Page 23 - Materials Chemistry, Second Edition

10 1 What Is Materials Chemistry?

• Soft materials, such as polymers and composites
• Biomaterials
• Nanostructural materials
• Thin films
The field of engineered biomaterials will be treated more explicitly in this second
edition. Medical breakthroughs have not only extended the life expectancy of
humans (currently 78 years in the U.S.), but have resulted in a way of life that
would have seemed impossible just a few decades ago. The market for materials
that interact with the body is now a $12 billion industry. Accordingly, the use of
orthopedic and dental implants, bone grafts, coronary stents, and soluble sutures are
now commonplace throughout the world. As one would expect, significant research
has been devoted to designing the best materials for medical implants that would
afford a specific function, with the longest lifetime possible. Throughout this book,
we will discuss design aspects for a variety of biomaterials that properly balance
structure/functionality and biocompatibility.
The definition used herein for a biomaterial is a biocompatible material or device
that is placed within a living system in order to perform, augment, or replace a
natural function. Common applications for biomaterials include implants (e.g.,
artificial limbs), devices (e.g., pacemaker), or components (e.g., contact lenses)
placed into a body, or the use of a material to deliver a chemical compound directly
to the site of treatment, known as a drug delivery agent. Prescription and over-the-
counter drugs are now widely used for everything from mild headaches to advanced
cancer treatment. The drug industry is now a staggering $350 billion-per-year
business, with rising costs for drug development that must be passed onto the
consumer. In Chapter 5, we will discuss the basics of drug design, with a focus on
the structural features that are required for time-release and targeted drug delivery in
order to minimize any deleterious side effects from the medication.
Any field of chemistry must make use of extensive characterization techniques.
For instance, following an organic synthesis, one must use nuclear magnetic reso-
nance (NMR) or spectroscopic techniques to determine if the correct compound has
been produced. The world of materials chemistry is no different; characterization
techniques must also be used to verify the identity of a material, or to determine why
a certain material has failed in order to guide the developments of improving
technologies. Hence, characterization techniques will also be provided in this text,
which will illustrate the sophisticated techniques that are used to assess the
structures/properties of modern materials. Since common techniques such as UV–
visible absorption spectroscopy, atomic absorption/emission spectroscopy, infrared
spectroscopy, mass spectrometry, and NMR are covered in a variety of other
textbooks, [5] Materials Chemistry will focus on the techniques that are frequently
used by modern materials chemists, such as:
• Surface/nanoscale analysis (partial list)
– Photoelectron spectroscopy (PES)
– Auger electron spectroscopy (AES)