Microencapsulation Flashcards
Explains how microencapsulation works
- thin polymer coatings are deposited on a very small solid particles or liquid droplets
- there are 2 components: active ingredients (solid or liquid) and the hard polymer shall
Name 4 reasons of use of mircoencapsulation
- prevents evaporation
- protects the active ingredient from external environment (heat, moisture, etc)
- odour masking
- allows controlled release of components
How are microcapsules applied to a fabric?
-fabric is coated in a bath of microcapsules and binder, then spin dried
Name 3 examples of active ingredients that can be used.
- fragrances and aromatherapy
- biocides (eg insect repellant)
- skin care / moisturising agents
How can active ingredients be released?
- bursting of polymer shell
- diffusion of active ingredient through the shell
- shell dissolves or biodegrades
What 2 factors effect the rate of release of an active ingredient?
- thickness of polymer shell
- strength of shell
Skintex is a brand that uses microencapsulation. How does it work?
5
- microcapsules embedded in fabric
- polymer shell contains chitosan, made form the shells of shrimp
- chitosan layer slowly eroded over time by body’s enzymes
- has skin care properties
- also has fragrance added
What are cyclodextrins? How do they work to prevent odour?
- molecular buckets or doughnuts
- recognise sweat and catches it to reduce odour
What is a microencapsulated PCM (phase change material)?
-substances that absorb or liberate large amounts of enters when they change phase (melt or solidify)
Explain the mechanics of a PCM.
4
- a large quantity of heat is absorbed
- temperature remains constant until completely melted
- the energy (latent heat ) is stored in the PCM
- during solidification, heat is liberated
What do PCMs do in a garment?
- control the heat flow
- ca absorb heat generated by the body during physical activity
What garments are PCM used in?
- sportswear
- trousers and boots
