Microreactor Lab Report

Residence time of the reaction mixture in microreactor
The microreactor system is contentious flow reactor system in which the fractional conversion of reactants depends on residence time of reactants in the microreactor. Hence the reaction time defines the extent up to which the reaction is complete, further the size and morphology of the colloidal nano systems. The design calculations of the microreactor are as follows.
The volume of the reactor is given by the equation (1)
Where d is inner diameter and L is the length of the microreactor
The residence time of the reactants in microreactor was given by [23]

The size of nano particles synthesized with CTAB increases with increase in concentration of precursor from 0.002 to 0.005 molL-1of FeCl3. The increase in size of the nano particles at higher concentration was due to instability of colloidal suspension obtained with CTAB. The high number density of nano particles causes the successful inter micelle exchange of content due to less stable surfactant film of CTAB. This inter micelle exchange was responsible for agglomeration and growth of nano particles hence larger nano particles were produced at higher concentration. A considerable narrow size distribution of nano particles was obtained at 0.001 molL-1 concentration (Fig.5), while ploydispersed nano particles were produced at higher concentration. The lower concentration process indicates diffusion limited growth process of nano particles which results in mono dispersed nano particles at lower precursor concentration. Greater rate of reaction at higher concentration of FeCl3 produced large number of metal ions. Therefore the growth process at higher precursor concentration was surface controlled in which the diffusion of growth species from the bulk to the growth surface was sufficiently rapid due to greater availability of metal ions. The mono nuclear growth mechanism of larger nano particles obtained at higher concentration was also responsible for broadening of size distribution of nano particles at 0.005 molL-1 concentration. [26] The XRD analysis (Fig.6) of the colloidal iron oxide nano particles synthesized with CTAB at 0.005 molL-1concentration suggests that maghemite form of iron oxide nano particles was