Sen D, Bahadur J, Das Avik, Mazumder S, Melo J S, Frielinghaus H, Loidl R
Solid State Physics, Division Bhabha Atomic Research Centre, Mumbai 400085, India.
Solid State Physics, Division Bhabha Atomic Research Centre, Mumbai 400085, India.
Colloids Surf B Biointerfaces. 2015 Mar 1;127:164-71. doi: 10.1016/j.colsurfb.2015.01.031. Epub 2015 Jan 29.
We have synthesized nano-structured silica-Escherichia coli composite micro-granules by spray drying of mixed suspension of silica and E. coli through evaporation-induced assembly. Synthesized micro-granules were subjected to calcination in order to form shape-matched macro-pores by removing the bacterial cells. The optimization of calcination temperature is crucial because calcination process leads to two contrasting effects, namely, (i) removal of E. coli from the granules and (ii) alteration of mesoscopic structure in the silica network. We have used small-angle neutron scattering and thermo-gravimetric analysis to determine the optimum temperature for calcination of these granules. It was found that calcination in the temperature range of 200°C to 400°C removes the cells without significant alteration of the nano-structured silica network. However, beyond 500°C, calcination results significant coalescence between the silica particles. Calcination at 600°C eventually collapses the meso-pore network of silica interstices.
我们通过蒸发诱导组装对二氧化硅和大肠杆菌的混合悬浮液进行喷雾干燥，合成了纳米结构的二氧化硅-大肠杆菌复合微粒。对合成的微粒进行煅烧，以通过去除细菌细胞形成形状匹配的大孔。煅烧温度的优化至关重要，因为煅烧过程会导致两种相反的效果，即：（i）从微粒中去除大肠杆菌；（ii）改变二氧化硅网络中的介观结构。我们使用小角中子散射和热重分析来确定这些微粒煅烧的最佳温度。结果发现，在200°C至400°C的温度范围内煅烧可以去除细胞，而不会显著改变纳米结构的二氧化硅网络。然而，超过500°C，煅烧会导致二氧化硅颗粒之间显著聚结。在600°C煅烧最终会使二氧化硅间隙的介孔网络坍塌。
