The acid hydrolysis treatment was conducted on the fibres after alkali treatment and bleaching at a temperature of 50 °C using 10.0 mol L−1 of sulphuric acid (pre-heated) for 40 min under continuous stirring. The fibre content ranged from 4 to 6 wt%. The hydrolysed material was washed by centrifugation at 10,000 rpm at 10 °C for 10 min. This centrifugation step was repeated several times before the suspension was dialysed against distilled water for several days until constant pH in the range of 5–6 was reached. The resulting suspension was then sonicated for 30 min before kept refrigerated for further used.