17757
The structure of the PDEA - grafted GO ( GO - PDEA ) were examined by Fourier - transform infrared spectroscopy , proton nuclear magnetic resonance spectroscopy , X - ray photoelectron spectroscopy , thermogravimetric analysis and atomic force microscopy .
 Chemical: PDEA - grafted GO; Chemical: GO - PDEA
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: PDEA - grafted GO; Chemical: GO - PDEA