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Microfabrication of Nanoporous Gold Patterns for Cell-material Interaction Studies
Published on: July 15, 2013
Photothermal patterning of microgel/gold nanoparticle composite colloidal crystals
Clinton D Jones1, L Andrew Lyon
1School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta 30332-0400, USA.
Journal of the American Chemical Society
|January 9, 2003
Summary
We developed a new laser-based method for patterning self-assembled hydrogel microparticle photonic crystals. This technique uses gold nanoparticles to control crystal-to-glass transitions, enabling tunable optical properties.
Area of Science:
- Materials Science
- Nanotechnology
- Photonics
Background:
- Self-assembled colloidal crystals exhibit unique optical properties based on their periodic structure.
- Thermoresponsive hydrogel microparticles (microgels) allow for dynamic structural changes.
- Photothermal effects can be harnessed to induce phase transitions in materials.
Purpose of the Study:
- To introduce a novel laser-based method for direct writing on hydrogel microparticle colloidal crystals.
- To investigate the use of photothermal excitation of co-assembled gold nanoparticles for material patterning.
- To demonstrate controlled, reversible transitions between crystalline and glassy states in photonic materials.
Main Methods:
- Assembly of close-packed colloidal crystals from thermoresponsive poly-N-isopropylacrylamide hydrogel microparticles (approx. 224 nm).
- Co-assembly of smaller colloidal gold nanoparticles (approx. 16 nm) with hydrogel microparticles.
- Photothermal excitation using a frequency-doubled Nd:YAG laser (532 nm) to induce transitions via localized heating.
Main Results:
- Hydrogel microparticle crystals show sharp Bragg diffraction peaks in the visible spectrum.
- Temperature-induced deswelling leads to reversible melting of the crystalline structure.
- Laser-induced photothermal excitation of gold nanoparticles controllably converts between crystalline and glassy states.
Conclusions:
- A new method for laser direct writing in self-assembled photonic materials is presented.
- Photothermal excitation of co-assembled gold nanoparticles offers precise control over material states.
- This technique enables the patterning of self-assembled photonic materials with tunable optical properties.
