13138
Additionally , hydrate - oil interfacial tension was observed to begin decreasing from the baseline value at significantly lower surfactant concentrations ( 1 - 3 orders of magnitude ) than those for the water - oil interfacial tension .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None