Resolution Electron Microscope ◽  
High Degree ◽  
Degree Of Order ◽  
Purine Pyrimidine

An ultimate design goal for an improved electron microscope, aimed at biological applications, is the determination of the structure of complex bio-molecules. As a prototype of this class of problems, we propose to examine the possibility of reading DNA sequence by an imaginable instrument design. This problem ideally combines absolute importance and relative simplicity, in as much as the problem of enzyme structure seems to be a much more difficult one.The proposed technique involves the deposition on a thin graphite lamina of intact double helical DNA rods. If the structure can be maintained under vacuum conditions, we can then make use of the high degree of order to greatly reduce the work involved in discriminating between the four possible purine-pyrimidine arrangements in each base plane. The phosphorus atoms of the back bone form in projection (the helical axis being necessarily parallel to the substrate surface) two intertwined sinusoids. If these phosphorus atoms have been located up to a certain point on the molecule, we have available excellent information on the orientation of the base plane at that point, and can then locate in projection the key atoms for discrimination of the four alternatives.

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