固态缩聚尼龙1010的熔化行为

本工作借助示差扫描量热法和X-射线衍射分析法(WAXD)首次研究了固态缩聚反应所得初生态尼龙1010的结晶特征和熔化行为。实验结果表明:固态缩聚反应的温度和时间以及产物分子量对初生态尼龙1010的熔化行为有着明显的影响。初生态尼龙1010结晶熔融双峰的显隐与其X-射线衍射峰特征没有明显的依赖关系,但随着尼龙大分子结晶的完善化而出现表观体积收缩观象。

尼龙1010盐固态缩聚反应的研究

采用测定转化率和分子量、红外光谱、X-射线衍射分析、元素分析、偏光显微镜和扫描电镜等方法研究了结晶尼龙1010盐的特性、尼龙1010盐固态缩聚反应的动力学及其相应的晶体结构形态,用DSC法探讨了其反应机理。

尼龙66-盐与碳纤维复合-固态缩聚的研究

本工作借助偏光显微镜,扫描电子显微镜和热分析方法(DSC,TGA)研究了尼龙66盐与碳纤维复合-固态缩聚反应历程及纤维-树脂之间的界面效应。发现对尼龙66盐的“原位固态缩聚”存有如碳纤维表面的成核结晶和催化效应之类的界面效应。讨论了碳纤维的界面效应对尼龙66基体的外延结晶和熔融行为及其热氧化稳定作用的影响。

STUDY ON THE PHYSICAL CHEMICALPROPERTIES OF FFA-1 ION EXCHANGE FIBER

The physical and chemical properties of FFA-1 ion exchange fiber have beencharacterized with IR spectrum. thermal analysis and SEM means. The PH titrationcurve, swelling rate, mechanical properties, resistance drop of filter layer as well asthe dynamic adsorption for SO2 was determined These experiments provided theessential parameters for the practical application of FFA-1 material in adsorption oftoxic gases.

PREPARATION AND THEIR ANTIBACTERIAL ACTIVITY OF ACTIVATED CARBON FIBER CONTAINING SILVER

Several kinds of activated carbon fiber（ACF）, Granule Activated carbon（AC） containing silver ion or fine silver particle(Ag-ACF/AC) have been prepared by soaking ACF or AC in the salt solution of silver. Ag, AgCl and AgI compounds have been loaded onto the fibers. The structure of the fibers was measured by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The Ag content in the fiber was obtained by an Atomic absorption spectroscopy (AAS). The Ag+ content in water after the antibacterial test was measured by an Inductively Coupled Plasma (ICP) emission spectroscopy. Antibacterial test was carried out against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus). The results show that Ag-ACF/AC have strong antibacterial activity against E.coli and S.aureus. After dealt with ACF/AC loading Ag, AgCl, AgI, no E.coli and S.aureus alive in solution can be detected. The analysis of Ag content in water after antibacterial test showed that the content of Ag meet the quality requirement of the National Potable Water Standard. It is indicated that ACF/AC-Ag in this experiment would be a safe antibacterial agent .

聚苯硫醚的动态力学行为研究

本工作借助TBA技术研究了聚苯硫醚(PPS)的动态力学行为。结果表明,PPS的端基和分子量,热处理方式(固相处理或熔融处理)和处理时间,试样的热历史(淬火或退火)及制辫子所用的纤维的表面性质(玻璃纤维、碳纤维和石墨纤维及其表面处理)等因素对其动态力学行为均有影响。这些动态力学行为特征的变化与这些因素所引起的PPS的分子结构和超分子结构的变化有关。

ORGANIC CHELATING REAGENT ON REDOX ADSORPTION OF ACTIVATED CARBON FIBER TOWARDS Au^(3+)

Organic chelating reagent influences upon the redox adsorption of activated carbon fiber towards Au3+ were systematically investigated. The experimental results indicated that the presence of organic chelating reagent on activated carbon fiber strongly affects adsorption capacity of activated carbon fiber towards Au3+. The reduction-adsorption amount of Au3+ increased three times by the presence of 8-quinolinol. Furthermore, The reduction-adsorption amount of Au3+ depended on the pH value of adsorption and temperature.

KINETICS OF DEPOSITION OF METAL IONS TO ACTIVATED CARBON FIBERS (ACFs) WITH FLUIDIZATION

The diffusion and mass transfer, reaction, integration and growth processes of the metal ions on the activated carbon fibers (ACFs) are discussed. Based on the diffusion film theory, the diffusion and the integration model are developed to describe the deposition processes of metal ions from the solution to ACFs in the fluidized beds. The model of heat transfer of this process is established to expound the important role-played in deposition processes by the influence of the reaction heat released at ACFs surface and the non-uniform temperature distribution caused by hydrodynamics.

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 prepared 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.

STUDY ON THE FACTORS AFFECTING REDUCTION CAPACITIES OF ACTIVATED CARBON FIBERS

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

MACRO-KINETICS BEHAVIOR OF GOLD RECOVERY BY ACTIVATED CARBON FIBERS (ACFs) IN A FLUIDIZED BED

The recovery of Au by activated carbon fibers (ACFs) was carried out in a 40mm diameter, 1200mm height fluidized bed. The rates of reaction of the functional fibers with Au3+ in the pure aurum solution and in the aurum-containing wastewater were measured respectively at the different solution flow rates, and compared with the results under the static solution conditions. Experimental results indicated that the reaction rates in fluidization are notably higher than those in the static state and increase with the increase of solution flow rate. It demonstrates that the thickness of the concentration boundary layer is decreased and a uniform temperature field is established in the bed due to increasing of the turbulent extent with the relative fiber/solution velocity.

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 with organic and inorganic materials such as Methylene blue(Mb)、p-nitrophenol (PNP)、NaCl or by oxidizing with KMnO4 or HNO3. The influence of pore filling or chemical treatment on their xenon adsorption properties was studied. The experimental results show that Mb and PNP filling of activated 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 adsorption capacity increases greatly with oxidizing treatment of activated carbon fibers by 7mol/L HNO3.

PROGRESS ON ACTIVATED CARBON FIBERS

Activated carbon fiber is one kind of important adsorption materials. These novel fibrous adsorbents have high specific surface areas or abundant functional groups, which make them have greater adsorption/desorption rates and larger adsorption capacities than other adsorbents. They can be prepared as bundle, paper, cloth and felt to meet various technical requirement. They also show reduction property. In this paper the latest progress on the studies of the preparation and adsorption properties of activated carbon fibers is reviewed. The application of these materials in drinking water purification, environmental control, resource recovery, chemical industry, and in medicine and health care is also presented.

REMOVAL OF THIOL BY ACTIVATED CARBON FIBER

Pitch based activated carbon fiber (PACF) was prepared, and influences of preparing condition such as activated temperature and time on the yield, specific surface area of PACF and its adsorption behavior towards n-butanethiol were studied. The results showed that simple PACF could not remove n-butanethiol from n-hexane solution. Therefore, dispersion of suitable catalyst such as cobalt salt on PACF is needed. Cobalt salt dispersed PACF can remove n-butanethiol quickly.

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 prepared with steam activation or with ZnCl2 activation. Zinc or its compounds were dispersed in them. The antibacterial activities of these activated carbon fibers were determined and compared. The research results showed that these sisal based activated carbon fibers supporting zinc have stronger antibacterial activity against Escherichia coli and S. aureus. The antibacterial activity is related to the precursors, the pyrolysis temperature, and the zinc content. In addition, small quantity of silver supported on zinc-containing ACFs will greatly enhance the antibacterial activity of ACFs.

SURFACE FUNCTIONALIZED OF NANODIAMONDS

Aminopropyl, ethylenediamine, ethenyl and glycidoxy groups functionalized nanoparticles, with average diameters ranging from 4 to 6 nm and containing 1.17mmol of groups/g, are readily obtained from nanodiamonds modified with silane coupling agent. For the study of these nanoparticles, TEM, IRS, XPS, and TG analysis methods have been used.

STUDIES ON THE CHEMICAL STRUCTURES OFACTIVATED CARBON FIBERS BY SOLID STATE NMR

The solid stale C13-NMR spectra of different ACFs from various precursor fiberswere recorded in this paper. The effects of activation conditions on chemical structuresOf ACFs, as well as the changes of chemical structures during carbonization and redoxreaction were investigated by NMR technique. At same time, the solid state P31-NMRspectra of ACFs are studied The C13-NMR spectra of ACFs can be divided into sixbands 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 andCFs. Moreover, most of them are stuck over the crystal face but not at the edge ofgraphite-like micro-crystaL The carbonization and activation conditions affect theC13-NMR spectra of ACFs. The experimental results indicate that the redox reactionof ACFs with oxidants greatly consumes C-H group.

ADSORPTION CHARACTERISTICS OF SACFs FORA VARIETY OF DYES

The isothermal adsorption of dyes on a variety of sisal based activated carbonfibers (SACFs), and the influence of PH and temperature on absorption are discussedin this paper The results indicate that the adsorption of methylene blue, crystal violetand Eriochrome blue black R on SACFs shows type I isotherms and can be describedby the Langnuir equation or the Freudlich equation. The acidity of solution hasgreatly ifluence over the adeorption amounts of methylene blue, crystal violet andEriochrome blue black R. As PHs of the solutions were adjusted to increase ordecrease from the original acidity of the solution (4. 7. 4. ) and 4. 0 for methylene blue,crystal violet and Eriochrome blue black R. respectively), the amounts of dyesadsorbed on SACFs increased. The adsorption temperature (in the range of 25~50℃)exerts little influence on the adsorption amount of methylene blue, crystal violet andfluorescein. For azo dyes (Eriochrome blue black R and Eriochrome black T), howeverthe absorption amount increases slightly with the elevation of temperature.

PREPARATION OF ACTIVATED CARBON FIBER AND THEIR XENON ADSORPTION PROPERTIES (II)-XENON ADSORPTION PROPERTIES

The adsorption of xenon from air has an interest in the monitoring of nuclear explosion or accident, or in the treatment of nuclear waste gas. In this paper, the pore structure of several series of activated carbon fibers has been characterized. The adsorption properties of xenon on these activated carbon fibers under different temperatures have been studied in details. The results show that the xenon adsorption amount on activated carbon fibers do not increase with specific surface area of adsorbents, but are closely related to their pore size distribution. Pores whose radius equal to or narrow than 0.4nm would be more advantageous to the adsorption of xenon.

ADSORPTION OF DYES ON ACTIVATED CARBON FIBERS

The adsorplion behavior of dyes on a variety of sisal based activated carbonfibers (SACF) has been studied in this paper The results show that this kind of ACFhas excellent adsorption capacities for some organic (dye) molecules. SACF canremove nearly all methylene blue, crystal violet, bromophenol blue and Eriochromeblue black R from water after static adsorption for 24 h. at 30℃ The adsorptionamounts can reach more than 400 mg/g when adding 50 mg SACF into 50 ml dyesolution. Under the same conditions, the absorption amounts of xylenol orangefluorescein and Eriochrome black T were lower On the other hand, the adsorptionamounts change along with the characteristics of adsorbents. The SACFs activatedabove 840 ℃ which have higher specific surface areas and wider pore radii, havehigher adsorption amounts for the dyes. The researching results also show that foeadsorption rates of dyes onto SACFs decrease by the order of methylene blue,Eriochrome blue black R and crystal violet.