27186
We used hydrophilic polystyrene colloids with four different shapes ( spheres , barrels , rods , and oblong disks ) , but otherwise identical surface properties .
 Chemical: polystyrene
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: polystyrene