1. Why is it more difficult to design a surface that is oleophobic rather than h
ID: 519171 • Letter: 1
Question
1.
Why is it more difficult to design a surface that is oleophobic rather than hydrophobic?
2.
Why is the adhesion of the ZnO tetrapods to glass surfaces poor? How does the TEOS coating help to improve adhesion?
3.
Why are plastic bottles used during the application of SAMs to the slides?
4.
Explain the differences between the Cassie-Baxter and Wenzelwetting regimes and how these alter Young’s equation.
5.
Why is the Zisman plot not a useful assessment of surface tension for surfaces with considerable roughness?
6.
How does a lock-in amplifier work?
7.
Explain the orientation of nanorods under an electric field and how changing frequency affects the lag between alignment and the field.
Explanation / Answer
1. It is more difficult to design a surface that is oleophobic rather than hydrophobic since it is harder to achieve surfaces with oleophobic than hydrophobic properties because most oils have low surface tension.
3. Plastic bottles are used during the application of SAMs to the slides since these bottles prevent pressure buildup.
6. A lock in amplifier is a detector which extract a known frequency in an extremely noisy environment.
Working:
It detects signal based on modulation at some known frequency
It measures within narrow spectral range, reduce noise bandwidth Hence shift measurement to high frequency
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.