Application
Silicone Tubing is a porous amorphous solid material with a three-dimensional structure. It is stable, non-toxic and non-flammable. The physical properties of the finished product, such as porosity and surface area, can be accurately controlled during preparation. [4] Because it has a hydrophilic surface and many pores, it has a large adsorption capacity for polar molecules (such as water and ammonia) and is often used as an adsorbent. [4] A study shows that when the pore size of the silica gel structure is less than 2 nanometers, the larger the pore size, the more water can be adsorbed. As for the case where the pore size is greater than 2 nanometers, further research is needed. [4] Saturated silica gel can be regenerated by heating at 120°C for two hours.
Soak silicic acid gel in cobalt chloride or ammonium chlorocobaltate ((NH4)2CoCl4) solution, and then dry and activate it to obtain color-changing silica gel, which can be used to indicate the degree of water absorption of the silica gel. This is because anhydrous cobalt chloride (CoCl2) is blue, while cobalt chloride hexahydrate (CoCl2·6H2O) is red.
In daily life, silica gel is often encountered in certain paper bags or bags made of semi-permeable membrane resin. It is used as a food or article desiccant to absorb water, control humidity, and prevent certain items from deteriorating. Silicone bags usually have “Do Not Eat” written on them. It can cause irritation to the respiratory system, digestive system, skin and eyes,[5] and some color-changing silica gel also contains humidity indicators such as cobalt chloride, and cobalt chloride is a toxic substance and belongs to IARC Category II carcinogens. May cause cancer.
