【作者】 徐昌曦；

【导师】 黄永秋；

【作者基本信息】 东华大学 ， 材料学， 2004， 硕士

【摘要】 活性炭纤维（Activated Carbon Fiber，ACF）具有优良的吸附性能、再生性能和操作性能，但ACF对大分子、高沸点吸附质的脱附再生能力很差。本课题正是从解决ACF对大分子、高沸点吸附质的再生难题入手，提高ACF的使用性能。 我们将光催化氧化技术与ACF结合，采用光催化氧化方式将吸附在ACF上的大分子吸附质氧化分解，从而达到ACF再生的目的。我们尝试了两种方法将光催化氧化技术与ACF结合： （1）采用溶胶-凝胶法，以钛酸四丁酯为前驱物在粘胶基活性炭纤维（Viscose-based activated carbon fiber，VACF）表面直接制备了锐钛矿相的二氧化钛。ACF经这种方法改性后，拥有很好的光催化再生能力，我们以PVA和柠檬酸作为大分子吸附质进行再生试验的结果表明：负载二氧化钛的ACF能很好地进行光催化再生，并且除第一次再生后试样的比表面积有约10％的下降外，以后再生其比表面积基本能长期保持稳定。在获得良好的光催化再生能力的同时，能基本保持原有的吸附能力。结合电子显微镜照片和试样等温吸附线的分析，我们还讨论了二氧化钛在ACF中的形态，推测了二氧化钛在ACF表面是以球缺的形式存。 （2）延长ACF的单次使用寿命，即增加ACF单次使用时间，从而减少ACF的再生频率，也可以提高ACF的使用性能。同时，考虑到直接在ACF上负载TiO₂会对ACF的性能造成一定的影响，我们用溶胶-凝胶法在玻璃纤维布上制备了TiO₂薄膜，并将此玻璃纤维布与ACF毡复合，得到了以负载TiO₂的玻璃纤维布为外层的夹心状复合光催化吸附材料。并用亚甲基蓝溶液模拟大分子有机废水，对此光催化吸附材料的去除有机物的能力做了测试。结果表明：该光催化吸附材料对有机物的消除效果大大优于单独使用ACF或TiO₂，这是由于ACF的吸附促进了TiO₂的光催化反应活性，而光催化氧化使吸附质大量的分解，减少了吸附质在ACF上的吸附，使ACF的使用寿命大为延长。 通过两种方案的实验，我们认为在ACF上直接负载Ti02在基本保持原有吸附能力的同时，使ACF具有良好的光催化再生能力，对大分子、高沸点吸附质有很好的再生能力。采用负载Tio:的玻璃纤维布复合ACF可以在ACF吸附同时分解掉大部分有机物，从而提高ACF的使用寿命。两种方案的出发点不同，但对ACF性能的提高都有显明的效果。更多还原

【Abstract】 Activated carbon fiber (ACF) is an excellent adsorbent with tremendous adsorptive capacity, rapid regeneration process and facility of operation. However, ACF has weak regeneration ability for macromolecular substance or high boiling point substance. In many cases the adsorptive environment contains these difficultly regenerating substances which would accumulate on the surface of ACF and block the entrance of the micropore. Thus, ACF may loss its adsorptive capacity for any substance. Moreover, ACF is expensive, only repetitive use could improve its cost performance and increase its competitive power in market. Our objective is to improve the regeneration ability of ACF for macromolecular or high boiling point substances. Photocatalytic oxidization technology has been introduced to remove the substances adsorbed on the surface of ACF. Because the photocatalytic oxidization not only has wide-ranging applied substances but also can degrade compounds rapidly and thoroughly.We developed two types of photocatylytic ACF adsorbent by combining the TiO2 photocalyst via sol-gel method. (1). TiO2 is directly supported on the surface of ACF. Ti(OC4H9)4 was used as the precursor of TiO2. Mixing Ti(OC4H9)4, alcohol, acetic acid,water and AcAc, undergoing a aging process of a week, the TiO2 sol was obtained. ACF felts were dipped into this sol for several minutes and then were disposed in a supercentrifuge machine to remove the redundant sol and control the amount of sol by centrifugal force. After centrifugation, the TiO2 sol coated ACF felts were heat treated in a carbonization furnace at 550癈 for 3 hours and anatase TiO2 coated ACF felts were obtained. The regeneration ability of this TiO2 coated ACF felts were investigated by using PVA and citric acid as macromolecular and high boiling point substances. TiO2 coated ACF felts were be soaking in to the PVA or citric acid aqueous solution to reach the saturated adsorption state, then the saturated adsorbent were irradiated under the UV light. The results show that the TiO2 on the ACF’s surface can degrade the organic compounds adsorbed on the ACF effectively under the irradiation of UV light. The special surface area and the adsorption capacity of ACF only decrease in the first photocatalytic regeneration slightly and maintain constant for the following regeneration process. The feasibility and superiority of regenerating ACF by photocatalysis were confirmed. Meanwhile, we investigated the morphology of TiO2 on the ACF’s surface by analyzing the nitrogen adsorption isotherm and SEM photos. The results indicated that the shape of TiO2on ACF’s surface was spherical segment with the diameter of about 250nm. (2). Improving the regeneration ability can enhance the total service lifeof ACF by increasing the repetitive use time, on the other hand, extending the service life of a single operation can prolong the total service life as well. Moreover, considering that TiO2 directly coated ACF would destroy the adsorption capacity of ACF in a certain extent, we employed TiO2 coated glass fiber mesh to give ACF the photocatalytic ability. Using the sol-gel procedures, we prepared titanium dioxide (TiOi) thin films on the surface of glass fiber mesh via using the tetra-n-butyl titanate (Ti(OC4H9)4) as precursor. After heat treatment at 550 degree centigrade for 3 hours, amorphous TiO2 films were transformed to anatase as comfirmed by the XRD analysis. Wrapped the ACF felts with this glass mesh coated with TiO2 films, the sandwich-like photocatalytic adsorbents were obtained. The decolorization capability and the decolorization kinetics of this photocatalytic adsorbent for methylene blue were investigated via determining the absorbance measurements of the methylene blue solution. Both static and dynamic reaction were performed with irradiation of two 40w UV lamp with dominant wavelength of 253.7nm. The results show that TiO2 and ACF in the photocatalytic adsorbent improve the performance in coordination: TiO2 prolong the service life of ACF and ACF accelerate th更多还原