Theses and Dissertations

Synthesis and Characterization of Force-Spun Composite Polyvinylpyrrolidone Hexagonal Boron Nitride Nanofibers

Date of Award

5-1-2026

Document Type

Thesis

Degree Name

Master of Science in Engineering (MSE)

Department

Electrical Engineering

First Advisor

Fahmida Alam

Second Advisor

Ahmed Jalal

Third Advisor

Hasina Huq

Abstract

Boron nitride (BN) is made up of an equal number of boron and nitrogen atoms; which its nucleus has a strong sigma bond by overlapping sp2 orbital. Thus, it has weak van der Waals forces between N and B atoms between neighboring layers which may also further enhance its anisotropic features. And as there exist four different crystalline forms of BN: cubic BN (c-BN), hexagonal BN (h-BN), wurtzite BN (w-BN), and rhombohedral BN (r-BN), our interest lies in hBN characteristics. The difference in the crystalline forms provides different benefits for different material characteristics. Thus, research into BN-based materials has steadily risen due to their great mechanical strength, chemical stability, etc.

In this work, we synthesize and characterize hexagonal boron nitride/ polyvinylpyrrolidone composite nanofibers which were successfully created by using force spinning methodology. This methodology involves solution mixtures containing boric acid, melamine, and deionized water. The obtained particulate is then treated through a heating process to become h-BN powder. h-BN powders are then mixed with Polyvinylpyrrolidone (PVP), to make force-spun solutions. These solutions are then used to make nanofibers through force-spinning. The solutions were then characterized using rheology, and analyzed on what aspects affects fiber formation in force-spinning. The resulting nanofibers had FTIR characterization to find h-BN and PVP bending and stretching peaks. Furthermore, the chemical composition of the powders and the nanofibers was analyzed using X-ray diffraction, resulting in peaks occurring at angles ~10 ° and ~27 ° at two-theta (2θ). Consequently, the effects of heating the nanofibers were investigated and optimized for nanofiber survivability and effective characterization from heat treatments. In which turn, TGA and DSC analysis was done to find the degradation points of the nanofibers. Scanning electron microscopy (SEM) images were gathered and showed that the nanofibers exhibited good fibrous structures with diameters averaging < 2 um. The composite nanofibers then went through further heating treatment, calcination, to obtain purer fibers, but several complications arose making it difficult to obtain pure h-BN nanofibers. The composite nanofibers have potential applications for thermal insulation, Electrical insulation, adsorption materials, gas sensors, or even bandages. But further refinement of methodology is needed.

Comments

Copyright 2026 Daniel Garza. All Rights Reserved. https://www.proquest.com/docview/3376268915/

This document is currently not available here.

Share

COinS