RAPID: Polymer Aerogels to Protect America's Waterways

Case Western Reserve University, Cleveland OH

Investigators

Abstract

TECHNICAL SUMMARY: A recent body of papers/patent applications describes the preparation, structure/properties and applications of aerogels produced from combinations of clays and polymers, using an environmentally-friendly freeze drying process. One material which resulted from this effort is a low density (<0.1 g/cm3) aerogel material which floats on, and rejects water, but has a high affinity for oil; the oil can be easily squeezed from the aerogels, which can then be placed back into service. Basic knowledge as to how polymer compositional changes in the aerogel composite materials determine the degree of oil absorption is lacking, as are details of the morphology of clay within the cellular structure and its impact upon the oil absorption process. A one year program at Case Western Reserve University (CWRU) is proposed during which the family of polymers which currently exhibit the greatest level of oil absorption when converted into aerogels, poly(amide-imides), would be compared with epoxy resins. The use of epoxy resins would represent a major cost reduction and would facilitate commercial adoption of this technology. Polymers (2-5 wt% solids in water) would be converted into aerogel structures, with the quantity and rate of oil uptake used to evaluate efficacy. The aerogel materials would be characterized by (i) density/BET surface area, (ii) compressive strength/modulus, and (iii) physical structure measured by SEM and XRD. The placement of clay particles within polymer/clay cell walls would be further investigated using high resolution SEM. Torlon® AI-30 and aliphatic/aromatic epoxies produced from combinations of 1,4-butanediol diglycidyl ether, bisphenol-A diglycidyl ether, and poly(ethylene glycol) diglycidyl ether, crosslinked by triethylene tetramine and/or 2,6-diamino pyridine would be evaluated; these are currently used in marine paint. Sodium montmorillonite and laponite would be used as the clay component (0-5 wt%) in the aerogel structures. An absorbance model would be a deliverable of this program. NON-TECHNICAL SUMMARY: At this moment, the Gulf of Mexico is awash with an oil spill of unprecedented size, representing one of the Nation's worst environmental disasters to date. Such oil spills, as well as more routine fugitive spills from refineries and marinas continue to impact and threaten marine life, the fisheries industry, and broadly the quality of life for a large number of Americans. Development of an effective material for efficiently removing oil from water is in the national interest. Research at Case Western Reserve University (Cleveland OH) has resulted in the development of polymer/clay "aerogel" materials which float on, and do not absorb water, but rapidly absorb 8 times their weight in oil; this oil can then be squeezed out of the aerogels, like with a sponge, and the aerogel can be returned to service in the water. A one year program is proposed which will identify the key factors necessary in optimizing this environmental protection product. The basic knowledge obtained in the proposed study will enable translation of the technology from the laboratory to manufacturing in the most effective and economical means possible. STEM workforce development will be impacted by this study as well. A high school student and an undergraduate researcher will combine with the funded Ph.D. student to form a work group; such teams have been demonstrated to work effectively together, and the PI and his institution have a significant track record of promoting young researchers into college and graduate institutions by using research as a means of making STEM fields attractive and relevant to students.