American and French scientists have recently discovered the mechanism behind the setting of toothpaste or cement over time if left in the environment.
Take a look inside the cap of the toothpaste, you will see that there are hard, white residues and to your surprise, it is the liquid and paste toothpaste mixture that you usually use. In fact, not only toothpaste, but many materials exist in such a paste form. For example, cement often changes from a liquid, viscous state to a solid after only a few hours.
The matter particles, after coming into contact with each other, will gradually harden and increase the hardness of the material.
According to Sciencedaily , material structure or changes in a material’s load over time are often thought to be the leading causes of this variation in stiffness . But for decades, scientists suspected there was more going on inside these materials.
Recently, professor of biomolecular and chemical engineering at the University of Delaware (USA), Eric Furst and colleagues from the Université Ecole des Ponts and the University of Paris-Est in France have discovered a process The process is called “contact-controlled aging” , roughly translated as “contact coagulation” . This process explains the changes in paste-like materials such as toothpaste and cement over time.
Specifically, the team discovered the contact morphology between the particles and the ability to stabilize the superstructure of this composite material. The matter particles, after contacting each other, will gradually harden and increase the hardness of the material, and at the same time create a solid block.
When people think about the curing of materials and their mechanical properties over time, we don’t think it’s caused by changes in the material’s organization or microstructure, says Furst. Whether.
Toothpaste when left outside for a while will solidify,
By understanding how materials agglomerate, many ways can be devised to fabricate materials and reduce undesirable effects related to material performance.
The team’s new study makes a lot of sense, says Furst, because we can actively control the setting of a paste-like material. Especially industries that will benefit from this research such as cement, clay, ink, paint, etc.
Researchers have used quite a few different methods to discover the coagulation of silica and polymers. Initial experiments showed that the microstructure of the material did not change over time. But if the particles don’t change positions then something must have happened between them. In many previous experiments, Furst used laser or optical tweezers to shine on materials to bend and break the microscopic structure of matter particles, thereby studying the bond stiffness in materials such as silica and latex.
The study by a group of American and French scientists was recently published in the journal Nature.