Identifying an initial growth process of calcium phosphate

A joint research team comprising DGIST's research team led by Professor DaeWon Moon from the Department of New Biology and Seoul National University's research team led by Professor Ki Tae Nam from the Department of Material Engineering, and KAIST's research team led by Professor Yong-Hyun Kim, has succeeded in identifying the early stages of material growth through a new analysis method that differs from previous theories of critical nuclear growth.

Classical nucleation theory (CNT), which is widely known in the scientific community, particularly in regard to material growth, is recognized throughout the scientific community as it has been published in various textbooks on materials, chemistry, and physics. This theory assumes that critical nuclei are created early in the material growth, that bulk materials are formed later around the critical nuclei, and that the material grows.

The researchers analyzed nanoparticles of calcium phosphate, a key component in bones, through 'Time-of-Flight Medium Energy Ion Scattering (TOF-MEIS)' spectroscopy. In addition, Professor Yong-Hyun Kim's research team conducted a study on the early growth of implementing a related theoretical calculation. As a result, it was found that in the early stages of nanomaterial growth, nanoparticles, rather than critical nuclei, continue to grow and transform into materials such as bulk materials.

Although the scientific community has recently published a study that differs from the existing theory on the early growth of materials, there have been controversies over the failure to provide direct research results. However, Professor Moon's team presented solid evidence to reverse the existing theory by accurately measuring the size and composition of nanoparticles.

The 'Time-of-Flight Medium Energy Ion Scattering (TOF-MEIS)' spectroscopy that the research team has developed for the first time in the world played a major role in measuring the early growth of materials. This nanometric technology can measure the process of material growth with an ionizing current that is 10,000 times lower than the MEIS (Medium Energy Ion Scatter). As such, it was able to quantitatively measure the average size and specific structure of nanoparticles in this study without any specific damage to the ions.

Professor Moon said, "This research was based on a long-term project that took seven years from planning experiments to measuring, writing papers and publishing. Based on the combined research of new nanotechnology, material science and theoretical chemistry, it has produced detailed theoretical calculations and research results that upset existing traditional theories." He then added, "In the future, it is expected to be used in research to control the growth and characteristics of nanoparticles."