Biomedical Engineering Reference
In-Depth Information
2
Scattering techniques for structural
analysis of biomaterials
N. SANJEEVA MURTHY, Rutgers University, USA
DOI
: 10.1533/9780857093684.34
Abstract
: Biomaterials often exhibit structures at multiple length
scales that infl uence the chemical, physical, mechanical and biological
properties of a material. This chapter discusses techniques used to
determine these structures: light scattering for the determination of
particle sizes ~0.1 µm; wide-angle X-ray scattering for analyzing the
molecular structure, crystallinity and morphology in the solid state
(~1 nm); small-angle X-ray scattering for obtaining structural
information at mesoscale (10 nm) to determine lamellar structure and
phase behavior in the solid state, and size and aggregation behavior of
particles in solution; and small-angle neutron scattering using molecules
labeled with deuterium for the analysis of single chain dimensions,
polymer mixtures and solvent diffusion in the solid state.
Key words
: structural analysis, light scattering, X-ray scattering, neutron
scattering, particle size, phase identifi cation, orientation, lamellar
structure, phase behavior, polymer mixtures, solvent diffusion.
2.1
Introduction
The development of new biomaterials relies on a knowledge of the
underlying relations between the properties and the structure of these
materials at multiple length scales. This requires the use of different
techniques. Analysis of structure at several length scales reveals the
hierarchical structure that is often present in both synthetic and natural
biomaterials (Fig. 2.1). The microscopic techniques described in Chapter
1 deal with the structure and morphology at micro- and macroscopic
length scales, 0.1-100 µm. Characteristics at these length scales are use-
ful in understanding properties such as diffusion, strength, degradation
and failure. At the other extreme, there are spectroscopic techniques,
nuclear magnetic resonance (NMR), Raman and infrared (IR), that
provide information at sub-nanometer length scale about interatomic
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