• The effects of temperature and concentration of soluble polymer on colloidal stability in concentrated aqueous polystyrene (PS) suspensions containing ethyl(hydroxyethyl) cellulose (EHEC) and carboxymethyl cellulose (CMC) were investigated. Both polysaccharides caused destabilisation of the PS suspensions. An investigation of the relative viscosity as a function of the concentration of polysaccharide indicated different destabilisation mechanisms depending on the nature of the solvent-polysaccharide interaction and on the concentration of polysaccharide. An increase in concentration of polysaccharide within the investigated concentration range resulted in substantially higher degree of flocculation of the EHEC-containing suspension at 55°C, which is a temperature 10°C below the cloud point of the used EHEC grade. This behaviour showed that the flocculation mechanisms close to the cloud point of EHEC involved a considerable amount of added polysaccharide, which is typical for colloid destabilisation by surface induced phase separation. The CMC-containing suspensions showed flocculation behaviour typical for destabilisation by depleted polymers. The suspensions were drawn-down on polyester substrate and the resulting surface structures were interpreted by calculating the pair distribution functions. The viscosity of the aqueous phase of the suspensions seemed to be the predominant factor governing the surface structure. However, the disordering effect of surface induced phase separation seemed to have similar effects as high suspension viscosity

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

Nyckelord

Kemiteknik

Chemical Engineering

Publikations- och innehållstyp

pop (ämneskategori)

kon (ämneskategori)