Water-soluble polymers, interaction with

Now it is known that a number of classes of water-soluble polymers interact with and are mutually coagulated by polysilicic acids and coiloidal silicas. These include polyethers (polyethylene oxide.s, methyl cellulose), polyamine salts (polyethylene iminc), poIyalcohoLs (polyvinyl alcohol), polyvinylpyrrolidone, and proteins (gelatin, albumin). 

HEC is generally compatible with other ceUulosic water-soluble polymers to give clear, homogeneous solutions. When mixed with an anionic polymer such as CMC, however, interactions between the two polymers may result in synergistic behavior, ie, viscosities higher than predicted and calculated. HEC has excellent compatibiUty with natural gums. 

VI. MECHANISM OF INTERACTION OF WATER-SOLUBLE POLYMERS WITH IONS IN AQUEOUS SOLUTION... 

Water-soluble pAM neutral polymer interacts with ions of the solution through the complex formation between amide groups and hydrated ions. 

Water-soluble pAANa anionic polymer interacts with ions through cation and anion exchange mechanisms. 

Water-soluble pAM-DAA-HCl and pAM-DAEA-HCl cationic polymers interact with ions by the following mechanisms ... 

The qualitative thermodynamic explanation of the shielding effect produced by the bound neutral water-soluble polymers was summarized by Andrade et al. [2] who studied the interaction of blood with polyethylene oxide (PEO) attached to the surfaces of solids. According to their concept, one possible component of the passivity may be the low interfacial free energy (ysl) of water-soluble polymers and their gels. As estimated by Matsunaga and Ikada [3], it is 3.7 and 3.1 mJ/m2 for cellulose and polyvinylalcohol whereas 52.6 and 41.9 mJ/m2 for polyethylene and Nylon 11, respectively. Ikada et al. [4] also found that adsorption of serum albumin increases dramatically with the increase of interfacial free energy of the polymer contacting the protein solution. 

In the case of water-soluble polymers, there is another factor that has to be taken into account when considering solubility, namely the possibility of hydrophobic interactions. If we consider a polymer, even one that is soluble in water, we notice that it is made up of two types of chemical species, the polar functional groups and the non-polar backbone. Typically, polymers have an organic backbone that consists of C—C chains with the majority of valence sites on the carbon atoms occupied by hydrogen atoms. In other words, this kind of polymer partially exhibits the nature of a hydrocarbon, and as such resists dissolution in water. 

A class of systems extensively investigated by means of PFG-NMR are colloids. They are usually hydrophobically modified water-soluble polymers, that is, polymers with a water-soluble skeleton bearing one or more hydrophobic units, which allow the self-assembling of the polymer in water solution and the interaction with surfactants.77... 

Binding behavior of transition metal ions with polyallylamine20), poly(e-A-methacryloyl-L-lysine)2,), branched poly(ethyleneimine)s 22), water soluble polymer-bound iminodiacetic acid analogue 23), and polyacrylamide gel 241 has been reported. In these works, the effect of the polymer backbone has been discussed in terms of interaction of metal ions with the polymer chains. 

In aqueous solutions of Cm-(EO)n amphiphilic molecules, two interesting features are observed. First, isotropic micellar solutions undergo phase separation on heating. Such behavior is typical of hydrophobic interaction and is also observed for several water-soluble polymers. Hydrophobic interaction results from a change of order in the water structure [54]. Second, at high concentration, liquid crystalline phase behavior is observed with several structures [55]. 

Usually, the fabrication of a close - packed assembly of amphiphilic molecules at an air - water interface by the Langmuir method requires suitable subphase conditions related to the ionic species and its concentration, pH, temperature and addition of another complementary solutes. In the last case, to explore the feasibility of enhancing the interactions of some amphiphilic polymers with water soluble polymers at the air - water interface, it was studied the system of poly(monomethyl itaconate) (PMMel) as subphase stabilizer of maleic anhydride - alt - stearyl methacrylate(MA-alt-StM) monolayers at the air - water interface. 

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