(93d) Nanocomposite Gamma-Ray Scintillators Created From Encapsulated Quantum Dots in Block Copolymer Nanogel-Particles

Our world is using radioactive materials to solve a vast number of complex problems such as developing nuclear power programs for achieving practical renewable energy resources, diagnosing and treating infectious diseases, sterilizing food products, and creating and disposing nuclear and chemical weapons of mass destruction (WMD). Portable, stable scintillation devices will be necessary for radiation detection in all of these areas of development. Current scintillation devices are composed of single-crystalline semiconductors, whose fabrication is non-trivial. In this research, multifunctional nanocomposite scintillators have been created via novel encapsulated quantum dot (QD) nanogel-particles. These stable nanogel ?containers? have been fabricated by cross-linking the outer shell of amphiphillic poly(ethylene oxide)-b-poly methyl methacrylate (PEO-b-PMMA) block copolymer micelles, which contain surface-functionalized, scintillating cadmium telluride (CdTe) QDs. The PEO core was burned off, and the nanogel-particles were dispersed within a transparent PMMA matrix. To test the performance of the scintillators, they were paired with a photomultiplier tube (PMT), demonstrating high gamma-ray stopping power and efficient light-pulsing intensity for exceptional radiation sensing and recognition devices. The novelty of these nanogel QD composites lies the ability to control the size and distance between nanoparticles, allowing for large concentrations (< 30%) for small (< 3nm) non-aggregating QD to achieve a highly dense, uniform, and transparent scintillating material. The QD chemistry can also be controlled, giving these novel scintillators the potential to outperform current single-crystal scintillator, at a reduced cost.