Topics What is glass Why glass breaks Chemically strengthened glass how it works make at home? Tempered glass Laminated glass Special types (Regular) glass Used everywhere Main compounds: Silicon dioxide (SiO2) Sodium oxide (Na2O Sodium carbonate (Na2CO3) Brittle Why glass breaks? Compression X Tension Microscopic defects Chemically strengthened glass Regular glass bathed in salt(s) Sodium atoms -> potassium atoms Only thin surface is treated Chemically strengthened glass Constant compression Higher force to break Flexible Gorilla glass Commercial brand Smartphones, tablets… Patented chemical mix, process (temperatures) … Try it at home? 2hours+ 400°C Molten KNO3 Strength increase: 3-4 times Youtube channel „Applied science“ Unbreakable? Nope… Tempered glass Thermal process Surface rapidly cooled 6 times stronger Shatters into small pieces good/bad? Laminated glass Glass+glue+glass Stays together Safety/security feature Skyscraper windows Windshields … Soud isolation Fused quartz/silica glass No added ingredients – pure SiO2 High temperature (2000°C) Halogen bulbs UV transparent Special applications Sugar glass Easy to break Used in movies or food decorations Molten sugar+water+corn syrup Questions? Every application needs another type Glass looks trivial but is it? Questions?