Hydrophilic optimal

Wang et al. (2002) demonstrated a composite membrane (subjected to PV) of an asymmetric poly(4-methyl-l-pentene) (TPX) membrane dip-coated with poly(acrylic acid) (PAA). To improve the interface peeling of the PA A/TPX composite membranes, the surfaces of TPX membranes were modified by residual air plasma in a tubular-type reactor. The plasma treatments were effective in rendering the asymmetric TPX membrane hydrophilic. Optimal results were obtained with PAA/TPX composite membrane prepared from the PAA/ethylene glycol (EG)/aluminum nitrate = 1/2/0.05 coating solution at 5 W/30 s plasma treatment condition. Concentration of the water in the permeate was nearly 100%, and a permeate flux of 960 g/m h was obtained with a 3 wt% feed acetic acid concentration. 

Irrespective of the development of media, many of the traditional media are successfully defending their position. This is due to their hydrophilic nature, preserving biological function of the separated molecules, but also the fact that columns may be prepared easily and, finally, some of the classical media, e.g., Sephadex, have a selectivity that is so far unsurpassed and therefore very fit for use. Intersting enough, Sephadex is still the premiere gel filtration medium for desalting due to the optimal pore size and particle size of this medium (see Section II,C). 

A great variety of polyolefin separator types are now used in Li ion batteries. They must be stable in the organic electrolytes. Typically they may not be properly wetted by the electrolytes of the optimized composition, e. g., mixtures with PC, PE, and others. Therefore some proprietary treatments are needed to provide hydrophilic behavior. Generally, a micro-porous nonwoven morphology with a large surface gives a good wettability. 

To extract and evalnate the color pigments from cochineals Dactylopius coccus Costa), a simple method was developed. The procednre is based on the solvent extraction of insect samples nsing methanol and water (65 35, v/v) and a two-level factorial design to optimize the solvent extraction parameters temperature, time, methanol concentration in mixtnre, and yield. For hydrophilic colorants that are more sensitive to temperatnre, water is the solvent of choice. For example, de-aerated water extraction at low temperatnre was applied to separate yellow saffrole and carthamine from saffron (Carthamus tinctorius) florets that contain about 1% yellow saffrole and 0.3% red carthamine. ... 

For suspensions primarily stabilized by a polymeric material, it is important to carefully consider the optimal pH value of the product since certain polymer properties, especially the rheological behavior, can strongly depend on the pH of the system. For example, the viscosity of hydrophilic colloids, such as xanthan gums and colloidal microcrystalline cellulose, is known to be somewhat pH- dependent. Most disperse systems are stable over a pH range of 4-10 but may flocculate under extreme pH conditions. Therefore, each dispersion should be examined for pH stability over an adequate storage period. Any... 

In the absence of alcohol the salinity/alkane sensitivity will be dominated by the nature of the surfactant hydrophile. A linear response was observed between optimal salinity and alkane chain length for the ICI NP6 surfactant with a recorded coefficient of ds /d EACN = 17.Sgdm "3/1 EACN. This high salt tolerance was expected for nonionics and can reflect an... 

Recently, Silva et al. have compared several techniques that have been applied to colonial marine invertebrates [13]. Catalan et al. [37] developed a technique in which sponges maintained in aquaria are attached to a plastic plaque. On the plaque, the sponge can be transferred, first to a smaller, aerated, vessel for treatment with an ethanolic or ethereal solution of the desired precursor. Then, after an incorporation period for uptake of the precursor, the sponge is returned to the sea, where metabolism is allowed to proceed in the animal s natural habitat. Silva et al. [13] found that optimal incubation time depended on the sponge, but generally was 20 to 90 days. These authors also reported on the effectiveness of lipophilic compared to hydrophilic precursors the former were taken up and metabolized more efficiently in sponges than hydrophilic ones. 

The following protocol for passive adsorption is based on methods reported for use with hydrophobic polymeric particles, such as polystyrene latex beads or copolymers of the same. Other polymer particle types also may be used in this process, provided they have the necessary hydrophobic character to promote adsorption. For particular proteins, conditions may need to be optimized to take into consideration maximal protein stability and activity after adsorption. Some proteins may undergo extensive denaturation after immobilization onto hydrophobic surfaces therefore, covalent methods of coupling onto more hydrophilic particle surfaces may be a better choice for maintaining native protein structure and long-term stability. 

Neither the hydrophilic portion nor the hydrophobic portion of the peptide is by itself sufficient for optimal secretagogue activity [99, 104, 108, 165-169, 170-175]. 

Introducing suitable substituents into the Copper Phthalocyanine Blue structure or covering the crystal surface with appropriate substances may specifically influence the hydrophilicity or the polarity of the pigment (Sec. 3.1.2.4). The ease of dispersion and wetting may thus be improved or optimized for certain applications, such as for aqueous media. 

In a previous section, the effect of plasma on PVA surface for pervaporation processes was also mentioned. In fact, plasma treatment is a surface-modification method to control the hydrophilicity-hydrophobicity balance of polymer materials in order to optimize their properties in various domains, such as adhesion, biocompatibility and membrane-separation techniques. Non-porous PVA membranes were prepared by the cast-evaporating method and covered with an allyl alcohol or acrylic acid plasma-polymerized layer the effect of plasma treatment on the increase of PVA membrane surface hydrophobicity was checked [37].The allyl alcohol plasma layer was weakly crosslinked, in contrast to the acrylic acid layer. The best results for the dehydration of ethanol were obtained using allyl alcohol treatment. The selectivity of treated membrane (H20 wt% in the pervaporate in the range 83-92 and a water selectivity, aH2o, of 250 at 25 °C) is higher than that of the non-treated one (aH2o = 19) as well as that of the acrylic acid treated membrane (aH2o = 22). 

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