The modifications of the cellulose fibres were carried out by grafting a long hydrocarbon chain through heterogeneous esterification of cellulose surface hydroxyl groups with octanoic anhydride using a solvent exchange procedure. Details of the method are given elsewhere [26,30]. Cellulose fibres (5g) were introduced in the flask containing 110ml of a mixture of toluene/triethylamine (80/20 v/v). The flask was firstly kept under reflux (T = 110–120 ◦ C) and constant stirring until all water contained on the fibres was evacuated by azeotropic distil- lation, then octanoic anhydride (5 g) was added drop-wise over a period of 1 h. The reflux was continued under nitrogen atmo- sphere over a period of 6 h. The obtained product was cooled and then purified by soxhlet extraction with THF/ethanol (50/50 v/v) for 24 h. The degree of substitution (DS) was determined by saponification and titration according to a well-described pro- cedure [27].