Polymer adsorption preparation

Stouffer J M and McCarthy T J 1988 Polymer monolayers prepared by the spontaneous adsorption of sulphur-functionalized polystyrene on gold surfaces Macromolecules 2 1204-8... 

The drawback of the described adsorbents is the leakage of the bonded phase that may occur after the change of eluent or temperature of operation when the equilibrium of the polymer adsorption is disturbed. In order to prepare a more stable support Dulout et al. [31] introduced the treatment of porous silica with PEO, poly-lV-vinylpyrrolidone or polyvinylalcohol solution followed by a second treatment with an aqueous solution of a protein whose molecular weight was lower than that of the proteins to be separated. Possibly, displacement of the weakly adsorbed coils by the stronger interacting proteins produce an additional shrouding of the polymer-coated supports. After the weakly adsorbed portion was replaced, the stability of the mixed adsorption layer was higher. 

Among the various branches in colloid and interface science, polymer adsorption and its effect on the colloid stability is one of the most crucial problems. Polymer molecules are increasingly used as stabilizers in many industrial preparations, where stability is needed at a high dispersed phase volume fraction, at a high electrolyte concentration, as well as under extreme temperature and flow velocity conditions. 

Flocculation is indeed dependent on polymer adsorption, and there are hypotheses correlating the two phenomena, but often these have been put forth without detailed measurement of the two phenomena simultaneously (10-13). In this paper, flocculation is investigated as a function of polymer and solution properties and hydrodynamic conditions by measuring different properties of the system, including adsorption, using well characterized kaolinite and polymer samples prepared specifically for this purpose. Also, the role of concentration and charge density of polyacrylamide and polyacrylamide-polyacrylic acid co-polymers in determining kaolinite flocculation is examined under controlled hydrodynamic conditions. 

Drugs may be incorporated into nanoparticles by addition to the polymerization medium or by adsorption to preformed particles [168]. Depending on the drug, polymer, and preparation method used, the drug can exist as ... 

SUMMATION. Those chemists who have embraced polymer adsorption successfully have either accepted or circumvented the three major disadvantages some have pioneered new and novel means of purification a few have prepared their own pure polymers others have waited for the availability of commercial polymers pure enough to suit their analytical or bioassay needs. 

Polymer adsorption has also been adapted to QCM sensing whereby biofunctional thin films are adsorbed on the crystal surface with non-specific binding controlled by tuning of polymer composition. This approach proved successful as applied to carbohydrate-protein interaction by Matsuura et al. through adsorption of lactose bearing amphiphilic polymers on hydrophobic surfaces which then showed RCA12o and peanut lectin (PNA) affinity [33]. Carbohydrate surfaces prepared by photo insertion into an adsorbed polymer were tested by QCM and showed the predicted affinities [34] while in another example a covalently bound glycopolymer demonstrated Concanavalin A detection ability [35]. 

The ability of monomeric Schiff base complexes or polymeric Schiff base ligands to absorb solvent molecules is well-known. Sawodny et al.27) found that the polymer Schiff base complexes exhibit this property much more markedly. The polymers were prepared by the polycondensation reaction of polymer ligands of the Schiff base (29) with metal salts (Eq. 8). The adsorption of solvent is reversible and the ability is dependent upon the nature of the central metal atom and of the ring size around the metal. This profile suggests that the above polymers can be used as a molecular sieve. 

Ruths, J., Essler, F., Decher, G., Riegler, H. (2000). Polyelectrolytes I polyanion/polycation multilayers at the air/ monolayer/water interface as elements for quantitative polymer adsorption studies and preparation of hetero-superlattices on solid surfaces. Langmuir 16 8871-8. 

Photoreaction 63 Photosynthesis 171 Plastic sulfur 43 Poly electrolytes 174 Polymer adsorption 174 -, preparation 87 -, rate of formation 90 -, structure 42 Polymerization theory 81 Polysulfanes 92-93 Polysulfide 176, 179, 183 -, oxidation 184... 

Ca salts of these polymers were prepared by addition of a saturated solution of CaCl2 to the aqueous solutions of their Na salts, followed by dialysis with deionized water. Intrinsic viscosities of the Na salts In buffered aqueous solutions (19) are noted in Table I, together with the degree of conversion of Na to Ca for the Ca salts, determined by atomic adsorption spectroscopy. A partially sulfated poly(vinyl alcohol) (PVA-S) was synthesized by esterification of PVA with sulfuric acid to a 20.7 mol % conversion and then neutralized with NaHC03. 

Cordova et al. explored the CE behavior of protein charge ladders obtained by acetylation of lysozyme and carbonic anhydrase II using noncovalent polycationic coated capillaries. Two of them, polyethylenimine and Polybrene, were very effective in preventing the adsorption of positively charged proteins. Conditions used were fused-silica capillary (50 p.m i.d. x 38 cm) coated with the polymer by flushing the capillary with a 7.5% (w/v) polymer solution, prepared in 25 mM Tris-192 mM Gly buffer (pH 8.3), for 15 min. The running buffer was 25 mM Tris-192 mM Gly buffer (pH 8.3) in the absence of polymer. Separations were obtained within 5 min. 

T. Serizawa, H. Takeshita, M. Akashi Electrostatic Adsorption of Polystyrene Nanospheres onto the Surface of an Ultrathin Polymer Film Prepared by Using an Alternate Adsorption Technique , Langmuir 1998,14(15), 4088-4094. 

However this description is based on composition only, and it assumes that for one given composition the system will always reach a unique equilibrium state. This may not be the case, because polymer adsorption on a particle may be irreversible if sufficiently many monomers are bound. Thus the path followed to prepare samples may be important, and depending on this path many different non equilibrium states could be. This question of approach to equilibrium is discussed next... 

Encapsulation of Enzyme. To prepare the enzyme-loaded PSt microcapsules, a primary emulsification was carried out on 20 mL of O.IM acetate buffer containing 600 mg of enzyme (invertase) and 800 mg of an emulsifier (Triton X-100) (5). The purification of the enzyme-loaded capsules, followed by polymer adsorption, was performed in the same manner as described in the previous section. 

This book presents coverage of the dynamics, preparation, application and physico-chemical properties of polymer solutions and colloids. It also covers the adsorption characteristics at and the adhesion properties of polymer surfaces. It is written by 23 contemporary experts within their field. Main headings include Structural ordering in polymer solutions Influence of surface Structure on polymer surface behaviour Advances in preparations and appUcations of polymeric microspheres Latex particle heterogeneity origins, detection, and consequences Electrokinetic behaviour of polymer colloids Interaction of polymer latices with other inorganic colloids Thermodynamic and kinetic aspects of bridging flocculation Metal complexation in polymer systems Adsorption of quaternary ammonium compounds art polymer surfaces Adsorption onto polytetrafluoroethylene from aqueous solutions Adsorption from polymer mixtures at the interface with solids Polymer adsorption at oxide surface Preparation of oxide-coated cellulose fibre The evaluation of acid-base properties of polymer surfaces by wettability measurements. Each chapter is well referenced. 

Molecular sieve carbons contain ultraflne micropores that permit the penetration of smaller molecules but impede the entry of larger molecules. The diffusion of certain gases and vapors into these materials is an activated process and is strongly temperature dependent. Thus, Marsh and Wyne-Jones observed that the uptake of nitrogen at 77 K for a polymer carbon was much smaller than its uptake of CO2 at 195 K. Kipling et al. observed that the surface area of a polymer charcoal prepared by carbonization at 700°C was very low when measured by adsorption of nitrogen at 77 K than when measured by the adsorption of CO2 at 195 K. 

Sio.4Tio.6O2 waveguides were used for the pH-dependence measurements and were prepared as described in the immediately preceding procedure. However, in this case, the solution consisted of 10 mM HEPES, titrated to the predetermined pH by the addition of either 1 M NaOH or 1 M HCl. The polymer concentration was 0.1 mg/mL in the same pH-adjusted FIEPES solution. After 1 h of polymer adsorption and 30 min of washing with the pH-adjusted solution, the solution was changed to the pH 7.4 bulfer (HEPES Zl), and the protein-adsorption performance was measured, as described in section... 

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