Identify 2 composites that are photoresponsive and answer th

Identify 2 composites that are photoresponsive and answer the following: What is the primary parent material? What is the limitation in using the parent material? What material has properties that will help reduce or eliminate the limitation of the parent material? How do the composite properties differ from those of the parent material? A sample answer would look like this: Primary parent material: titanium dioxide (TiO_2) Limitation in using parent material: it absorbs only in the UV (4-5% of solar spectrum) Materials that will reduce/eliminate limitation: Chalcogenides (cadmium sulfide or CdS) absorbs in visible part of solar spectrum Difference in composite and parent: a TiO_2 - CdS composite will be able to absorb both UV and visible spectrum resulting in improved optical properties

Solution

1) Primary parent material :mineral rock

2) Limitations in using parent material: rock and minerals glow in the UV.

3) Materials that will reduce/eliminate limitation:fluoroscent minerals absorbs in visible part of solar spectrum.

4) Difference in composite and parent: rock will be able to absorb in UV in improved optical properties.