Negatively charge polymers

The process of adsorption of polyelectrolytes on solid surfaces has been intensively studied because of its importance in technology, including steric stabilization of colloid particles [3,4]. This process has attracted increasing attention because of the recently developed, sophisticated use of polyelectrolyte adsorption alternate layer-by-layer adsorption [7] and stabilization of surfactant monolayers at the air-water interface [26], Surface forces measurement has been performed to study the adsorption process of a negatively charged polymer, poly(styrene sulfonate) (PSS), on a cationic monolayer of fluorocarbon ammonium amphiphilic 1 (Fig. 7) [27],... 

Irish moss extract, or carrageenin, is a negatively charged polymer which reacts with positively charged protein molecules, imparting rapid increase in mix viscosity. There are many types used for ice cream, depending on the final use. It is generally used in conjunction with CMC or locust bean to prevent mix separation. Levels between 0.02 and 0.10% are recommended. 

Figure 20 Ion exchange of positively charged drug bound to negatively charged polymer network with hydronium ion generated by electrolysis of water by electric current.

Among other methods to render surfaces of implanted materials bio-compatible, in particular to prevent them from initiating blood clotting, one may activate the surfaces by radiation and then graft water soluble, or negatively charged, polymers onto the active sites. 

Similarly, we can describe the n-doping process due to exposure to a reducing agent, say M, as the formation of a negatively charged polymer complex ... 

First, consider oligonucleotide structure. Unmodified nucleic acid probes may be viewed as negatively charged polymers (they are polyanions)... 

The rate of reaction of eaq with charged polymers such as polynucleotides is much lower than that of parent bases (Shragge et al. 1971). An electrostatic repulsion of eaq" by the negatively charged polymer adds to the effect discussed above. These much lower rates of polymers as compared to their subunits also allows one to determine the binding constants of drugs, e.g., ethidium bromide to DNA (Greenstock et al. 1977). 

Ni2+ pH-SFET LOD = 7 x 10 5moir1 The use of the negatively charged polymer/re generation with EDTA ... 

Ichiba, Y. and Yoshikawa, K. (1998) Single chain observation on collapse transition in giant DNA induced by negatively-charged polymer. Biochem. Biophys. Res. Commun., 242, 441 145. 

Answer Protein C has a net negative charge because there are more Glu and Asp residues than Lys, Arg, and His residues. Protein A has a net positive charge. Protein B has no net charge at neutral pH. A cation-exchange column has a negatively charged polymer, so protein C interacts most weakly with the column and is eluted first, foUowed by B, then A. 

A second factor is the nature of the polymer backbone its flexibility, steric regularity, electric charge, and branching. This factor also reflects the compatibility and penetration ability of the polymer and the stability of the complex. A polynucleotide has a flexible, sterically regular and negatively charged polymer backbone, whereas that of a vinyl polymer obtained by free-radical polymerization is probably less flexible, sterically inhomogeneous and neutral. 

Narnia, J. Torchihn, V.P. Petrov, A. Khaw, S. Trubetskoy, V.S. O Dormell, S.M. Nossiff, N.D. Khaw, B.A. In-vivo targeting of acute myocardial infarction with negative charge, polymer-modified antimyosin antibody use of different cross-linkers. J. Nucl. Cardiol. 1995, 2, 26-34. 

It is commonly accepted that without the PG/HA interaction, the PGs would not be retained within cartilage. Since the prime task of the negatively charged polymers of the proteoglycans is the binding of water, absence of HA would result in a loss of water and subsequently in a loss of the mechanical properties of cartilage [65]. The interaction with collagen is, however, primarily mediated by the keratan and chondroitin sulfate of the individual PGs. 

For exploring SECM features of the electrochemical robotic system, two electrodes were controlled by the robotic system to electrochemically deposit spots of an anodic electrodeposition paint82 on a surface. The deposition of the negatively charged polymer is realized by anodic water oxidation under generating of protons. The process is schematically illustrated in Fig. 14.28. The pH shift in the vicinity... 

Deposition of Polyquaternium-7 and Polyquaternium-10 from anionic shampoos has been reported to be greatly decreased as a result of the formation of negatively charged polymer/surfactant complexes that are repulsed by negatively charged keratin surfaces [152,157], As was stated earlier, however, these association complexes are still resistant to removal from hair [51]. 

Counterions, i.e., A+ for negatively charged polymers and X for positively charged polymers, respectively, are concentrated in the polyion domain, and the counterion activity ratios between the two phases, i.e., (aA)v/aA and (ax)v/ax, respectively for anionic and cationic polymers, can be related to the activity ratio of singly charged H+ ions by the equations... 

T Miyajima, K Yoshida, Y Kanegae, H Tohfuku, JA Marinsky. Metal complexation of negatively charged polymers evaluation of the electrostatic effect on the complexation equilibria. React Polym 15 55-62, 1991. 

FIGURE 12.9 Force needed (F) to bring two particles to a distance h if the particles are covered by negatively charged polymer layers and the solvent contains divalent cations. The scales are only meant to indicate an order of magnitude. The dotted line is conjectural. 

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