ly cop rote ins ▁mut ually ▁interact ▁by ▁means ▁of ▁inter pen etr ation ▁of ▁their ▁ch ains ▁and ▁the ▁forming ▁of ▁secondary ▁semi - per man ent ▁ad hes ive ▁b onds . ▁It ▁is ▁necessary ▁that ▁the ▁mu co ad hes ive ▁device ▁has ▁features ▁or ▁properties ▁that ▁favor ▁both ▁chemical ▁and ▁mechanical ▁interactions ▁for ▁the ▁mac rom ole cular ▁inter pen etr ation ▁theory ▁to ▁take ▁place . ▁M ole cules ▁that ▁can ▁present ▁mu co ad hes ive ▁properties ▁are ▁mole cules ▁with ▁hydro gen ▁bond ▁building ▁groups , ▁high ▁mole cular ▁weight , ▁flexible ▁ch ains , ▁and ▁surface ▁active ▁properties . ▁ ▁It ▁is ▁perce ived ▁that ▁increase ▁in ▁ad hes ion ▁force ▁is ▁associated ▁with ▁the ▁degree ▁of ▁pen etr ation ▁of ▁polym er ▁ch ains . ▁Liter ature ▁states ▁that ▁the ▁degree ▁of ▁pen etr ation ▁required ▁for ▁efficient ▁bio ad hes ive ▁b onds ▁lies ▁in ▁the ▁range ▁of ▁ 0 . 2 - 0 . 5 μ m . ▁The ▁following ▁equation ▁can ▁be ▁used ▁to ▁estimate ▁the ▁degree ▁of ▁pen etr ation ▁of ▁polym er ▁and ▁m uc us ▁ch ains : ▁ ▁with ▁ ▁as ▁contact ▁time ▁and ▁ ▁as ▁the ▁diffusion ▁coefficient ▁of ▁the ▁mu co ad hes ive ▁material ▁in ▁the ▁m uc us . ▁Max imum ▁ad hes ion ▁strength ▁is ▁reached ▁when ▁pen etr ation ▁depth ▁is ▁approximately ▁equal ▁to ▁polym er ▁chain ▁size . ▁Properties ▁of ▁mut ual ▁sol ub ility ▁and ▁struct ural ▁similarity ▁will