ORCID
0009-0007-5286-4651
Keywords
Surface engineering, Polydopamine-mediated metal deposition Core–shell nanoparticles, Cellulose nanocrystals, Copper-based antimicrobials, Sustainable crop protection
Subject Categories
Chemical Engineering | Materials Science and Engineering | Nanoscience and Nanotechnology
Abstract
Conventional approaches to nanomaterial synthesis often struggle to achieve precise control over surface composition, structure, and function, limiting both the reproducibility of nanoparticle fabrication and the performance of nanomaterials deployed in real-world applications such as sustainable agriculture. This dissertation addresses these challenges by developing surface and interface engineering strategies for two distinct nanomaterial platforms: plasmonic metal nanoparticles and cellulose-based agricultural nanocomposites. Chapter 1 introduces the structural and synthetic principles governing nanomaterial design, with emphasis on controlled metal deposition during seed-mediated growth and copper-based crop protection technologies and their limitations. Chapter 2 presents a polydopamine-mediated strategy for directing secondary Au and Ag deposition on gold nanoparticle seeds with different geometries, including spheres, rods, bipyramids, and cubes. By placing metal-binding and redox-active functionality at the nanoparticle surface, the PDA interlayer promotes interfacial metal growth and reveals how PDA thickness, seed geometry, and secondary metal identity control morphology retention, overgrowth, and plasmonic response. Chapter 3 reports the design of copper-loaded cellulose nanocrystal nanocomposites synthesized through in situ precipitation of copper species onto cellulose nanocrystals derived from a mixed-acid hydrolysis route. These nanocomposites exhibit strong antibacterial activity against copper-sensitive and copper-tolerant Xanthomonas perforans strains while improving foliar copper retention and reducing phytotoxicity compared with a leading commercial copper bactericide at equivalent copper doses. Mechanistic studies indicate that the hydrophilic, porous cellulose nanocrystal network contributes to antimicrobial performance by promoting bacterial localization and contact near copper-containing residues. Chapter 4 summarizes the key findings of both systems and outlines future directions for improving structural control, field translation, and structure–function understanding. Collectively, this dissertation demonstrates how rational surface and interface design can improve synthetic control, functional performance, and environmental compatibility across diverse nanomaterial systems, offering practical platforms for plasmonic nanotechnology and safer, more effective crop protection strategies.
Completion Date
2026
Semester
Summer
Committee Chair
Santra, Swadeshmukul
Degree
Doctor of Philosophy (Ph.D.)
College
College of Sciences
Department
Chemistry
Format
Document Type
Dissertation
Language
English
Release Date
8-15-2028
STARS Citation
Sharma, Bhanu, "Surface-Localized Reactivity In Functional Nanomaterials: Polydopamine-Mediated Metal Deposition And Copper-Loaded Cellulose Antimicrobials" (2026). Graduate Studies Theses and Dissertations 2026. 352.
https://stars.library.ucf.edu/gradstudies_etd_2026/352
Included in
Chemical Engineering Commons, Materials Science and Engineering Commons, Nanoscience and Nanotechnology Commons
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