Physics Department, Jadavpur University, Kolkata-700 032, India.
Physics Department, West Bengal State University, Barasat, India.
Mater Sci Eng C Mater Biol Appl. 2012 Aug 1;32(6):1358-65. doi: 10.1016/j.msec.2012.04.011. Epub 2012 Apr 16.
The increasing accumulation of fly ash from thermal power plants poses a major problem to the environment. The present work reflects the novel utilization of this profusely available industrial waste in the form of an antibacterial hard ceramic material by treating fly ash with ferric oxide (Fe2O3) and titania (TiO2) during sintering process at 1600 °C. The developed material shows more than 90% bacterial reduction against both Gram-positive and Gram-negative bacteria. The mechanism of their antibacterial action was studied by transmission electron microscopy (TEM) image analysis of the bacterial cross-section. The developed ceramic material acquires hardness due to the enhancement of the natural mullite content in the matrix. The mullite content and the crystallinity of mullite have shown their increasing trend with increasing concentration of the metal oxide during sintering process. A maximum of ~37% increase in mullite was obtained for 7% w/w Fe2O3 and TiO2. Metal oxide lowered the activation energy of the reaction and enhanced the reaction rate of alumina (Al2O3)-silica (SiO2) to form mullite which increases the hardness. The study highlights novel utilization of fly ash as a hard ceramic antibacterial product (bioceramics) for both structural and hygiene applications in an eco-friendly way.
热电厂日益增多的粉煤灰堆积对环境构成了重大问题。本工作反映了以氧化铁（Fe2O3）和二氧化钛（TiO2）处理粉煤灰的形式，将这种丰富的工业废料用作抗菌硬陶瓷材料的新颖利用，在 1600°C 的烧结过程中进行处理。所开发的材料对革兰氏阳性菌和革兰氏阴性菌的细菌减少率均超过 90%。通过对细菌横截面的透射电子显微镜（TEM）图像分析研究了其抗菌作用的机制。由于基体中天然莫来石含量的增加，开发的陶瓷材料获得了硬度。在烧结过程中，随着金属氧化物浓度的增加，莫来石含量和莫来石的结晶度表现出增加的趋势。在 7%w/wFe2O3 和 TiO2 的情况下，莫来石的含量最多增加了~37%。金属氧化物降低了反应的活化能并提高了氧化铝（Al2O3）-二氧化硅（SiO2）形成莫来石的反应速率，从而提高了硬度。该研究强调了粉煤灰作为一种硬陶瓷抗菌产品（生物陶瓷）的新颖利用，以生态友好的方式用于结构和卫生应用。
