Demixing of Colloid- Polymer Mixtures: Influence of

properties. How does the stability of colloid- polymer mixtures depend on competition between depletion-induced attractive ...
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Dem ixin g o f Co llo id - Po lym er Mixt u r es : In flu en ce o f Elect r o s t a t ic In t er act io n s a n d Po lym er Co n fo r m a t io n s Alan R. Den t on , Nort h Dakot a St at e Un ivers it y, PRF# 44365- AC7 Su s p en s ion s of colloid al p art icles are en cou n t ered t h rou gh ou t recovery an d p roces s in g of p et roleu m – from d rillin g flu id s t o well s t im u lat ion s u s p en s ion s , oil s an d s s lu rries , an d t ailin gs p on d s . Pet roleu m s u s p en s ion s are oft en m ixt u res of ch arged colloid s an d n on ad s orbin g p olym ers . Mis cib ilit y is of great p ract ical im p ort an ce, as bu lk p h as e s ep arat ion can d ras t ically alt er t h erm al an d rh eological p rop ert ies . How d oes t h e s t abilit y of colloid - p olym er m ixt u res d ep en d on com p et it ion bet ween d ep let ion - in d u ced at t ract ive in t eract ion s an d elect ros t at ic rep u ls ive in t eract ion s ? Ou r com p u t at ion al m od elin g p red ict s t h at p h as e s t abilit y (m is cibilit y) can b e s ign ifican t ly en h an ced by am p lifyin g t h e effect ive elect ros t at ic in t eract ion s bet ween colloid s , via eit h er in creas in g t h e effect ive m acroion ch arge Z or d ecreas in g t h e s alt con cen t rat ion (ion ic s t ren gt h ) of t h e s olven t . Elect ros t at ic in t er action s s tab iliz e m ixtu r es of ch ar ged colloid s an d n eu tr al, id eal p olym ers .