Nuclear Waste Capture using Pillared Nanosheet Materials

Abstract

Nuclear energy currently accounts for 8% of the United States annual energy generation, and a solution to the long term storage and recapture of nuclear wastes has yet to be achieved. Specifically the capture and storage of high level waste products such as cesium- 137 and strontium-90, which are easily transported through biological systems and environments, is still challenging. Pillared nanosheets may offer a potential solution to both the issues of environmental contamination and long term storage of high level nuclear wastes. æPillared nanosheets consist of a hierarchical structure of inorganic layers of approximately 1 nm thickness spaced by inorganic pillars; due to tunable porosity within and between the nanosheets, high density of ion-exchange sites, and controllable thermal stability, these materials show promises at capturing large amounts of nuclear wastes than methods currently employed. Pillaring of nanosheet layers occurs in a three-stage process, consisting of hydrothermal synthesis of the nanosheet precursor, swelling of the material through the introduction of long chain organics and silica containing groups, and calcination. The spaces created between the organic moieties and the layers become a template for the pillaring process, allowing us to create a periodic structure of nanosheets with pore channels of tunable dimensions. The choice of the organic linkers, which have various chain lengths and functional groups, will allow for the physical and chemical control of the pore space.