Search results for "Particle growth"
showing 5 items of 5 documents
Aerosol Chemistry Resolved by Mass Spectrometry: Insights into Particle Growth after Ambient New Particle Formation
2016
Atmospheric oxidation of volatile organic compounds (VOCs) yields a large number of different organic molecules which comprise a wide range of volatility. Depending on their volatility, they can be involved in new particle formation and particle growth, thus affecting the number concentration of cloud condensation nuclei in the atmosphere. Here, we identified oxidation products of VOCs in the particle phase during a field study at a rural mountaintop station in central Germany. We used atmospheric pressure chemical ionization mass spectrometry ((-)APCI-MS) and aerosol mass spectrometry for time-resolved measurements of organic species and of the total organic aerosol (OA) mass in the size r…
Synthesis of single crystalline sub-micron rutile TiO2 rods using hydrothermal treatment in acidic media
2014
Size engineered rutile sub-micron rods were obtained from nanostructured titania under acidic conditions. The synthesis was performed by hydrothermal treatment starting from TiO2-P25 and HCl. The synthesis proceeds in less than two hours and can be up-scaled to several grams in a one-pot reaction by increasing the reaction time. The product is single-phase, and the particles are single crystalline as confirmed by electron diffraction and powder X-ray diffraction analysis. The length of the particles can be varied over a wide range from 100 nm to 1.3 μm by changing the acid concentration. Particle growth is proposed to proceed by a dissolution-recrystallization process via soluble [TiCl6]2− …
Time evolution of size and polydispersity of an ensemble of nanoparticles growing in the confined space of AOT reversed micelles by computer simulati…
2005
The time dependence of size and polydispersity of an ensemble of nanoparticles growing in the confined space of water-containing AOT reversed micelles has been investigated by computer simulations. It has been found that, in a wide time range, the mean nanoparticle size can be described by power laws whose exponent is critically dependent on the efficiency of the intermicellar material exchange process while the nanoparticle polydispersity increases with time. From the analysis of all the disentangled effects arising from the variation of internal and external parameters provided by simulations, useful suggestions for a better and rationale control of the nanoparticle synthetic procedure ar…
Microfluidic continuous flow synthesis of rod-shaped gold and silver nanocrystals
2009
We present a continuous flow synthesis of gold and silver nanorods allowing tailored design of particles with desired shapes and online monitoring of particle growth.
Synthesis of Monodisperse Spherical Nanocrystals
2016
Nanoparticles, small units of matter with dimensions in the range 1-100 nm, exhibit many advantageous size-dependent magnetic, electrical, chemical and optical prop- erties, which are not observed at the microscale or bulk. These properties are extremely sensitive to particle size, and thus the ability to produce monodisperse particles is critical. Due to its ease of use and flexibility, precipitation of nanoparticles from solution is one of the most widely used synthesis methods. The main disadvantage of this method is that the relationship between particle growth and system conditions is not fully understood. In practice, the optimal reaction conditions are usually ascertained empirically…