Polymer gels are solid-like materials that are mostly composed of liquid. They appear in a wide variety of applications ranging from food and cosmetic products, to agricultural uses, to pharmaceuticals and biomedical devices, and also are relevant to water sustainability. Nearly all research on "loaded gels" thus far has concentrated on water-based materials since water is abundant, versatile, and biocompatible. However, loaded gels comprised of hydrocarbon solvent (e.g., mineral oil), instead of water, offer many benefits including greatly improved shelf life and elimination of complicated water-polymer and water-nanocarrier interactions. This RUI (Research in Undergraduate Institutions) project will deliver an approach to fabricate hydrocarbon-based gels loaded with nanocarriers. Then, principles correlating gel formulation quantities with resultant nanoscale structure and subsequently nanoscale structure with release rate of the nanocarriers and gel physical characteristics (e.g., flexibility and strength) will be established. These results will provide a fundamental understanding of the isolated effects of loaded gel nanostructure on practical properties. Furthermore, the findings will contribute to future developments of loaded gel materials in the health, agricultural, water-sustainability, and related industries. Of equal importance to its technical contributions, this work will be partially conducted by undergraduate STEM students, thereby cultivating their scientific/technical expertise and interests. The students will also be exposed to cutting-edge instrumentation and research at national laboratories. The principal investigator, along with support from these aspiring engineers/scientists, will apply acquired knowledge in undergraduate teaching and middle/high school outreach activities.
Part 2: TECHNICAL SUMMARY
Polymer gels extend the usefulness of macromolecules, including their ability to be loaded with nanocarrier species such as micelles, vesicles, and nanoparticles. Nanocarrier-loaded polymer gels exhibit superior properties over their stand-alone constituents (i.e., payload-containing gels and nanocarriers dispersed in liquids), which is particularly beneficial in applications where high payload storage and slow, steady release are desired, such as in agricultural and pharmaceutical delivery devices. This RUI award supports investigation of loaded block copolymer organogels (referred to as dual domain organogels (DDOGs) or their block copolymer and nanocarrier domains) wherein the solvent and block copolymer are nonpolar hydrocarbons and the nanocarriers are reverse micelles. This makeup eliminates the complex, long-range interactions, such as electrostatic and dipole-dipole forces, present in hydrogels as well as eradicates dependence on a single solvent and greatly extends shelf-life. Objectives of the work include: (i) synthesis of formulation-structure design rules for DDOGs such that a number of their nanoscale features can be methodically tailored, and (ii) establishment of structure-property relationships for reverse micelle diffusion and mechanical behavior in the tailored organogels. The results from this work will not only advance the scientific communities' understanding of loaded gel formulation and properties, but may also inform use of these materials in a number of high-impact technologies including sensors, water purification, ion-exchange processes (e.g., batteries), agriculture, and health. Of equal importance, the work will cultivate the careers of undergraduate STEM students including exceptional experiences to operate cutting-edge instrumentation at national laboratories, interpret resultant data, and present their findings. The principal investigator, along with support from these aspiring engineers/scientists, will extend acquired knowledge to inform undergraduate teaching and middle/high school outreach activities. .
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.