基于花状MoS2微米材料的葡萄糖生物传感器的制备及其性能研究

本研究采用水热法制备了花状MoS₂微米材料, 将其作为电极构建葡萄糖生物传感器, 并研究了相关性能。结果表明: 水热法制备的MoS₂呈花状, 具有较好的结晶质量, 尺寸约为3.6 μm, 比表面积约为9.646 m²/g; MoS₂电极具有优良的电催化活性, 且电阻抗较小, 使得传感器对葡萄糖具有较好的响应。葡萄糖检测结果表明, 该传感器在0~20 mmol/L范围内, 氧化峰电流与葡萄糖浓度呈良好的线性关系, 相关系数(R)为0.9653, 灵敏度为262 μA•L/mmol。     

低温水热合成由纳米颗粒自组装而成的CdS亚微米和微米球

通过传统的水热技术,以CdCl2.2.5H2O和Na2S2O3.5H2O为镉源和硫源,在相对低的温度(100℃)下水热合成了CdS亚微米和微米球。X射线衍射(XRD)分析表明了产物是六方相CdS,电子扫描电镜(SEM)和透射扫描电镜(TEM)观察展示了产物是由大量的粒径为10~20nm的颗粒自组装成的亚微米和微米球;对微米球的拉曼(Raman)谱图、光致发光(PL)谱图和影响产物形貌的因素等进行了分析。     

可吸入颗粒粒径声学夹带法测量的实验研究

1引言可吸入颗粒物(空气动力学直径小于10μm)是目前我国城市大气环境的首要污染物,尤其是空气动力学直径小于2.5μm的颗粒物(PM2.5),这些细颗粒物主要来源于燃煤电厂的粉尘排放和城市中的机动车尾气排放,其数目浓度高,颗粒粒径小,富集了大量的重金属和有机化合物,不能在人体体     

利用酸性CuCl2蚀刻废液制备微米级Cu2O粉体

以含CuCl2酸性蚀刻废液为原料,葡萄糖为还原剂,采用液相还原法制备分散性好的微米级Cu2O粉. 实验确定最佳制备条件为：反应温度80℃,终点pH值8~9,反应时间1 h,还原剂和铜离子摩尔比为0.8. 所制Cu2O产品纯度为99.34%,Cu回收率可达99.7%. 进一步采用XRD, SEM, LZS, TG等手段对产物进行表征,结果表明产品为高纯Cu2O,粒径为1.8~2.2 mm,空心多面体结构,且常温下抗氧化性好,有可能用于催化剂、涂料、染料等的制备.     

微米TiO-2的表面改性及其分散性研究

为提高微米TiO2的分散性,采用偶联剂(KH570)法、无机包覆(铝包覆)法、超声法、非离子表面活性剂(PEG)法、阴离子表面活性剂(月桂酸钠)法,分别对微米TiO2进行表面改性。分析了改性前后微米TiO2的亲油化度、表面形态以及粒径大小。结果表明:超声法(功率90 W、时间15min、温度40℃、分散剂质量分数0.5%)和阴离子表面活性剂法(pH为5、月桂酸钠浓度0.050mol/L、时间30min)改性微米TiO2的效果比较显著,更有利于改善其分散性。     

Preparation and characterization of spray-dried granulated bioactive glass micron spheres

Owing to its superior bioactivity, biocompatibility, and biodegradability, bioactive glass (BG) has been attracting significant attention within biomedical science fields. However, BG powders with variable particle sizes are required targeting different applications, such as dermal fillers. Thus, in this study, granulated BG powders were prepared via the spray drying and granulation method. Size-controlled BG micron sphere with diameters of up to tens of microns can be mass-produced and their phase information, particle morphology, and specific surface area were characterized via X-ray diffraction, scanning electron microscopy, and nitrogen adsorption/desorption isotherm, respectively. In addition, the in vitro bioactivity was evaluated following Kokubo's protocol, and the formation of a hydroxyapatite (HA) layer after immersion into the simulated body fluid was confirmed via energy-dispersive and Fourier transform infrared spectroscopy. The cytotoxicity was examined using a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Finally, the resulting morphologies and corresponding properties are shown, and the related mechanisms are discussed.     

含微米级AP的HTPB推进剂工艺性能和力学性能

制备了含微米级AP(质量分数大于50%)的HTPB推进剂药浆和标准试件,利用流变仪测试了+20℃和-40℃时药浆的表现黏度,用材料试验机测试了标准试件的力学性能,讨论了增塑比、AP粒度级配、键合剂等对HTPB推进剂工艺性能和力学性能的影响。结果表明,当增塑比为0.42、AP粒度级配采用25%的120μm AP、30%的6~8μm AP和20%的1μm AP时,推进剂样品6h的表观黏度为1 267Pa·s,低温延伸率达到38%。     

碳纤维添加对低温固相反应法合成锰锌铁氧体微粉结构和性能的影响

通过在锰锌铁氧体原料粉末中添加适量的亲水碳纤维,在900℃反应合成了不经粉碎即可使用的锰锌铁氧体微粉。利用SEM、XRD、VSM等手段观测粉体的形貌、结构、性能,确定了热处理的工艺条件,并分析了碳纤维添加量对样品磁性能的影响。结果表明,粉体粒径随碳纤维添加量的增加而增大,当碳纤维添加过量时则会损害样品的磁性能。对于本实验的铁氧体组成,碳纤维的添加为0.5wt%时所得锰锌铁氧体微粉的尖晶石相含量最高,添加量为0.64wt%时饱和磁化率Ms最高。     

Highly crosslinked micron‐sized,monodispersed polystyrene particles by semicontinuous dispersion polymerization. II. Semicontinuous,delayed addition and seeded semicontinuous processes

A highly crosslinked, monodispersed polystyrene (PS) particle was prepared by the seeded semicontinuous dispersion polymerization using ready‐made monodispersed PS seed particles. The effects of Styrene (in 2nd stage)/Styrene (in PS seed) ratio, addition point and feeding time of divinylbenzene (DVB), concentration of DVB and polymerization temperature on the particle size, size distribution and morphology of the resulting particles were investigated. Monodispersed PS particles with 15 wt % of the DVB were prepared at 1/1 in St/St ratio, In comparison, highly crosslinked monodispersed and smooth‐surfaced PS particles containing up to 70 wt % of the DVB were effectively prepared at 0/1. 5% weight loss of the PS particles determined by TGA occurred from 353.3 to 389.6°C and the degree of swellability in toluene decreased from 113 to 101% as the DVB concentration increased from 10 to 70 wt %, implying increased thermal stability and solvent resistance due to the increase of the crosslink density. This study demonstrates that the seeded semicontinuous process, primarily with the starved condition at the second stage, is an efficient way to obtain highly crosslinked, monodispersed PS particles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Heterostructured (Ba,Sr)TiO3/TiO2 core/shell photocatalysts: Influence of processing and structure on hydrogen production

Heterostructured powders composed of microcrystalline (mc-) BaTiO₃ and SrTiO₃ cores coated with nanostructured (ns-) TiO₂ shells were prepared using a sol–gel method. The influences of annealing temperature, coating thickness, cocatalyst loading, and core size on photocatalytic hydrogen production were experimentally determined. The amount of hydrogen produced depends on the annealing temperature, which influences the interface, phase composition, light absorption, crystallinity, mesoporosity, and surface area. The heterostructured powders produced more hydrogen than ns-TiO₂ alone when annealed between 500 °C and 800 °C. The amount of hydrogen produced by heterostructures with 100–150 nm thick nanostructured titania coatings was greater than for thicker or thinner coatings. The optimum Pt loading was determined to be 1% by weight. Heterostructured powders consisting of mc-BaTiO₃/ns-TiO₂ produce more hydrogen than those with nano-sized BaTiO₃ cores, suggesting a size effect that is counter to the conventional relationship between catalytic activity and particle size.