共查询到20条相似文献,搜索用时 0 毫秒
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Franco Cataldo Mihai V. Putz Ornella Ursini Giancarlo Angelini 《Fullerenes, Nanotubes and Carbon Nanostructures》2016,24(6):406-413
It is shown that the differential scanning calorimetry (DSC) analysis of water desorption from activated carbon fabric (ACF) surfaces having different degrees of oxidation, is a valid alternative to immersion calorimetry in determining the desorption/adsorption energy of an adsorbate on the oxidized ACF surfaces. Processing the DSC endotherm relative to water desorption through the Clausius-Clapeyron equation it is possible to calculate either the water desorption energy from the oxidized ACF surfaces and also the hydrogen bond energy through which the water molecules are bound to the oxidized ACF surface. The DSC analysis of the ozonized ACF has revealed that secondary ozonides and peroxides are formed together with other oxygenated groups on the ACF surface, and were detected through an exothermal transition with two peaks at 118°C and 142°C with the measured decomposition enthalpy directly proportional to the degree of oxidation of the ACF surface. The ESR analysis on pristine ACF has revealed the presence of clustered paramagnetic centers. The reaction of the ACF with ozone greatly enhances the ESR signal since more free radicals are formed on the surface mainly in the form of oxygen-centered peroxide-type. 相似文献
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Franco Cataldo Mihai V. Putz Ornella Ursini Giancarlo Angelini 《Fullerenes, Nanotubes and Carbon Nanostructures》2016,24(5):313-323
Two samples of activated carbon fabrics (ACF) with very high surface area (>1300 to >1800 m2/g) were reacted with ozone inside a closed flask under static conditions. The kinetics of ozone decomposition and reaction with the ACF surface was measured in the gas phase using Fourier transform infrared analysis (FT-IR) spectroscopy. The ozone consumption under these conditions was following the pseudofirst-order kinetics law and was accompanied by the production of CO2 and CO. The ozone-oxidized ACF were studied by FT-IR spectroscopy following the growth of key oxidized functional groups, i.e. phenolic OH, ketone groups intended as carboxyl, lactone, and anhydride, as well as quinone groups as a function of the amount of ozone reacted. The weight uptake of the ACF reacted with ozone was followed gravimetrically. The ACF having >1800 m2/g was able to reach a weight increase of 25% of its original weight due to the formation of oxygenated surface functional groups. Raman spectroscopy was used for the evaluation of defective structures formed in ACF because of ozonization reaction. 相似文献
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以平板、旁通、折叠三种结构形式的活性碳纤维过滤器为实验对象,选择甲醛和氨气作为室内典型污染物,以分光光度法测定在变风量和变污染物浓度的条件下过滤器的吸附过滤效果;实验数据的分析表明,从综合角度考虑,平板式过滤器较为理想,折叠式效率较高,但阻力相对偏大,而旁通式则效率偏低;提出了一些对活性碳纤维过滤器的发展和改进有价值的建议。 相似文献
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以沥青基炭纤维为原料,用水蒸气活化的方法制备了三种不同比表面积的活性炭纤维,并采用氮吸附法和拉曼光谱对活性炭纤维进行了表征。本文研究了活性炭纤维在常温下对模拟空气中50 ppm NO的催化氧化性能,结果表明,活性炭纤维可将NO部分催化转化为NO2,较低比表面积的活性炭纤维因为其较窄的孔径分布和较大的类石墨微晶有利于对NO的催化氧化。 相似文献
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负载含银介孔分子筛活性碳纤维的制备与性能 总被引:2,自引:0,他引:2
将CAF加入由以十二胺,正硅酸乙酯,乙醇,水等组成的介孔分子筛(MS)合成反应液中制备负载MS的活性碳纤维(ACF-MS),MS含量由反应液中ACF的含量确定,通过真空浸渍和热分解使ACF-MS载银,载成新型净水材料-负载含银介孔分子筛的活性碳纤维(ACF-MS(Ag)),银含量由浸渍时间控制,在流动水的冲刷下ACF-MS(Ag)样品中的银含量缓慢下降,下降速率随着水流速和样品含银量的增加而增加,与ACF(Ag)相比,ACF-MS(Ag)的耐水冲刷性能显著提高。 相似文献
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Franco Cataldo 《Fullerenes, Nanotubes and Carbon Nanostructures》2018,26(6):379-388
Trimethyl phosphate (TMP) is a typical simulant of the CWA nerve agents and its adsorption on pristine and ozonized ACF has been studied by FT-IR and ESR spectroscopy. The FT-IR analysis is effective in putting in evidence the strong interaction of TMP with the ACF surfaces through the P = O stretching band shift toward lower frequencies after adsorption. Ozonized ACF ensures a stronger interaction with the adsorbate through the hydrogen bond formation between the adsorbed TMP and the oxygenated functional groups present on carbon surface. At room temperature the ozonized ACF is able to adsorb larger amounts of TMP than the pristine ACF and shows also a better retention of the adsorbate at room temperature. The TGA-FTIR analysis of TMP desorption from both ozonized and pristine ACF has shown that TMP undergoes a partial thermal decomposition into methanol and phosphoric acid above 175°C. The maximum methanol production rate was observed at 250°C in the TMP desorption process from ozonized ACF and at 280°C from TMP desorption from pristine ACF. 相似文献
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通过改变溶剂热法和水热法中材料的配比和温度制备了18种四氧化三钴/活性炭纤维(Co3O4/ACF)复合材料,并将这些复合材料用于催化过一硫酸盐(PMS)降解染料橙黄Ⅱ。考察了制备材料的配比(Co2+和ACF)和温度对制得的Co3O4/ACF复合材料催化降解橙黄Ⅱ效率的影响,并采用X射线衍射仪、扫描电镜等对复合材料的元素组成和形貌进行了表征。结果表明:水热法制得的复合材料催化性能好,3 min内可完全降解100 mg/L橙黄Ⅱ。从表征结果可见,水热法能更有效地使Co3O4颗粒以纳米尺寸分散负载在ACF上。材料的配比对产品的催化降解效率无显著影响,温度对水热法制得的产品的催化降解效率影响不大。水热法在320 ℃条件下煅烧制得的复合材料催化性能好且ACF能基本保持结构完整,Co负载量约为17.2 mg/g。水热法制备的Co3O4/ACF复合材料循环利用性能优于溶剂热法制得的材料,在循环使用四次后,28 min内橙黄Ⅱ降解效率仍能达到99%。其高效降解与Co3O4/ACF和溶解态Co2+的催化作用均有关。正交试验表明,降解过程中时间对降解效果的影响最大,其次是PMS的浓度,催化材料的加入量对降解效率无明显影响。因此,在复合材料应用中,应保证充足的降解时间,并适当提高PMS的浓度。 相似文献
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含炭黑PAN纤维制备活性炭纤维过程中中孔的形成 总被引:3,自引:1,他引:3
由炭黑改性聚丙烯腈原丝制得了中孔发达的活性炭纤维,并结合低温氮气吸附仪、高分辨透射电子显微镜、广角X-射线衍射仪及小角X-射线衍射仪对所得活性炭纤维孔结构的研究结果,提出了该活性炭纤维的中孔形成机理。 相似文献
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活性炭的制备及应用新进展 总被引:32,自引:0,他引:32
综述了活性炭材料研究开发的新进展。重点介绍了煤、石油焦、沥青基活性炭的制备方法及针对不同用途的活性炭改性技术,为选择合适的活化方法和制备特殊功能的改性活性炭提供了参考。 相似文献
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中孔活性碳纤维的研究 总被引:3,自引:0,他引:3
活性碳纤维具有比表面积大,微孔分布窄,吸附容量大,吸附脱速度快等特点,但一般活性碳纤维属于微孔型,不能吸附大分子物质,使其应用受到限制。近年来,中孔活性碳纤维的研究拓宽了其应用领域。综述了中孔活性碳纤维的国内外研究进展,着重介绍了活化工艺法、金属催化法、非金属添加剂法等制备方法。 相似文献
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Thermal decomposition of natural dolomite 总被引:2,自引:0,他引:2
Thermal decomposition behaviour of dolomite sample has been studied by thermogravimetric (TG) measurements. Differential thermal
analysis (DTA) curve of dolomite shows two peaks at 777·8°C and 834°C. The two endothermic peaks observed in dolomite are
essentially due to decarbonation of dolomite and calcite, respectively. The TG data of the decomposition steps have also been
analysed using various differential, difference-differential and integral methods, viz. Freeman-Carroll, Horowitz-Metzger,
Coats-Redfern methods. Values of activation entropy, Arrhenius factor, and order of reaction have been approximated and compared.
Measured activation energies vary between 97 and 147 kJ mol−1. The large fluctuation in activation energy is attributed to the presence of impurities such as SiO2, Al2O3, Fe2O3, Cl− etc in the samples. FTIR and XRD analyses confirm the decomposition reaction. SEM observation of the heat-treated samples
at 950°C shows cluster of grains, indicating the structural transformation. 相似文献
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纳米碳管与活性炭复合电极电吸附脱盐性能的研究 总被引:1,自引:0,他引:1
为考察纳米碳管(CNTs)、活性炭(AC)及其复合电极的电吸附脱盐性能,将其粉末压制成电极,组装成脱盐器,比较电极电吸附脱盐能力和脱盐能耗。结果表明,在活性炭电极中添加纳米碳管有效地降低了电极电阻和脱盐能耗,少量纳米碳管的添加能在一定程度上提高其电极比表面积、孔容以及在盐水中的比电容;当复合电极中纳米碳管的含量为10%时,其电极在盐水中的电吸附比电容达到113.5F/g,其电极脱盐效果最为显著,其脱盐耗能比活性炭电极降低约67%左右。 相似文献
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用比表面积1183m2/g的活性炭和酚醛树脂分别作为吸附剂和粘结剂,考察了成型工艺对活性炭孔结构及其CO2吸附性能的影响。结果表明,活性炭成型后,比表面积有所下降,但对成型活性炭进行CO2二次物理活化可使其比表面积提高60.7%;粘结剂含量为30wt%、成型压力10MPa条件下所制的成型活性炭在800℃用CO2二次活化2h后,其比表面积、压缩强度和对CO2的平衡吸附量分别为1323m2/g、12.7MPa和0.67mmol/g。 相似文献