Nuclear energy is one of the best sources of clean energy. One major concern is the disposal of the used nuclear fuel, any process for its disposal needs to have a minimal impact on the environment. Globally plutonium and uranium recovery for MOX fuel is performed using the PUREX process. However, this comes with certain disadvantages such as the requirement for large quantities of separation reagents and the generation of significant volumes of secondary waste that might increase the threat of proliferation. With long term storage of used nuclear fuel, there is potential for contaminating ground water due to the performance of interim and long-term geologic storage containers. Novel magnetic nanosorbents-surface functionalized magnetic nanoparticles conjugated with specific metal chelators-has been developed for separation of metal ions from aqueous systems, which offers a simple, fast, effective, and environmentally benign technique in spent nuclear separation. The unique properties of magnetic nanoparticles (MNPs), such as their extremely small size and high surface area to volume ratio, provide better kinetics for the adsorption of metal ions from aqueous solutions. The high magnetic susceptibility of MNPs aids in an efficient separation of particles from waste solution. In this work, we demonstrated the separation of minor actinides using complex conjugates of MNPs with DTPA chelator. The uptake behavior of Am(III), Pu(IV), U(VI), and Np(V) from 0.1M NaNO3 solution was determined. The sorption results show the strong affinity of DTPA towards Am(III) and Pu(IV) by extracting 97% and 80% of actinides, respectively. Advanced magnetic separation nanotechnology proves an effective method for used nuclear fuel recycling as it is a simple, versatile, compact, and cost-efficient process that minimizes secondary waste and improves storage performance.

Statement of the Problem: Hierarchical superstructures (HSSs) are 3-D structures with a significant improvement in some properties as compared to isolated nanoparticles. However, formation of HSSs has been conducted by intricate methods that usually involve synthesis of the building blocks and the assembly in superstructures in a second step. Methodology & Theoretical Orientation: As alternative one-pot procedure, we propose the use of bicontinuous microemulsions (BCME). The channels of BCMEs have a thickness in the nanometer scale. Both water and oil channels are continuous phases, having infinite lengths. Thus, it is feasible to imagine the growth of HSS inside them, as the narrow thickness of the channels will allow the formation of nanometer building blocks, whilst their interconnection allows for the self-assembly of these nanoparticles into macroscopic 3D networks. The use of BCME for the synthesis of inorganic nanomaterials is rare, in comparison to the use of W/O and O/W ME. When BCME were used, isolated and well dispersed NPs has been obtained, mostly using ionic surfactants and water-soluble precursors. In this investigation, we used BCME based on the nonionic system water/ Synperonic 91/5 /isooctane for the synthesis of Pt, PtCo3O4, PtCoNi,  and Ag HSSs. The use of both water- and oil-soluble precursors were compared. Findings: HSSs resembling nanocorals, made by interconnected NPs or nanoneedles were obtained (Pt, PtCo, PtNi, PtCo3O4), both by chemical reduction and electrodeposition. These materials were explored as electrocatalysts. On the other hand, for Ag superstructures, it was necessary to add a stabilizer (sodium citrate) in order to form a Ag HSS, which was assessed as Surface Enhanced Raman Spectroscopy (SERS) substrate, resulting in analytical enhancement factors in the order of 109 for Rhodamine 6G.  These results demonstrate the usefulness of employing certain BCME for HSSs synthesis of, although the concept is not universal to all BCMEs.

Because of the grown demand for the energy and also grown price of materials, it is significant to present low price and energy efficient materials. This should be said that the amount of fossil fuels throughout the world is decreasing because of grown energy demand. To relate the energy demand, it is imperative to rely on the solar energy, as it is renewable energy, freely available in the world. Recently, the temperature of the earth's atmosphere is growing which can be used and then converted to beneficial energy in the shape of heating of water. One of the techniques is using a flat plate collector. One of the innovative passive methods which is used by several researchers is Nanotechnology. Different nanomaterials can be used for solar applications and among them, Aluminum oxide has attracted the attention of researchers. Utilizing twisted tapes can generate swirls and disturb boundary layers, thus this technique is the most extensively-employed one to improve convection.