These data correlate well with the depletion flocculation predicted for the lower concentration and the depletion stabilization predicted for the higher dextran concentration. At dextran (Mw ≈ 500,000) concentrations from 2 to ≈10%, suspensions of normal human erythrocytes flocculate in small convex agglutinates. At d
Depletion flocculation in colloidal dispersions," Adv. Colloid Interface Sci. ... We present a simple mean-field theory to describe the polymer-mediated depletion attraction between colloidal particles that accounts for the polymer's chain st.
Depletion flocculation was associated with an increase in viscosity of BG or AX-stabilised emulsions compared with BG/AX alone, whereas bridging flocculation with PTN caused a decrease in viscosity. All three polysaccharides reduced lipid digestion rate and extent, but the bridging flocculation induced by PTN had the greatest effect. ...
Conversely, depletion mediated interactions are commonly considered in the general field of colloid chemistry, and several previous reports have dealt with the experimental and theoretical aspects of depletion aggregation, often termed depletion flocculation [3-7].
Recently, depletion-induced flocculation has been recognized as a potential approach for purification of nanostructures [34, 35].In a colloidal solution of nanoparticles involving micelles or polymers, there is a region around each nanoparticle inaccessible to the small solutes due to steric constraint, namely excluded volume (V …
In this case, obvious creaming was found to occur within hours of sample preparation. We attribute the reversible flocculation in these systems, and the resulting enhanced creaming, to a depletion flocculation mechanism (9,13). This is most likely to have been caused by the presence of caseinate sub-micelles in the aqueous phase of …
Depletion flocculation occurs in the same systems at much higher PVME volume fractions. INTRODUCTION In a previous publication [ 1 ] we presented a pragmatic theory for calculating the depletion interaction energy between so-called "soft-sphere" particles, i.e. particles carrying a layer of terminally-grafted polymer chains in the …
The emulsion with ϕ = 0.10 was used to investigate flocculation processes induced by xanthan as a semi-flexible linear nonabsorbing polymer. Different time regimes in the development of the reduced scattering coefficient μs′ could be identified. First, a rapid, temperature-dependent change in μs′ during the depletion process was observed.
Depletion flocculation is not so readily found in emulsions prepared from other milk protein sources such as skim milk powder, milk protein concentrate and whey protein concentrate [64]. This is attributed to the more aggregated form of protein in these samples. Solutions of globular whey protein molecules also do not cause depletion …
Flocculation is a process whereby small particles in suspension are caused to aggregate, giving large clusters (flocs) that are much more easily separated than the original …
Efficient controlling of depletion flocculation can be an excellent rheology modification strategy that is principally unexplored in the 3D- process, yet can …
Depletion Flocculation of Beverage Emulsions . . . deformation and disruption of flocs in the shear field as the shear stress is increased (McClements 1999). The nonflocculated emulsions exhibited Newtonian behavior, that is, their viscosity was independent of shear stress. The influence of biopolymer concentration on the apparent viscosity (at ...
The flocculation behavior of anionic and cationic latex dispersions induced by addition of ionic surfactants with different polarities (SDS and cetyltrimethylammonium bromide (CTAB)) have been evaluated by rheological measurements. ... which means that this weak flocculation will be due to the depletion effect from the free micelles after ...
Flocculation could be nondestructively monitored by measuring the decrease in ultra-sonic attenuation of the emulsions. These results show that depletion flocculation by gum arabic and modified starch can have an adverse effect on the stability of beverage emulsions. Key Words: gum arabic, modified starch, beverages, emulsions, flocculation
Depletion flocculation is a well-known instability mechanism that can occur in oil-in-water emulsions when the concentration of non-adsorbed polysaccharide exceeds a certain level. This critical flocculation concentration depends on the molecular characteristics of the polysaccharide molecules, such as their molecular weight and hydrodynamic ...
The phenomenon known as depletion flocculation was observed, which was caused by the reduction of the excluded volume. The interactions of the system were studied by ultraviolet–visible spectroscopy (UV–Vis), optical microscopy, and cryogenic transmission electron microscopy (cryo-TEM), which demonstrated the presence of the …
The process of serum separation and rheology, clearly differ between emulsions gelled by depletion- and bridging-flocculation. In depletion-flocculated emulsions, the initial velocity of serum separation, due to network contraction, is generally low but the system can rearrange up to a random closed packing (ϕ ≈ 0.45) of the oil …
Since Weitz et al. showed that thermoresponsive NIPAAm-based MG precipitate in aqueous droplets when heated above VPTT, temperature—in addition to electrostatic interactions and depletion flocculation—plays a role in the coacervation of MG/NG. 28 Further experiments should be directed towards understanding the influence of the reaction ...
We study the mechanism of depletion stabilization and the resultant microstructure of aqueous suspensions of nanosized silica and poly(vinyl alcohol) (PVA).
An approximate theory of depletion stabilization and depletion flocculation (i.e., stabilization and flocculation of colloidal particles by polymers in free solution) is presented. This is based upon the rotational isomeric state-Monte Carlo procedures for calculating the conformation of macromolecules between two particles and the Flory ...
Flocculation, monitored by turbidity measurements, was observed in the absence of electrolyte at critical polymer concentrations (C*) at 0.4%, 0.02% and 0.3% for HEC, SCMC and SPSS, respectively. The flocculation was reversible to dilution and weak shear forces and was attributed to polymer depletion.
Depletion flocculation in colloidal dispersions Paul Jenkinsa, Martin Snowdenb** aZan Wark Research Institute, University of South Australia, Warrendi Road, b The Levels SA 5095, Australia ...
DOI: 10.1016/j.foodhyd.2018.05.018 Corpus ID: 52894905; Influence of oat components on lipid digestion using an in vitro model: Impact of viscosity and depletion flocculation mechanism
Depletion flocculation in colloidal dispersions. Author links open overlay panel Paul Jenkins a, Martin Snowden b. Show more. Add to Mendeley. Share. ... the behaviour of polymers at or near an interface are also examined together with an outline of their relevance to the depletion interaction. The depletion interaction itself is also ...
The depletion flocculation of stable suspensions of charged microparticles (1.2 μm diameter polystyrene) by mixtures of silica nanoparticles (7 nm) and poly (acrylic) acid (PAA, Mn = 24 500) was …
The effect of addition of free polymer to sterically stabilised dispersions, i.e. depletion flocculation, was investigated using rheological measurements. The latter was applied to calculate the ...
lem, but depletion flocculation can be brought on, for example, by excess surfactant added with a colorant. Depletion Flocculation Depletion flocculation is actually an osmotic pressure phenomenon which occurs when nonadsorbed thicken-er molecules are excluded from the space between par-ticles.6 It is dependant upon the particle volume …
depletion flocculation, was investigated using rheological measurements. The latter was applied to calculate the energy of separation Esep between the particles in a flocculated structure. Esep ...
A depletion flocculation mechanism was suggested. Guar gums are derived from corn starch in which hydroxyethyl groups have been substituted by hydroxyl groups and the final product depends in the degree of substitution. Table 7.2 Classification of water-soluble polymer according to origin and physiochemical properties Polymer Non …
In nearly all practical applications, adsorption of polymer is necessary to promote flocculation, and we shall restrict attention to such cases. Nonadsorbing polymers can cause depletion flocculation, but this aspect, although of some fundamental interest, is hardly ever relevant to practical flocculation processes and will not be discussed ...