SURFACE FUNCTIONALIZATION OF MESOPOROUS HOLLOW CARBON NANOPARTICLES USING UV/OZONE TREATMENT

Abstract

Carbon nanoparticles have been widely used in various applications. However, they are commonly known to have low dispersibility and chemical inertness which limit their practicallability in medical or biological area. Some studies have been performed to modified carbon nanoparticles such as carbon nanotubes using UV-Ozone system. However, little is known on the effect of such system towards other types of carbon nanoparticles such as mesoporous hollow carbon nanoparticles (MHCNs). Thus in this study, improvement of MHCNs physiochemical properties have been studied using UV-Ozone treatment for the first time. The treatment was conducted in water as dispersant agent at ozone flowrate of 1.0 L/min and exposure time of 45 min. SEM images observed that MHCNs morphology and surface structure remain intact after the treatment. Observations on the dispersibility of MHCNs in phosphate buffered saline (PBS) solution shows that the dispersibility was improved compared to the untreated ones. This was supported by the low Z-average and PDI values  of treated MHCNs obtained at ~400 nm and 0.2 respectively when compared to  untreated MHCNs which obtained at 970 d.nm and 0.417 respectively. Thermogalvimetric analysis (TGA) also shows an increased in weight loss of treated MHCNs at lower temperature compared to untreated ones. Results from fourier transform infrared (FTIR) shows an increased number of new functional groups that include carboxylic acid group presence at surface of treated MHCNs which contributed to the improvement of their dispersibility, thermal properties and chemical functionality. These findings opened a new possibility of using UV/Ozone treatment to improve physicochemical properties of MHCNs for medical area such as in drug delivery application in addition to their excellent drug storage and carrier system.