Temperature dependence of structure and density for D 2O confined in MCM-41-S

William A. Kamitakahara, Antonio Faraone, Kao Hsiang Liu, Chung Yuan Mou

研究成果: 雜誌貢獻文章同行評審

13 引文 斯高帕斯(Scopus)

摘要

Using neutron diffraction, we have tracked the temperature dependence of structural properties for heavy water confined in the nanoporous silica matrix MCM-41-S. By observing the correlation peak corresponding to the porepore distance, which is determined by the scattering contrast between the silica and the water, we monitored the density of the confined water. Concurrently, we studied the prominent first diffraction peak of D 2O at ≈ 1.8 Å 1, which furnishes information on the microscopic arrangement of the water molecules. The data show the presence of a density maximum at ≈275K (±10K), a property similar to bulk water, and the occurrence of a density minimum at ≈180K (±10K). The prominent diffraction peak of D 2O is found to shift and sharpen over a wide T range from 200 to 270K, reflecting structural changes that are strongly correlated with the changes in density. We also observe the continuous formation of external ice, arising from water expelled from the pores while expansion takes place within the pores. An efficient method for monitoring the density of the confined D 2O using a triple-axis spectrometer is demonstrated.

原文英語
文章編號064106
期刊Journal of Physics Condensed Matter
24
發行號6
DOIs
出版狀態已發佈 - 2月 15 2012
對外發佈

ASJC Scopus subject areas

  • 材料科學(全部)
  • 凝聚態物理學

指紋

深入研究「Temperature dependence of structure and density for D 2O confined in MCM-41-S」主題。共同形成了獨特的指紋。

引用此