Chelating Agent Functionalized Substrates for the Formation of Thick Films via Electrophoretic Deposition

Abstract

Incorporating nanoparticles into devices for a wide range of applications often requires the formation of thick films, which is particularly necessary for improving magnetic power storage, microwave properties, and sensor performance. One approach to assembling nanoparticles into films is the use of electrophoretic deposition (EPD). This work seeks to develop methods to increase film thickness and stability in EPD by increasing film-substrate interactions via functionalizing conductive substrates with various chelating agents. Here, we deposited iron oxide nanoparticles onto conductive substrates functionalized with three chelating agents with different functional moieties and differing chelating strengths. We show that increasing chelating strength can increase film-substrate interactions, resulting in thicker films when compared to traditional EPD. Results will also be presented on how the chelating strength relates to film formation as a function of deposition conditions. Yield for EPD is influenced by deposition conditions including applied electric field, particle concentration, and deposition time. This work shows that the functionalization of substrates with chelating agents that coordinate strongly with nanoparticles (phosphonic acid and dopamine) overcome parameters that traditionally hinder the deposition of thicker and more stable films, such as applied electric field and high particle concentration. We show that functionalizing substrates with chelating agents is a promising method to fabricate thick, stable films of nanoparticles deposited via EPD over a larger processing space by increasing film-substrate interactions.

Electro-Biofabrication. Coupling Electrochemical and Biomolecular Methods to Create Functional Bio-Based Hydrogels

“…Our focus was biological functions, and we initially focused on molecular-based biological function (e.g., conferred by nucleic acids , and proteins , ), while cell-based function awaited the discovery of alginate’s electrodeposition. Other groups focused on non-biological functions and used co-deposition mechanisms to create composite films and especially composites with ceramics. ,,,,− A major recent focus of many groups (including ours) are functions conferred by integrating catecholic moieties (including polydopamine) with electrodeposited films. ,,,, …”

0‐3 magnetic nanocomposites via EPD: Current status for power component fabrication and future directions

“…An illustration of substrate functionalization is shown schematically in Figure 3. 30 By functionalizing conductive gold substrates with chelating agents, the deposited films of particles are thicker and were shown to have increased stability on the deposition substrate, as observed by general handling and the tape test (ASTM-D3359-17), which measures the adhesion of films via the application and removal of pressure-sensitive tape from the film. The observed improvement in film deposition can be attributed to both the particular chelating agent and the conditions (applied field and particle concentration) under which the EPD was performed.…”

“…There are, however, a few drawbacks of this functionalization approach, especially F I G U R E 4 Plot showing the normalized thickness (defined as the average functionalized film thickness divided by the average non-functionalized thickness) comparing the films that were both non-functionalized and functionalized with nitrilotriacetic acid, phosphonic acid, or dopamine. Reproduced from Mills et al 30 (CC-BY 4.0). the time for functionalization, which was set at 24 h in this work.…”

“…28 However, depositing iron oxide nanoparticles via EPD, which previously had not been extensively studied, and challenges of film adhesion are addressed in this work via EPD parameter optimization and substrate functionalization for film stability. 29,30 Next, the use of EI for infiltrating a magnetic material within the nanoparticle film with the subsequent crosssectional and magnetic characterization of the fabricated 0-3 nanocomposites with this novel method are presented, showing the cumulative fabrication process. EI, a method utilized by Wen et al 26 and Hayashi et al 31 utilizes a typical electroplating set-up to "infiltrate" the porous nanoparticle film with the electroplated metal of choice.…”

Sensing Alzheimer’s Disease Utilizing Au Electrode by Controlling Nanorestructuring

“…The use of SH-PEG-NHS on anchoring the antibody Aβ (1-42) facilitates a straightforward and stable crosslinking process with no other activation steps required. The SH-PEG-NHS is a common linker used in modifying proteins and drugs since the NHS ester reacts with the primary amine group of antibody/proteins at pH 7-8.5 to form a stable amide bond [43,44]. It can also suppress the non-specific binding of charged molecules to the modified surfaces.…”