Identifying an initial growth process of calcium phosphate

After conducting a fusion study, a team of scientists from various fields reports a new process for early growth of substances that contradicts existing theories of material growth.

The multi-institutional collaborative 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. 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 spectroscopy (TOF-MEIS). In addition, Professor Yong-Hyun Kim's research team conducted a study on the early growth of implementing a related theoretical calculation. They 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 TOF-MEIS spectroscopy that the research team has developed 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 medium energy ion scatter (MEIS). 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. In the future, it is expected to be used in research to control the growth and characteristics of nanoparticles."

More information:
Jimin Park et al, Quantitative Analysis of Calcium Phosphate Nanocluster Growth Using Time-of-Flight Medium-Energy-Ion-Scattering Spectroscopy, ACS Central Science (2018). DOI: 10.1021/acscentsci.8b00436

Provided by DGIST (Daegu Gyeongbuk Institute of Science and Technology)