Thermophoretic coating with molybdenum oxide nanoparticles

Thermophoretic and electrophoretic coatings are the main viable mechanisms for the coating of objects with nanoparticles. Unlike electrophoretic coating, thermophoretic coating has the advantage that electrically conductive substrates are not a requirement. This paper investigates the thermophoretic deposition and uniformity of molybdenum oxide nanoparticles, generated by a glowing wire generator, on various surfaces at three different flow rates (0.3, 1 and 1.5Lmin). The quantitative evidence of the presence of particles collected by a suggested thermophoretic precipitator at different flow rates has shown that a uniform distribution of the particles could be achieved across the whole area of the precipitator. SEM and TEM micrographs of the film confirmed that a homogeneous densely packed network of molybdenum oxide nanoparticles was built across the precipitation area at the flow rate of 1.5Lmin

A new thermophoretic precipitator for off-line particle analysis

A new thermophoretic particle precipitator has been developed for representative and efficient collection of aerosol particles from the ambient air and technological pipelines. The device consists of hot and cold plates (5×5cm) capable of operation at temperature gradients ranging from 20000 to 100000K/m. A gas sample is made to pass through a 1-mm slot between the plates at a flow rate of up to 1.5L/min, which makes the device suitable for operation in conjunction with common aerosol instruments including DMA and diffusion batteries with similar operational flow rates. It was shown that the efficiency of the device was highest for the lowest gas flow rate used (0.3L/min) reaching a level of above 99%. The efficiency was decreased reaching its minimal values at the highest flow rate investigated (1.5L/min). However, even for highest flow rate, the average efficiency for removal of particle smaller than 60nm was around 50%

An influence of a gas velocity on morphology of molybdenum oxide nanoparticles generated by a glowing wire generator

In this paper we report the results of investigation of a gas carrier velocity influence on morphology and structure of molybdenum oxide nanoparticles, produced by a glowing wire generator. The device operational principle is based on electrical resistance related heating of a metal wire and placement it into relatively cool and not ionized gas carrier for rapid solidification of vapour released from the wire surface. The results show that the suggested system is capable of producing a variety of nanostructures by changing a single process parameter-velocity of the gas carrier