On the Micromixing Behavior of a Spinning Disk Reactor for Metallic Cu Nanoparticles Production

Abstract

The interest in producing copper nanoparticles is high, mainly due to their enhanced properties, a wide range of possible and different applications, and the possibility for their use in the framework of catalysis. The purpose of this study is to synthesize copper nanoparticles by chemical reduction of copper sulfate with L-ascorbic acid and sodium borohydride capable to eliminate free radicals providing an antioxidant environment promoting pure copper nuclei formation. The micromixing conditions necessary for the nanoparticles production are provided by a spinning disk reactor (SDR). Relevant operational parameters, such as the disk speed velocity and the position of the reactant injectors, will lead to different product outcomes. The latter was checked by means of a dynamic light scattering instrument (DLS). At the end, depending on the adopted operating conditions, the SDR was able to produce particles between 16 nm and 39 nm, with a particle size distribution (PSD) characterized by a narrow, monomodal plot. In comparison to the smallest particles obtained in a stirred reactor tank, that is, 132 nm, the obtained results appear to be very promising.

Review of Experimental Setups for Plasmonic Photocatalytic Reactions

“…In SDRs (Figure 2h and Figure 3a) [24,[55][56][57][58][59][60][61], a reaction disk rotates to drive the fluid to move on top of it. The fluidic layer near the deposited photocatalyst moves faster than other layers above.…”

ZnO Nano-Particles Production Intensification by Means of a Spinning Disk Reactor

“…Indeed, at fixed r i , an increase in Q caused a yield reduction of approximately 1–3% (see Table 2 ), whereas when maintaining Q as constant, an increase in r i led to a yield reduction of 1–2%. These parameters also influenced the average dimension of the obtained nanoparticles, mainly due to the different specific power values dispersed in the rotating liquid film ε [W/kg] and mixing time τ mix [s], as already observed in previous works [ 10 , 24 ]: where v r [m/s] is the average radial velocity calculated according to a simplified centrifugal model [ 35 ]. Figure 6 displays the influence of ε (a) and of τ mix (b) on the nZnO particles mean diameter.…”

“…Nowadays, nanoparticle production has increased in a notable way due to its widespread number of applications in different sectors—such as electronic and energy storage [ 1 , 2 , 3 , 4 ], industrial catalysis [ 5 , 6 ], pharmaceutical and biomedical [ 3 , 7 , 8 , 9 ], food [ 10 , 11 , 12 ], civil and waste re-use [ 13 , 14 , 15 , 16 ], and the environment [ 13 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. The production of nanoparticles requires particular operating conditions and equipment, in particular the achievement of micro-mixing conditions [ 24 , 25 ] to avoid rapid aggregation phenomena [ 26 , 27 ], or the use of complexing agents to reduce surface electrostatic attraction among nanoparticles, such as carboxy-methyl-cellulose, alginate, xanthan and other organic compounds [ 28 , 29 ]. Metallic and metal oxide nanoparticle synthesis has been widely studied, and many articles can be found in the literature [ 30 ].…”