Pluronic adsorption

Figure 9.3. Characterization of mesoporous Ti02 films templated by Pluronics block copolymers using diverse characterization techniques XRD pattern (a), transmission electron microscope (TEM) image (b), dark-field TEM image (c), and isotherms of Kr adsorption (d).The Pluronic-templated Ti02 films were calcined at 400°C (solid points) and 600°C (open points). The films were prepared according to Alberius et al. (Ref. 14).

Lin and Yang (1987) also calculated the thermodynamic parameters of diazepam for micellar solubilization in Pluronic surfactant solutions at different temperatures (Table 13.4). For all systems, AG was negative, indicating micellar solubilization was spontaneous. The sign of entropy has been associated with the location of solubilized molecules within the micelles. Positive values have been observed for molecules embedded in the micelle center and negative values for adsorption of the molecules on the micelle surface. The results in this paper indicate that in the F-108 and F-88 Pluronics, diazepam molecules can penetrate into the micelle interior, whereas for F-68 and lower concentrations of F-88, diazepam is adsorbed on the micelle surface without penetration into the micellar core. 

A disordered mesoporous silica material (sample Cl) was obtained by the route outlined for SBA-15, when the Pluronic P123 used as the template was replaced with an equal-weight mixture of Pluronic and trimethylbenzene. SEM micrographs indicate that this material constitutes a system of spherical pores of wide size distribution, connected and accessible by small mesopores and/or micropores only. The nitrogen adsorption isotherm indicates a wide pore size distribution and a H2 type hysteresis loop. Some properties of this material are included in Table 1. 

Plasma protein interactions with polymer colloids Symmetrical Measurement of changes in particle (PS latex) size due to aggregation and adsorption of proteins effect of Pluronic surfactants on aggregation and protein adsorption [J.-T. Li and K. D. Caldwell, Colloids Surf. B Biointerfaces 7 9-22 (1996)]... 

The amount of adsorption was greater than for homopolymers, and the adsorbed layer thickness was more extended and dense. For a triblock copolymer A-B-A, with two buoy chains and one anchor chain, the behaviour was similar to that of diblock copolymers this is shown in Figure 6.15 for the PEO-PPO-PEO block (Pluronic). 

Figure 12.4 Schematic representation of the structure of Pluronics, and their adsorption at the O/W interface.

Maartens et al. modified ultrafiltratiOTi membranes by adsorption of ncmirmic surfactants TritOTi X-100 and Pluronic F 108 [31]. Although a reduced fouling was observed, the modification was not stable under filtration conditions, due to the physisorption of the surfactants to the membrane surface by hydrophobic interactions. 

Surfactants Ce.g., Tween 80, Pluronic F68) Prevention of adsorption and aggregation... 

Hence, noncrystallizing sugars (sucrose, trehalose) or polyols (dextran, polyethylene glycol) are added to the formulation to minimize cold denaturation during freeze-thaw or during lyophiliza-tion. Also, nonionic surfactants like polysorbates or Pluronics are included to prevent mAb adsorption at the interface of ice, air, or other product contact surfaces. Use of ionic surfactants like SDS is not advisable due to their potential to cause tissue irritation and hemolysis. Preformulation studies are important to identify the pH of maximum stability. For most mAbs, it is in the range of pH 5.0 to 6.5. Common buffers used to control the pH of the solution include phosphate, citrate, histidine, and glycine. 

J. Lee, P.A. Martic, and J.S. Tan. Protein adsorption on Pluronic copolymer-coated polystyrene particles. J. Colloid Interface ScL 131 252-266 (1989). 

FIGURE 3.6 A schematic representation of the adsorption of nonionic surfactants onto membranes (a) Triton X-100 and (b) Pluronic F108. (Reprinted from Journal of Membrane Science, 209, Maartens, A., et al., 81-92, Copyright (2002), with permission from Elsevier.)... 

We also examined the impact of the surface wettability change before and after photoirradiation on the adsorption of Pluronic to the surfaces. For this study, we synthesized another silane-coupling agent, I-(2-nitropheny) ethyl Il-trichlorosilylundecanoate (5),... 

---