Surface Energies of Borosilicate Glass Surfaces Modified with n -Alkyl Silane Coupling Agents viaDynamic Contact Angle Measurements● In various solution environments, contact angles increase with both increasing alkyl silane concentration and increasing water fraction in the mixed solutions. ○ In an aqueous environment, the alkyl chain is "folded" and shows the hydrophobicity, whereas in aqueous ethanol solvent the chain is "brush-like" or "extended" ● In mixed solvents, the trend of contact angles as a function of concentration was generally similar to that of the aqueous case● As the portion of methanal increases, the contact angle decreases dramatically like that in the caseof decreased concentration.○ total surface energies and the polar term increase, whereas the disperse term gently decreases. ● At high concentrations, the bonded alkyl chains are more prevalent and are probably relatively densely packed with the higher silane solution concentrations used. Summary: This article provides information about the impact of Silane in various environments. The researchers wanted to test if different environments have an impact on Aklyl Silane coupling agents. In addition, they also used methanal and mixed solvents to test if different intermolecular adhesion will be affected. Based on the results, they found that mixed solvents reacted very similarly to aqueous environments and at higher concentrations, alkyl chains are more densely packed with a higher silane solution. A Wettability Gradient Method for Studies of Macromolecular Interactions at the Liquid/SolidInterface● The shape of the gradient was determined with the capillary rise method. ● The lateral resolution of the capillary rise method was investigated on glass slides which had a sharp border between a hydrophilic and a hydrophobic region.○ These slides were made by first covering one-half of a glass slide with tape○ Silane was evaporated onto the slide and the tape was then removed.○ the hydrophilic area was apparently vertical indicating a high lateral resolution of the capillary rise method. ● Since naturally occurring proteins vary largely in biological function, size, electric charge, and hydrophobicity, an equally large diversity of binding forces and conformational changes of proteins adsorbed on solid surfaces can be expected. ● The distribution of chemical groups along the surface is of general importance for the interaction between the surface and the protein molecules. ○ In principle, the groups could be dispersed at the molecular level or form "patches" of different sizes on the surface.Summary: This article provides information about macromolecular interactions at liquid and solid interface. They used a capillary rise method to test glass slides and had a border between a hydrophobic/hydrophilic region. They used tape and evaporated silane on the other slide. They found that hydrophobic regions are indicated based on lateral resolution. They also concluded thatchemical groups being used on the surface can affect the interaction between the protein molecules. Application: These two articles are important for the lab, because it provides us background knowledge of the properties and interactions of Saline. This will give us a better understanding of what is occurring and it gives us a more educated hypothesis of what can happen in the lab, since we are applying Saline to the slides as well. It will also allow us to experiment with different times tosee how the development will change the properties of the aqueous solutions. It can also allow us a general idea of the contact angles. 6 9 12Pink and