UTPA STEM/CBI Courses/Materials/Material Properties

Course Title: Material Properties

Lecture Topic: Nanomaterials

Instructor: Dr. Kamal Sarkar

Institution:UTPA

Backwards Design

Course Objectives

Primary Objectives- By the next class period students will be able to:
- Understand behaviors of materials at the "nano" level. "Nano" is a dimension that is a billionth of a meter. Billion is real big numbr, like there are six and a half billion people in the world. If you reduce the size of the earth by a billion times, it will become the size of a soccer ball. If you do reduce it agian by billion times, it will become the size of a "Bucky Ball", one of the famous carbon nanomaterial.
- Material behavior is significantly different in the nano level and significantly different from their "bulk" cousins. Example, a typical rope made by,say carbon nanofibers, can stop a 747 jet!
- Nanomaterials have interesting properties that are not found in common bulk materials. Example, melting point of gold nanoparticles depend on size!

Sub Objectives- The objectives will require that students be able to: Why nanomaterials behave differently?!
- Bulk properties of materials are controlled impurities, defects, etc. In nanomaterials most of these defects and impurities do not exist because of sheer size. Typical defects are in the size of microns. Since defects are significantly larger than nanomaterials, they are typically extremely pure. As a result, their strengths increase significantly and behave diffrently.
- Another interesting aspect of nanomaterials is the increase in surface by several orders of magnitude. As a result, any propery that depends on surface area increases by orders of magnitude. Solubility is a good example. Catalytic behavior is another one. These properties increases by several orders of magnitude.

Difficulties- Students may have difficulty:
- Understanding the size of a nanometer. How small is a nanometer?
- They understand millimeter and probably micron size. One millimeter is 1,000 microns. Understanding hunderds of micron ie tenths of a millimeter is conceivable. Beyond that is difficult to fathom.

Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
- Our hair is about 50 microns. To get 50 nm (nanometer) you have to divide the hair to thousand pieces to make each piece 50 nm. (Talk about splitting hairs!)
- To understand the consequence of size increase, let's do a thought experiment. If you take a palm size sugar crystal and drop it in a bucket of water, it will take days to dissolve. Take the same crystal and grind it into small grains, it will take, may be an hour, to dissolve. If we could make nano-sugar, the whole thing will dissolve in seconds.

Model of Knowledge

Concept Map
- Developing understanding of how small is small. Edinburg is samll town in Texas and students are familiar with it. UT Panam is a building in the city of Edinburg. Students have a pretty good idea about it because they go through different parts of the univeristy on a daily basis. Engineering is a relatively small building in it. Class room is a fraction of the building. Cell phone of a student is a tiny equipment in the class room. Cell phone has lots of chips in it. Each chip has hundreds of electrical components (say, resistors) in it. Now consider a resistor relative to the city of Edinburg. Current through a resistor or power needed for a chip is orders of magnitude relative to the power needed for the city of Edinburg. Similarly, nanomaterials are orders of magnitude smaller compared to its cousin bulk material.

Content Priorities
- Enduring Understanding
  - Small is different!
  - Problems of city of Edinburg is fundamentally different from the defects in chip or resistor! Good thing about problems of big things is that you can see it. Say a building lost its power supply and there is no electricity in the building. You cannot see the defects in a chip or resistor. You cannot see them. You have to use different tools to "measure" the defects to fix it. Therefore, problem solving tools and techniques will be fundamentally different.

- Important to Do and Know
  - Small is different!

Size is different. Our hair is 50 microns. Smallest thing you can see is 10 microns. Anything smaller than that cannot be seen without magnification. Spider web is one of the most common stuff we have seen that is closest to nanofibers. If you can see under a powerful microscope (say electron microscope), you could see some nanofibers. At such a small size the material behavior also changes dramatically. Color of silver nanoparticles changes with size. Inherently, nanofibers are significantly stronger than their "bulk" cousins because nanofibers are too small to have defects and hence significantly stronger.

- Worth Being Familiar with
  - Nanomaterials are a new class of materials that have dramatically different behaviors than commonly available bulk materials. As a result, they have important new applications. Since nanomterials have significantly higher surface area and hence significantly increased solubility (in water), they can have potential application as a carrier for drugs that are typically insoluble in water. Important research is going on to use nanomaterials as a carrier of drugs. One imortant benefit of such an application is dramatic reduction in side effects of the carrier of the drug, typically, a lipid (castor oil, as an example). Since nausea, lack of appetite, weight loss, loss of hair are typical side effects of typical cancer drugs, nanofibers can potentially remove those side effects.

Assessment of Learning

Formative Assessment
- In Class (groups)
  - Identify methods of making nanomaterials.
  - Find out few nanomaterials that are commonly available.
- Homework (individual)
  - Identify two nanomaterials of your interest and compare their physical properties.

Summative Assessment
- Write a reoprt on application of biologically active materials that are commonly used for regeneration of bone tissue.

Legacy Cycle

OBJECTIVE

By the next class period, students will be able to:

Understand the
What are nanomaterials?
Why they are different from bulk materials? Identify few selected applications of nanomaterials.

The objectives will require that students be able to:

Google by identifying key words like nano, electrospinning, micron, electron microscope, etc.
Research on application of nanomaterials for biomedical applications

THE CHALLENGE

How small small can be?

GENERATE IDEAS

What is small? Relative or absolute? How we measure small? Just seeing? Or with Microscope? How powerful microscopes can be? How small can we see with electron microscope? Bugs? Bacterias? Large molecules? Atoms?! Electrons?!!!

MULTIPLE PERSPECTIVES

Small bugs. Spider webs? Optical microscope. Microscope. Google images.

RESEARCH & REVISE Google image, electron microscope, nanofibers, gold nanoparticles, bacteria, cells, ECM (Extracellualr matrix), nanopores in cell, Ion channels,...

TEST YOUR METTLE

Identify a biologically active nanomaterial and see how how many research articles have bee published on that nanomaterial in last five years.

GO PUBLIC

Instructor will discuss these questions with the the students both as individuals & groups.

Pre-Lesson Quiz

What is nano?
What is a nanomaterial?
Is there a difference between gold powder and gold nanoparticle?
Does size matter?
Which is more easily dissolved? Sugar crystal? Granulated sugars from the same crystal? Why?
What is size of your hair?
What is the smallest size you can see with the naked eye?

Test Your Mettle Quiz

What is electrospinning?
What are the advantages of nanomaterials?
What specific characteristic of nanomaterials you can use for biomedical applications?
What characteristics of nanomaterials we can take advantage in the next five years?
"There is plenty of room at the bottom." Who said this? (He is considered the father of nanotechnology.)
Explain: "There is plenty of room at the bottom."
Can you think of a strategy to deliver drug to a cancer cell?