18701
By means of potential mean forces ( PMFs ) calculation , no energy barrier was observed during the sliding assembly of two graphene nanosheets , while the PMF profiles could be impacted by the contact forms of nanographene and the MWF within the interplate of two graphene nanosheets .
 Chemical: graphene; Chemical: nanographene; 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: graphene; Chemical: nanographene; Chemical: graphene