SEM images (a, b) CMC-COOH before silica coating, (c) microcoil after silica-coating and calcination. The initial weight ratios for the silica coating process were CTAB/NH3(aq.)/CMC-COOH/TEOS = 13.9/70.4/0.6/15.1. The black arrows indicate silica particles adhered to the coils whereas white arrows indicate translucid coil sections.
Rodriguez-Abreu et al. Nanoscale Research Letters 2011 6:330 doi:10.1186/1556-276X-6-330