Synthesis of colloidal inorganic nanomaterials and their interactions with soft matter

Turner, Jacob

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https://hdl.handle.net/2142/113146 Copy

Description

Title

Synthesis of colloidal inorganic nanomaterials and their interactions with soft matter

Author(s)

Turner, Jacob

Issue Date

2021-07-08

Director of Research (if dissertation) or Advisor (if thesis)

Murphy, Catherine J

Doctoral Committee Chair(s)

Murphy, Catherine J

Committee Member(s)

• Leal, Cecilia
• Vura-Weis, Josh
• Lu, Yi

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• nanomaterials
• gold nanorods
• protein corona
• nanocomposites
• surface chemistry

Abstract

Nanomaterials have garnered a lot of attention the last several decades due to the unique material properties observed on the nanoscale (1-100 nm). In particular, colloidal nanoparticles have been a main focus of the research community due to their large surface areas and resulting high surface energies. This leads to nanoparticles having very different optical properties, electrical properties, and reactivities compared to their bulk counterparts. These properties are largely influenced by the chemical composition, shape, and size of the colloidal nanoparticles. Nanoparticles are often combined with other materials for specific applications to make use of their unique nanoscale properties. Therefore, furthering the understanding of how these nanoparticles interact with other forms of matter is necessary for the continued development of nanotechnology. This dissertation focuses on a few types of colloidal inorganic nanoparticles and how they interact with soft materials. The inorganic nanoparticles of focus are gold nanorods (AuNRs), metal-organic framework (MOF) nanoparticles (nanoMOF), and the core-shell combination of the two (AuNR@MOF). This work demonstrates how these inorganic nanoparticles interact with two important forms of soft matter, polymer composites and biomolecules. In Chapter 1, colloidal inorganic nanoparticles are explained in detail with a focus on AuNRs and nanoMOFs. The plasmonic properties and applications of AuNRs are outlined, along with the synthesis and surface engineering of AuNRs. The unique properties of MOFs and their applications is discussed with an emphasis on what makes them advantageous over other porous nanomaterials. Chapter 1 will also introduce the basic concepts regarding these nanoparticle interactions with soft matter. This portion will highlight the nano-bio interface and explain the importance of the protein corona. In addition to biological soft matter, polymer nanocomposites will be explained with attention on hydrogel-nanoparticle composites. A layer-by-layer method developed for growing a MOF around a AuNR is discussed in Chapter 2. MOFs lend themselves to a layer-by-layer growth method due to their distinctive building block nature. Using the layer-by-layer method, a HKUST-1 shell was grown on the AuNR surface with a sub-nanometer level control over the shell thickness. Interestingly, the surface charge is also easily controlled by the terminal layer either being the metal nodes (positive charge) or the organic linker (negative charge). It was also found that with the proper surface modification of the AuNRs, a very conformal MOF shell could be grown. These materials with highly porous shells around AuNRs have promise in areas such as sensing and catalysis. Chapter 3 examines the synthesis of MOF shells around AuNRs using reported one-pot methods as opposed to the developed layer-by-layer method. These one-pot synthetic methods produce much larger shells and they are not as conformal. However, these methods allow for a larger quantity of material to be produced in a much timelier manner. The MOF shell produced was made of ZIF-8, which is one of the more aqueous stable MOFs, a necessity to probe the interactions with biomolecules. The synthesis of nanoMOFs is also discussed in Chapter 3. The characterization of AuNR@ZIF-8 and nanoZIF-8 particles is shown and the properties of these two materials are compared. Chapter 4 advances on the work in Chapter 3 and discusses how the synthesized porous nanoparticles interact with different proteins. Three proteins with very different sizes and isoelectric points were studied. It was determined that the AuNR@ZIF-8 particles had a higher amount of protein adsorption per unit surface area compared to nanoZIF-8. The thermodynamics of this adsorption process was also determined using isothermal titration calorimetry. Furthermore, the orientation of the proteins at the surface was evaluated and it was determined that certain proteins had a preferred orientation. This work shows the potential for porous nanoparticles to be used to create engineered protein coronas. In Chapter 5 the focus shifts away from nanoparticle interactions with biological soft matter and towards polymer composites. AuNRs of varying surface chemistries were successfully dispersed into the pre-gel mixture of a tough and stretchable hydrogel. The hydrogel formed with the AuNRs present and maintained its phenomenal mechanical properties. The ability of the stretchable hydrogel to control AuNR orientation by reversibly aligning the AuNRs was also demonstrated. This work outlines the fundamentals of nanoparticles dispersed into multi-polymer systems, and the capability of using a biocompatible hydrogel to control AuNR alignment.

Graduation Semester

2021-08

Type of Resource

Thesis

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http://hdl.handle.net/2142/113146

Copyright and License Information

Copyright 2021 Jacob Turner

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