Polymer Surfaces and Interfaces
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Questions and Answers

What is the primary reason for the end groups of polymers residing perpendicular to the bulk of the polymers?

  • The polymer surfaces are faced with an oil atmosphere
  • The polymer surfaces are always flat
  • The end is more hydrophilic compared to the bulk
  • The end is less hydrophobic compared to the bulk (correct)

What is the shape of the polymer chain at the surface when the amount of polymer is small?

  • Brush shape
  • Tangled shape
  • Pancake shape (correct)
  • Mushroom shape

What happens as the concentration of polymer increases?

  • The polymer ends form brushes (correct)
  • The surface becomes more hydrophobic
  • The polymer chain lays parallel to the surface
  • The polymer chain becomes more tangled

What is the definition of a surface used in this context?

<p>The outermost atomic layers (B)</p> Signup and view all the answers

Why do the polymer surfaces generally differ from the bulk material?

<p>Because of the chemical and physical composition (A)</p> Signup and view all the answers

What happens when the concentration of polymer is increased, but not high enough to form brushes?

<p>The polymer chain forms a mushroom shape (A)</p> Signup and view all the answers

What is the primary focus of Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS)?

<p>To identify the elemental composition of a surface (D)</p> Signup and view all the answers

What is the depth of analysis for AES and XPS?

<p>To a depth of about 1 nm (A)</p> Signup and view all the answers

What is the process that occurs during an Auger transition?

<p>Incident electrons interact with inner shell electrons (B)</p> Signup and view all the answers

What is the equation that expresses the energy of the Auger electrons?

<p>Ea = E1 - Ei + E2 (B)</p> Signup and view all the answers

What is the process that occurs during XPS?

<p>X-rays interact with core electrons (C)</p> Signup and view all the answers

What is the energy equation that expresses the kinetic energy of the x-ray photoelectrons?

<p>Ek = hν - Eb - ϕ (A)</p> Signup and view all the answers

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