Molding Process Retaining Gold Nanoparticle Assembly Structures during Transfer to a Polycarbonate Surface.

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Immobilizing ordered gold nanoparticle (AuNP) assemblies on polymer surfaces is crucial for developing advanced optical devices.
• Preserving the precise arrangement of nanoparticles during processing is a significant challenge.

Purpose of the Study:

• To investigate the immobilization of AuNP linear surface assemblies on polycarbonate (PC) melt surfaces using molding.
• To assess the structural fidelity and preservation of plasmonic properties during the injection molding process.

Main Methods:

• Utilizing molding techniques to transfer AuNP assemblies onto PC melt surfaces.
• Employing Scanning Electron Microscopy (SEM) and image analysis to quantify structural order using an orientational order parameter.
• Characterizing optical properties via ultraviolet-visible-near-infrared (UV-Vis-NIR) spectroscopy to determine dichroic ratios.

Main Results:

• The order of AuNP assemblies was preserved during the molding process, with an order parameter of approximately 0.98.
• The assemblies exhibited strong plasmonic coupling and dichroic properties, quantified by dichroic ratios of 0.28 and 0.52.
• The immobilized AuNP assemblies demonstrated robustness, withstanding harsh processing conditions and chemical treatments.

Conclusions:

• Injection molding is an effective method for embedding AuNP assemblies onto polymer surfaces while maintaining structural integrity and optical properties.
• This technique bridges self-assembly methods with polymer processing, paving the way for scalable fabrication of plasmonic devices.
• The resulting AuNP line assemblies on PC serve as a foundation for applications such as surface-enhanced Raman scattering (SERS) sensors and nanowire precursors.