Designing materials with low-surface energy (weak strength of adhesion) and mechanical robustness have become a major objective in the scientific community. Various nano-fillers have been blended into polymers in order to improve overall system performance as non-wetting surfaces.
Of these fillers, a sub-class of particles possessing long-chain fluoroalkyl groups, Fluoroalkyl Polyhedral Oligomeric SilSesquioxanes (F-POSS), has recently been developed and observed to be an excellent nano-filler for low-surface energy applications. F-POSS compounds have been blended in polymer matrices and cast to produce super-hydrophobic and super-oleophobic surfaces. These qualities are valued in touch screens found on smartphones, tablets, and interactive kiosks.
F-POSS compounds have been used in standalone form without further reactive chemical functionality. However, this limits solubility in common solvents and sacrifices some of the mechanical robustness and abrasion resistance of surfaces containing these materials. Unfortunately, none of the conventional synthesis strategies are viable to produce long-chain (more than three carbon atoms) F-POSS compounds possessing additional reactive or non-reactive functionality beyond alkyl or aryl peripheries.
Air Force researchers working with F-POSS have developed a method for manufacture by opening a single edge of a closed-cage F-POSS and bridging the opened, single edge with a sulfate group. The sulfate group is converted to a disilanol, which is then reacted with a functional dichlorosilane having an organic functional group comprising at least three carbon atoms. This allows for the addition of a wide variety of functional groups and holds promise for greatly extending the utility of F-POSS compounds.
This US patent 9,790,377 is a divisional of US patent 9,249,313.
- Functionalized F-POSS may be cast onto a substrate or blended with copolymers to produce surfaces having robust, abrasion resistant, superhydrophobic, and oleophobic material properties
- US patent 9,790,377 available for license
- Potential for collaboration with Air Force researchers