Preferential interactions between

A thiol-terminated PS was used as a sample in the experiment. It was based on a living polymerized carboxyl-terminated PS with M = 93,800 and Mu = 100,400. The polydispersity was Mp( /M = 1.07. The degree of polymerization was about 900 and, thus, its contour length was about 220 nm. The thiol groups were substimted for the carboxylic ends using 1,10-decanedithiol by means of thiolester bonding, anticipating the preferential interaction between... 

The quality of the thin film depends on preferential interactions between precursor and coating substrate. However, the initial layer is clearly the most important and, in the case of nanocarbons, the surface chemistry must be tailored. For most ALD precursors, hydrophilic surface groups enhance deposition, which can be achieved by functionalizing the nanocarbon prior to placement in the ALD reaction chamber or by treating the sample within the chamber with reactive plasma. Among the many in situ hybridization techniques, ALD provides best control of thin film thickness. 

MD simulations have provided a unique molecular description of cholesterol-phospholipid interactions [31]. Atomistic simulations have succeeded in reproducing the condensing effect of cholesterol on phospholipid bilayers [32-34], With atomistic detail, many properties can be determined, such as the effect of cholesterol on lipid chain ordering or on hydrogen bond formation. Other simulations have focused on the interaction of cholesterol and SM [35-37], Aittoniemi et al. [38] showed that hydrogen bonding alone cannot explain the preferential interaction between cholesterol and SM compared to cholesterol and POPC. 

Lactoglobulin A in 40% 2-Chloroethanol. Previous light scattering and differential refractometry measurements (8, 23) have shown that / -lactoglobulin exhibits strong preferential interactions with solvent components in the water-2-chloroethanol system. Since the preferential interaction between protein and 2-chloroethanol in this system was found to be maximal at 40% (v/v), the effect of this interaction on the partial specific volume of the protein was determined. 

A more sophisticated class of optical sensors with high selectivity towards ions are the ion-selective optodes (ISOs) [21], where the matrix (hydrophobic polymer such as PVC) contains a selective lipophilic ionophore (optically silent), a chromoionophore, a plasticizer and an anionic additive. The measurement principle is based on a thermodynamic equilibrium that controls the ion exchange (for sensing cations) or ion coextraction (for sensing anions) with the sample. The source of optode selectivity is a preferential interaction between the target ion and an ionophore. For a dye to act as a chromoionophore, it must... 

As earlier reported for electrochemical sensing, often the active chromo-phore will be dispersed in a polymeric matrix. For example, Mohr and Wolfbeis reported a nitrate sensor [121] where the active chromophore is a rhodamine B dye which had been modified with an octadecyl side chain to render it hydrophobic and prevent leaching. The dye was dispersed in a plasticised PVC membrane containing a hydrophobic anion carrier (tridodecylmethylammo-nium chloride). On exposure to nitrate, the fluorescence of the dye increased. This membrane, however, only displayed Hofmeister-type selectivity and was also affected by pH. Replacing the quaternary ammonium anion carrier with a palladium phospine chloride carrier led to selectivity for nitrite [ 122], probably due to a preferential interaction between Pd and nitrite ion. 

Asymmetric hydroboration of ketones with catecholborane in the presence of 0.02-0.025 equivalents of (R,R)-8, which was prepared from LiGaH4 and 2 equivalents of 2-hydroxy-2 -mercapto-l,r-binaphthyl, afforded the corresponding alcohols in a high yield and with high enantioselectivity (Scheme 6) [46]. The solid-state structure of 8 is drawn in this scheme. The preferential interaction between soft Ga metal and soft thiolate is supposed to prevent the replacement of the chiral ligand by the alkoxide product. 

It seems likely that the cationic CPC micelles, which have a large positive charge at or near the micellar surface, interact attractively with the n-molecular orbital system of benzene, and that this interaction contributes to the fact that the solubilization constant for benzene in CPC is approximately twice as large as that in SDS micelles. A preferential interaction between cationic surfactants and aromatic solutes has been reported by several groups of investigators (25-27), and recent work in our laboratory shows that 1-hexadecyltrimethylammonium bromide micelles also solubilize benzene more effectively than do the anionic alkylsulfate surfactant micelles (28). Thus, the tendency of benzene molecules to solubilize near the surface of the cationic micelles, at low XB values, may lead to a partial saturation of surface "sites" by benzene, diminishing the ability of additional benzene molecules to bind near the surface. Such an effect could be responsible for the initial increase in activity coefficient that occurs, particularly in the CPC solutions, as Xg increases. 

The preferential interaction between [SiOAl] and Na+ at one hand and between [SiOB]" and TPA+ at the other can be understood on the basis of the hard and soft acid-base interaction. It is well known that hard acids accompany better hard bases and soft acids link preferentially to soft bases. As Na+ is a harder acid than TPA+, [SiOAl] is also a harder base than [SiOB]. The preferential interactions lead then to the TPA+-[SiOB] pairs, as it was demonstrated previously [22]. 

A. Corma et al. assume that the positive effect of the support on the activity can be attributed to the increase concentration of hydrogen due to the zeolitic support. A preferential interaction between the substrate and the zeolitic surface increases the enantioselectivity. Another explanation can be given assuming that the zeolite acts as a supramolecular ligand. The activity and selectivity of the catalyst are then a consequence of the solvatation by the zeolite framework (surface curvature) (24). 

The addition of dimethylsiloxane units (dilution) leads to a further swelling of the polysiloxane sublayer without disturbing the preferential interactions between the mesogenic side chains too much, thus retaining the mesomorphic properties. 

It is not possible to measure preferential interactions between solutes and proteins in frozen samples. Therefore, it is not known if cryoprotectants are actually preferentially excluded from frozen proteins. However, a recent study by Heller et al. [82] has provided direct evidence that the influence of a solute on protein chemical potential accounts for the solute s effect on protein stability during freezing. First, it was found with infrared spectroscopy that hemoglobin s secondary structure was perturbed in the frozen state. To test the effect of increasing the protein s chemical potential on inhibiting freezing-induced structural perturbation, hemoglobin was... 

Cellular metal ion transport is biologically important because our muscular and nervous systems are regulated by charged species. Cells use membrane channels to extract potassium ions selectively from environments containing both K+ and Na+. Because the K+ ion is /argerthan the Na+ ion, this process cannot be accomplished by simply restricting the channel diameter. Dr. Roderick MacKinnon showed that potassium selectivity arises from a preferential interaction between the potassium cation and the atoms of the protein amino acids composing the channel walls. 

The preferential interactions between molecules due to cell confinement are considered by Turk-MacLeod et al. as examples of groupings, for example of genes or of individual living organisms, that are widespread in nature and which can be treated in terms of altruistic and non-altmistic traits, and thus related to Darwinian evolution. 

Fig. 7 Representation of the preferential interactions between bromide and H2 of the imidazolium cation, liberating acetate for dissolving interaction with cellulose (left), and non-specific interactions of [NTf2] , leading to cation-acetate rather than dissolving acetate-cellulose interactions (right)...

Preferential interaction between polymer-nanoparticle, nanoparticle-nanoparticle and polymer-polymer can be observed in all blends, determining the system stability and free energy [34]. 

Preferential interactions between a solvent component and a protein determine the effect of that co-solvent on protein solubility and protein stability [92 T, 93 T]... 

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