16578
Interestingly , while tin ( II ) bis ( 2 - ethylhexanoate ) and aluminum salan - catalyzed PLA - b - PEG copolymers exhibited similar micellization behavior , the aluminum salen - catalyzed PLA - b - PEG exhibited unique behavior at high micelle concentration in the presence of the pyrene probe .
 Chemical: tin ( II ) bis ( 2 - ethylhexanoate ); Chemical: aluminum salan; Chemical: PLA - b - PEG; Chemical: aluminum salen; Chemical: PLA - b - PEG; Chemical: pyrene
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: tin ( II ) bis ( 2 - ethylhexanoate ); Chemical: aluminum salan; Chemical: PLA - b - PEG; Chemical: aluminum salen; Chemical: PLA - b - PEG; Chemical: pyrene