Hemp-Derived Nanocellulose

Hemp bast fibre, with high alpha-cellulose content (70–74%) and crystallinity (65–75%), is an excellent feedstock for nanocellulose production: cellulose nanocrystals (CNC, length 100–400 nm, diameter 5–20 nm, aspect ratio 10–30) produced by sulphuric acid hydrolysis (64 wt% H₂SO₄, 45°C, 45–90 min) and cellulose nanofibrils (CNF, length 500–2,000 nm, diameter 10–50 nm) produced by mechanical fibrillation (microfluidisation, 1,500–2,000 bar, 5–10 passes) after TEMPO oxidation (TEMPO 0.1 mmol/g, NaClO 5 mmol/g, pH 10, 25°C). Hemp CNC yield is 25–40% from bleached pulp; CNF yield is 85–95%. Tensile modulus of hemp CNC (axial) is 100–160 GPa. Hemp nanocellulose reinforces polymer matrices at 1–10 wt% loading: tensile modulus of PVA increases from 1.5 to 5–12 GPa at 5 wt% CNC. Global nanocellulose market is projected to reach $1.1 billion by 2028, with hemp as a premium feedstock due to high crystallinity and non-wood origin.