Biomaterials
Lecture
Lecturer: TA THI PHUONG HOA
Teaching Assistant: DINH THI NHUNG
1Advanced Program Biomedical Engineering – HUST, Viet nam
About Materials
2 Advanced Program Biomedical Engineer ing – HUST, Viet nam
“
“Understanding the history of materials
Understanding the history of materials
means understanding the history of
means understanding the history of
mankind and civilization
mankind and civilization”
”
“
“Who can master the materials, can
Who can master the materials, can
master the future
master the future”
”
Part 1: Material Science & Engineering
3 Advanced Program Biomedical Engineer ing – HUST, Viet nam
Chap. 1. Properties of materials
- The structure of solids
- Mechanical properties of materials
- Surface properties of materials
- Role of water in biomaterials
Chap. 2. Classes of materials used in medicine
- Polymer
- Silicone
- Medical fibers & biotextiles
- Hydrogels
- Applications of “Smart Polymers” as biomaterials
- Bioresorbable and bioerodible materials
Part 1: Material Science & Engineering
4 Advanced Program Biomedical Engineer ing – HUST, Viet nam
Chap. 2.(cont.)
- Natural materials
- Metals
- Ceramics, glasses, and glass-ceramics
- Composite
- Nonfouling (Anti-fouling) surfaces
- Surface modification of materials used in medicine
- Textured and porous materials
- Surface-immobilized Biomolecules
5 Advanced Pr ogram Biom edical Engineering – HUST, Vietnam
The periodic table
Chap.1. Properties of materials- The structure of solids
Chap.1. Properties of materials- The structure of solids
6 Advanced Program Biomedical Engineer ing – HUST, Viet nam
1.1. Structure of solids
Which states of materials do you know? The differences of them?
What determine the properties of material?
What are solids?
- Their constituent atoms are held together by strong interatomic
forces
- Structure, physical properties: depend on the nature and
strength of the interatomic bonds
- Strong bonds: ionic, covalent and metallic
Structure of solids: on many levels of scale
- Atomic or molecular: 0.1- 1 nm
- Nanoscale or ultrastructural: 1 nm- 1 µm
- Microstructural: 1 µm- 1 mm
- Macrostructural: > 1mm
Chap.1. Properties of materials- The structure of solids
7 Advanced Program Biomedical Engineer ing – HUST, Viet nam
Atomic bonding: primary interatomic bonds and secondary bonds
Primary interatomic bonds (strong bonds)
Ionic bonding:
Ionic bonding:
* Formed by exchanging electrons between metallic and nonmetallic
atoms
- Electron donor atoms (metallic) transfer one or more electron to an
electron acceptor (nonmetallic) to form cation and anion
- Cations and anions strongly attract each other by Coulomb effect
- The attraction of cations and anions constitutes IB (Hummel, 1997)
•Ionic solid structures are limited in their atomic arrangement
•Bonding energy: relative large, between 600- 1500 kJ/mol (3-8 eV/atom),
leads to relative high melting temperature
•Poor electrical conductor, relative low chemical reactivity
•Examples: NaCl, MgO
Chap.1. Properties of materials- The structure of solids
8 Advanced Program Biomedical Engineer ing – HUST, Viet nam
Fig. 1. Schematic
representation of ionic
bonding in sodium chloride
(NaCl)
Loosely bound electrons are
tightly held in the locality of the
ionic bonding
Chap.1. Properties of materials- The structure of solids
9 Advanced Program Biomedical Engineer ing – HUST, Viet nam
Covalent bonding:
Covalent bonding:
- Elements between metals and nonmetals (equal tendency to donate and
accept electrons), many nonmetals, molecule containing dissimilar atoms
- Bonding by sharing valence electron to form stable electron structure
(all valence electrons in pair localized at valence bonding)
- Bonding is highly directional and strong, may be very strong (diamond),
•Materials as poor electric conductors
•Examples: H2, Cl2; Si, C; CH4, H2O
Chap.1. Properties of materials- The structure of solids
10 Advanced Pr ogr am Biom edical Engineering – HUST, Vietnam
Fig. 2: Schematic representation of covalent bonding in a molecule of methane (CH4)