How Ions Move in Phosphate Glass – ScienceDaily
Phosphate glass is a versatile compound that has generated interest for its use in fuel cells and as biomaterials to deliver therapeutic ions. P.2Ö5-the compound that forms the structural network of phosphate glass consists of phosphorus, an element that, when combined with oxygen, can assume many different bond configurations.
The physico-chemical properties that are decisive for the practical applicability of phosphate glass – such as the hydration reaction, which determines how quickly a biomaterial based on phosphate glass dissolves in the body – depend on the diffusion of ions into the glass. Therefore, in order to improve the physicochemical properties of phosphate glasses, it is important to understand the relationship between structure and ion diffusion. However, studying such interactions at the atomic level is extremely difficult, prompting scientists to look for a suitable approach to shed light on the details of the ion diffusion process.
Recently, a team of researchers from the Nagoya Institute of Technology, led by Dr. Tomoyuki Tamura theoretically deciphered the ion diffusion mechanism involved in the hydration reaction process of phosphate glasses. Your study was in the. released Physical chemistry chemical physics Diary.
With a fully connected P2Ö5-based phosphate glass, three of the oxygen atoms in each phosphate unit are bonded to adjacent phosphorus atoms. To study the dynamics of ions in the phosphate glass during the hydration process, the researchers used a model made of phosphates with QP.2 and QP.3 Morphologies, the two and three bridging oxygen per PO. contain4th Tetrahedron or together with six coordinated silicon structures.
The researchers implemented a theoretical computational approach known as “First-Principles Molecular Dynamic (MD) Simulation” to study the diffusion of proton and sodium ions into the glass. The reasons for their unconventional approach are explained by Dr. Tamura: “The MD simulation based on the first principles made it possible for us to assume the initial stage of water infiltration and diffusion in silicophosphate glass and to explain the diffusion of protons and inorganic ions for the first time.”
Based on their observation, the researchers proposed a mechanism in which the protons “hop” and are adsorbed via hydrogen bonds to the non-bridging oxygen or “dangling” oxygen atom of neighboring phosphates. In the phosphate glass model they used was the Q. HoweverP.2 Phosphate units contributed more to the diffusion of protons than the Q.P.3 Phosphate units. They found out that the morphology of the phosphate network structure or the “skeleton” of the glass has a strong influence on the diffusion of ions. They also found that if a sodium ion was nearby, adsorption of a proton to a QP.2 Phosphate moiety weakened the electrostatic interaction between sodium and oxygen ions and induced the chain diffusion of sodium ions.
The demand for new biomaterials for effective prevention and treatment is increasing and phosphate glasses are well equipped to meet this growing need. A large proportion of the population, consisting of older and younger people, suffer from diseases related to bone and muscle weakness. Dr. Tamura speculates, “Water-soluble silicophosphate glass is a promising candidate for the delivery of drugs or inorganic ions that promote tissue regeneration, and our study brings glass technology research one step closer to that goal.”
Therefore, the researchers’ new findings are sure to have profound effects on real life and lead to breakthroughs in research on fuel cells and bioresorbable materials!