共查询到20条相似文献,搜索用时 109 毫秒
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纳米氢氧化铝镁改性PVDF膜性能的研究 总被引:1,自引:0,他引:1
采用相转化法制备了纳米氢氧化铝镁/PVDF杂化膜,考察了纳米氢氧化铝镁的加入对膜的纯水通量、截留率、孔径、孔隙率、微观结构、机械性能、热稳定性和吸附性能的影响.并通过X射线光电子能谱(XPS)和X射线能谱(EDS)分析了膜表面和断面的元素含量.与不添加纳米氢氧化铝镁的PVDF膜性能对比,结果表明,纳米氢氧化铝镁的加入明显提高了膜的纯水通量、截留率、机械性能和吸附性能,而对膜的孔径和孔隙率影响不大.SEM和热重分析表明,纳米氢氧化铝镁的加入明显改变了膜的孔结构,其热性能却略有降低. 相似文献
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采用纳米金红石型TiO2为Ti源, 水热法合成了Ti纳米晶须, 将其表面负载磷酸三丁酯(TBP)制备出修饰Ti纳米晶须。用SEM、 TEM及傅里叶红外光谱仪对Ti纳米晶须及修饰Ti纳米晶须的形貌和结构进行表征, 分别研究了两种材料对铀离子的吸附性能, 考察了修饰Ti纳米晶须吸附铀的动力学及等温吸附模型。电镜表征结果表明, 水热温度为160 ℃成功合成出Ti纳米晶须, 其粒径范围为80~100 nm。吸附铀研究结果表明, 在3 mol/L NO-3介质中修饰Ti纳米晶须表现出较高的吸附性能, 修饰Ti纳米晶须对铀的吸附动力学模型符合准二级动力学, 吸附等温线符合Langmuir和Freundlich等温吸附模型。将修饰Ti纳米晶须用于自来水中低浓度铀的回收, 结果较好。 相似文献
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K. Itatani K. Koizumi F. S. Howell A. Kishioka M. Kinoshita 《Journal of Materials Science》1989,24(7):2603-2609
The agglomeration process of MgO powder derived from Mg (OH)2 was investigated at fixed temperatures of 600, 800, 900 and 1200° C; these temperatures were chosen as representative of four regions, i.e. below 600° C, 650 to 850° C, 850 to 1050°C and 1050 to 1200° C previously reported. At 600° C, coherent crystallites coalesced within the heating time of 60 min; on further heating till 300 min, the primary particles which consisted of crystallites grew rapidly. The original Mg (OH)2 framework or pseudomorphs, composed of minute crystallites and primary particles, still remained in the powder. At 800° C, the pseudomorphs had disintegrated into fragments. The crystallite growth and primary particle growth were accelerated with increasing the heating times beyond 60 min. At 900° C, a further fragmentation of agglomerates occurred with increasing the heating times; the crystallite and primary particle growth in fragments brought about the pore coalescence. At 1200° C, the crystallite and primary particle growth proceeded with the coarsening of pores; on heating beyond 240 min, the crystallites and primary particles grew rapidly due to the entrapment of pores within them. 相似文献
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Indra Puspitasari T.P. Gujar Kwang-Deog Jung Oh-Shim Joo 《Materials Science and Engineering: B》2007,140(3):199-202
In this research article, we present the results concerning the characterization of copper sulfide nanowhiskers fabricated by a simple and cost effective chemical deposition method from aqueous solution. The chemically deposited copper sulfide nanowhiskers were investigated for their structural, surface morphological, compositional and optical characterizations. 相似文献
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Agglomeration of magnesium oxide particles formed by the decomposition of magnesium hydroxide 总被引:1,自引:0,他引:1
Kiyoshi Itatani Kiyotaka Koizumi F. Scott Howell Akira Kishioka Makio Kinoshita 《Journal of Materials Science》1988,23(9):3405-3412
Agglomeration of magnesium oxide (MgO) particles was studied by decomposing magnesium hydroxide (Mg(OH)2). The properties of agglomerates varied according to the decomposition temperature region: (i) below 650° C, (ii) 650° C to 850° C, (iii) 850° C to 1050° C, and (iv) 1050° C to 1200°C. In region (i), the original Mg(OH)2 frameworks or pseudomorphs remained in the powder and showed agglomeration. The strength of agglomerates containing the pesudomorphs was about 50 MPa; the primary particles in pseudomorphs are bonded chemically by the interaction of MgO and residual water. In region (ii) the pseudomorphs began to show some fragmentation: the bonding strength of these pseudomorphs reduced rapidly. In region (iii), both crystallite and primary particles were grown by the sintering; this growth may be due to an increase in contact area based on the collapse of pseudomorphs. The primary particles whose necks were grown by the sintering could be easily pulled apart by grinding. In region (iv) pore growth due to the rearrangement of primary particles caused the suppression of both densification rate and crystal growth of MgO. 相似文献
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A facile synthesis route for furcated PZT nanowhiskers was developed by simple hydrothermal reactions under the assistance of PVA or blend of PAA and PVA. XRD, SEM and TEM were used to characterize the nanowhiskers. The nanowhiskers were over 70 μm in length and ca. 100 nm in width. Investigations on the samples in various concentration polymer showed that the polymer additives played an important role in controlling the morphology of crystals. 相似文献
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Chika Takai-Yamashita Masafumi Ando Masashi Noritake Hadi Razavi Khosroshahi Masayoshi Fuji 《Advanced Powder Technology》2017,28(2):398-405
A water-in-oil (W/O) emulsion, in which the water phase including poly (acrylic acid) (PAA), ammonium hydroxide (NH3 aq.), and sodium hydroxide aqueous solutions (NaOH aq.) dispersed in ethanol (EtOH), was proposed for producing hollow silica nanoparticles. The PAA molecules with the NH3-NaOH mixture are insoluble in EtOH and can be a template. When tetraethoxysilane (TEOS) is added as a silica source, a silica shell is formed on the PAA-NH3-NaOH template to form a core-shell particle and the addition of water removes the template to form hollow silica nanoparticles. The optimum volume ratio of 25% NH3:1.0 M NaOH was 2:1 to obtain high-dispersed hollow silica nanoparticles. A thermogravimetric analysis indicated that the condensation force of the PAA molecules in the PAA-NH3-NaOH template is similar to that in the PAA-NH3 template. The small angle X-ray scattering (SAXS) analysis also showed that the electron densities in the PAA-NH3-NaOH and PAA-NH3 templates are similar. In the proposed PAA-NH3-NaOH system, NH3 aq. mainly contributes to form PAA condensation by an ionic interaction and NaOH aq. preferentially work as a sol-gel catalyst for the fast silica coating on the template surface. 相似文献
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以氯化镁、氢氧化钠、尿素和硬脂酸钠为原料,采用沉淀法制备出改性氢氧化镁(MH)粉末材料。结果表明,制备的MH为无规则的、粒径为30~120nm的,且至少有一维是纳米结构的片状材料。在应用方面,采用熔融挤出法制备了多组不同配方的尼龙66(PA66)复合材料。研究发现,MH单独使用时阻燃效率低,将它与微胶囊红磷(MRP)复配使用后能有效地提高材料的阻燃性能。当x(PA66)∶x(MRP)∶x(MH)=100(phr)∶10(phr)∶8(phr)时,MRP/MH/PA66复合材料的垂直燃烧为V-0级,LOI能达到32%。此外,还探讨了可能的阻燃机理,并通过TG、TG-MS等手段研究了材料的热氧稳定性及热氧分解气态产物。 相似文献