How to turn liquid glass and food additives into “plastic”

Obtaining a self-solidifying liquid

Safe­ty pre­cau­tions

Wear pro­tec­tive gloves, eye­wear, and a mask. Per­form this ex­per­i­ment in a well-ven­ti­lat­ed area.

Reagents and equip­ment

  • 2 g cal­ci­um hy­drox­ide (food ad­di­tive Е526);
  • 10 mL dis­tilled wa­ter with dye;
  • 15 mL liq­uid glass (sodi­um sil­i­cate so­lu­tion);
  • a wood­en stick;
  • 2 dis­pos­able plas­tic cups;
  • a Petri dish.

Step-by-step in­struc­tions

In one of the two cups, mix 2 g of cal­ci­um hy­drox­ide with 10 mL of dis­tilled wa­ter tint­ed with food col­or­ing. Add 15 mL of liq­uid glass (sodi­um sil­i­cate so­lu­tion). Pour the liq­uid back and forth be­tween the two cups to mix. Watch the mass so­lid­i­fy with time.

Process de­scrip­tion

The re­ac­tion of liq­uid glass (usu­al­ly a sodi­um sil­i­cate so­lu­tion) with cal­ci­um hy­drox­ide (food ad­di­tive Е526) forms an in­sol­u­ble pre­cip­i­tate of cal­ci­um sil­i­cate. Since cal­ci­um hy­drox­ide is poor­ly sol­u­ble in wa­ter, the cal­ci­um sil­i­cate crys­tals be­gin to grow on the sur­face of the in­sol­u­ble cal­ci­um hy­drox­ide par­ti­cles. Over time, the crys­tals in­ter­twine to form a sol­id mass rem­i­nis­cent of a poly­mer – firm and able to re­tain its shape.

Na₂­SiO₃ + Ca(OH)₂ = Ca­SiO₃ + 2NaOH

Try it