18851
ODPA did not strongly adsorb onto UV - untreated gallium substrates , suggesting that the ODPA adsorption mainly originates from hydrogen bond interaction of a phosphonate group with surface oxide .
 Chemical: ODPA; Chemical: gallium; Chemical: ODPA; Chemical: hydrogen; Chemical: phosphonate; Chemical: oxide
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: ODPA; Chemical: gallium; Chemical: ODPA; Chemical: hydrogen; Chemical: phosphonate; Chemical: oxide