Desorption of polymer

While the static aspects of the adsorption of single chains at walls have been studied for a long time [2], the dynamic properties of adsorbed polymers have received much less attention [30-32]. Most work considers the kinetics of either adsorption or desorption of polymers at a solid surface [31], or the... 

Letey, J. 1994. "Adsorption and desorption of polymers in soil." Soil Science 158 244-248. 

Cotten and Boonstra (150) also investigated stress relaxation in swollen vulcanizates. In these experiments, very near elastic equilibrium, n was found to be of the order of 0.01 or less for unfilled vulcanizates and vulcanizates filled with graphitized black. For rubbers reinforced with fully reinforcing furnace black n was two to three times the value for the unfilled rubber. The additional relaxation appears to be due to slow desorption of polymer segments held relatively tightly at the filler surface. 

Desorption of polymer JR from hair by distilled water is very slow, and less than f5% was removed in a time period of 30min [25,32]. Sodium dodecyl sulfate (SDS at 0.1 Af) solution, analogous to a shampoo, was much more effective, removing more than 50% of the polymer in 1 min and nearly 70% in 30min. However, a small amount of strongly bound polymer was still attached to the hair after SDS treatment [32]. Attempts to remove this strongly bound polymer by multiple treatments with SDS were not examined. 

Lehrle, R. S. and Sarson, D. S., Degradation and Selective Desorption of Polymer Can Cause Uncertainty in MALDI (Matrix-assisted Laser Desorption Ionisation) Measurements, Polym, Deg, and Stab., 51, 197, 1996. 

While thermal desorption of polymers generally causes thermal degradation, one can generalize that many polymers— as well as other complex molecules—can be lifted into the gas phase intact, provided the heating rate is fast enough. Heating rates of the order of lO degrees Kelvin/second are... 

It should be noticed that not all experimental parameters have been published in the literature. Specifically, the molar mass of samples, the dimensions of column, the pore diameter of column packing, the flow rate, pressure, temperature or injected both concentration and volume are ofter not stated and are, therefore, missing in selected parts of Tables 1-3. The relationship between polymer and solvent (a component of the mixed mobile phase is a solvent or non solvent for a polymer) and the relationship between solvent and sorbent adsorli, i.e., adsorption of polymer supporting liquid desorli, i.e., a desorption of polymer supporting liquid), when defined in the literature, is noted in Tables 1-3. Measurements, which require other techniques as LC, are denoted by abbreviation (TLC or SFC). The abbreviations employed have been defined separately in list of symbols and abbreviations. 

The free energy change on adsorption of polymer onto a particle surface is negative. If collision between two polymer-coated particle results in desorption of polymer, then as AG for desorption is positive stability will be enhanced. 

Table 3 Desorption of Polymer JR 400 from Brown Hair...

Zimin D, Craig VSJ, Kunz W (2004) Adsorption and desorption of polymer/surfactant mixtures at solid-liquid interfaces substitution experiments. Langmuir 20 8114... 

The authors also describe the effect of temperature on the Payne effect. With increasing temperature the amplitude of the Payne effect decreases significantly (Fig. 12). Very surprisingly, enhanced Payne-like behavior was observed for rubber vulcanizates at room temperature where filler-filler and filler-polymer interaction are not observed in comparison to the typically filled vulcanizates. The authors concluded that in addition to the contribution from the filler-filler network, there are many other factors that affect the nonlinear viscoelastic behavior. Nevertheless, the Payne effect is assumed to arise from the elementary mechanism consisting of adsorption-desorption of polymer chains from the surface of the particles [50]. Besides the experimental investigation, the authors have applied the Maier... 

Stuart L. Cooper (University of Wisconsin) Have you considered desorption of polymer from surfaces into pure solvent, as opposed to a solution of polymer and solvent Studies of protein adsorption show the process to be somewhat irreversible, especially when the protein solution is replaced by pure solvent (water). For example, it has also been shown using radio-labelled protein that adsorbed protein will exchange with protein in solution, but that very little will desorb into pure solvent. 

Desorption of polymer molecules from a surface can be either rapid, Le, completely displaced within 1-2 h, or, as is more often found, no measurable desorption occurs at all. 

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