Adsorption of poly(N-isopropylacrylamide) on glass substrata

Solid–liquid separations with a temperature-responsive polymeric flocculant: Effect of temperature and molecular weight on polymer adsorption and deposition

“…This is in good agreement with the increase in shear yield stress with temperature most noticeable at higher solids volume fractions (Fig. 17), as well as the findings of AFM studies that have shown that there is an increase in adhesive force between a substrate and both surface grafted- [46,47] or free-PNIPAM molecules [7] as temperature is increased. On the other hand, when the polymer is added to suspension already at 50°C, poor sedimentation results because the polymer associates with itself rather than adsorbing onto the surface of the particles.…”

Influence of collagen denaturation on the nanoscale organization of adsorbed layers

“…At very high concentration of completely denatured collagen (den90, 1000 µg/ml), aggregates add to the first layer, constituting islands. This recalls the behavior of poly(N -isopropylacrylamide) adsorbed on glass, which readily formed a continuous layer at the surface, while single-chain coils, globules or aggregates were formed on top of this layer, depending on concentration and temperature [38]. Similarly, an amphiphilic diblock copolymer was found to readily form a layer of adsorbed individual molecules at a surface, on top of which micelles or micellar aggregates were retained above the critical micelle concentration [39].…”

Temperature responsive flocculation and solid–liquid separations with charged random copolymers of poly(N-isopropyl acrylamide)

“…The increase in settling rate that occurs when a suspension dosed with PNIPAM is heated above the LCST is a result of the phase separation attributed to the difference in free volume of the polymer and aqueous solvent [6,[31][32][33][34][35][36][37][38]. The polymer that has adsorbed on the surface at T below the LCST becomes insoluble as the temperature is raised and acts as a nucleation site for additional polymer deposition at T > LCST [4,39,40]. The increased settling rates of the suspensions dosed with neutral homopolymer and counter-ionic polymers at 50°C is due to increased hydrophobic attraction between particles as a result of the insoluble polymer deposited on the surface [8,16].…”