Editing Diamond (section)

=== Surface property ===
Diamonds are naturally [[lipophilicity|lipophilic]] and [[hydrophobe|hydrophobic]], which means the diamonds' surface cannot be wet by water, but can be easily wet and stuck by oil. This property can be utilized to extract diamonds using oil when making synthetic diamonds. However, when diamond surfaces are chemically modified with certain ions, they are expected to become so [[hydrophile|hydrophilic]] that they can stabilize multiple layers of [[ice|water ice]] at [[human body temperature]].<ref>{{cite journal | vauthors = Wissner-Gross AD, Kaxiras E | title = Diamond stabilization of ice multilayers at human body temperature | journal = Physical Review E | volume = 76 | issue = 2 Pt 1 | pages = 020501 | date = August 2007 | pmid = 17929997 | doi = 10.1103/physreve.76.020501 | url = http://www.alexwg.org/link?url=http%3A%2F%2Fwww.alexwg.org%2Fpublications%2FPhysRevERapidComm_76-020501.pdf | url-status = live | s2cid = 44344503 | bibcode = 2007PhRvE..76b0501W | archive-url = https://web.archive.org/web/20110724214405/http://www.alexwg.org/publications/PhysRevERapidComm_76-020501.pdf | archive-date = July 24, 2011 }}</ref>

The surface of diamonds is partially oxidized. The oxidized surface can be reduced by heat treatment under hydrogen flow. That is to say, this heat treatment partially removes oxygen-containing functional groups. But diamonds (sp<sup>3</sup>C) are unstable against high temperature (above about {{convert|400|C}}) under atmospheric pressure. The structure gradually changes into sp<sup>2</sup>C above this temperature. Thus, diamonds should be reduced below this temperature.<ref>{{cite journal | vauthors = Fujimoto A, Yamada Y, Koinuma M, Sato S | title = Origins of sp(3)C peaks in C1s X-ray Photoelectron Spectra of Carbon Materials | journal = Analytical Chemistry | volume = 88 | issue = 12 | pages = 6110–6114 | date = June 2016 | pmid = 27264720 | doi = 10.1021/acs.analchem.6b01327 | doi-access = free }}</ref>