zinc oxide nano-particles with the average diameter of about 25 nm were modified with different mole ratios of trimetoxyvinyl silane (tmvs) and oleic acid, as coupling agents, in order to modify their surface properties and render them more hydrophobic. then, dispersibility of the surface modified nano-particles was examined in some monomers with different levels of hydrophobicity, including me...

the occurrence of soil water repellency and its intensity were studied in three sites under pinus teada, petrocarya fraxinifolia and sombucus ebulus in talesh township, western part of guilan province. seventy nine undisturbed soil samples from 0–5 cm depth were collected for water repellency and water-soil contact angle to be determined in a dry season. soil water repellency was assessed using...

We have developed a simple optimization procedure for assigning binary values to amino acids. The binary values are determined by a maximization of the degree of pattern conservation in groups of closely related protein sequences. The maximization is carried out at fixed composition. For compositions approximately corresponding to an equipartition of the residues, the optimal encoding is found ...

The surface net hydrophobicity and local hydrophobicity of green fluorescent protein was evaluated by using the aqueous two-phase partitioning method. The surface net hydrophobicity of GFP allowed it to be classified as a hydrophobic protein although the local hydrophobicity was low. The local hydrophobicity of the GFP was increased by a pH shift to acidic conditions and was maximal at pH 4. Th...

Zinc oxide nano-particles with the average diameter of about 25 nm were modified with different mole ratios of trimetoxyvinyl silane (TMVS) and oleic acid, as coupling agents, in order to modify their surface properties and render them more hydrophobic. Then, dispersibility of the surface modified nano-particles was examined in some monomers with different levels of hydrophobicity, including me...

Substrate roughness influences the wetting properties of self-assembled monolayers (SAMs), but details on this dependency at the sub-nanometer level are still lacking. This study investigates the effect of surface roughness on interfacial properties of n-alkanethiolate SAMs, specifically wetting, and confirms the predicted limit to the observation of the odd-even effect in hydrophobicity. This ...

The classical Voorn-Overbeek thermodynamic theory of complexation and phase separation of oppositely charged polyelectrolytes is generalized to account for the charge accessibility and hydrophobicity of polyions, size of salt ions, and pH variations. Theoretical predictions of the effects of pH and salt concentration are compared with published experimental data and experiments we performed, on...

Objective. To determine whether several topical compounds and other chemical entities are able to diminish the surface hydrophobicity of yeast cells. Method. Hydrophobicity of yeast cells was determined by binding styrene microspheres to the surface of untreated yeast or yeast pre-incubated with various substances with potential for cell surface modification. The degree of microsphere adherence...

In this study, the thermal, chemical and structural stability of 1H,1H,2H,2H-perfluorodecyl acrylate polymers (p-PFDA) synthetized by initiated chemical vapor deposition (iCVD) were investigated. PFDA polymers are known for their interesting crystalline aggregation into a lamellar structure that induces super-hydrophobicity and oleophobicity. Nevertheless, when considering applications which in...

Coxsackie B virus protein 2B contains near its C terminus a hydrophobic domain with an amino acid composition that is characteristic for transmembrane regions. A molecular genetic approach was followed to define the role of this domain in virus reproduction and to study the structural and hydrophobic requirements of the domain. Nine substitution mutations were introduced in an infectious cDNA c...