The shear viscosity of polyampholyte (gelatin) stabilized colloidal dispersions

The synthesis and properties of nanoscale ionic materials

“…These extra layers increase the value of the effective volume fraction of the core nanoparticle and in turn lead to dramatic increases in the zero‐shear viscosity. Similar effects have been observed before where the presence of an extended corona on the surface of a particle increases the zero‐shear viscosity of a suspension and has been attributed to an increase in the repulsive interactions between the particles 64. There are then complex interactions among the constituents of NIMs which depends on their architecture and composition.…”

“…4 was fitted with a modified form of the Krieger–Dougherty (K‐D) equation to quantify the effective volume fraction of the cores and to gain some insight as to the degree of volume fraction increase which arises from the attached corona and associated canopy counter‐ions. The modified K‐D equation for this case has the form:64–66 where η ° is the zero‐shear viscosity, µ is the viscosity of the pure amine, the effective volume fraction is defined as φ eff = C φ, φ m is the maximum packing fraction, R is the radius of the core particles and δ is the thickness of the extra layer of material surrounding the core which represents the corona and canopy (δ = corona thickness + canopy thickness).…”

Silver nanoparticle (AgNPs) doped gum acacia–gelatin–silica nanohybrid: An effective support for diastase immobilization

“…As the concentration of gelatin was increased (>10 mg/10 mL), the resulting hybrid gel looses its smoothes and transparency, indicating gelatin precipitation takes place at this concentration, which is the possible saturation concentration of gelatin under the present experimental conditions for obtaining the homogeneous gel. With the increase in gelatin amount, gelation time decreases due to increase in the viscosity as gelatin that is now adsorbed on the surface of silica colloids [43]. Addition of gelatin enhances the applicability of the resulting gels for diastase immobilization as compared to the gel obtained by single templation by gum acacia (A series hybrids).…”

Rheology and stability of oil-in-water nanoemulsions stabilised by anionic surfactant and gelatin 2) addition of homologous series of sugar-based co-surfactants

“…At pHs above its iso-electric point (which is typically 4.9), gelatin adsorbs to such interfaces to form hydrated films of thickness 20-50 nm, dependent on MW and solution conditions. Therefore, gelatin provides excellent steric and electrostatic stabilisation of photographic emulsions [5][6][7] as, indeed, it does for other emulsions [8]. The structure of adsorbed gelatin layers on hydrophobic colloidal surfaces has been studied by SANS [9][10][11].…”

“…Gelatin has a significant impact on the rheology of suspensions of small colloidal particles as the adsorbed layer can increase the effective hydrodynamic size substantially [5,[12][13][14][15][16][17]. The emulsions studied here contain polydisperse glassy oil droplets of diameter approximately 100 nm stabilised by the alkylnaphthalene sulfonate surfactant Alkanol-XC and surrounded by the shell of aqueous gelatin of hydrodynamic thickness 20-50 nm; the droplets are similar to those described in reference [12], however this study concerns emulsions with a high concentration of non-adsorbed gelatin.…”