Development of new detector based on aerogel with fiber shape.

在以前的生产方法中，气凝胶的折射率被优化为1.010\sim1.030 $的较低折射率，当折射率大于1.030时，光学性能迅速下降。为了改善这种情况，在胶态形成过程中引入了一种新的溶剂二甲基甲酰胺（DMF），制备了醇凝胶。将DMF与甲醇混合，并在此醇混合物中进行溶胶-凝胶步骤。由该方法获得的气凝胶块在400 nm波长处的透射长度测量为约40 mm，而如果仅使用甲醇作为醇溶剂，则达到约23 mm。通过测量气凝胶的内部孔隙率，我们认为这种显著的改善是基于DMF液体可以帮助形成更小的孔作为醇凝胶结构的事实。我们在制备醇凝胶样品时改变了液体组分中的一些量，这可能会影响所得的光学特性，以研究溶胶-凝胶过程中使用的化学量对透射率的依赖性。用这种方法，我们成功地生产出高透明的样品。除此之外，还保持了疏水特性。因此，我们发现，任何形状的气凝胶，包括纤维状的形状，可以通过使用“水射流切割装置”切割来生产，其中高压水通过小孔注入到过程中的材料中。

In the previous production method, aerogel transparencies were optimized for lower refractive indices of $1.010\sim1.030$, and the optical properties were quickly degraded when the refractive index became bigger than 1.030. To improve this situation, a new solvent of di-methyl-formamide (DMF) was introduced in the colloidal formation, where alcogel was made. DMF was mixed with methanol, and the sol-gel step proceeded in this alcohol mixture The transmission length of the aerogel block obtained from this method was measured to be about 40mm at 400nm wave length, while ~23mm was achieved if only methanol was used as an alcohol solvent. It is considered that this remarkable improvement is based upon the fact that DMF liquid can help to form smaller pores as the alcogel structure from measuring the aerogel internal porosity.We varied some quantities in the liquid components when making alcogel samples, which may have affected the resulting optical characteristics to investigate the transmission dependence on the chemical quantities used in the sol-gel process. With this method, we were succeeded in produced highly transparent samples. In addition to this, hydrophobic feature has been kept. Therefore, we found that any shape of aerogels, including fiber-like shape, can be produces by cutting out with "water jet cutting device", where highly pressurized water is injected through small spot into materal in process.