Search results for "Micromixer"
showing 7 items of 7 documents
Time-resolved velocity measurements in a magnetic micromixer
2015
Abstract Mixing efficiency is lower in passive micromixers due to viscous forces and substantial research effort is focused on designing high performance micromixers. Active micromixers make use of external forces to enhance mixing efficiency. Among these, magnetic forces are popular because they are non-contact and therefore the micromixer design can be kept simple. Laser-based diagnostic tools have great potential in providing multi-parameter information in microfluidics research on mixing. MicroPIV experiments are performed to investigate the transient flow field in a magnetic micromixer undergoing labyrinthine instability. Velocity and interface front information is extracted from a seq…
Design and fabrication of an acoustic micromixer for biological media activation
2014
International audience; The bioassay of infinitesimal quantities of protein markers in biological samples is the way to early cancer detection. However, this detection can be limited by the diffusion of these macromolecules (analytes) from the bulk to the sensor chip (surface of ligands). Here, we propose a new method to overcome this drawback by the activation of the biological media during the detection step. The principle consists in using ultrasonic vibrations in order to disrupt the equilibrium states of such biomolecular reactions and performing simultaneous detection inside an acoustic micromixer. Technological realization and initial characterizations of the device have been perform…
Simulating Copolymeric Nanoparticle Assembly in the Co-solvent Method: How Mixing Rates Control Final Particle Sizes and Morphologies
2018
Abstract The self-assembly of copolymeric vesicles and micelles in micromixers is studied by External Potential Dynamics (EPD) simulations – a dynamic density functional approach that explicitly accounts for the polymer architecture both at the level of thermodynamics and dynamics. Specifically, we focus on the co-solvent method, where nanoparticle precipitation is triggered by mixing a poor co-solvent into a homogeneous copolymer solution in a micromixer. Experimentally, it has been reported that the flow rate in the micromixers influences the size of the resulting particles as well as their morphology: At small flow rates, vesicles dominate; with increasing flow rate, more and more micell…
Ionic Liquids on Demand in Continuous Flow
2009
We report on the development of an alternative protocol for the facile, solvent-free synthesis of various novel imidazolium-based ionic liquids (ILs) that affords highly pure products without the necessity of subsequent purification steps. The continuous approach is based on the combination of HPLC pumps with a micromixer and a capillary residence tube. Our system provides a high degree of control over the alkylation reactions due to a high surface-to-volume ratio and superior heat and mass transport. Within the scope of our studies, we focused on ionic liquids containing differently substituted phenyl rings and characterized these compounds with respect to further use for direct applicatio…
Continuously manufactured magnetic polymersomes--a versatile tool (not only) for targeted cancer therapy.
2013
Micromixer technology was used to prepare polymeric vesicles (Pluronic® L-121) dual loaded with the anti-cancer drug camptothecin and magnetic nanoparticles. Successful incorporation of the magnetic nanoparticles was confirmed by transmission electron microscopy. Dynamic light scattering measurements showed a relatively narrow size distribution of the hybrid polymersomes. Camptothecin polymersomes reduced the cell viability of prostate cancer cells (PC-3) measured after 72 h significantly, while drug-free polymersomes showed no cytotoxic effects. Covalent attachment of a cancer targeting peptide (bombesin) as well as a fluorescent label (Alexa Fluor® 647) to the hybrid polymersomes was perf…
Living Anionic Polymerization in Continuous Flow: Facilitated Synthesis of High-Molecular Weight Poly(2-vinylpyridine) and Polystyrene
2014
We describe the living anionic polymerization of 2-vinylpyridine (2VP) and styrene (S) in continuous flow, comparing two micromixing devices with different mixing principles. The use of a continuous flow setup reduces the experimental effort for living anionic polymerizations significantly, compared to a conventional batch system. By adjusting the ratio of the flow rates of the monomer and initiator solutions a variety of different molecular weights can be rapidly synthesized within several minutes, using one setup. Additionally, a comparison of the influence of the two different mixing devices—an interdigital micromixer (SIMM-V2) leading to laminar mixing and a tangential four-way jet mixi…
Microflow Technology in Polymer Synthesis
2012
Microflow technology, i.e., the use of microfluidic devices for continuous flow synthesis, represents a highly useful and increasingly popular method in organic chemistry. Recently, also an increasing number of polymer synthesis protocols attain benefit from this technique. In particular, the control of highly exothermic, fast polymerization reactions can be improved due to the excellent heat and mass transfer within the small dimensions of the microreactors. Continuous flow setups with different micromixer geometries and flow patterns are currently used for the preparation of a variety of macromolecular architectures by ionic and (controlled) radical polymerization techniques. This Perspec…