Hydrophobicity, molecular

New Adsorbent Materials. SihcaUte and other hydrophobic molecular sieves, the new family of AlPO molecular sieves, and steadily increasing families of other new molecular sieves (including stmctures with much larger pores than those now commercially available), as well as new carbon molecular sieves and pillared interlayer clays (PILCS), will become more available for commercial appHcations, including adsorption. Adsorbents with enhanced performance, both highly selective physical adsorbents and easily regenerated, weak chemisorbents will be developed, as will new rate-selective adsorbents. 

Creation of laiger and more hydrophobic molecular species. 

The number of carbon atoms of saturated straight-chain compounds correlates with hydrophobicity, molecular volume, and molecular length. All three could affect the interaction of an odorant ligand with the olfactory receptors (Johnson and Leon, 2001). 

Griseofulvin, a BCS class II drug (Fig. 2), is a well-known example whose poor aqueous solubility causes low and erratic oral bioavailability. As shown below, griseofulvin has a hydrophobic molecular structure, and is practically insoluble in water. Its oral absorption is highly variable, ranging from 25% to 100%, depending on the crystal size. Ultramicrosize griseofulvin preparations were shown to have 100% oral absorption (12). 

Some polyanionic dendrimers act as micellar molecules [58]. Newkome et al. first synthesised water-soluble dendrimers, whose hydrophobic molecular niches can accommodate guests. The periphery of such dendrimers was furnished with... 

How does this relate to the formation of hydrophobic molecular host-guest complexes by cyclo-phanes (Chapter 6) ... 

Silicalite powderc Linde Hydrophobic molecular sieve 3.68 0.07... 

Silicalite pelletc Linde Hydrophobic molecular sieve 4.01 0.05... 

Zeolite-based materials are also promising for the removal of organic compounds from industrial waste water (13). This is particularly true for chlorinated pollutants and the preferred process is based on adsorption/separation using hydrophobic molecular sieves (HMS). Compared to carbon adsorbents, HMS presents a good compromise between sorption capacities, selectivity to organics compared to water, and regenerability (vide infra, section 16.3.1.). 

In the field of biology, the effects of hydration on equilibrium protein structure and dynamics are fundamental to the relationship between structure and biological function [21-27]. In particular, the assessment of perturbation of liquid water structure and dynamics by hydrophilic and hydrophobic molecular surfaces is fundamental to the quantitative understanding of the stability and enzymatic activity of globular proteins and functions of membranes. Examples of structures that impose spatial restriction on water molecules include polymer gels, micelles, vesicles, and microemulsions. In the last three cases since the hydrophobic effect is the primary cause for the self-organization of these structures, obviously the configuration of water molecules near the hydrophilic-hydrophobic interfaces is of considerable relevance. 

Atjan Giaya A, Thompson RW, and Denkewicz R. Liquid and vapor phase adsorption of chlorinated volatile organic compounds on hydrophobic molecular sieves. Micropor Mesopor Mater 2000 40 205-218. 

Among others, chain flexibility/rigidity, crystallinity, hydrophilicity/hydrophobicity, molecular weight, chemical property, biodegradability, thermal property, mechanical property, and electrochemical property of polymers are considered to affect the performance of membranes most strongly. Moreover, these properties are often mutually interrelated. 

Munoz-Muriedas, J., Perspicace, S., Bech, N., Guccione, S., Orozco, M. and Luque, E.J. (2005) Hydrophobic molecular similarity from MST fractional contributions to the octanol/water partition coefficient. J. Comput. Aid. Mol. Des.,... 

The number and structural diversity of porosils should increase substantially as research into their synthesis continues. Interest could centre upon the zeosils as very stable, hydrophobic molecular sieves and catalyst carriers. Their synthesis requires at least partial occupation of channels or cavities by stabilising guest molecules. 

The QSAR paradigm for structure-permeability expresses the passive permeability as a function of hydrophobicity, molecular size, and hydrogen-bond capacity. 

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