In addition, pores with diameter of a few micrometers and severe wrinkles are present. In contrast, ethanol drying caused significant improvement on the maintenance of the spherical shape and led to the decrement of the cracks on the surface
In addition, pores with diameterof a few micrometers and severe wrinkles are present. Incontrast, ethanol drying caused significant improvement on themaintenance of the spherical shape and led to the decrement ofthe cracks on the surface