Thus, {HEAD ~ the nanoparticles} and TiO2 interact by {TAIL ~ a mechanism} resulting in improved spacing of the TiO2 particles 
Thus , { HEAD ~ the nanoparticles } and TiO2 interact by { TAIL ~ a mechanism } resulting in improved spacing of the TiO2 particles
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH