STUDIES ON THE PREPARATION OF ZINC-CONTAINING ACTIVATED CARBON FIBERS AND THEIR ANTIBACTERIAL ACTIVITY

Several kinds of activated carbon fibers, using sisal fiber as precursors, were preparedwith steam activation or with ZnCl2 activation. Zinc or its compounds were dispersed in them. Theantibacterial activities of these activated carbon fibers were determined and compared. The researchresults showed that these sisal based activated carbon fibers supporting zinc have strongerantibacterial activity against Escherichia coli and S. aureus. The antibacterial activity is related tothe precursors, the pyrolysis temperature, and the zinc content. In addition, small quantity of silversupported on zinc-containing ACFs will greatly enhance the antibacterial activity of ACFs.     

载银磷酸活化剑麻基活性炭纤维的抗菌性能研究

本文利用磷酸化方法，制备各种剑麻基活性炭纤维，并利用活性炭纤维的氧化还原特性及吸附性能，在其上负载金属银，研究并比较了这些载银活性炭纤维对大肠杆菌和金黄色葡萄球菌的杀灭作用，结果表明，磷酸浓度，活化方法，活化时间，纤维的比表面积等因素的均对材料的抗菌性能有一定的影响，磷酸活化的活性炭纤维表现出强的抗菌杀菌能力，高浓度磷酸活化后的纤维抗菌能力有所提高，并且抗菌能力随活化时间的延长而增加，抗菌前后纤维上负载的银未曾大量脱落，经5次抗菌试验后材料仍显示出很强的抗菌能力。     

活性碳纤维对银离子还原吸附能力的改进

活性碳纤维不仅对有机物有高的吸附容量,对贵金属离子也具有强的还原吸附能力,可将Pd(Ⅱ）,Ag（Ⅰ）,Au（Ⅲ）等离子还原为金属单质。因而可用于提取矿液或加收废液中的贵金属。由此,提高或改善贵金属在活性碳纤维上的还原吸附容量或分布形成,显得非常重要。本文研究了活性碳纤维制备条件、表面氧化改性、以有负载有机物等对活性碳纤维还原能力的影响。结果表明,（1）制备条件对剑麻基活性碳纤维的还原能力有很大的影响。用H3PO4或ZnCl2活化的活性碳纤维对银离子具有更高的还原吸附容量,分别可达250和700mg/g,约为水蒸汽活化剑麻基活性碳纤维对银离子还原吸附容量的2倍和5倍。（2）过氧化氢、高锰酸钾、或硝酸等无机氧化剂对活性碳纤维进行表面改性,也能提高活性碳纤维的还原能力。结果表明,虽然改性活性碳纤维的比表面积和孔体积下降10-20%左右,但基表面含氧量及含氧基团的种类发生了改变。这些改性活性碳纤维对Ag(NH3)2^ 的还原吸附量大幅度提高,可达550mg/g以上。推断表面改性在活性碳纤维表面创造了更多有利于碱性条件下发生氧化还原的活性点。（3）在活性碳纤维表面负载适当的有机物如亚甲基蓝、苯胺或对硝基苯酚,也能显著提高活性碳纤维对Ag(NH3)2^ 的还原吸附能力。     

STUDY ON THE FACTORS AFFECTING REDUCTION CAPACITIES OF ACTIVATED CARBON FIBERS

1. INTRODUCTION The discharge of effluent containing precious metal ions, which comes from electroplating, mining, smelting, and other industries, not only contaminate the environment where people live, but also cause the waste of natural resources. From…     

STUDY ON THE FACTORS AFFECTING REDUCTION CAPACITIES OF ACTIVATED CARBON FIBERS

The reduction adsorption of silver diamminonitrate on different kinds of activated carbonfibers (ACF) has been studied in this paper. The effect of different parameters, including adsorptiontemperature, concentrations of activation agents, and activation time on the silver adsorptioncapacities of activated carbon fibers has been investigated The results show that higher temperaturein which the silver complex interacts with ACF. or higher concentration of activation agent, will makehigher reduction adsorption capacities of ACFs. More over, ACFs activated with phosphoric acidhave higher reduction capacities than those activated with zinc chloride or steam.     

Antibacterial behavior of transition-metals-decorated activated carbon fibers

The antibacterial behavior of transition metals (Cu or Ag)-plated activated carbon fibers (ACFs) was investigated. The pore structure of the ACFs before and after metal electroplating was studied by N(2)/77 K isothermal adsorption. The antibacterial behavior against Staphylococcus aureus and Klebsiella pneumoniae was tested by a modified dilution method. As experimental results, the ACFs showed a decrease in specific surface area and micro- and total pore volume with increasing metal content. The antibacterial behavior of the ACFs was predominantly increased and showed over 99% against S. aureus as well as K. pneumoniae, attributed to the presence of metal nanoparticles in this system.     

Preparation and characterization of activated carbon fibers supported with silver metal for antibacterial behavior

In this work, the effect of immersion in silver nitrate solution on activated carbon fibers (ACFs) was investigated in relation to adsorption behavior and antibacterial activity of ACFs supported with silver (ACF/Ag). The pore and surface properties were studied in terms of BET volumetric measurement with nitrogen adsorption, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The antibacterial activities of ACF/Ag were studied in broth dilution tests against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) from a point of view of water purification. As an experimental result, the silver content of ACF/Ag increased with increasing concentration of silver nitrate. It was found that the micropore structure slightly decreased as the silver nitrate concentration increased. Otherwise, it was revealed that the ACF/Ag possessed a strong antibacterial activity and an inhibitory effect for the growing of E. coli and S. aureus, respectively. Silver content on ACF/Ag decreased rapidly because of rough morphology of silver particles in water erosion.     

Studies on pore structures and surface functional groups of pitch-based activated carbon fibers

The present study concerns the physical activation and chemical oxidation of pitch-based activated carbon fibers (ACFs) as ways to improve the adsorption properties. The surface oxides of the ACFs studied were determined by Boehm's titration and the pore structures were studied by the BET method with N(2)/77 K adsorption. Also, the adsorption properties of the ACFs were investigated with chromium ion adsorption by different adsorption models. As a result, it was observed that carboxyl groups were largely created after nitric acid treatment on ACFs. The affinity for chromium ions increases with increasing specific surface area, micropore volume, and surface functionalities of ACFs as the activation time increases.     

PREPARATION OF ACTIVATED CARBON FIBERS AND THEIR XENON ADSORPTION PROPERTIES（Ⅰ）-PREPARATION AND PORE STRUCTURE CHARACTERIZATION

A series of sisal based activated carbon fibers were preqared with steam activation at temperature from 750℃ to 900℃.Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using different theories.The results showed that t-plot method and DR-plot method could suitably be used to characterize the mesopore structure and the multi-stage distribution of pore size of activated carbon fibers.It also showed that the pore size widens with the increase of activation temperature.     

Macroporous Activated Carbon Fibers from Rayon Precursors Impregnated with Phosphoric Acid

Novel activated carbon fibers (ACFs) from rayon precursors impregnated with phosphoric acid (H₃PO₄), containing abundant macropores (pore size>50 nm), were successfully obtained. The physical properties of these ACFs were examined. The BET surface was obtained; SEM observations showed that the concentration of H₃PO₄ impregnation strongly influenced the surface morphology and the porous texture of the resulting ACFs. The shape of the pores was nearly round and we could estimate the pore size was distributed between 20 and 150 nm. Infrared spectroscopy (IR) was applied to investigate the pyrolysis process of the rayon precursors with H₃PO_4. In addition, P‐containing substances, which should perhaps be acid phosphates or polyphosphates, can be observed on the surface of the resulting ACFs from SEM photos. Impregnation made the dehydration become more predominant during the pyrolysis process.     

活性碳纤维的结构修饰及其吸附氙性能的研究

活性炭纤维对氙的吸附容量与其孔结构密切相关，为了提高活性炭纤维对氙气的吸附容量，本文分别用亚甲基蓝、对硝基苯酚等有机物，或氯化钠、碘等无机化合物填充的方法修饰活性炭纤维的孔结构；以及利用高锰酸钾或硝酸等氧化处理修饰活性炭纤维的表面化学性质，同时，利用低温氮等温吸附表征了这些改性活性炭纤维的孔结构，以及通过光电子能谱表征了改性活性炭纤维的表面化学结构，上述化合物充填或氧化改性活性炭纤维对氙的吸附性能的研究结果表明，适量化合物填充，或合适浓度硝酸对活性炭纤维的表面处理，可以有效地修饰活性炭纤维的孔结构或改变活性炭纤维表面对氙的亲和力。因而可有效地提高改性活性炭纤维对氙的吸附容量。     

PREPARATION OF ACTIVATED CARBON FIBER AND THEIR XENON ADSORPTION PROPERTIES（Ⅲ）-ADSORPTION ON MODIFIED ACTIVATED CARBON FIBER

Structures of a series of activated carbon fibers were modified by impregnating them withorganic and inorganic materials such as Methylene blue(Mb)、 p-nitrophenol (PNP)、 NaCl or byoxidizing with KMnO4 or HNO3. The influence of pore filling or chemical treatment on their xenonadsorption properties was studied. The experimental results show that Mb and PNP filling ofactivated carbon fibers result in the decrease of xenon adsorption capacities of these treated ACFs,which is due to the decrease of their surface area and micro-pore volume. However, the adsorptioncapacity increases greatly with oxidizing treatment of activated carbon fibers by 7mol/L HNO3.     

CuZnAl/碳纤维复合材料催化合成气制备低碳醇

采用共沉淀法制备CuZnAl类水滑石,将其担载于活化碳纤维（ACFs）表面,通过焙烧还原合成功能化复合催化剂（CuZnAl/ACFs）。借助XRD、FT-IR及N₂吸附-脱附等方法对该复合物进行表征,并将其应用于合成气制备低碳醇的反应中,进行活性评价。结果表明,复合催化剂中活性组分在碳纤维表面均匀分散,碳纤维表面催化剂的颗粒尺寸减小,比表面积增大。ACFs的导电性加速醇合成过程中的电子传递,促进反应进行,因而CO转化率的提高（最高可达47%）。同时,ACFs提高催化剂表面ZnO的分散度,从而促进Cu与ZnO形成金属氧化物界面。这有利于低碳醇的生成,因而使C2以上醇的选择性高达39%。     

CuZnAl/碳纤维复合材料催化合成气制备低碳醇

采用共沉淀法制备CuZnAl类水滑石,将其担载于活化碳纤维(ACFs)表面,通过焙烧还原合成功能化复合催化剂(CuZnAl/ACFs)。借助XRD、FT-IR及N2吸附-脱附等方法对该复合物进行表征,并将其应用于合成气制备低碳醇的反应中,进行活性评价。结果表明,复合催化剂中活性组分在碳纤维表面均匀分散,碳纤维表面催化剂的颗粒尺寸减小,比表面积增大。ACFs的导电性加速醇合成过程中的电子传递,促进反应进行,因而CO转化率的提高(最高可达47%)。同时,ACFs提高催化剂表面ZnO的分散度,从而促进Cu与ZnO形成金属氧化物界面。这有利于低碳醇的生成,因而使C2以上醇的选择性高达39%。     

Modification of Activated Carbon Fibers and Their Characterizes of Adsorption for Xenon

Activated carbon fibers (ACFs) are characterizes by their highly developed internal surface area and porosity. Especially the development of micro- and mesopores is of great importance because it allows the carbons to adsorb large amounts and various types of chemicals from gases or liquids. Due to such a valuable feature, activated carbon fibers have been in use for many years. Porous carbon materials have now become extremely versatile adsorbents of major industrial significance. The high surface area and porosity of activated carbon fibers are the result of the activation process; physical or chemical activation. However, the complexity of the carbon structure, although voluminous research has been done and great effort has been made toward the control of pore size and its distribution^[1-3]. The recent development of industrial technology provides new application fields for porous carbons and,at the same time, requires the carbon to have a desired pore structure. To meet such a requirement, many novel approaches to control pore structure have been proposed.     

STUDIES ON THE CHEMICAL STRUCTURES OF ACTIVATED CARBON FIBERS BY SOLID STATE NMR

The solid state C13-NMR spectra of different ACFs from various precursor fibers were recorded in this paper,The effects of activation conditions on chemical structures of ACFs,as well as the changes of chemical structures during carbonization and redox reaction were inverstigated by NMR technique,At same time,the soild state P31-NMR spectra of ACFS are studied.The C13-NMR spectra of ACFs can be divided into six bands that are assigned to methyl and methylene groups,hydroxyl and ether groups.acetal (or methylenedioxy) carbon,graphite-like aromatic carbon structure,phenol,and quinone groups,respectively.Only phosphorous pentoxide exists on ACFs and CFs.Moreover,most of them are stuck over the crystal face but not at the edge of graphite-like micro-crystal.The carbonization and activation conditions affect the C13-NMR spectra of ACFs.The experimental rsults indicate that the redox reaction of ACFs with oxidants greatly consumes C-H group.     

乙烯渣油沥青基活性炭纤维和粘胶基活性炭纤维的表面性质与脱硫活性

研究了在O2和H2O存在下,乙烯渣油沥青基活性炭纤维(ETPACF)和粘胶基活性炭纤维(CelluloseACF)的脱硫活性.结果表明,在比表面积相近的情况下,ETPACF的脱硫活性明显低于CelluloseACF,这可归因于后者具有较强的吸附和催化氧化SO2能力及较大的吸水量,尤其是具有较强的催化氧化SO2的能力,这些能力又与其表面含有含氮官能团以及某些含氧官能团有关,因此ACF的表面官能团对其脱硫活性影响很大.     

Quantum sieving effect of modified activated carbon fibers on H2 and D2 adsorption at 20 K

Quantum sieving of activated carbon fibers (ACFs) and their fluorides was observed for H(2) and D(2) adsorption at 20 K. Fluorination reduced the slit-shaped pore width of ACFs by 0.2 nm. The activated carbon fibers can act as highly efficient quantum sieves for H(2) and D(2), because the effective size of an H(2) molecule is larger than that of a D(2) molecule due to the uncertainty principle and the molecular size difference between H(2) and D(2) is significant in the micropore space. The D(2)/H(2) selectivity of ACFs evaluated by ideal adsorption solution theory was larger than that of the fluorinated ACFs.     

Influence of heat treatment of rayon-based activated carbon fibers on the adsorption of formaldehyde

The influence of heat treatment of rayon-based activated carbon fibers on the adsorption behavior of formaldehyde was studied. Heat treatment in an inert atmosphere of nitrogen for rayon-based activated carbon fibers (ACFs) resulted in a significant increase in the adsorption capacities and prolongation of breakthrough time on removing of formaldehyde. The effect of different heat-treatment conditions on the adsorption characteristics was investigated. The porous structure parameters of the samples under study were investigated using nitrogen adsorption at the low temperature 77.4 K. The pore size distributions of the samples under study were calculated by density functional theory. With the aid of these analyses, the relationship between structure and adsorption properties of rayon-based ACFs for removing formaldehyde was revealed. Improvement of their performance in terms of adsorption selectivity and adsorption rate for formaldehyde were achieved by heat post-treatment in an inert atmosphere of nitrogen.     

Carbon molecular sieves for air separation from Nomex aramid fibers

Activated carbon fibers prepared from aramid fibers have proved to possess outstanding homogeneity in pore size, most of all when Nomex aramid fiber is used as precursor. Taking advantage of this feature, microporous carbon molecular sieves for air separation have been prepared through carbon vapor deposition of benzene on Nomex-derived carbon fibers activated to two different burnoff degrees. Carbon molecular sieves with good selectivity for this separation and showing acceptable adsorption capacities were obtained from ACFs activated to the two burnoff degrees chosen.