BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Vrije Universiteit Amsterdam//NONSGML v1.0//EN NAME:PhD defence N.Q. Nguyen METHOD:PUBLISH BEGIN:VEVENT DTSTART:20260608T134500 DTEND:20260608T151500 DTSTAMP:20260608T134500 UID:phd-defence-n-q-nguyen@8F96275E-9F55-4B3F-A143-836282E12573 CREATED:20260922T053045 LOCATION: SUMMARY:PhD defence N.Q. Nguyen X-ALT-DESC;FMTTYPE=text/html:

Mie, my shells, and I

Smart gold particles control light and chemical reactio ns

The research focused on so- called core-shell nanoparticles: extremely small gold particles coate d with a thin layer of another material. By precisely controlling the size, shape and composition of these particles, it turns out that it is possible to specifically modify their optical properties.

A mong other things, Nhu Nguyen developed a method for coating gold par ticles with a shell of aluminum-doped zinc oxide. In doing so, she wa s able to independently vary the size of the gold core, the thickness of the shell and the amount of aluminum. This created a great deal o f control over how the particles absorb and scatter light.

In a ddition, Nhu Nguyen discovered that light itself can be used to grow a silver difference on gold particles. In the process, it was found t hat small spherical gold particles use absorbed light particularly ef ficiently to drive chemical reactions. In contrast, in gold particles with sharp edges and corners, silver growth proceeded differently: t here, silver formed mainly on the edges of the particle.

To inv estigate the processes, Nhu Nguyen made the nanoparticles step by ste p in liquid with colloidal chemistry. Then she analyzed the propertie s with spectroscopy and electron microscopy. This allowed her to trac k exactly how light, shape and material combine to determine the beha vior of the nanoparticles.

Nanomaterials that can efficiently d irect or amplify light play an important role in future technologies. For example, they can be used in highly sensitive sensors for medica l diagnostics or environmental measurements. They also offer opportun ities for photonics, which uses light instead of electricity for info rmation processing.

In addition, the technology can contribute to more efficient solar energy and more sustainable chemical processe s. Because the particles use light to drive reactions, the prospect o pens up for new forms of chemistry that use less energy and are more precise.

According to Nhu Nguyen, the work especially demonstra tes the importance of nanoscale design: by cleverly building material s at the atomic and nano levels, completely new properties can emerge that do not occur at larger scales.

Learn more about the d issertation

DESCRIPTION: Mie, my shells, and I

Smart gold particles control li ght and chemical reactions

Physicist Quynh Nhu Nguyen has develop ed a new way to precisely tune tiny gold particles to interact with l ight. The results could contribute to more efficient sensors, better solar cells and new forms of light-controlled chemistry.The research focused on so-called core-shell nanoparticles: extremely small gold p articles coated with a thin layer of another material. By precisely c ontrolling the size, shape and composition of these particles, it tur ns out that it is possible to specifically modify their optical prope rties.Among other things, Nhu Nguyen developed a method for coating g old particles with a shell of aluminum-doped zinc oxide. In doing so, she was able to independently vary the size of the gold core, the th ickness of the shell and the amount of aluminum. This created a great deal of control over how the particles absorb and scatter light.In a ddition, Nhu Nguyen discovered that light itself can be used to grow a silver difference on gold particles. In the process, it was found t hat small spherical gold particles use absorbed light particularly ef ficiently to drive chemical reactions. In contrast, in gold particles with sharp edges and corners, silver growth proceeded differently: t here, silver formed mainly on the edges of the particle.To investigat e the processes, Nhu Nguyen made the nanoparticles step by step in li quid with colloidal chemistry. Then she analyzed the properties with spectroscopy and electron microscopy. This allowed her to track exact ly how light, shape and material combine to determine the behavior of the nanoparticles.Nanomaterials that can efficiently direct or ampli fy light play an important role in future technologies. For example, they can be used in highly sensitive sensors for medical diagnostics or environmental measurements. They also offer opportunities for phot onics, which uses light instead of electricity for information proces sing.In addition, the technology can contribute to more efficient sol ar energy and more sustainable chemical processes. Because the partic les use light to drive reactions, the prospect opens up for new forms of chemistry that use less energy and are more precise.According to Nhu Nguyen, the work especially demonstrates the importance of nanosc ale design: by cleverly building materials at the atomic and nano lev els, completely new properties can emerge that do not occur at larger scales.Learn more about the dissertation END:VEVENT END:VCALENDAR