Adhesion

Question 1

the bond fails at the interface between 2 surfaces

Answer 1

adhesive failure

Question 2

for adhesive failure, the bulk of adhesive retained on -

Answer 2

only one surface

Question 3

the bond fails within one of the substrates but not at the interface

Answer 3

cohesive

Question 4

for cohesive failure, the adhesive is retained on –

Answer 4

both surfaces

Question 5

angle formed when a drop of liquid is placed on a solid surface

Answer 5

contact angle

Question 6

contact angle is a useful measure of – of solids by liquids

Answer 6

wettability

Question 7

low contact angle (< 90)

Answer 7

good wetting

Question 8

high contact angle (> 90)

Answer 8

poor wetting

Question 9

adherend – energy

Answer 9

surface

Question 10

high surface energy – attachment

Answer 10

good

Question 11

low surface energy or – is poor attachment

Answer 11

contaminated

Question 12

examples of high surface energy

Answer 12

metals, oxides

Question 13

examples of low surface energy

Answer 13

wax, Teflon

Question 14

forces of physical adhesion

Answer 14

secondary interatomic/intermolecular forces

weak, short range forces

Question 15

secondary interatomic or intermolecular forces in physical adhesion

Answer 15

H bond, van de Waals

Question 16

weakest bonding

Answer 16

physical adhesion