Hydrophilic additive

The micellization and adsorption properties of industrial sulfonate/ ethoxylated nonionic mixtures have been assessed in solution in contact with kaolinite. The related competitive equilibria were computed with a simple model based on the regular solution theory (RST). Starting from this analysis, the advantage of adding a hydrophilic additive or desorbing agent to reduce the overall adsorption is emphasized. 

As has been pointed out earlier in this chapter, the dietary consumption and historical medicinal use of carotenoids has been well documented. In the modern age, in addition to crocin, 3.7, and norbixin, 3.8, several carotenoids have become extremely important commercially. These include, in particular, astaxanthin, 3.6 (fish, swine, and poultry feed, and recently human nutritional supplements) lutein, 3.4, and zeaxanthin, 3.3 (animal feed and poultry egg production, human nutritional supplements) and lycopene, 3.2 (human nutritional supplements). The inherent lipophilicity of these compounds has limited their potential applications as hydrophilic additives without significant formulation efforts in the diet, the lipid content of the meal increases the absorption of these nutrients, however, parenteral administration to potentially effective therapeutic levels requires separate formulation that is sometimes ineffective or toxic (Lockwood et al. 2003). 

Water uptake in plasticized polyvinylchloride based ion selective membranes is found to be a two stage process. In the first stage water is dissolved in the polymer matrix and moves rapidly, with a diffusion coefficient of around 10 6 cm2/s. During the second stage a phase transformation occurs that is probably water droplet formation. Transport at this stage shows an apparent diffusion coefficient of 2 x 10 8 cm2/s at short times, but this value changes with time and membrane addititives in a complex fashion. The results show clear evidence of stress in the membranes due to water uptake, and that a water rich surface region develops whose thickness depends on the additives. Hydrophilic additives are found to increase the equilibrium water content, but decrease the rate at which uptake occurs. 

In 1991 Vandichel and Appleyard (15) described a new promising approach for the production of "soft" flexible slabstock urethane foam blown exclusively by COj generated by the water-isocyanate reaction. These workers found that by the addition to the formulation of certain hydrophilic materials a substantial hardness reduction is obtainable, thereby permitting a considerable reduction, or even total elimination, of CFC-11 from some "conventional" foam formulations. The hydrophilic additive is called CARAPOR 2001. An example is a foam produced with an ILD value of 80N at a density of 21.5 kg/m" (1.34 Ib/ft ) (15). 

The initial burst was further decreased by tiie fact that upon the addition of the hydrophilic additive, the glass transition temperature of the PGLA decreases from 42.5°C to 36.7°C. This allows annealing of the PLGA molecules to take place upon subcutaneous administration (where tire ambient temperature is 37°C). This annealing process causes tire initial porous structures of tire microcapsules to disappear and allows "melted" microcapsules to fuse with each other. A decreased number of surface pores and a decreased surface area to volume ratio serves to limit tire release of insulin from tire annealed microparticles. ... 

Dang, H. T., Amelot, C., Rana, D., Narbaitz, R. M., Matsuura, T., and Cedex, L. 2010. Performance of a newly developed hydrophilic additive blended with different ultrafiltration base polymers. Journal of Applied Polymer Science 116 2205-2215. 

I. Amar-Yuli, E. Wachtel, D. Shalev, A. Aserin, N. Garti, Low viscosity reversed hexagonal mesophases induced by hydrophilic additives. J. Phys. Chem. B 112, 3971-3982 (2008)... 

Hydrophilic additives, such as LiCl and polyvinylpyrrolidone (PVP), are used to modify the morphology of PVDF membranes by acting on the thermodynamic and kinetic mechanisms occurring during the phase inversion process. These additives are soluble both in A/,V-dimethylacetamide (DMA) and HjO, and are leached out of the cast solution exchanging with the coagulation bath. 

In the area of membranes, DOE research strategies include studies of hydrophilic additives, non-aqueous proton conductors, and phase segregation control - both in polymers and two-polymer composites. The DOE s catalysts strategies include lowering platinum group metals (PGM) content, developing affordable platinum-based alloys, and developing non-platinum catalysts. 

Cellulose acetate (CA) can also be used as a hydrophilic additive to enhance the performance of PVDF microfiltration membranes cast by the phase inversion process... 

The presence of Tinuvin 770 on the PP6s surface has been confirmed by TOF-SIMS measurements [18]. But peaks corresponding to fragments belonging to both other additives (Irganox 1010 and Irgafos 168) also appear in the SIMS spectra. The three additives, initially contained in the bulk of the polymer, are thus present on the surface after material processing. However, AFM data seem to indicate that only the hydrophilic additive is detected at the outermost surface. 

Nafion-Type Membranes with Hydrophilic Additives... 

A microporous pol mier membrane with a hydrophilic additive or filler has been used in an improved membrane exchange humidifier (156). Such membranes may be competitive with regard to water transmission rate and be dimensionally stable, and bondable by the use of adhesives or via melt bonding. The use of membranes with such properties allows a simpler configuration of a membrane exchange humidifier. 

The water permeable membrane should contain sufficient amounts of a hydrophilic additive to render it wettable to water. Thus, when the second fluid stream contains liquid water, the membrane may become wetted and satiuated with liquid water. This may effectively seal the membrane sufficiently so as to hinder the unwanted transfer of other gases across it. The second fluid stream comprises liquid water when the dewpoint temperatiue of the second fluid stream is greater than its actual temperature. Suitable hydrophilic additives include sdica or alumina, in fiber or powder forms. 

The aim of this review is to summarize and discuss the kinetic data of the emulsion polymerization and copolymeiization of vinyl chloride. The current understanding of the kinetics of free-radical polymerization of conventional monomer is briefly described and kinetic data of radical polymerization and copolymerization of vinyl chloride in the presence of hydrophobic and hydrophilic additives are summarized. Efiects of the initiator type and concentration, the reaction conditions and the type of diluent are evaluated. Variation of kinetic and molecular weight parameters in the heterogeneous polymerizations with emulsifier type and concentration are discussed. 

The miniemulsion polymerization can be applied for the preparation of the composite particles containing the hydrophobic and/or hydrophilic domains and/or phases. The hydrophobized material, which is to be incorporated, has to be dispersed in the monomer phase. Then, miniemulsification in the water phase has to be carried out. The hydrophilic additives themselves require a hydrophobic surface so that they can be dispersed into the hydrophobic monomer phase. Erdem et al. described the encapsulation of Ti02 particles via miniemulsion in two steps mentioned above. First, TiOs was dispersed in the monomer using OLOA 370 (poly(butene... 

Z. Yuan and X. Dan-Li. (2008). Porous PVDF/TPU blends asymmetric hollow fiber membranes prepared with the use of hydrophilic additive PVP (K30), Desalination ITi 438-447. 

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