Room temperature, water-based, microreactor synthesis …

T1 - Synthesis of copper nanocolloids using a continuous flow based microreactor

Basics of flow microreactor synthesis

In the Phase I project, TDA demonstrated the technical feasibility of using nanocatalysts in a microreactor for direct synthesis of H2O2. The catalysts developed in Phase I showed a very high activity and selectivity.

Synthesis in a microreactor - SinapTec

AB - This study aims at demonstrating the application of a microreactor combinatorial system for multiple parameter synthesis of nanoparticles. In order to meet this aim, an automatic system for combinatorial synthesis of CdSe nanoparticles was developed, and more than 3300 datasets were obtained to optimize and understand the effect of reaction parameters on nanoparticle properties. A microreactor was used and programmable equipments were employed for additional speed up. Six reaction condition parameters were systematically combined to produce sets of CdSe nanoparticle synthesis conditions. The 3387 datasets under different reaction conditions, with an average time of 7.5. min were generated and characterized. The total experimental time including data handling analyses is approximately one month. The absorbance, absorption peak wavelength, photoluminescence (PL) peak, and PL full width of half maximum (FWHM) were calculated from each spectrum by using computer-aided processing. Based on the results of several multivariate analyses using the numerous and complicated data, we were able to conclude the following (1) nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and limitations of the reaction system, (2) weighting evaluation method is an efficient way to find the condition for balanced nanoparticle properties, and (3) neural network is an effective tool to analyze data generated from combinatorial synthesis.

N2 - This study aims at demonstrating the application of a microreactor combinatorial system for multiple parameter synthesis of nanoparticles. In order to meet this aim, an automatic system for combinatorial synthesis of CdSe nanoparticles was developed, and more than 3300 datasets were obtained to optimize and understand the effect of reaction parameters on nanoparticle properties. A microreactor was used and programmable equipments were employed for additional speed up. Six reaction condition parameters were systematically combined to produce sets of CdSe nanoparticle synthesis conditions. The 3387 datasets under different reaction conditions, with an average time of 7.5. min were generated and characterized. The total experimental time including data handling analyses is approximately one month. The absorbance, absorption peak wavelength, photoluminescence (PL) peak, and PL full width of half maximum (FWHM) were calculated from each spectrum by using computer-aided processing. Based on the results of several multivariate analyses using the numerous and complicated data, we were able to conclude the following (1) nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and limitations of the reaction system, (2) weighting evaluation method is an efficient way to find the condition for balanced nanoparticle properties, and (3) neural network is an effective tool to analyze data generated from combinatorial synthesis.


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The copper (Cu) nanocolloids were prepared by sodium borohydride (NaBH4) reduction of metal salt solutions in a T-shaped microreactor at room temperature. The influence of NaBH4 molar concentrations on copper particle's diameter, morphology, size distribution, and elemental compositions has been investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The ultraviolet-visible spectroscopy (UV-vis) was used to verify the chemical compounds of nanocolloids and estimate the average size of copper nanocolloids. The synthesized copper nanocolloids were uniform in size and non-oxidized. A decrease in the mean diameter of copper nanocolloids was observed with increasing NaBH4 molar concentrations. The maximum mean diameter (4.25 nm) occurred at the CuSO4/NaBH4 molar concentration ratio of 1:2.

(486b) Supercritical Continuous Microreactor Synthesis …

In recent years, the concept of miniaturization has been applied to many areas of chemistry, one of which is the synthesis arena with the development of new microreactor technology. Compared with conventional scale vessels, microreactors are advantageous in many aspects, such as faster mixing, better heat transfer, minimal reagent use and great safety. However, the technology of microreactors is still immature and most organic reactions are simply carried out based on the existing concept and setup of 'lab-on-a-chip'. The analysis-oriented chips are always incompatible with demands of organic synthesis and so the development of synthesis-oriented microreactors is of great need. Our laboratory developed a novel capillary-based reactor system that was specific for high-throughput synthesis and screening. The computer-controlled reactor system integrated standard HPLC apparatus (autosampler, pump), fused-silica capillaries and GC in which separate zones of reactants and catalysts can be combined and loaded serially into a single reactor capillary, reacted in parallel and ejected serially for online GC analysis. One of the applications of our microreactor was to study peptide-catalyzed aldol reaction. We chose a model aldol reaction with benzaldehyde and acetone substrates and known catalyst L-proline. Chiral GC separation conditions were optimized for determination of chiral aldol products. The optimum reaction conditions were 10 mol% L-proline catalyst, DMSO and acetone 1:1 (v/v), room temperature and 4 hr reaction time. A little amount of acetic acid was added to increase L-proline solubility in organic solvents. Several peptides were preliminarily screened in the microreactor. Unfortunately, all of them showed poor activities. The next step is to keep screening active peptide catalysts by our microreactor. Besides, novel solvents will be studied to further increase product yield and selectivity. The microreactor will also be optimized to increase its throughput and efficiency. The optimization process will be based on the combination of mathematical calculation (Mathcad software) and experiments. Moreover, the design of the microreactor will be improved in some units to make the system capable of accommodating more types of reactions such as multi-step reactions, gas-phase reactions or gas/liquid multiphase reactions.