19818
Polyhedral oligomeric silsesquioxane ( POSS ) cubic cage systems ( octa - n - octadecyloctasilsesquioxane , ( T8C18 ) and octakis ( n - octadecyldimethylsiloxy ) octasilsesquioxane , ( Q8C18 ) ) were synthesised with eight long n - alkyl chain ( R = C18H37 ) substituent arms , as model nano - functionalized compounds .
 Polyhedral oligomeric silsesquioxane, POSS, octa - n - octadecyloctasilsesquioxane, T8C18, octakis ( n - octadecyldimethylsiloxy ) octasilsesquioxane, Q8C18, C18H37
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Polyhedral oligomeric silsesquioxane, POSS, octa - n - octadecyloctasilsesquioxane, T8C18, octakis ( n - octadecyldimethylsiloxy ) octasilsesquioxane, Q8C18, C18H37