Hydrophilic Hydrophilicity

Hydro-peroxyd, n. hydrogen peroxide, -per-sulfid, n. hydrogen persulfide, hydro-phil, n. hydrophile, hydrophil(ie). -phob, a. hydrophobe, hydrophobie. 

Hydrophobic Amicus hydrophilii Mildly hydrophilic Hydrophilic... 

Hydrophilicity Hydrophilicity is the tendency of a molecule to be solvated by water (IUPAC). 

Polar Nonpolar Polar Nonpolar Hydrophilic Hydrophilic Hydrophobic Hydrophobic ... 

Most lattice methods rely on an extremely simple potential function, either a two state interresidue contact energy corresponding to native/nonnative contacts, or a three state model, corresponding to hydrophobic-hydrophobic, hydrophilic-hydrophilic, and hydrophobic-hydrophilic interactions. The interaction of the twenty naturally-occurring amino acids in real proteins are obviously more complex. 

Genetic code also seems to have some error correcting capabilities. One particular property was noticed by M.V. Volkenstein, and can hardly be accidental. To explain the point, let s imagine that we have a gene — DNA sequence coding for a certain protein. If one DNA nucleotide is accidentally replaced by another, there is a more than even chance (in fact, about 2/3) that this will lead to the safest, that is, hydrophobic-hydrophobic or hydrophilic-hydrophilic substitutions in the coded protein. 

For a large number of textile applications, we need to obtain additional properties such as a high hydrophilicity. Hydrophilic properties are most conveniently introduced by grafting of polyether chains. Therefore, we developed new functional polysiloxanes containing polyether and HALS moieties on the same backbone [14] ... 

Hydrophilic Refers to the ability of an atom or a molecule to engage in attractive interactions with water molecules. Substances that are ionic or can engage in hydrogen bonding are hydrophilic. Hydrophilic substances are either soluble in water or, at least, wettable. Compare hydrophobic. 

Controlled structure polymeric betaines were reported for the first time only recently (286). The first examples were those prepared from the post-polymerization modification of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), and its block copolymers, which had been prepared imder GTP conditions (286,287). Initial reports detailed the modification of hydrophilic-hydrophobic block copolymers, but this was subsequently extended to the selective modification of diamino hydrophilic-hydrophilic block copolymers (276). 

Furlong, S. A., and Armes, S. P. (2000). Facile synthesis of hydrophilic-hydrophilic copolymers via atom transfer radical pol5merization. Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.), 41(1) 450-451. 

More specific topics, such as block copolymer synthesis by changing the polymerization mechanism [18], by step-growth polymerization [19], via macroinitiators [20], living free-radical polymerization [21, 22] or ionic polymerization [23] were reviewed later on, as well as the synthesis of selected block copolymer types, for example hydrophilic-hydrophilic copolymers [24], copolymers based on PEO [10,16]. 

The particular interest of the strategy developed by Liu and Armes [ 191 ] is that a new category of stimuli-responsive hydrophilic-hydrophilic block copolymers becomes available for micellar studies as outlined in the following section. 

Hydrophilic-hydrophilic also called double-hydrophilic block copolymers, consist of water-soluble blocks of different chemical nature. In aqueous solution they behave as unimers like classical polymers or polyelectrolytes, whereas their amphiphilic characteristics, such as surface activity and micelle formation, only appear under the influence of a given external stimuli, mainly temperature, pH or ionic strength changes. Micellization of these copolymers can further be induced by complex formation of one of their blocks, either by electrostatic interaction with oppositely charged polymers, by hydrophobic interactions such as with surfactants, or by insolubilization in the presence of metal derivatives. These polymer intercomplexes, mainly polyion complexes (PIC), with their application possibilities will be outlined in more detail in Section 7.3.13. 

Figure 7.7 Reversible micellization of hydrophilic-hydrophilic diblock copolymers under the influence...

Table 7.6 Stimuli-induced micellization of hydrophilic-hydrophilic A-B comprising at least one non-ionic sequence diblock copolymers...

Our purpose is therefore in the following to illustrate with typical examples the large variety of amphiphilic and hydrophilic-hydrophilic branched structures recently described in the literature (see Table 7.9). 

The present overview demonstrates that there is almost no limits in the design of original structures and new types of amphiphilic copolymers, including those of hydrophilic-hydrophilic type, that are of promising interest as shown for instance by Colfen [213]. 

Forder, C., Patrickios, C.S., Billingham, N.C. and Armes, S.P. (1996) Novel hydrophilic-hydrophilic block copolymers based on poly(vinylalcohol). Chem. Commun., 7, 883-884. Saegusa, T. and Ikeda, H. (1973) Preparation of block copolymer of 2-oxazoline and butadiene. Macromolecules, 6, 805-809. 

In general, the capillary forces between two vertical walls and between two vertical cylinders are attractive when they have similar wettability (hydrophilic-hydrophilic or hydrophobic-hydrophobic) and are repulsive when they have opposite wettability (hydrophilic-hydrophobic). However, this statement is not applicable for the latter two configurations (i.e., between two floating spheres and between a spherical particle and a vertical wall). Additional parameters (for example, the size and the density of floating objects) are crucially important to determine the lateral component of the capillary force. The effect of the floating object density was particularly discussed for the latter two configurations. 

Besides the inclusion complexes, calix[6]arenes may fomi co-crystals with other molecules. An interesting example is a co-crystal formed by para-sulphonatocalrx [6]arene hexaammonium with cucurbit[6]uril. As the Authors mention in the paper this structure not only exhibit an intriguing topology but also show clearly the role of hydrophobic—hydrophobic and hydrophilic hydrophilic interactions in directing the supramolecular assembly [51]. It is interesting to notice a significant amount of free space in the crystal lattice (Fig. 38.24). 

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