Ancient Warriors and the Origin of Chinese Purple

LECTURER
Prof. Zhi Liu
(ShanghaiTech University)

DATE: 22nd August 2018
TIME: 15:00 – 16:00 am
LOCATION: Crociferi Foundation, Venice

In 1974, while sinking irrigation wells in the Chinese province of Shaanxi, a group of farmers made an astonishing archeological discovery. Today many puzzles still surround these statues. One of the most intriguing of these mysteries is the origin of a synthetic purple pigment, often called “Chinese purple” or “Han purple,” that their ancient creators used to adorn the soldiers and their accessories.

Until the 19th century, most pigments were made from naturally occurring minerals or organic dyes. One well-known exception is “Egyptian blue,” which is chemically very similar to the Chinese purple. Because the Egyptian and Chinese pigments are so chemically close in composition, some have proposed that the technology to create Chinese purple was in fact derived from the Egyptians. In this study, we used a series of synchrotron-based x-ray techniques to characterize the exact chemical make-up of the pigments in Chinese purple. Researchers found that deep within the structure of Egyptian blue, calcium plays a key role in the pigments’ molecular identity, whereas in Chinese purple, that same slot is filled by the element barium. Based on these findings, we concluded that, despite the two pigments’ structural similarity, these two pigments are invented independently.

It is also important to point out that culture and religion had a very strong influence on the synthesis techniques of man-made materials in the early ages of human history. Without the modern scientific knowledge, culture and religion played important roles in determining what to make and what raw materials to use, at least initially. Therefore, cultural changes in early human society can be reflected in the changes in the making and use of such materials. This is the main motivation for me to go a step further to discuss the intertwinement between the scientific development and cultural changes in early Chinese society.

Surface and Interface Science. Particularly, phenomena at gas-solid interface and liquid-solid interface. Synchrotron base in-situ characterization techniques and instrumentation.

Education   

B.S.      1989-1994    Peking University      Geophysics/ Physics

M.S.     2003   Stanford University  Electronical engineering

Ph.D.   1998-2005    Stanford University  Physics

Work Experience   

Research Assistant    1994-1997    China  CSSAR, CAS

Research Assistant    1999-2005    US       Stanford University

Research Associate    2005-2007    US       SSRL/ Stanford University

Research Associate    2006-2007    US       Stanford University

Scientist, Staff Scientist

Career Staff Scientist            2007-2014    US       ALS, LBNL

Professor        2013-now      China  SIMIT, CAS

Awards   

Recipient of One Thousand Talents Program

Publications    

  1. Stephanus Axnanda, Marcus Scheele, Ethan Crumlin, Baohua Mao, Rui Chang, Sana Rani,, Mohamed Faiz, Suidong Wang, A. Paul Alivisatos, and Zhi Liu*, Direct Work Function Measurement by Gas Phase Photoelectron Spectroscopy and its Application on PbS Nanoparticles,Nano Letters, 2013
  2. Chunjuan Zhang, Yi Yu, Michael E. Grass, Catherine Dejoie, Wuchen Ding, Karen Gaskell, Naila Jabeen, Young Pyo Hong, Andrey Shavorskiy, Hendrik Bluhm, Wei-Xue Li, Gregory S. Jackson, Zahid Hussain, Zhi Liu* and Bryan W. Eichhorn*, Mechanistic Studies of Water Electrolysis and Hydrogen Electro-Oxidation on High Temperature Ceria-Based Solid Oxide Electrochemical Cells, Journal of the American Chemical Society, 2013
  3. Xiaosong Liu, Wanli Yang,* and Zhi Liu*, Recent Progress on Synchrotron-Based In Situ Soft X-ray Spectroscopy for Energy Materials, Adv. Materials, 2014
  4. Michael F. Lichterman, Shu Hu, Matthias H. Richter, Ethan J. Crumlin, Stephanus Axnanda, Marco Favaro, Walter Drisdell, Zahid Hussain, Thomas Mayer, Bruce S. Brunschwig, Nathan S. Lewis,* Zhi Liu* and Hans-Joachim Lewerenz*, Direct observation of the energetics at a semiconductor/liquid junction by operando X-ray photoelectron spectroscopy, Energy & Environmental Science, 2015
  5. Stephanus Axnanda, Ethan J. Crumlin, Baohua Mao, Sana Rani, Rui Chang, Patrik G. Karlsson, Mrten O. M. Edwards, Mns Lundqvist, Robert Moberg, Phil Ross, Zahid Hussain & Zhi Liu*, Using “Tender” X-ray Ambient Pressure X-Ray Photoelectron Spectroscopy as A Direct Probe of Solid-Liquid Interface, Scientific Reports, 2015
  1. Z. Liu, A. Mehta, N. Tamura, D. Pickard, B. Rong, T. Zhou, P. Pianetta, Influence of Taoism on the invention of the purple pigment used on the Qin terracotta warriors
  2. Reply to ‘‘Taoism (Daoism) and ‘Chinese Purple’: a note on some historical issues’’

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