富勒烯制备方法研究的进展

评述了近几年来富勒烯物质的发展过程。论述了不同形态的富勒烯的各种制备方法及其提纯分离工艺,并对各种制备工艺进行了分析和探讨性研究,在此基础眩指出了每种方法的优缺点,就富勒烯的基础研究、宏量制备和应用研究提出了一些看法,并简述了本研究小组采用电子束辐照法,金属纳米微粒诱发催化非晶炭膜转变成泮葱头状富富勒烯的工作。     

硼异质富勒烯制备过程中巴基管与巴基葱的异常生长行为

电弧法制备掺硼富勒烯过程中发现，与纯富勒烯相比，掺硼富勒烯烟灰的电导率提高一个数量级以上。电镜观察显示掺硼富勒烯烟灰中含有较多的巴基管和巴基葱，而阴极沉积物中则发现含有珠链状巴基葱。     

不对称炭膜的制备及结构性能研究

以Kapton型聚酰胺酸(PAA)为前体,以N,N-二甲基乙酰胺(DMAc)为溶剂和凝胶浴添加剂,分别以水、乙醇、正丙醇、正丁醇为凝胶介质,采用干湿相转化法制备不对称聚酰亚胺膜,经高温炭化制备不对称炭膜.探讨了相转化制膜工艺如铸膜液浓度、蒸发时间、凝胶介质及炭化温度等因素对不对称炭膜微结构和气体分离性能的影响,并采用SEM、XRD等手段对不对称炭膜的表面形态及微结构进行表征.研究表明,采用相转化的方法成功地制备了具有不对称结构的炭膜,相转化制膜工艺、炭化工艺对所制备不对称炭膜的结构及气体分离性能有较大的影响;控制适宜的铸膜液浓度、预蒸发时间有利于制备具有高通量、高分离选择性的不对称炭膜;提高炭化温度可以改变其微观结构,使炭膜的有序度和致密度增加,进而对膜的气体分离性能产生影响。SEM分析表明,所制备的不对称炭膜表面致密无缺陷,且具有明显的致密皮层和多孔支撑层结构;XRD显示,制备的不对称炭膜的微结构为乱层炭结构.     

炭分子筛膜的制备及应用研究进展

炭分子筛膜(CMSM)是用于气体分离的一种高效节能新型材料,在气体分离中具有极大的工业化应用潜力.综述了炭分子筛膜的前躯体选择、制备工艺及气体分离应用方面的研究进展,并对炭分子筛膜的发展方向进行了展望.     

通过高温裂解酚醛树脂制备气体分离用炭膜——裂解温度及臭氧后处理的作用分析(英文)

炭膜可以通过各种前驱体,如酚醛树脂的高温裂解方法制备。该过程中,裂解条件对炭膜的性质有较大影响。研究不同裂解温度及臭氧后处理对炭膜的孔隙率及气体吸附行为的影响。结果表明,当裂解温度升高(由500℃提高到800℃),炭膜的平均孔径减小,孔体积与气体吸附能力先增大后减小。在800℃下,炭膜表现出分子筛的分离性能。臭氧后处理过程使炭膜孔径增大,气体吸附效率及动态吸附选择性降低,弱化了炭膜的分离性能。     

椰壳制备液体分离用炭膜的研究

以海南椰壳为原料，经一次炭化、成型、再炭化，制得炭膜。研究了原料椰壳的热解特征，考察了炭膜制备工艺条件对炭膜分离性能的影响，并对炭膜用于细菌分离的过程进行了初步的探索。结果表明：椰壳热解在４５０℃左右已趋于完全，进一步提高温度有助于炭化物孔结构的改善。炭膜的分离性能与成型压力、粘结剂含量等工艺条件有关。所制炭膜的最大孔径范围为：０．５μｍ～１．０μｍ，分离过程属微滤。通过对水中细菌（０．５×１．５μｍ～１．８μｍ）分离实验结果表明：炭膜可有效截留细菌，且炭膜本身容易再生利用     

炭膜制备及其孔结构调控

炭膜作为近年发展起来的一种新型无机分离膜,有着广阔的应用前景.炭膜的孔结构是影响炭膜性能的根本性因素.评述了炭膜的分类和制备,着重阐述了原料性质、添加剂、炭化条件等主要因素对炭膜支撑体孔结构的影响以及预氧化条件对沥青基非支撑体炭膜孔结构的影响.并详细介绍了炭膜分离层孔结构的调控方法.     

聚醚酰亚胺基炭分子筛膜的形成及其气体分离性能研究

以商用聚醚酰亚胺(PEI)作为前驱体,采用经过ZrO2-Al2O3复合溶胶修饰的陶瓷氧化铝为支撑体,浸渍涂膜制备聚合物膜,在空气中预氧化处理后,经500～800℃不同的炭化温度下制备出气体分离炭分子筛膜。为了考察炭化温度对炭膜结构和气体分离性能的影响,采用热重分析(TG)、拉曼光谱(Raman)、X射线衍射(XRD)、扫描电镜(SEM)和气体渗透等测试手段,对热解过程聚合物膜热稳定性、炭微晶结构及石墨化进程、微观形貌和气体分离性能进行了系统研究。结果表明,不同的炭化温度对所形成炭膜表现出不同物理和化学结构、炭结构和孔结构,最终影响炭分子筛膜的气体渗透性和分离选择性。     

气体分离炭膜的结构设计、制备及功能化

气体渗透性低、机械强度差是炭膜产业化道路上的两大难题.研究发现,根源在于炭膜的蠕虫状孔道结构与均质炭膜的特有性质.为了解决炭膜渗透性低的问题,通过选择适宜的聚合物前驱体的分子结构与空间构型结合填充纳米粒子为功能基团等手段,实现对炭膜蠕虫状孔结构有效地调控与重新构建.在保证高选择性的条件下,不仅使炭膜的气体渗透性能提高了2个数量级以上,而且还使炭膜对某些气体具有较高分离选择性的功能化效果.为了改善炭膜的机械强度,将自主研发的廉价煤基炭膜支撑体与前驱体相复合,采用简单的制膜工艺,制备得到复合性能好、气体分离性能高的复合炭膜.     

炭膜制备及其高效氧氮分离性能

通过论述炭膜的制备方法及其关键影响因素，系统总结了炭膜的氧氮分离性能，并将其与高性能聚吡咙膜和聚苯胺膜进行了比较，提出了今后的发展方向。指出炭膜具有优异的氧氮分离性能，其氧氮分离因子一般为10以上，最高可达36。聚酰亚胺基和聚吡咙基炭膜均表现出较好的综合氧氮分离性，大大突破了富氧膜材料的Robeson上限，位于极具吸引力的商业化区域，在空气分离中显示出了极大的应用潜力和工业化前景。     

Radical-scavenging Ability of Hydrophilic Carbon Nanoparticles: From Fullerene to Its Soot

We have recently developed a facile synthetic method for highly water-soluble fullerene, so-called fullerenol, for the treatment of fullerene with hydrogen peroxide. This method was applied to fullerene soot to yield the corresponding new hydrophilic carbon materials, and the obtained products were subjected to infrared spectroscopy and elemental analysis. The DLS particle size analysis demonstrated the relatively high dispersion of hydrophilic fullerene soot with a diameter of ?70 nm in water, while the hydrophilic activated carbon obtained by the same treatment showed the larger aggregation with diameters of 200 and 970 nm. The surface analysis using FE-SEM showed the difference in morphology between fullerene soot and activated carbon as well as between before and after hydrophilic treatment of the soot with hydrogen peroxide. Moreover, this hydrophilic fullerene soot exhibited high antioxidant activity (%AOA) up to 87% compared with fullerenol C₆₀(OH)₃₆ (54%) and C₆₀ (50%) evaluated by β-carotene bleaching method.     

Influence of C60 and Fullerene Soot on the Oxidation Resistance of Vegetable Oils

The influence of fullerene soot as well as pure C₆₀ on the oxidation stability of rapeseed oil is studied. Fullerene soot (C₆₀ content between 0-6 wt.%) was synthesized by using a carbon arc method. Differential scanning calorimetry was applied to estimate the oxidation induction time of fullerene-oil composites. The addition of fullerene soot significantly hampered the peroxide formation thus increasing of oxidation stability of tested oils.     

乙炔等离子体热解法制备C60的研究

用乙炔高频等离子体热解法连续大批量合成含富勒烯的碳灰。用透射电镜（TEM）、X射线衍射（XRD）、紫外－可见光谱（UV－Vis）、红外光谱（IR）等测试手段对碳灰进行了分析研究，并测定了富勒烯C60的产率为2．5g／h。     

Hydrogen sorption by carbon-based substances formed in carbon-helium plasma

Hydrogen sorption by various carbonaceous products formed during arc discharge in carbon-helium plasma has been studied. The main product fractions included a fullerene-containing soot, a fullerene mixture extract, a condensate containing carbon nanotubes, and carbonized aluminum oxide. Molecular hydrogen is most effectively sorbed by single-wall carbon nanotubes contained in the carbon condensate fraction.     

Model of Improved Arc Generator for Fullerene Production

Process of fullerene formation and fragmentation is studied in various zones of fullerene generator. Fullerenes are produced utilizing carbon arc method, in which graphite electrodes are vaporized in a low pressure helium atmosphere by passing an electrical current through the electrodes. The effects of the gas pressure and intensity of the direct current on fullerene yield are investigated. Maximum fullerene yield of 8% is found in a raw soot after the evaporation of graphite by a 60 A direct current, in a helium ambient under the pressure of 8 kPa.     

C60 and Giant Fullerenes in Soot Condensed in Vapors with Variable C/H2 Ratio

A transmission electron microscope (TEM) study of individual soot grains forming fluffy carbon particles produced using the arc-discharge technique revealed close-packed arrangements of single-wall ring structures with average diameters of 0.7, 1.1, 3.0, 5.5, and 8.2 nm. These structures were hypothesized to be C₆₀ and giant, C₅₄₀, C₉₆₀, and C₁₅₀₀, fullerenes that could form by coalescence during condensation and soot agglomeration, although in situ solid-state growth cannot be excluded. Mass spectroscopy and high performance liquid chromatography (HPLC) chromatography of the samples confirmed the presence of C₆₀ fullerene in all samples giving confidence to the giant fullerene growth scenario. Our results suggest that fullerenes could be common in soot grains produced by this technique as well as being an important carbon phase in C-rich accretion disks around young stellar objects and among the dust in the interstellar medium.     

Influence of charged particles on the fullerene formation process

The influence of charged particles on the process of fullerene formation is determined. Systematic experiments are used to show that the presence of carbon ions in the fullerene formation zone substantially increases the fullerene content in the soot. Pis’ma Zh. Tekh. Fiz. 25, 35–40 (March 12, 1999)     

A STUDY ON THE THERMAL STABILITY TO 1000°C OF VARIOUS CARBON ALLOTROPES AND CARBONACEOUS MATTER BOTH UNDER NITROGEN AND IN AIR

The thermal behavior of graphite, C₆₀ fullerene, fullerene black (carbon soot containing fullerenes), extracted fullerene black and diamond has been analyzed to 1000°C by TGA-DTA (thermogravimetric analysis and differential thermal analysis) under a nitrogen flow at a heating rate of 20°C/min. Very small weight losses have been recorded in the case of graphite and diamond. Furthermore no diamond graphitization has been observed. The sublimation of pure C₆₀ and the fullerene fraction of fullerene black (both pristine and extracted) has been observed and discussed.

The combustion reaction in air flow of graphite, C₆₀ and C₇₀ fullerenes, fullerene black (both unextracted and extracted), carbon nanotubes and diamond has been studied by TGA-DTA at a heating rate of 20°C/min. C₇₀ fullerene and fullerene black have been found to be the most reactive carbon materials with O₂. The role played by C₇₀ in the degradation of fullerites has been discussed. Among the carbon materials examined, the best resistance to O₂ attack has been shown by diamond and carbon nanotubes. The behavior of graphite is intermediate between diamond and fullerene blacks. The behavior of C₆₀ fullerene appears closer to that of graphite although it appears to be more reactive with O₂. Samples of graphite and carbon blacks N375 and N234 have been studied by TGA-DTA in air flow before and after a radiation treatment with neutrons or γ radiation. The effect of the radiation damage in the combustion reaction of these carbon materials has been discussed.     

Extracting of fullerene-like nanoparticles from environmental soots

It is well known that burning graphite electrodes in electric arc is an efficient method for obtaining of fullerenes. However, fullerenes form in any sooting flames. Therefore, detection fullerene in natural burning fuel is of a great interest for understanding of mechanism of soot formation. This research extracted samples of environmental soots in toluene. Soots and products of extraction were characterized by UV-vis spectroscopy, sedimentation analysis, atomic force microscopy. Analysis of extracts found fullerene-like clusters. The concentration of particles decreased in the following sequence: charcoal – carbon black – gas soot.     

A STUDY ON THE THERMAL STABILITY TO 1000°C OF VARIOUS CARBON ALLOTROPES AND CARBONACEOUS MATTER BOTH UNDER NITROGEN AND IN AIR

ABSTRACT

The thermal behavior of graphite, C₆₀ fullerene, fullerene black (carbon soot containing fullerenes), extracted fullerene black and diamond has been analyzed to 1000°C by TGA–DTA (thermogravimetric analysis and differential thermal analysis) under a nitrogen flow at a heating rate of 20°C/min. Very small weight losses have been recorded in the case of graphite and diamond. Furthermore no diamond graphitization has been observed. The sublimation of pure C₆₀ and the fullerene fraction of fullerene black (both pristine and extracted) has been observed and discussed.

The combustion reaction in air flow of graphite, C₆₀ and C₇₀ fullerenes, fullerene black (both unextracted and extracted), carbon nanotubes and diamond has been studied by TGA–DTA at a heating rate of 20°C/min. C₇₀ fullerene and fullerene black have been found to be the most reactive carbon materials with O₂. The role played by C₇₀ in the degradation of fullerites has been discussed. Among the carbon materials examined, the best resistance to O₂ attack has been shown by diamond and carbon nanotubes. The behavior of graphite is intermediate between diamond and fullerene blacks. The behavior of C₆₀ fullerene appears closer to that of graphite although it appears to be more reactive with O₂. Samples of graphite and carbon blacks N375 and N234 have been studied by TGA–DTA in air flow before and after a radiation treatment with neutrons or γ radiation. The effect of the radiation damage in the combustion reaction of these carbon materials has been discussed.