8052
Polyvinylidene fluoride ( PVDF ) ultrafiltration membranes were investigated for the first time in vanadium redox flow battery ( VFB ) applications .
 Chemical: Polyvinylidene fluoride; Chemical: PVDF; Chemical: vanadium
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: Polyvinylidene fluoride, PVDF, vanadium 
Answer:
 Chemical: Polyvinylidene fluoride; Chemical: PVDF; Chemical: vanadium