The total thickness of each interlayer can be in {HEAD ~ the range} of {TAIL ~ about 5 Å} to 20 μm 
of
The total thickness of each interlayer can be in { HEAD ~ the range } of { TAIL ~ about 5 Å } to 20 μm
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH