超细化豆渣作为皮克林乳液稳定剂的特性研究

将普通粉碎豆渣进行湿法超细化处理,研究超细化豆渣作为皮克林乳液稳定剂的特性,考察颗粒浓度、油相体积分数、pH及离子强度对乳液液滴尺寸、稳定性和流变学性质的影响。研究发现,超细化提升了豆渣颗粒的悬浮稳定性,且当油相分数φ=0.6,水相中豆渣颗粒质量分数≥0.4%时,形成皮克林乳液的粒径为80~140μm,在1~30 d存放期内乳析指数未发生显著变化。水相pH=7时乳液的粒径最大,pH降低时乳液的平均粒径呈单调递减,且乳液稳定性增强。水相中NaCl浓度在100~350 mmol/L对乳液粒径无显著影响。研究还表明,超细化豆渣稳定的皮克林乳液为剪切变稀型流体,其流变学特性受颗粒添加量及水相pH的影响。此研究表明,超细化豆渣具有良好稳定O/W型皮克林乳液的能力。

超细煤粉NO_x和SO_2排放特性与燃烧特性

将合山煤分别制成常规粒度的煤粉与超细化煤粉 .在单只水平直流燃烧器燃烧室内进行了常规煤粉与超细化煤粉的燃烧特性、空气分级燃烧NOx 排放特性、炉内喷钙对超细化煤粉与常规煤粉燃烧SO2 排放特性的影响的燃烧试验研究 .试验研究表明 ,超细化煤粉与常规煤粉比较 ,着火提前 ,着火稳定性好 ,燃尽效果好 ;分级燃烧对超细煤粉的NOx 排放量的降低效果更显著 ;在Ca/S摩尔比相同的条件下 ,超细化煤粉的固硫特性明显优于常规煤粉 .

氢氧化镁基阻燃剂的研究进展

氢氧化镁基阻燃剂作为重要的无机阻燃剂材料,因其无卤无毒的绿色环保性能,在阻燃材料研究中受到了广泛关注。但因其表面极性强、与高聚物相容性差和均匀分散困难等特点,极大地影响了其性能。通过颗粒超细化和表面改性,能够有效地改善氢氧化镁基阻燃剂的性能。主要介绍了氢氧化镁颗粒超细化和表面改性的相关进展,结合阻燃剂材料的发展趋势,对未来氢氧化镁基阻燃剂的研究方向和发展做出展望。

Fabrication of ultrafine Pd nanoparticles on 3D ordered macroporous TiO_2 for enhanced catalytic activity during diesel soot combustion

Nanocatalysts consisting of three‐dimensionally ordered macroporous(3DOM)TiO2‐supported ultrafine Pd nanoparticles(Pd/3DOM‐TiO2‐GBMR)were readily fabricated by gas bubbling‐assisted membrane reduction(GBMR)method.These catalysts had a well‐defined and highly ordered macroporous nanostructure with an average pore size of 280 nm.In addition,ultrafine hemispherical Pd nanoparticles(NPs)with a mean particle size of 1.1 nm were found to be well dispersed over the surface of the 3DOM‐TiO2 support and deposited on the inner walls of the material.The nanostructure of the 3DOM‐TiO2 support ensured efficient contact between soot particles and the catalyst.The large interface area between the ultrafine Pd NPs and the TiO2 also increased the density of sites for O2 activation as a result of the strong metal(Pd)‐support(TiO2)interaction(SMSI).A Pd/3DOM‐TiO2‐GBMR catalyst with ultrafine Pd NPs(1.1 nm)exhibited higher catalytic activity during diesel soot combustion compared with that obtained from a specimen having relatively large Pd NPs(5.0 nm).The T10,T50 and T90 values obtained from the former were 295,370 and 415°C.Both the activity and nanostructure of the Pd/3DOM‐TiO2‐GBMR catalyst were stable over five replicate soot oxidation trials.These results suggest that nanocatalysts having a 3DOM structure together with ultrafine Pd NPs can decrease the amount of Pd required,and that this approach has potential practical applications in the catalytic combustion of diesel soot particles.

Ultrafine Ni-B nanoparticles for efficient hydrogen evolution reaction

The search for active,stable,and cost-effective electrocatalysts for hydrogen evolution reaction(HER)is desirable,but it remains a great challenge in the overall water splitting.Here,we report the synthesis of nickel boron nanoparticles supported on Vulcan carbon(Ni-B)via a simple,yet scalable,two-step chemical reduction–annealing strategy.The results of the electrochemical measurements suggest that the overpotentials of Ni-B-400 are 114 and 215 mV(in 1 mol L^–1 KOH)at current densities of 10 and 40 mA cm^?2,respectively,indicating an exceedingly good electrocatalytic activity in the HER.More importantly,Ni-B maintains a current density of 7.6 mA cm^-2 at an overpotential of 0.15 V for 20 h in the durability test.The excellent HER activity of Ni-B-400 is derived from the small particle size and the expanded lattice of Ni,which can optimize the hydrogen absorption energy and enhance the electrocatalytic properties.

Carotenoids Particle Formation by Supercritical Fluid Technologies

Based on the solubility in supercritical CO2,two strategies in which CO2 plays different roles are used to make quercetine and astaxanthin particles by supercritical fluid technologies.The experimental results showed that micronized quercetine particles with mean particle size of 1.0-1.5 μm can be made via solution enhanced dispersion by supercritical fluids(SEDS) process,in which CO2 worked as turbulent anti-solvent;while for astaxanthin,micronized particles with mean particle size of 0.3-0.8 μm were also made successfully by rapid expansion supercritical solution(RESS) process.

Enhancement of fine particle filtration with efficient humidification

Filtration is one of the most effective methods to remove suspended fine particles from air. In filtration processes,pressure drop of compact dust cake causes problems in efficiency and economy, which has received increasing attention and still remains challenging. In this study, we developed a novel technique to intensify the filtration of fine particles with efficient humidification. Two strategies for humidification, including ultrasonic atomization and steam humidification(controlling of ambient humidity), were employed and proved to be both effective. The regeneration frequency of the filter could be reduced by 55% with ultrasonic atomization, while steam humidification could lead to a 78% reduction in regeneration frequency. The effect of operating conditions on pressure drop and the mass loading during filtration were investigated. The dust cake showed a loose and porous structure with an optimized droplet-to-particle ratio. With the ratio of 1.53 and 0.0282, the maximum mass loading was 552 g·m-2upon the ultrasonic atomization and 720 g·m-2upon the steam humidification. The results show that humidification could slow down the increase of pressure drop during filtration and improve the efficiency of process.