26764
The 3D macroporous structures were created via templating of polystyrene spheres , followed by infiltration of the desired precursor solution and annealing at high temperature .
 Chemical: polystyrene
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: polystyrene 
Answer:
 Chemical: polystyrene