26297
By changing to another polymer , poly ( 4 - vinylpyridine ) / graphene shows a stable and reversible response to pH , and demonstrates its potential for sensor application .
 Chemical: poly ( 4 - vinylpyridine ); Chemical: graphene
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: poly ( 4 - vinylpyridine ); Chemical: graphene