Contact Angle Modification
Contact Angle Modification - Related Videos
01:13
Contact Angle
0 Views •
2023
When a solid is dipped inside a liquid, the liquid surface becomes curved near the contact. For some solid–liquid interfaces, the liquid is pulled up along the solid, while for others, the liquid surface is convex or depressed near the solid surface. This phenomenon can be explained using the concept of cohesive and adhesive forces. The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive force...
02:32
Histone Modification
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2020
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:25
Spreading of Chromatin Modifications
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2020
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex. Writers The writer is an enzyme that can...
08:53
Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
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Cited by 8 •
2012
The overall goal of this method is to determine the low-energy electronic structure of solids at ultra-low temperatures using Angle-Resolved Photoemission Spectroscopy with synchrotron radiation.
08:48
Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment
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Cited by 1 •
2015
We report on a process of in situ alteration of HF treated Si (001) surface into a hydrophilic or hydrophobic state by irradiating samples in microfluidic chambers filled with H2O2/H2O solution (0.01%-0.5%) or methanol solutions using pulsed UV laser of a relative low pulse fluence.
FAQs
Surface chemistry and roughness determine how a droplet interacts with a treated solid. Changing either can shift the balance between liquid cohesion and solid–liquid adhesion, making spreading more favorable or less favorable. This mechanism lets engineers tune a surface for a targeted wetting response rather than relying only on the original material.
These treatments modify the surface through different engineering routes. Plasma exposure, chemical functionalization, and surface coating can each change surface chemistry, while treatments may also alter roughness. Because the resulting surface properties differ, the selected approach should match whether the design requires greater spreading, reduced spreading, improved bonding, or controlled liquid interaction.
Liquid cohesion holds molecules together, whereas solid–liquid adhesion describes attraction between the droplet and the surface. Their balance influences whether the liquid spreads across the material or remains more localized. Controlling that balance helps engineers create surfaces that either promote liquid coverage or prevent unwanted spreading during manufacturing and device operation.
First, measure the contact angle on the untreated surface to establish a reference. Apply a selected treatment, such as plasma exposure, chemical functionalization, or a surface coating, and then measure the contact angle again. Comparing the two measurements reveals whether processing changed wettability in the intended direction and supports optimization of treatment conditions.
Engineers may adjust wettability when a liquid must spread sufficiently across a surface for bonding or printing. A treatment can change the interaction between the liquid and solid so coverage becomes more suitable for the process. Comparing contact angles before and after treatment helps determine whether the modified surface provides the intended processing response.
In microfluidic devices, controlled wettability can help regulate liquid movement. In coatings, it can tailor how liquids interact with the treated material, while biomaterials may require a deliberately adjusted surface response. Contact-angle measurements provide a practical way to assess these changes and compare processing conditions during engineering development.