Paper NM-WeM11
Surface Modification with Polyhedral Oligomeric Silsesquioxanes Silanols

Wednesday, December 10, 2014, 11:20 am, Room Hau

Hydrophobicity, water repellency, is a desirable surface property for materials in many industries. Water repellent surfaces are used to prevent deleterious effects of water such as; corrosion and degradation, on various materials. There are several methods which can be used to modify the properties of surfaces. Some of these techniques include sol-gel method, plasma, chemical vapor deposition, atomic layer deposition, and also traditional wet chemistry methods. Some novel materials for surface modification are Polyhedral oligomeric silsesquioxanes (POSS) silanols. These materials possess some of the surface modification characteristics of other silicon-based materials.In this project, Polyhedral Oligomeric Silsesquioxanes (POSS) were used to treat hydrophilic materials such as cotton and glass. Two POSS silanols, TriSilanollsooctyl POSS and TrisilanolPhenyl POSS, were deposited by immersion methods on glass and polymeric surfaces. Several concentrations and curing temperatures were evaluated. Contact angle measurements of water and other liquids were used to calculate the surface properties and wettability. Dynamic capture mode was used to calculate the hysteresis of advancing and receding contact angles. The hysteresis provided information regarding the wettability properties of the obtained surfaces. Statistical Analysis was performed on the contact angle data collected from the glass, cotton, and PVA samples. The analysis of the PVA films coated with TrisilanolIsooctyl POSS demonstrated an effect of the curing temperature in the water repellency. Whereas the PVA coating with the TrisilanolPhenyl POSS had a lower variability in the contact angle as the curing temperature was increased. The cotton samples coated with POSS where compared with contact angles measured at 10 seconds and 60 seconds after placing the droplet. The results for 0.1% TrisilanolPhenyl POSS cotton samples proved that only water repellency is achieved at higher curing temperatures. The results of 4% TrisilanolPhenyl POSS cotton samples showed a higher repellency even at lower curing temperatures at 10 seconds. The results of the contact angles at 60 seconds demonstrated that as the curing temperature is increased, the coating prevents the absorption of water. The results demonstrated that POSS can impart hydrophobic properties to these materials even at low concentrations. The unique properties of POSS silanols for surface modification are also discussed.