11829
We investigated the surface , adhesion , friction , and cracking properties of polydopamine ( PDA ) thin films for their effective transfer to functional devices and biocompatible coatings .
 Chemical: polydopamine; Chemical: PDA
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: polydopamine; Chemical: PDA