Hydrophilization, separators

Figure 15-25 shows a combination device containing coalescers and both hydrophobic and hydrophilic separating membranes. Coalescers... 

Figure 13. A few microstructural parameters for Nafion and sulfonated poly(arylene ether ketone)s,i as a function of the solvent (water and/or methanol) volume fraction Xy. (a) the internal hydrophobic/hydrophilic interface, and (b) the average hydrophobic/hydrophilic separation and the diameter of the solvated hydrophilic channels (pores).

Kinetics of formation and dissociation of lanthanide complexes [La(III) = Pr, Eu, Tb, Ho, and Yb] with l-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP) in toluene-water phase were studied by monitoring the fate of La3+— arsenazo III (AZ) complex (MAZ) in the aqueous phase with the hydrophilic separator. The structures of the ligands and AZ are given below ... 

For lipophilic-hydrophilic separations the gel has a large sample capacity and the recoveries are quantitative as is demonstrated by the data summarized in Table II. A 5-cm X 1-m long column was used with solvent flow rates of 500 mL per hr. 

FIGURE 27.19 Schematic representation of the microstructures of Nation and a sulfonated polyetherketone illustrating the less-pronounced hydrophobic/hydrophilic separation of the latter compared to the former. (Reprinted from Kreuer, K.D., J. Memb. Sci., 185, 29, 2001. With permission from Elsevier.)... 

Is there anything similar in the physics of biopolymers, any general laws that are not affected by the random choices There certainly are They control the formation of knots in DNA (see Section 2.6), the hydrophobic-hydrophilic separation of a globular protein (Section 5.7), and many other properties most of these laws may still be unknown. 

The smaller hydrophobic/hydrophilic separation and the lesser flexibility of the polymer backbone of SPEEK produce narrow proton channels and a highly branched structure, which baffles the transfer of methanol. 

Figure 1. Schematic representation of the microstructures of the NAFION and S-PEEK illustrating a comparison in terms of hydrophobic/hydrophilic separation. Reprinted from [4] with permission from Elsevier.

Fig. 11.15 Left-. A schematic representation of the fully hydrated morphology of a PFSA ionomer (e.g., Nafion) under the assumptions of a cubic lattice model which fitted data from small angle X-ray scattering (SAXS) experiments. Right. SAXS spectra of hydrated Nafion and a hydrated sulfonated polyetherketone. The characteristic hydrophobic/hydrophilic separation lengths are obtained from the position of the ionomer peaks while the internal hydrophobic/hydrophilic interfaces are obtained from the intensities in the Porod regime. First reported in Ref. [66]...

Dynamic coating appears to he especially attractive for plastic microchips, as estahhshed surface chemistry such as silanization is often not apphcahle to polymeric materials. Permanent coatings are often regarded as the most effective way to perform surface modification in order to reduce analyte-wall interactions and to modify elec-troosmotic flow (EOF). Permanent surface modification is, however, often more laborious in the production process and might, accordingly, be less attractive for disposable devices. Dynamic coating methods are applied not only to control EOF and reduce analyte adsorption but also to make a hydrophobic surface more compatible with a hydrophilic separation medium. 

Figure 1.21. Changes in water weight in the three sections in the (a) hydrophobic porous separator and (b) hydrophilic separator.

FIG. 3.11 Scheme for the comparison between hydrophobic/hydrophilic separation regions in the microstructures of Nation and sPEEK. (Reprinted with permission from Elsevier (2001). Copyright 2001 Elsevier [178].)... 

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