The importance of silicon and its compound in daily life

1. The importance of silicon and its compound in daily life 7S04 Chan Siu Yee 7S08 Chiu Yin Ling

2. Introduction of silicon • The 2nd most abundant element in the universe by mass, making up 25.7% of the crust. • rarely occurs as the pure element in nature more widely appeared as a compound most common form is SiO2, or silica dioxide • At room temperatures, silicon exists in two forms, Amorphous ---- brown powder while crystalline silicon --- metallic luster and a grayish color.

3. Introduction of silicon • has many industrial uses pure silicon is the principal component of most semiconductor devices, most importantly integrated circuits integrated circuits or computer-chips. SiO2 is mined both as sand and as vein or lode deposits, for use in industry.

4. Importance of silicon:1. As Silicon oxides - Construction materials • Silicon dioxide forms giant covalent structure, • The pure form ---- Quartz. The impure form ---- sand. • both are rigid and hard materials. • Especially sand, it as a principal constituent of natural stone, glass, concrete and cement. • sand is a principal component of glass. • important to the construction industry as building materials.

5. Importance of silicon:1. As Silicon oxides - Essential elements in Biology • Silicon is important to plants. • it contributes to form sand, • sand it is the raw material of soil and all plants need soil as a place to grow. • It is also a element for plants growth • Silicon dioxide, indirectly affects the growth of plants and food resources of us.

6. Importance of silicon:2. As Pure Silicon - Essential parts of electronic devices • Pure Silicon --- grey colour and a metallic lustre. • rather strong, very brittle, and prone to chipping. • used to produce ultra-pure silicon wafers used in the semiconductor industry, • Hydrogenated amorphous silicon is used in the production of low-cost, large-area electronics in applications such as LCDs, and of large-area, low-cost thin-film solar cells.

7. Importance of silicon:2. As Pure Silicon - Making alloys • manufacture of aluminium-silicon alloys to produce cast parts, mainly for the Car industry. • important constituent of electrical steel, • ferrosilicon or silicocalcium alloys to improve the performance in casting thin parts, and to prevent the formation of cementite at the surface of products.

8. Importance of silicon:3. Compounds containing silicon-oxygen and silicon-carbon bonds • act as bonding intermediates between glass and organic compounds, • form polymers with useful properties such as impermeable to water, • flexible and resistance to chemical attack. • used in waterproofing treatments, moulding compounds and mould-release agents, mechanical seals, high temperature greases and waxes, caulking compounds and even in applications as diverse as breast implants and explosives.

9. Importance of silicon:4. Mica • Mica has a high dielectric strength and excellent chemical stability, • a favored material for manufacturing capacitors for radio frequency applications. • used as an insulator in high voltage electrical equipment. • used to separate electrical conductors in cables that are designed to have a fire-resistance rating in order to provide circuit integrity. • keep the metal conductors from fusing in order to prevent short-circuit so that the cables remain operational during a fire, which can be important for applications such as emergency lighting.

10. Importance of silicon:5. Silica gel • granular, porous form of silica made synthetically from sodium silicate. • most commonly encountered in everyday life as beads packed in a semi-permeable plastic.

11. Importance of silicon:5. Silica gel - Desiccant • By adding packets of silica gel, • prevent moisture encourages the growth of mold and spoilage • Condensation may also damage other items like electronics and may speed the decomposition of chemicals • items can be preserved longer.

12. Importance of silicon:5. Silica gel - Chemistry • used in chromatography as a stationary phase • the method is referred to as reverse phase chromatography. • Silica gel is also applied to aluminum, glass, or plastic sheets for thin layer chromatography.

13. Importance of silicon:5. Silica gel - Cat litter • by itself or in combination with more traditional materials, such as clays including bentonite. • It is trackless and virtually odorless, albeit expensive

14. Reference: • Wikipedia • mineral.galleries.com/minerals/silicate/quartz/quartz.htm • www.answers.com/topic/silicon-dioxide • www.chemguide.co.uk/atoms/structures/giantcov.html • www.timedomaincvd.com/CVD_Fundamentals/films/SiO2_properties.html

15. THE END* thankyou..