{HEAD ~ The degree} of {TAIL ~ hydrophobicity ratio} of a hydrophobic silica is indicated by a value of methanol wettability and is preferable to be less than 15 
of
{ HEAD ~ The degree } of { TAIL ~ hydrophobicity ratio } of a hydrophobic silica is indicated by a value of methanol wettability and is preferable to be less than 15
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH