The Intelligent Properties of Micro-reactors for Preparating Nanoparticles

TiO2 nanoparticles were synthesized by using micro-reactors. The shape and size of the nanoparticles produced from the original micro-reactors and the five times recycled micro-reactors mother liquor were investigated on transmission electron microscopy (TEM) by using the original sample, freeze prepared sample, and dyeing treated sample, respectively. UV-VIS spectrometry was used to study the growth process of TiO2 nanoparticles in main reactors. The results showed that micro-reactors with nanometer magnitude had spherical or oval structures, and could restore to their original structure after they were destroyed. The products prepared in the original micro-reactors were similar to that in the micro-reactors recycled for many times, suggesting that the micro-reactors had memory function.

Improved picoliter-sized micro-reactors for high-throughput biological analysis

High-throughput pyrosequencing,carried out in millions of picoliter-sized reactors on a fiber-optic slide,is known for its longer read length.However,both optical crosstalk(which reduces the signal-to-noise ratio of CCD images)and chemical retention adversely affect the accuracy of chemiluminescence determination,and ultimately decrease the read length and the accuracy of pyrosequencing results.In this study,both titanium and oxidized aluminum films were deposited on the side walls and upper faces of micro-reactor slides to enhance optical isolation;the films reduced the inter-well crosstalk by one order of magnitude.Subsequently,chemical retention was shown to be caused by the lower diffusion coefficient of the side walls of the picolitersized reactors because of surface roughness and random pores.Optically isolated fiber-optic slides over-coated with silicon oxide showed smoother surface morphology,resulting in little chemical retention;this was further confirmed with theoretical calculations.Picoliter-sized micro-reactors coated with titanium-silicon oxide films showed the least inter-well optical crosstalk and chemical retention;these properties are expected to greatly improve the high-throughput pyrosequencing performance.

八步连续流全合成维生素B_(1)工艺研究

Vitamin B_(1) is widely applied in the healthcare and food industry as an antineuritic and antioxidant to maintain the normal functioning of nerve conduction,the heart,and the gastrointestinal tract.This study reports on an integrated eight-step continuous-flow synthesis of vitamin B_(1) from commercially available 2-cyanoacetamide.The proposed continuous-flow process is based on advances in chemistry,engineering,and equipment design,and affords improved performance and safety compared with batch-mode manufacturing.Several challenges were precisely investigated and controlled,including mixing,unexpected clogging,solvent switches,an exothermic reaction,and the prevention of side reactions,using various micro-channel flow reactors,mixers,separators,and continuous filters.Vitamin B_(1) was produced with a separated yield of 47.7% and high purity,with a total residence time of about 3.5 h.This eight-step continuous-flow protocol enables technology involving up to six of the key principles of green chemistry.Hence,the application of flow technology is of paramount importance for improving security,reducing waste,and,in particular,improving the efficiency of batch operations that require several days for manufacturing.

Methane conversion into higher hydrocarbons with dielectric barrier discharge micro-plasma reactor

We reported a coaxial,micro-dielectric barrier discharge(micro-DBD)reactor and a conventional DBD reactor for the direct conversion of methane into higher hydrocarbons at atmospheric pressure.The effects of input power,residence time,discharge gap and external electrode length were investigated for methane conversion and product selectivity.We found the conversion of methane in a micro-DBD reactor was higher than that in a conventional DBD reactor.And at an input power of 25.0 W,the conversion of methane and the total C2+C3 selectivity reached 25.10% and 80.27%,respectively,with a micro-DBD reactor of 0.4 mm discharge gap.Finally,a nonlinear multiple regression model was used to study the correlations between both methane conversion and product selectivity and various system variables.The calculated data were obtained using SPSS 12.0 software.The regression analysis illustrated the correlations between system variables and both methane conversion and product selectivity.

Catalytic Oxidative Properties and Characterization of CuO/CeO_2 Catalysts

The oxidative properties and characterization of CuO, CeO 2 and CuO/CeO 2 cata lysts were examined by means of a CO micro-reactor GC system, TPR, XPS and X-r ay diffraction Rietveld methods. The results show that either CuO or CeO 2 ac tivity is quite low for CO oxidation. However, when CuO and CeO 2 are mixed, the oxidative activity of the catalyst increases significantly, probably owing to the valency status of copper species (Cu 2+ and Cu+) on the CeO 2 surfa ce, the dispersion and reducibility. XPS surface analysis shows that CuO loading is very important in forming of either Cu 2+ or Cu+. Rietveld analysis s hows that some CuO, which has smaller ion radius than Ce 4+, enters the Ce O 2 lattice after CuO and CeO 2 are mixed. When the CuO loading reaches 5.0%, the size of CuO crystals is a minimum (6.1 nm) and the micro-strain value i s a maximum (2.86×10 -3), resulting in high surface energy and the best ac tivity for CO oxidation.

Continuous synthesis of few-layer MoS_(2) with highly electrocatalytic hydrogen evolution

As one of the most promising alternative fuels,hydrogen is expected with high hopes.The electrolysis of water is regarded as the cleanest and most efficient method of hydrogen production.Molybdenum disulfide(MoS_(2))is deemed as one of the most promising alternatives HER catalysts owing to its high catalytic activity and low cost.Its continuous production and efficient preparation become the key problems in future industrial production.In this work,we first developed a continuous micro-reaction approach with high heat and mass transfer rates to synthesize few-layer MoS_(2)nanoplates with abundant active sites.The defective MoS_(2)ultrathin nanoplates exhibit excellent HER performance with an overpotential of 260 m V at a current density of 10 m A cm^(-2),small Tafel slope(53.6 m V dec^(-1))and prominent durability,which are comparable to most reported MoS_(2)based catalysts.Considering the existence of continuous devices,it's suitable for the synthesis of MoS_(2)as highperformance electrocatalysts for the industrial water electrolysis.The novel preparation method may open up a new way to synthesize all two-dimension materials toward HER.

Semi-Automated Synthesis of [F-18]FBAM, a Thiol Reactive Prosthetic Group, Using Continuous Flow Chemistry

[F-18]FBAM, a thiol reactive bifunctional agent, was successfully synthesized using continuous flow chemistry in a micro reactor that is part of Advion NanoTek Micro-fluidic Synthesizer. As the radiofluorination was carried out microfluidically, a very small amount of precursor was used and over all radiochemical yield was 38% ± 4% (n = 8, decay corrected) and the radiochemical purity was ≥98% with specific activity of 430 mC/μmol. The total reaction time including HPLC purification was 55 min that is 14 min more than manual synthesis and 6 min less than fully automated synthesis.

A confined micro-reactor with a movable Fe_(3) O_(4) core and a mesoporous TiO_(2) shell for a photocatalytic Fenton-like degradation of bisphenol A

Photocatalysis and Fenton process are two primary and promising advanced oxidation processes to degrade organic pollutants.However,the practical applications of single photocatalysis and Fenton process are still limited.Introducing one of them into another to form a combined photocatalytic Fentonlike system has shown great potential but still faces challenges in designing a well-tailored catalyst.Herein,a confined photocatalytic Fenton-like micro-reactor catalyst with a movable Fe_(3) O_(4) core and a mesoporous TiO_(2) shell has been constructed via a successive Stober coating strategy,followed by an ultrasound assisted etching method.The resulting micro-reactor possesses well-defined yolk-shell structures with unifo rm mesopores(~4 nm),a large Brunauer-Emmett-Teller(BET) surface area(~166.7 m^(2)/g),a high pore volume(~0.56 cm^(3)/g) and a strong magnetization(~51 emu/g),as well as tunable reactor sizes(20-90 nm).When evaluated for degrading bisphenol A under solar light in the presence of peroxymo no sulfate,the micro-reactor exhibits a superior catalytic degradation perfo rmance with a high magnetic separation efficiency and an excellent recycle ability.The outstanding performance can be attributed to its unique textual structure,which leads to a great syne rgistic effect from the photocatalytic and Fenton-like process.This study gives an important insight into the design and synthesis of an advanced micro-reactor for a combined advanced oxidation processes(AOPs).

STUDY ON PREDICTING THE DATA OF INDUSTRIAL CRACKER FROM A PULSED MICRO-PYROLYZER SYSTEM

The studies on chemical kinetics of pyrolysis and coking reaction of various reactants such as propane, ethane-propane mixture and light gas-oil as well as screening cokinginhibitors for pyrolysis have been done at the pulsed micro-pyrolyzer system designed and assembled by the authors and their co-workers. This system has the following advantages: less feedstock consumption, simple operation, easily changeable operating conditions and rapidly available experimental data, better reproducibility and higher reliability.