Optimization and Characterization of Acetic Acid-Hydrolyzed Cassava Starch Nanoparticles for Enhanced Oil Recovery Applications

This study presents an optimized and sustainable route for synthesizing cassava starch nanoparticles (CSNPs) tailored for enhanced oil recovery (EOR) applications. Conventional inorganic acid hydrolysis methods often produce low nanoparticle yields and large particle sizes due to extensive degradation of both amorphous and crystalline starch regions. To overcome these challenges, ultrasonic-assisted acetic acid hydrolysis coupled with response surface methodology (RSM) was applied. Under optimal conditions, two distinct CSNPs were produced: CSNP A (206.77 nm, 96.23% yield in 3 days) and CSNP B (99.4 nm, 96.07% yield in 7 days). Characterization via Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed enhanced crystallinity, while rheological analyses revealed shear-thickening behavior and improved viscosity, key factors for effective polymer flooding in EOR. DSC and TGA measurements highlighted robust thermal stability, essential for high-temperature reservoir conditions. A preliminary assessment suggests CSNP B's small size (99.4 nm), high viscosity, and thermal stability make it particularly promising for EOR in low-permeability reservoirs, with future core flooding studies needed for validation. These attributes position CSNPs as sustainable alternatives for polymer flooding in challenging reservoir environments.