Nanodiamonds (NDs) have gained increasing interest in the field of biomedical applications due to their low cytotoxicity, versatile surface chemistry, and intrinsic biomarker capabilities. Unfortunately, NDs suffer from severe aggregation phenomenon due to the myriad functionalities existing on the ND surface. This work is centered on a method to disaggregate NDs and increase the surface area. Impurities on the surface of NDs were removed using HNO3 and H2SO4 to eliminate weak van der waals interactions. Subsequent surface modification of the ND was then accomplished via covalent bonding between the biopolymer, chitosan (CS), and the carboxylated ND (ND-COOH) surface. The surface coverage of the ND surface by CS was studied by modifying the ratios between the ND-COOH and CS (w/w%). Fourier Transform infrared spectroscopy (FTIR) showed characteristic bands of CS (3429 cm-1 due to -OH and -NH groups in chitosan, 2902 cm-1 attributed to C-H bands, 1656 cm-1 due to amide band C-O stretching, along with N-H deformation, and 1592 cm-1 due to the characteristic peak of the NH2 groups). Modified nano-diamond chitosan composites (ND-COOH-CS) were also studied using zeta potential analysis (ZPA), particle size analysis (PSA), thermal gravimetric analysis (TGA) and scanning electron microcopy (SEM). Stability of the nanodiamond dispersions were shown to be acheived as evidenced by the incerease in zeta potential.

Functionalized nanodiamonds in the investigation of aggregation phenomena

256th National Meeting (2018)

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