Exam 1 (Ch. 1-2)

Question 1

biomaterials interface with biological systems to ________, ______, ________, or ________ any tissue, organ, or body function

Answer 1

evaluate (diagnostic), treat, augment, or replace (therapeutic)

Question 2

biocompatibility is the ability of a material to perform with an appropriate _____ ________ in a specific application

Answer 2

host response

Question 3

two of the biggest markets in biomaterials are ________ and ___________ devices

Answer 3

cardiac (replacement valves, vascular grafts), orthopedic (hip and knee replacements)

Question 4

common issues with vascular grafts and replacement valves are…

Answer 4

blood clotting, infection, tissue overgrowth

Question 5

the field has transitioned from ______ biomaterials, which reduced risk for negative immune response, to __________ biomaterials, which promote localized healing

Answer 5

inert, bioactive

Question 6

______________ usually occurs immediately after implantation, but is temporary and can be resolved as the material integrates fully

Answer 6

inflammation

Question 7

while it is sometimes undesirable, _____________ of an implant can be good for bone support applications to ensure integration

Answer 7

calcification

Question 8

in vitro

Answer 8

“in glass” - in a laboratory environment

Question 9

in vivo

Answer 9

in a living system - animal or human

Question 10

the FDA approves ___________, not ___________

Answer 10

devices, not materials

Question 11

metals are (organic/inorganic) materials possessing (metallic/ionic/covalent) bonds which have the benefit of _______________

Answer 11

inorganic, metallic, being easy to form into complex shapes and conduct electricity, typically crystalline

Question 12

ceramics are (organic/inorganic) materials possessing (metallic/ionic/covalent) bonds which have the benefit of _______________

Answer 12

inorganic, ionic, being very hard, more resistant to degradation, and mimicking native bone well, can be crystalline or amorphous

Question 13

downsides of ceramics?

Answer 13

very brittle because of ionic bonding

Question 14

polymers are (organic/inorganic) materials possessing (metallic/ionic/covalent) bonds which have the benefit of _______________

Answer 14

organic, covalent, broad range of possible properties, can be crystalline or amorphous

Question 15

elastomers

Answer 15

type of polymer, can sustain lots of deformation at low stresses and return quickly to their original dimensions upon release of the stress (good for CV applications)

Question 16

hydrogels

Answer 16

type of polymer, swell in water and can retain water without their structures completely dissolving (soft tissue applications)

Question 17

____________ materials combine two or more chemically distinct components, one of which is often a polymer

Answer 17

composite

Question 18

collagen, fibrin, and alginate are examples of __________ polymers

Answer 18

natural - these can often mimic native tissue better and become more fully integrated, but it is hard to obtain large amounts and they have weak mechanical properties

Question 19

what is an example of a natural polymer which is derived from sugars (carbohydrates)

Answer 19

hyaluronic acid

Question 20

benefits/drawbacks of synthetic polymers?

Answer 20

easily mass-produced, properties can be tailored, but do not interact as well with native tissue and few have been approved for use in humans

Question 21

the ________ refers to the outermost atomic layers of an object, while the _______ refers to the rest

Answer 21

surface, bulk

Question 22

hydrophobicity/philicity and roughness are examples of _______ properties

Answer 22

surface

Question 23

strength, stiffness, crystallinity, and melting point are examples of _________

Answer 23

bulk

Question 24

exhibiting distinctly different mechanical properties in different directions is _________

Answer 24

anisotropy (opposite of isotropy)

Question 25

________________ can be both a surface and bulk property

Answer 25

hydrophobicity/philicity

Question 26

_____________ measures how compounds absorb different types of energy and their resulting excitation

Answer 26

spectroscopy

Question 27

_____________ physically separates molecules by charge or size

Answer 27

chromatography

Question 28

_______ bonds occur between atoms with large differences in electronegativity

Answer 28

ionic, most commonly found in ceramics (hard and brittle)

Question 29

__________ bonds share electrons

Answer 29

covalent, most commonly found in polymers

Question 30

_________ bonds are formed in materials that contain electropositive elements, creating a sea of mobile electrons surrounding a core of cations

Answer 30

metallic (nondirectional electron sharing), this is why they are highly conductive of electricity

Question 31

while good for small applications in the body, polylactic acid is problematic for large fixation devices why?

Answer 31

too much lactic acid (degradation product) builds up, pH decreases, bones dissolve

Question 32

higher surface area/volume ratio has what effect on degradation rate?

Answer 32

increases degradation rate

Question 33

despite having a smaller SA/V ratio, why might a larger sample degrade faster?

Answer 33

degradation byproducts have to travel throughout the material, accelerating degradation as a catalyst

Question 34

the _____-_____________ model is the most realistic depiction of electron behavior

Answer 34

wave-mechanical

Question 35

the ______ ______ is a small section of a crystal which is repeated again and again

Answer 35

unit cell

Question 36

what is a common crystal structure for metals?

Answer 36

face-centered or body-centered cubic

Question 37

a ________ ________ is a unique combination of lattice parameters

Answer 37

crystal system (ex: cubic, tetragonal)

Question 38

with Miller indices, points are written as

Answer 38

x, y, z

Question 39

with Miller indices, planes are written as

Answer 39

(x y z)

Question 40

vacancies (missing atoms) and self-interstitials (extra, crowding atom) are examples of what kind of defect

Answer 40

point defects

Question 41

why is the creation of defects favorable?

Answer 41

they increase entropy (muahaha)

Question 42

point defects cause what kind of strain?

Answer 42

lattice strain

Question 43

in an ___________ solution, the solute atoms fill space between the solvent atoms

Answer 43

interstitial

Question 44

in a ____________ solution, the solute atoms take the place of the solvent atoms

Answer 44

substitutional

Question 45

concentrations of species in an alloy can be described with ________ or ________ percent compositions

Answer 45

weight or atom

Question 46

in _____________, atoms exchange positions, while in ______________, atoms of another type diffuse into a metal

Answer 46

self-diffusion, inter-diffusion

Question 47

__________ diffusion occurs when an atom jumps to an adjacent vacancy

Answer 47

vacancy

Question 48

between vacancy and interstitial diffusion, which occurs faster and why?

Answer 48

interstitial because the diffusing species is small and better able to move compared to the original species

Question 49

though carbon-based materials like graphite do not neatly fall into the main three categories, where are they sometimes placed?

Answer 49

ceramics

Question 50

describe Schottky defects

Answer 50

seen in ceramics, double vacancy (one positive and one negative)

Question 51

describe Frenkel defects

Answer 51

seen in ceramics, vacancy/interstitial pair (one leaves, another comes)

Question 52

polymers are also called ______________ because of their size

Answer 52

macromolecules

Question 53

monomers < ____________ < polymers

Answer 53

oligomers

Question 54

polydispersity index is the ratio of what to what

Answer 54

weight-average molecular weight to number-average molecular weight

Question 55

the (conformation/configuration) is the part of a structure that can be changed by bond rotation

Answer 55

conformation

Question 56

the (conformation/configuration) is the part of a structure that cannot be changed except by breaking and reforming primary bonds

Answer 56

configuration (fig = fixed)

Question 57

three types of configurations

Answer 57

isotactic (R groups on same side), syndiotactic (R groups alternate), and atactic (R groups random)

Question 58

polymers may be _________ (end-to-end repeat units) or _________ (chains coming off the main chain)

Answer 58

linear or branched

Question 59

__________ polymers are joined at certain points via covalent bonds, forming a 3D network

Answer 59

cross-linked

Question 60

three types of polymerization

Answer 60

addition, condensation, and genetic engineering

Question 61

________ polymerization results in a product which has the same chemical structure as the mer unit, and a variety of chain lengths (PI > 1)

Answer 61

addition

Question 62

_________ polymerization results in a product which has a different chemical structure than the mer unit, and occurs through elimination of one molecule (typically water)

Answer 62

condensation

Question 63

__________________ polymerization allows for greater control over polymer architecture and weight distributions

Answer 63

genetic engineering

Question 64

_____ polymerization requires a monomer and a monomer-soluble initiator, and has issues with heat dissipation (like bone cement)

Answer 64

bulk

Question 65

________ polymerization addresses the heat dissipation problem by putting the monomer and initiator (both soluble) in a solvent

Answer 65

solution

Question 66

_________ polymerization addresses the heat dissipation problem by putting the monomer and initiators (not soluble in water) in water, leading to formation of droplets which act as small reactors

Answer 66

suspension

Question 67

_________ polymerization uses a hydrophobic monomer, a water soluble initiator, and surfactant

Answer 67

emulsion

Question 68

a large amount of branching (increases/decreases) crystallinity of a polymer

Answer 68

decreases, it is more difficult to form ordered structures

Question 69

what type of chromatography is often used for metals and ceramics?

Answer 69

X-ray diffraction (they're highly crystalline)

Question 70

what type of spectroscopy induces changes in nuclei rather than in electrons by holding frequency constant and changing the strength of a magnetic field?

Answer 70

nuclear magnetic resonance (NMR) - shows peaks for various parts of the molecule - remember orgo?

Question 71

mass spectrometry (primarily used with polymers) separates particles by mass by...

Answer 71

bombarding the sample with electrons and then forcing them through a magnetic field, which deflects them

Question 72

________________ chromatography filters by size with a mobile and stationary phase to determine a polymer's molecular weight

Answer 72

size-exclusion