Surface Sensitivity
Surface Sensitivity - Related Videos
10:30
Dye-sensitized Solar Cells
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2023
Source: Tamara M. Powers, Department of Chemistry, Texas A&M University Today's modern world requires the use of a large amount of energy. While we harness energy from fossil fuels such as coal and oil, these sources are nonrenewable and thus the supply is limited. To maintain our global lifestyle, we must extract energy from renewable sources. The most promising renewable source, in terms of abundance, is the sun, which provides us with more than enough solar energy to fully fuel our...
11:15
A Simple Way to Measure Ethanol Sensitivity in Flies
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Cited by 33 •
2011
A simple assay to measure the sedating effects of ethanol on Drosophila flies, based on the loss of righting reflex, is described.
06:58
Surface Plasmon Resonance (SPR)
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2023
Surface plasmon resonance (SPR) is the underlying optical phenomenon behind label-free biosensors to evaluate the molecular affinity, kinetics, specificity, and concentration of biomolecules. In SPR, biomolecular interactions occur on a biosensor made of a thin layer of metal on a prism. Real-time interactions of biomolecules can be monitored by measuring the changes of light reflected off the underside of the metal. This video describes the basic concepts of SPR and how it is used to analyze...
01:16
Surface Tension and Surface Energy
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2023
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension. Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
07:05
Handling Air- and Water-Sensitive Chemicals Using a Schlenk Line
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2023
Robert M Rioux, Ajay Sathe, Zhifeng Chen, Pennsylvania State University, University Park, PA The use of reagents sensitive to oxidation or moisture necessitates the use of air-free techniques. A Schlenk line is a routinely used glass apparatus to perform air and moisture free manipulations in a chemical laboratory1. The Schlenk line is widely utilized by many chemists since it allows them conduct air or water sensitive reactions even without the expense and restriction of a glove box. The...
FAQs
Limited sampling depth restricts the detected signal to material near the exterior rather than allowing substantial contributions from the bulk. For electron-based measurements, electrons generated close to the surface can escape before inelastic scattering attenuates them. This depth limitation makes the resulting chemical information especially responsive to outer-layer composition, structure, and reactivity.
Inelastic scattering reduces the ability of electrons to leave a solid and reach the measurement signal. Electrons originating deeper within the material are therefore more strongly attenuated than those produced near the surface. The contrast between escaping and attenuated electrons establishes the measurement's surface emphasis and helps distinguish interfacial chemistry from bulk composition.
Surface sensitivity can distinguish several chemically meaningful features at an interface, including elemental composition, chemical states, and adsorbed species. These measurements therefore do more than indicate which elements are present. They help connect the identity and condition of outer-layer species with surface reactivity, adsorption behavior, and changes produced during material modification.
X-ray photoelectron spectroscopy and Auger electron spectroscopy use electron signals whose escape from the solid favors information from near-surface regions. Their surface emphasis enables chemical examination of outer layers, including elemental composition, chemical states, and adsorbed species. Together, these methods provide complementary routes for studying interfacial chemistry in materials and chemical systems.
It is particularly valuable when chemical behavior depends on interfaces rather than on the material's interior. Applications identified for these measurements include catalysis, corrosion, adsorption, thin-film growth, and surface modifications. In each case, examining outer-layer chemistry can relate molecular-scale interfacial behavior to broader changes in material performance.
For catalysis and corrosion, the relevant chemical transformations occur at or near material interfaces, where adsorbed species and chemical states can influence reactivity. Surface-sensitive measurements help characterize those outer-layer features while minimizing bulk contributions. The resulting information supports links between interfacial composition or condition and the observed performance of the material.