Nasim Abuali Galehdari – Seminar/PhD Thesis Defense – Monday, March 19, 2018 at 3:00 P.M.

JSNN – Nasim Abuali Galehdari – Ph.D. Thesis Defense/Friday Seminar

Candidate: Nasim Abuali Galehdari

Major Advisor: Ajit D. Kelkar, Ph.D.

Department: Nanoengineering

Time: 3:00 P.M. – 5:00 P.M.

Location: JSNN Auditorium

2907 E. Gate City Blvd., Greensboro, NC 27401

Title: “Fabrication, Characterization and Modeling of Radiation Shielding Sandwich Structures.”

Abstract:

High-energy radiation hazards are one of the major concerns in different industries including aerospace, hospitals, nuclear reactors and related facilities. For example, flights involving long term durations in space, exposure to high energy radiation particles not only can cause serious biological damages to crew, such as carcinogenesis, cardiac problems and damages to the neural system, but also it can induce damages to the structural materials and electronic components. As the current radiation shielding materials are heavy, bulky and not able to block all types of radiation, especially the emission of secondary neutrons, there is an increasing demand and urgent need to develop efficient, lightweight, cost effective multifunctional radiation shielding materials, which can provide structural integrity and damage tolerance. The main objective and significance of the proposed research is to develop lightweight multifunctional hybrid sandwich composite structures that can not only provide radiation shielding but also help to improve mechanical strength of the aerospace structures. In order to optimize the design of these structures, their radiation shielding performance and their mechanical, rheological and thermophysical properties were investigated through wide range of experiments. In addition, for these class of radiation shielding materials, molecular dynamics models to understand a dynamic crosslinking – relaxation methodology are developed, which allows the construction of polymer network from the given monomers. The results of these atomistic simulations provide quantitative characterization of various physical and thermal properties of polymer network and its composite with different nanoparticles. The results obtained using atomistic models are compared with the experimental data and results show a good agreement between simulations and experiments.