چكيده به لاتين
Laboratory equipment based on microfluidics has attracted much attention in various applications such as laboratory technologies on chips, tissue engineering, cell culture, nanoparticle preparation, drug delivery, and biosensors. microfluidic droplet technology is a new way to produce biocompatible composite droplets on a micro-scale. The production process of these droplets can be carefully controlled and monitored. On the other hand, these composite droplets have advantages over conventional technologies for the production of bulk materials. The size of the produced droplets is controlled by adjusting the flow rate of each fluid. The micro-scale of the droplet size increases the heat-mass transfer rate of the composite droplets. First, a mathematical model based on the computational fluid dynamics method was developed to better understand the shape and size of droplets in a concentrated stream microchannel using two Newtonian incompressible non-miscible fluids in COMSOL Multiphysics® 5.4 software.
In the first stage, FC-40 oil/ water fluid was used to optimize the model, and then chitosan solutions with different concentrations were used as discrete fluid and vegetable oil as continuous fluid. The parameters of channel geometry, channel dimensions, channel inlet angle, volume change rate of inlet fluid flow as well as change of dynamic characteristics of discrete fluid in size and shape and droplet production process were discussed. Depending on the different scenarios, 360 simulations are performed to fully investigate the effect of fluid velocity, geometry and channel dimensions for the FC-40 oil/ water system and 192 simulations for the chitosan / vegetable oil system as well as discrete fluid concentrations Based on the final results, it was done. At the end of the simulation section, using particle tracking module, release simulation and loading of magnetite nanoparticles in discrete fluid were discussed.
In the laboratory section, first, the chip was designed based on the simulation results and then the design was made by the lithographic method of silicone mask, and then moulded by PDMS polymer and finally, the chip was bonded to the glass plate using oxygen plasma machine. Chitosan solution was used with different concentrations in the chip and chitosan drops were produced. In the loading section of magnetite nanoparticles, 1% w /v chitosan solution along with 0.5 wt% magnetite nanoparticles was inserted into the chip and chitosan-magnetite drops were produced.
