纳米α-Fe/PS复合材料的制备及其热力学性能研究

采用油包水(W/O)的微乳液体系制备了粒度为20~100 nm的α Fe。对纳米Fe进行表面有机改性后分散到苯乙烯（St）单体中,得到分散均匀的Fe/St分散体系,用本体聚合的方法制备了纳米Fe/PS复合材料。利用XRD,TEM,FTIR,SEM及TG DSC分别研究了所得纳米Fe的性能、复合材料的结构、纳米Fe在PS中的分散情况以及掺杂量对纳米Fe/PS复合材料的热力学行为的影响。研究结果表明：增加纳米α-Fe的掺杂量能提高PS的降解率,降低降解温度,增大热分解的焓变。     

原位聚合纳米Ni/聚苯乙烯复合材料及其热力学性能

磁性聚苯乙烯(PS)材料有利于实现惯性约束聚变靶丸在辐射场中的无接触支撑。采用液相还原法制备了粒度为75~200 nm的Ni球形粒子,用原位聚合的方法制备了纳米Ni/PS复合材料。利用X射线衍射仪、傅氏转换红外线光谱分析仪、扫描电子显微镜及热重差示扫描量热仪分别研究了所得纳米Ni的特性、复合材料的结构及掺杂量对纳米Ni/PS复合材料的热力学行为的影响。研究结果表明：纳米Ni的掺杂能提高玻璃转变温度;纳米Ni的掺杂可以增大PS热分解焓变,在掺杂质量分数为1%~2%之间焓变达到最大;纳米Ni的掺杂降低了纳米Ni/PS复合材料热分解的比热容。     

原位聚合纳米Ni/聚苯乙烯复合材料及其热力学性能

 磁性聚苯乙烯(PS)材料有利于实现惯性约束聚变靶丸在辐射场中的无接触支撑。采用液相还原法制备了粒度为75~200 nm的Ni球形粒子,用原位聚合的方法制备了纳米Ni/PS复合材料。利用X射线衍射仪、傅氏转换红外线光谱分析仪、扫描电子显微镜及热重差示扫描量热仪分别研究了所得纳米Ni的特性、复合材料的结构及掺杂量对纳米Ni/PS复合材料的热力学行为的影响。研究结果表明：纳米Ni的掺杂能提高玻璃转变温度;纳米Ni的掺杂可以增大PS热分解焓变,在掺杂质量分数为1%~2%之间焓变达到最大;纳米Ni的掺杂降低了纳米Ni/PS复合材料热分解的比热容。     

聚苯乙烯/纳米铝复合材料的流变特性及纺丝研究

为有效制得Z箍缩氘代聚苯乙烯/纳米铝(DPS/AlNPs)导电丝阵材料,采用PS中掺入AlNPs制备PS/AlNPs复合材料纤维进行模拟研究。研究了温度及剪切速率等因素对PS/AlNPs复合材料流变性能的影响、复合材料熔体的结构变化及流动状态与可纺性能的关系,以及PS/AlNPs纤维的形貌、热稳定性能和力学性能。结果表明：PS/AlNPs熔体属于典型剪切变稀型非牛顿流体,熔体的表观粘度与温度呈现负相关,240~260 ℃时复合材料的非牛顿指数介于0.462~0.546,结构黏度系数介于1.8~2.1,黏流活化能介于77.2~104.6 kJ·mol^-1,具有良好的可纺性。PS/AlNPs纤维表面光滑,对AlNPs粒子包覆良好且对其抗氧化非常有利,其中当AlNPs质量分数为1%时纤维的断裂伸长率突出、掺量为5%时其断裂强度较高。     

自悬浮定向流法制备纳米铜微粒及其结构表征

采用自悬浮定向流法制备金属铜纳米微粒,并用TEM,XRD和AES等分析手段研究了铜纳米微粒的形貌、粒度、结构及其表面氧化层特性。结果表明,在一定的参数条件下采用自悬浮定向流法可制备出单晶纳米铜微粒,并且通过工艺参数的调控可达到对微粒粒度的控制。     

自悬浮定向流法制备纳米铜微粒及其结构表征

 采用自悬浮定向流法制备金属铜纳米微粒，并用TEM，XRD和AES等分析手段研究了铜纳米微粒的形貌、粒度、结构及其表面氧化层特性。结果表明，在一定的参数条件下采用自悬浮定向流法可制备出单晶纳米铜微粒，并且通过工艺参数的调控可达到对微粒粒度的控制。     

ICF物理实验用纳米Cu块体靶材的制备研究

 采用自悬浮定向流法制备了金属纳米粉体并采用真空手套箱专利技术和冷压法在高压（1.5 GPa）作用下保压40 min后，成功制备出了相对密度达97％和显微硬度达1.85 GPa的金属Cu纳米晶材料。经XRD分析，其晶粒大小为20 nm。正电子湮没(PAS)实验结果表明，其空隙大小和数量与采用惰性气体冷凝法原位压制(IGC)的样品相比，空位簇数量较多，微空隙的大小和数量基本相当。激光惯性约束聚变（ICF）模拟实验表明：采用该方法制备的纳米Cu块体材料靶的激光转换效率比常规Cu材料靶高5倍。     

纳米壳聚糖复合材料的制备与性能研究

为了提高壳聚糖的水溶性及其止血方面的性能,将壳聚糖(CS)纳米化,并引入具有抗菌作用的Ag~+离子和凝血辅助作用的Ca~(2+)离子,制备出纳米壳聚糖金属离子复合止血材料。首先,采用离子交换法制备纳米壳聚糖(nmCS),再分别加入AgNO_3和饱和CaCl2溶液,制得nmCS-Ag、nmCS-Ca、nmCS-Ag-Ca复合材料。然后,采用FTIR、XRD、SEM等手段对复合材料的结构进行表征。最后,对复合物的凝血、止血性能进行了测试。实验结果表明:改性后的壳聚糖IR图谱在1647cm-1和1560cm-1处出现了纳米壳聚糖钠盐的特征吸收峰;复合了金属离子的纳米壳聚糖在XRD图谱中表现出了Ag~+、Ca~(2+)的晶型特征;扫描电镜显示nmCS-Ag中Ag~+有部分析出而nmCS-Ca的复合效果较好;nmCS-Ag-Ca的凝血、止血效果要优于nmCS-Ag和nmCS-Ca,同时nmCS-Ag和nmCS-Ca的凝血、止血效果要优于nmCS。测试结果表明,成功制备了纳米壳聚糖金属离子复合止血材料。     

纳米晶复合Pr2 Fe14 B/α-Fe永磁材料磁性的研究

采用熔体快淬的方法制备Pr2Fe14B/α-Fe纳米晶复合永磁材料.使用振动样品磁强计(VSM)测量样品的室温磁性能.实验合金成分为(PrxFe94.3-xB5.7)0.99Zr1(其中x=8.2,8.6,9.0,9.4,9.8,10.2,10.6,11.0,11.4(原子分数,%)).系统地研究了辊速及合金成分对快淬带磁性能的影响,当Pr原子分数由8.2%-11.4%变化时,矫顽力Hci升高,但剩余磁极化强度Jr却降低了,这是导致最大磁能积(BH)max下降的原因.当x=8.2(%)时,尽管样品的Hci较低,但高的Jr使(BH)max的值达到很高,在辊速为25m/s时得到最佳磁性能为:Jr=1.37T,Hci=501.19kA/m,(BH)max=227.93kJ/m3.同时发现垂直带面方向的Jr和(BH)max远高于平行带面方向.     

纳米晶复合Pr2Fe14B/α-Fe永磁材料磁性的研究

采用熔体快淬的方法制备Pr₂Fe₁₄B/α-Fe纳米晶复合永磁材料.使用振动样品磁强计(VSM)测量样品的室温磁性能.实验合金成分为(Pr_xFe_94.3-xB_5.7)_0.99Zr₁(其中x＝8.2，8.6，9.0，9.4，9.8，10.2，10.6，11.0，11.4(原子分数，%)).系统地研究了辊速及合金成分对快淬带磁性能的影响，当Pr原子分数由8. 关键词： 纳米复合永磁材料 熔体快淬 2Fe₁₄B/α-Fe')" href="#">Pr₂Fe₁₄B/α-Fe 磁性     

触发电压对±100 kV多级多通道开关性能的影响

研制了一种用于快脉冲直线型脉冲变压器的±100 kV多级多通道火花开关,研究了触发电压极性、幅值对多级多通道火花开关触发性能的影响,分析了不同触发电压下开关各部分延时及抖动。研究结果表明:触发电压的极性对双极性多级多通道火花开关触发性能影响较小;开关的触发放电延时和抖动随着触发电压的增大而减小。进一步分析了多级多通道火花开关的触发击穿模式以及影响开关击穿延时和抖动的主要因素,提出了减小开关触发击穿延时及抖动的技术途径。     

Superhydrophobicity of silica nanoparticles modified with polystyrene

Polystyrene/silica nanoparticles were prepared by radical polymerization of silica nanoparticles possessing vinyl groups and styrene with benzoyl peroxide. The resulting vinyl silica nanoparticles, polystyrene/silica nanoparticles were characterized by means of Fourier transformation infrared spectroscopy, scanning electron microscopy and UV-vis absorption spectroscopy. The results indicated that polystyrene had been successfully grafted onto vinyl silica nanoparticles via covalent bond. The morphological structure of polystyrene/silica nanoparticles film, investigated by scanning electron microscopy, showed a characteristic rough structure. Surface wetting properties of the polystyrene/silica nanoparticles film were evaluated by measuring water contact angle and the sliding angle using a contact angle goniometer, which were measured to be 159° and 2°, respectively. The excellent superhydrophobic property enlarges potential applications of the superhydrophobic surfaces.     

Synthesis of α- and β-FeOOH iron oxide nanoparticles in non-ionic surfactant medium

Forced hydrolysis of Fe(III) ions in acidic media was performed under controlled synthetic conditions to produce α- and β-FeOOH iron oxides. The forced hydrolysis synthesis was carried out, separately, in an aqueous medium and the lamellar lyotropic liquid crystalline phase of a commercial non-ionic surfactant/water system. The FT-IR analyses confirmed formation of α- and β-FeOOH iron oxides in the aqueous and the surfactant media with slight formation of ferrihydrite and haematite. TEM micrographs have shown that particles formed in the lamellar lyotropic phase are smaller than those produced in the aqueous medium with their smallest size dimension being constrained in the nanometre scale with a size ranging between 5 and 100 nm. Particles produced in the nanoscale size appeared to have different optical properties compared to their counterparts produced in the microscale size.     

Composite Nanoarchitectonics with iron nickel bimetallic nanoparticles and carbon composite for efficient electrocatalysis in hydrogen evolution reaction

The poor efficiency and stability of cost-effective metal compounds are major hurdles to substitute expensive metal-based nanomaterials for the hydrogen evolution reaction (HER). As a result, new concepts and tactics for developing electrocatalysts based on earth-abundant elements must be developed. We present iron-nickel alloy nanoparticles that are supported with carbon (FeNi@C) to improve HER performance in alkaline conditions. FeNi particle was supported on Trimesic acid (TMA) based carbon. In particular, the high conductivity of the carbon and a large number of catalytically active sites in the FeNi demonstrated a synergistic effect, making the hybrid structure a good choice for HER catalyst. Moreover, the physicochemical interaction between the carbon and FeNi metal enhanced the electrocatalytic performance and resulted in achieving 10 mA/cm² current density at 190 mV overpotential with 15 h chronopotential cycling, proving the possibility for replacing costly Pt-based catalysts.     

物理掺杂用纳米Fe粉的制备与结构表征

 根据惯性约束聚变靶材料研究的需要采用自悬浮定向流技术制备了金属纳米Fe粉,通过透射电子显微镜和X射线衍射分析技术研究了颗粒的形貌、粒度和相组成。结果表明,所制备的纳米Fe粉为规则的球状颗粒,其粒径分布在30~70 nm之间,在空气中颗粒表面有氧化膜生成,其氧化产物为Fe₃O₄。     

自悬浮定向流技术中铜纳米微粒的粒度控制研究

 采用自悬浮定向流技术制备了金属铜纳米微粒，根据TEM的行貌像对样品平均粒度进行标定，并结合样品制备的条件对制备工艺进行了研究。结果表明，自悬浮定向流技术可以方便地制备出不同粒度的金属铜纳米微粒，微粒平均粒径随熔球温度的降低而减小，随冷却气体流速的增大而减小；在1 200℃下微粒平均粒径随惰性气体压强的增大而减小，而在1 300℃时惰性气体压强对微粒平均粒径的影响不再具有规律性。     

Synthesis of magnetic rhenium sulfide composite nanoparticles

Rhenium sulfide nanoparticles are associated with magnetic iron oxide through coprecipitation of iron salts with tetramethylammonium hydroxide. Sizes of the formed magnetic rhenium sulfide composite particles are in the range 5.5-12.5 nm. X-ray diffraction and energy-dispersive analysis of X-rays spectra demonstrate the coexistence of Fe₃O₄ and ReS₂ in the composite particle, which confirm the formation of the magnetic rhenium sulfide composite nanoparticles. The association of rhenium sulfide with iron oxide not only keeps electronic state and composition of the rhenium sulfide nanoparticles, but also introduces magnetism with the level of 24.1 emu g^-1 at 14 kOe. Surface modification with monocarboxyl-terminated poly(ethylene glycol) (MPEG-COOH) has the role of deaggregating the composite nanoparticles to be with average hydrodynamic size of 27.3 nm and improving the dispersion and the stability of the composite nanoparticles in water.     

Synthesis and characterization of nanoparticles with an iron oxide magnetic core and a biologically active trialkylsilylated aliphatic alkanolamine shell

Water-soluble double-coated magnetic nanoparticles (NPs) containing cytotoxic decyldimethyl(β$\beta$-dimethylaminoethoxy)silane methiodide (AA) molecule sorbed at biocompatible magnetic particles, which consist of magnetite pre-coated with oleic acid (OA), have been prepared. X-ray line profile broadening analysis was used for crystallite size determination. The method of magnetogranulometry has been used for determination of diameter of iron oxide magnetic core and magnetic properties of NPs prepared. In vitro cytotoxicity on monolayer tumor cell lines HT-1080 (human fibrosarcoma), MG-22A (mouse hepatoma) and normal mouse fibroblasts (NIH 3T3) has been studied. It was revealed that all the water-based colloidal solutions obtained are non-toxic and possess high NO-induction ability.     

Bar-shaped nanoparticles of iron(II) hydroxide

Formation of elongated nanoparticles was observed when was precipitated from solutions containing excess of Fe²⁺. The average diameter of the particles was 23 nm; the length to diameter ratio was up to 14. This shape was an unexpected phenomenon because bar- or needle-like nanoparticles have been earlier reported only for Fe(III)-based materials. Chemical analysis revealed Fe(OH)₂ nature of the obtained particles. In addition, this conclusion was verified with a new simple method for quantitative evaluation of the particle morphology. Application of this method to the mixed samples allowed to distinguish between the two different compounds and to attribute different morphologies to Fe(OH)₂ or Results indicate that bars are frequent shapes of nano-sized iron oxides/hydroxides.