Hydrogels

Question 1

Define hydrogels

Answer 1

Hydrophilic, polymeric network capable of absorbing large amounts of water.

Question 2

Describe the viscosity of a hydrogel?

Answer 2

Usually doesn’t flow

Question 3

What are hydrogels mostly made out of?

Answer 3

Water or Polysaccharides

Question 4

What does the degree of swelling depends on?

Answer 4

cross linking

Question 5

What is the most abundant protein in bone, skin and muscle?

Answer 5

Collagen

Question 6

Structure of collagen

Answer 6

triple helical structure

Question 7

What are the two types of synthesis

Answer 7

polymerisation and hydrolysis

Question 8

Physical cross linking is caused by

Answer 8

polymer chain entanglements or physical interactions

Question 9

Chemical cross linking is caused by

Answer 9

covalent bonds between polymer chains

Question 10

Bulk polymerisation

Answer 10

Carried out by adding a soluble radical initiator to pure monomer in liquid state. The initiator should dissolve in the monomer. The reaction is initiated by heating or exposing to radiation.

Question 11

Solution polymerisation

Answer 11

Ionic or neutral monomers are mixed with a multifunctional cross-linking agent and polymerisation is initiated through UV-irradiation or by a redox initiator system.

Question 12

Suspension polymerisation

Answer 12

Monomer-forming droplets, with the initiator in them, are completely insoluble and suspended in a solution.

Question 13

Radiation Polymerisation

Answer 13

Light interacts with light-sensitive compounds, creates free radicals, and initiates polymerisation to form cross-linked hydrogels.
Radiation/Photo polymerisation can and is often used for the 3D printing of hydrogels.

Question 14

Three integral parts of hydrogel preparation are:

Answer 14

monomer, initiator, cross-linker