{HEAD ~ and 0.93 wt %} of {TAIL ~ 7 mercaptopropyltrimethoxysilane}; and 
{ HEAD ~ and 0.93 wt % } of { TAIL ~ 7 mercaptopropyltrimethoxysilane } ; and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH