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:2026/phd-defence-n-q-nguyen@8F96275E-9F55-4B3F-A143-836282E12573 CREATED:20260610T111314 LOCATION:(1st floor) Auditorium, Main building De Boelelaan 1105 1081 HV Amsterdam SUMMARY:PhD defence N.Q. Nguyen X-ALT-DESC;FMTTYPE=text/html:

Mie, my shells, and I

Smart gold particles control light and chemical reactions

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

Among ot her things, Nhu Nguyen developed a method for coating gold 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 thickness of the shell and the amount of aluminum. This created a great deal of contr ol over how the particles absorb and scatter light.

In addition , Nhu Nguyen discovered that light itself can be used to grow a silve r difference on gold particles. In the process, it was found that sma ll spherical gold particles use absorbed light particularly efficient ly to drive chemical reactions. In contrast, in gold particles with s harp edges and corners, silver growth proceeded differently: there, s ilver 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 o r amplify light play an important role in future technologies. For ex ample, they can be used in highly sensitive sensors for medical diagn ostics or environmental measurements. They also offer opportunities f or photonics, which uses light instead of electricity for information processing.

In addition, the technology can contribute to more efficient solar energy and more sustainable chemical processes. Beca use the particles 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 nanoscale design: by cleverly building materials at th e atomic and nano levels, completely new properties can emerge that d o not occur at larger scales.

Learn more about the disserta tion

DESCRIPTION:

Smart gold particles control light and chemical react ions

Physicist Quynh Nhu Nguyen has developed a new way to preci sely tune tiny gold particles to interact with light. The results cou ld contribute to more efficient sensors, better solar cells and new f orms of light-controlled chemistry. The research focused on so-called core-shell nanoparticles: extremely small gold particles coated with a thin layer of another material. By precisely controlling the size, shape and composition of these particles, it turns out that it is po ssible to specifically modify their optical properties. Among other t hings, Nhu Nguyen developed a method for coating gold particles with a shell of aluminum-doped zinc oxide. In doing so, she was able to in dependently vary the size of the gold core, the thickness of the shel l and the amount of aluminum. This created a great deal of control ov er how the particles absorb and scatter light. In addition, Nhu Nguye n discovered that light itself can be used to grow a silver differenc e on gold particles. In the process, it was found that small spherica l gold particles use absorbed light particularly efficiently to drive chemical reactions. In contrast, in gold particles with sharp edges and corners, silver growth proceeded differently: there, silver forme d mainly on the edges of the particle. To investigate the processes, Nhu Nguyen made the nanoparticles step by step in liquid with colloid al chemistry. Then she analyzed the properties with spectroscopy and electron microscopy. This allowed her to track exactly how light, sha pe and material combine to determine the behavior of the nanoparticle s. Nanomaterials that can efficiently direct or amplify 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 photonics, which use s light instead of electricity for information processing. In additio n, the technology can contribute to more efficient solar energy and m ore sustainable chemical processes. Because the particles use light t o drive reactions, the prospect opens up for new forms of chemistry t hat use less energy and are more precise. According to Nhu Nguyen, th e work especially demonstrates the importance of nanoscale design: by cleverly building materials at the atomic and nano levels, completel y new properties can emerge that do not occur at larger scales. Learn more about the dissertation Mie, my shells, and I END:VEVENT END:VCALENDAR