A random walk model of chain polymer adsorption at a surface. II. Effect of correlation between neighboring steps

A rand om wa lk latti ce mode l of a dsorption of a n iso la te d pol yme r c hain at a so lu t ion s urface is inves ti gated . Th e mode l is a modifi catio n of a s impl e c ubi c latti ce in whi c h th e re is a co rre la ti on bet ween s uccess ive s te ps. Th e direc tion of eac h s te p is at right a ngles to th e direc ti on of th e precedin g step (a ll bo nd a ngles are 90). O ne -dim e ns ional c harac te ri s ti cs of th e mono me r unit di s tributi o n a re de termin e d a nalyti c all y in th e limit of lo ng polyme r c ha in s neglec tin g th e self-ex cluded vo lum e. T he mea n numbe r of monome r units ad sorbe d in t he surface laye r V(() , N) is de termin e d ass umin g th a t o ne end of th e po.lymer c hain li es in th e s urface layer, wh e re N is th e mea n nu mber of mono me r unit s in th e c ha in and () is th e a dsor ption e ne rgy of eac h monome r unit in th e s urface layer meas ure d in units of kT . In a dditi on, th e mea n di s tan ce of th e free e nd of th e c ha in from the s urface laye r z(() , N) is d ete rmin e d . Th e prope rties of thi s co rre lated ste p mod el a re q ua lita ti ve ly s imil a r to th e pro pe rti es whi ch ha ve bee n fo und in un co rre la te d s te p mod e ls. In pa rti c ula r, th ere is a c riti ca l va lu e of th e ad so rpt ion e ne rgy ()c such th at for () > ()c, vii!, N) is proporti ona l to N. Num eri cal va lu es of N-'v(() , N) a nd z( () , N) a re p resente d for () > ()c = In (V5-1). Key Wo rd s: C ha in polym e r , adso rpti on , ra ndo m wa lk , latti ce mod e l, s hort ra nge correlati o n, c riti ca l e ne rgy, pa rtiti on fun c ti o n, ge ne ra tin g fun c ti on.