Functionalization of SPION nanoparticle with malic acid for the development of superfinish optical surface

Optical instruments such as X-ray optics, high-power laser systems, synchrotron beamlines, lithography, and laser-based sensors, require a superfine optical surface to meet their tight optical performance tolerances. This study describes the development of a nanocomposite-based nanoabrasive that can provide a superfinish optical surface via optical polishing. The Malic acid as an organic surface modifier is functionalized with the superparamagnetic iron oxide nanoparticles (SPION). Strong chemical attachment between SPION nanoparticles and the Malic acid is verified through fourier transform infrared spectroscopy. A significant enhancement in the surface area and zeta potential value of SPION nanoparticles is observed when it is functionalized with the Malic Acid. The particle size distribution of the functionalized nanoabrasive is also narrowed down to 8-26 nm. The polishing performance of the functionalized SPION nanoabrasive has been investigated on the BK7 and Fused Silica glasses for precision optical polishing. The polishing results showed superfine surface finishing of the BK7 glass and the Fused silica glass down to the Ra value of 0.23 nm and 0.1 nm, respectively.

Automated summary

This study presents the development of a nanocomposite-based nanoabrasive for achieving superfine optical surfaces through optical polishing. The nanocomposite consists of superparamagnetic iron oxide nanoparticles (SPION) functionalized with Malic acid as an organic surface modifier. The successful chemical attachment between SPION and Malic acid is confirmed by Fourier transform infrared spectroscopy. The functionalized nanoabrasive exhibits increased surface area and zeta potential of SPION as well as narrowed particle size distribution. The polishing performance of the functionalized SPION nanoabrasive is demonstrated on BK7 and Fused Silica glasses, achieving superfine surface finishing with Ra values of 0.23 nm and 0.1 nm, respectively.